Is the Nat Geo Tumbler Too Fast? Let's Look Inside.

[@LouJustlou]

I did manage to slow mine down.....fairly safely I think. I do run at the orignal speed for the first coarse tumble and then slow down for the other grits. I do it by using the original 12 volt power supply or my 10 volt supply for the slower speeds. Either way I use the larger 3D printed pulley since it stops belt slip with larger loads. Here is my video: kzbin.info/www/bejne/oJ-vqZiOg5mHd6c Thanks for all the great content and help getting this tumbler to produce good results!

[@MichiganRocks]

Thanks, Lou! I think you've got some great ideas here. This will be very helpful for anyone trying to improve their Nat Geo tumbler, although voiding the warranty is a bit of a risk.

[@invictusfarmer7188]

oh i know just the doodad for this. a constant voltage/constant current buck converter. once it was set up you could vary the voltage to adjust the speed. be like having low range hahaha

[@LouJustlou]

@@invictusfarmer7188 once the dreaded E error code took out the electronics I ended up with a variable 12 volt supply. Works great!

[@invictusfarmer7188]

@@LouJustlou i knew it! im trying to design a solar version at the moment lol. mainly just because i can lolol

[@invictusfarmer7188]

@@LouJustlou to expand on this i was curious if i could add the buck converter in line with the motor. leave the original front electronics on their 12v power but basically add a motor controller. it wouldnt be for everybody but someone that knows electronics could easily do this unless the wiring is hidden inside the tumbler base to bad to be worked on

[@KatyDidRocks]

Awesome idea, Rob! It was cool to see the interior of a rotary tumbler while it was working.

[@MichiganRocks]

Fun, huh?

[@jonathanyoung7785]

Hmm. I'd say the jury is still out. Not surprisingly, faster barrel speed means faster rocks= movement in the barrel. There did seem to be some centrifugal force action in the Nat Geo, especially on speed 3, evidenced by an arc in their travel. But it's not clear if that made the action any more gentle. If you have a newer smart phone you may be able to take super slow motion video. I think my Samsung records at 960 frames per second (bright light needed). You could actually see the rocks bounce off of one another at that speed. Although you probably don't want to use SiC grit with your glass lid, I wonder if the grit changes the action. Starting with slurry instead of water would certainly make for a gentler tumble, but like you, I do a full clean out when grit needs refreshed. Saving slurry is messy. I fill with water to the top of the rocks with this tumbler, and I usually throw in a palm full of quartz aquarium gravel or ceramics as well. I have actually gotten in the habit of using more water and some quartz gravel in all my barrels. They all seem to tumble gentler that way, and I have not noticed it slowing down the grind or overloading the motors.

[@MichiganRocks]

We know what it looks like inside now. You're right about using grit with the glass lid. It wouldn't be transparent for long. A thicker slurry would be another variable that would likely change the action inside. Jim will have an opinion on this. I'll go tell him about the video.

[@jonathanyoung7785]

I saw a comment below about using the KZbin slow motion function to slow things down further. That is enormously helpful is seeing what is going on. At speed 3 the rocks aren't aren't hitting each other very much, and the reason does appear to be centrifugal force. As someone else pointed out, until a slurry is formed, the grit is likely "stuck" to the inside wall of the barrel, and the grinding action would be primarily rocks against barrel, as opposed to rocks against rocks. Rocks hitting the soft-ish rubber barrel at high speed is certainly not going to fracture them...

[@jonathanyoung7785]

@@MichiganRocks Jim will tell you -- you need a thick slurry, use clay. Works for him. Looks like a big mess to me.

[@dawnmorning]

Use .25 playback speed on youtube to see slow. Awesome experimemt.

[@MichiganRocks]

@@jonathanyoung7785 Good point. Although the high speed rock to barrel impacts are probably not hard on the rocks, it's probably also not grinding as much as it could be. Slurry probably would make the rocks stickier and therefore grind better. I have tried adding kitty litter (clay) to thicken the slurry, but as you said, it's much harder to do a clean out and uses more water in the process. Then I need to dispose of the water. I have been running on the slowest speed and the slurry is completely smooth after three day, so I know the grit is completely broken down by then. I'm going to stick with that because I don't really want to clean out the barrels more often that that anyway.

[@vickizeller2010]

Thanks for doing this! I received the Nat Geo tumbler for Mother's Day and am going to start it up tomorrow...... after I read all the instructions & re-watch a few your instructional videos. I appreciate all the info you provide!

[@MichiganRocks]

That's great. I think you will be able to get some shiny rocks out of this. I'd add some ceramic media, harder rocks, and some better media. Put in more rocks than I did in this video. That was a ridiculously small amount of rocks that I had in there by the end.

[@juli6497]

I have a Nat Geo and you're asking a lot of the same questions I was asking my self. I was concerned that the higher speed would lead to centrifugal force not rubbing the stones enough. I was also concerned about it just beating up the rocks and not grinding on them. I have to keep reminding my self of what I'm trying to accomplish. I'm looking to speed up the natural process of grinding and rubbing on the rocks to shape and polish them. I don't use my Nat Geo at the higher speed for anything. I do use the lower speed for really grinding on rocks that have alot to remove. Good stuff! Thanks!

[@MichiganRocks]

I'm not going to run mine at anything but the slowest speed either. It sure does grind fast, even at that speed.

[@simonwolstencroft6128]

That was great Rob, that's a community service experiment you've done there. Very interesting to see what the rocks are doing. I do my first 80 grit (quality grit not NG) on the higher speed then slow it down on the 600 and oxcide stage. The slowest still looks a bit fast. I fill it 2/3 with smooth finished smaller tumbled rocks on the final polish and burnish. They come out nice and shiny like proper flash shop brought ones. I use the foam too in the burnishing stage. Once again thanks for another informative video, they're a pleasure to watch👍

[@MichiganRocks]

I thought we could all learn something by watching this. It's fun to have a discussion with everyone about the results.

[@ushldguess]

thanks for showing us this with the glass, helps us see the action and come to our own conclusions.

[@MichiganRocks]

I wasn't really sure what to say, so I thought it would be best to let everyone judge for themselves. It was fun to see anyhow.

[@NeedethNot]

Kinda off topic, but what do you think about doing a mineral identification video with your son in law David? In a previous video David mentioned that color is the last thing you should use to identify a mineral, but I always thought it would be one of the first things you would use. So it got me thinking, how *do* you identify a mineral then?

[@MichiganRocks]

He has suggested doing something like that. I'm all for it, we just have to get together and do it. He lives four hours away, so we're not together all the time.

[@BlueSteelRabbit]

Does anyone know what is the rpm for a lortone 33b or 3a is???

[@MichiganRocks]

My 33B turns at 41 rpm.

[@BlueSteelRabbit]

@@MichiganRocks Okay thanks for the Information. :)

[@dunny3032]

Great experiment. You really go the extra mile. Thanks for sharing.

[@MichiganRocks]

No problem.

[@RufotrisRootedRockhound]

I hadn’t thought about it being that it was too fast when I find chips in the end of my barrel I actually just thought maybe it wasn’t full enough which gave more room for the rocks to fall so when I did the next batch and filled it a bit more full I found no chipped rocks. Could have just been the type of rocks I had going too. I bought tumbler medium to fill gaps to hopefully help with chipping.

[@MichiganRocks]

It's not unusual to get a few corners chipped off, especially in the first run of the first stage. This happens with much slower tumblers too. Any weak spots with pre-existing fractures tend to break right away. That's not necessarily bad. I often break rocks along fractures to avoid having fractures in the finished rocks. It's when rocks start getting chips or cracks that were not there ahead of time that's a problem.

[@Unclewalnut]

Amazing video Michigan Rocks. I now own both thanks to your suggestion and having recently obtained a Lortone. I think Nat Geo is fantastic for Phase 1 and 2. I also like the 4 lb barrel shape quite a lot.

[@MichiganRocks]

I think that's a good idea to use the Nat Geo for the first stage or two.

[@ashleytruthhurts532]

I'm new to this. Just did my first batch and polished, but the stones are still cloudyish? What can I do to make them shine?

[@RufotrisRootedRockhound]

Look up mineral oils to use on the rocks. The tumbling grit that comes with those kits does not give a super fine polish. you can buy a finer polish to do a final run or hand polish them or just oil them as is.

[@MichiganRocks]

I had the same results when using the directions, grit, and rocks that came with the tumbler. I'm working on a video showing how to use the tumbler properly. I'd get some agates or jasper, and better polish. I buy my grit and polish from The Rock Shed. They sell quality polish. There's a link to their store in the description. I have their grit in my Amazon storefront too if that's better for you. I'd also pick up some of their ceramic media. I mixed the large and small ceramic cylinders. These two videos might be helpful too: kzbin.info/www/bejne/fWiUiZWQidGEra8 kzbin.info/www/bejne/moqqd5SiZcpkjbs

[@RufotrisRootedRockhound]

@@MichiganRocks same! I promote the tumbler grit and pellets I use on my KZbin videos and use Amazon affiliate links in my description 😄 way better than the stuff it comes with. And I always recommend people don’t just throw all the rocks it comes with into one barrel.. very different hardness levels on those included rocks, best to figure out the hardness and tumble them with similar rocks.

[@davidhile5363]

Watch Rob’s “ Rock Tumbling Tutorial For Rotary Tumblers And Ceramic Media “ video. Follow his instructions to a “T” and you can’t go wrong !!!

[@MichiganRocks]

@@RufotrisRootedRockhound In my opinion, mineral oil is cheating. I don't mind if someone uses it, but for myself, I like to get a polish from actually smoothing out the rock.

[@wyomingadventures]

Whoa I just read some of the comments. Interesting hearing everyone's opinions about this. Great topic!

[@davidhile5363]

Hi there, Wyoming !!!

[@nathjack241]

Great videos! I have a couple of cut geodes....if cut in smaller pieces would it be good material for tumbling ? Thank you

[@MichiganRocks]

I think that most geodes are interesting because of the crystals that grow inside them. If you tumbled the crystals so they were smooth, I don't think they'd be interesting anymore. But if you have a lot of them and are curious, I'd suggest giving it a try and then you'll know. That's what I have done with rocks that I find. I give them a try and then I know whether I should pick up more of that type of rock in the future.

[@nathjack241]

Thank you for the info. Actually my geode does not have any crystals ! It pretty much looks like agate!

[@tasnimweaver1492]

@@nathjack241 I have some of those in the Net Geo tumbler now with some corundum and so far after a week all it seemed to do was clean off the outer crust and maybe soften any small points..I would swear those things are higher than their rating of 6.5-7.5 on the scale

[@criddyboy1968]

hi,would the faster speed also mean a increase in cost for a complete start to finish tumble,in regards to the electricity used compared to the slower tumble machines,thanks

[@MichiganRocks]

I don't think it would make any noticeable difference. Tumblers don't use much electricity and this one uses less than most because it has a DC motor. Even if it did use more electricity by going faster, that could also mean they would get done faster and therefore the motor would be turned off sooner.

[@criddyboy1968]

@@MichiganRocks very true,never thought they would finish sooner

[@mwakelin]

It would be interesting to see you polish stones using the NG tumbler and your own grits and experience to see how good a result you can achieve.

[@MichiganRocks]

I'm working on that video now.

[@ruthchapman3847]

Very interesting and detailed demo, took a lot of time to accomplish. I think the higher speed would be harder on the rocks, easier to crack them or blow out a weak spot. But I'm a newbie so what do you think?

[@MichiganRocks]

I agree, but the question is, can most rocks handle this degree of rough crashing around? If they can, then this tumbler does accomplish grinding faster.

[@dtperry11]

Interesting experiment. I bought a NG before watching your original review of it. So glad I watch your review before I actually used it. I bought better grit from from The Rock Shed as per your suggestion, used speed 3 for stage one and speed 1 for the other three stages. Used the ceramic media in the latter stages. Finished the batch with 6 hours of Borax and am absolutely delighted with the result. Fantastic shine! Thanks for your help!

[@MichiganRocks]

I'm still working on my second batch. I'm glad to hear that my suggestions worked for you.

[@sergeboivin566]

Great comparison! You should go into business and sell transparent lids. I'd watch that for a long time :-)

[@MichiganRocks]

If you put grit in, the lid wouldn't stay transparent for long. It was also pretty precariously attached. The Thumler's barrel is made for a lid like this. The Lortone and Nat Geo is not made for this type of lid.

[@sergeboivin566]

@@MichiganRocks Maybe a diamond lid? Surely that would be affordable :-)

[@powerlinekid4296]

Fast tumbling seems okay with very rough rock. However, after viewing this video the smoother rounded rocks appear to stay in one place and don't appear to grind enough. A slower speed allows gravity to help tumble the rocks.

[@MichiganRocks]

That's a good observation. The rocks appear to be getting "lighter" at faster speeds.

[@produceman13]

Yea, it looks like they are flying around instead of grinding...

[@CJR12212012]

Thank you, How full the barrel is definitely changes how the rocks tumble. I wonder how much the slurry thickness would be a factor?

[@MichiganRocks]

We will know one of these days because I'm going to make a video to find out.

[@Lunchmeat_Larry]

Bought this same tumbler (Dan & Darcy) version about a year ago when I started getting into tumbling. My first couple batches turned out horribly. Eventually I realized that the barrel was spinning way too fast (96 rpm on the “low” setting) and turning my rocks into mud. To solve the problem, I installed a DC motor speed controller. Now the tumbler speed is fully adjustable. Got much better results after making this mod.

[@MichiganRocks]

That's cool. Do you have a link to the motor controller or any information about how to install it. Somebody reading these comments might be interested in doing this themselves. Thanks.

[@Lunchmeat_Larry]

@@MichiganRocks Here's the link to the speed controller: www.amazon.com/gp/product/B00F839VNQ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 A pretty easy and inexpensive mod overall. The only "drawback" is that you lose the use of the factory timer & speed control, but in my opinion those are pretty much worthless any way. I've got pics of the process but am unable to post them here. If anyone is interested in performing this mod please reply to this message & I'll walk you through the process.

[@MichiganRocks]

@@Lunchmeat_Larry Thanks a lot for adding that, Marc. I agree that the speed control and timer are useless, so no loss in bypassing them.

[@CityRockhounding]

Glad you made this video, not only for this model, but just something to look into when buying one.

[@wolfe1970]

I like the barrel of the NG tumbler, it has the uneven surface inside that helps to tumble the rocks, and it has a bigger diameter than even the 3lb barrels so more pressure on the rocks, and the rubber seems softer so could help to reduce the shock to the rocks tumbling, i also like the steel lid, the barrel of the NG has alot going for it, only wish it was a 3lb instead of a 2lb

[@MichiganRocks]

I like the barrel too. It is almost the exact same volume as the Lortone 3 lb. barrel. I filled the Lortone barrel with water and dumped it in the Nat Geo two pound barrel. There was very little difference.

[@wolfe1970]

@@MichiganRocks Thats interesting about the weight, i hadn't realized that both barrels where similar capacity's Thanks

[@OccamsSledgehammer]

I go off of volume, not weight. I can fit “3 pounds” in the NG tumbler.

[@joshmartin7558]

Question for someone who knows what they're talking about. I got my daughter a tumbler that had great reviews. Looks similar to this one but not the same. It has days to run and speed. Judging by this video, too fast doesn't get much "tumble". I was wondering if you doubled the speed than the slowest setting, can you cut down on tumble time. My daughter is fairly patient, but she doesn't have the patience to wait weeks for a several week start to finish, and if I can cut a corner, would it be best to be on the coarser grit or faster on the polish grit. Thank you in advance!!!

[@MichiganRocks]

I'd go slow on polish. You don't want them banging around at that stage. Even at the slowest speed, this tumbler (and probably yours) grinds very quickly. I prefer doing all stages slower, but if you're impatient, you probably got the right tumbler. I have done several videos on this one. Here are two that might be of interest to you: How to use a Nat Geo Tumbler: kzbin.info/www/bejne/eaS3lGShjbqohtE Tumbling Beach Rocks in a Nat Geo Tumbler: kzbin.info/www/bejne/lYfQnmVqe8hqoJY

[@ronaldsteele5740]

I personally still have concerns considering once the water becomes a slurry it seems to stick like pudding. Thus my concerns when I hear no rumbling in the barrel. Gonna get a better one & use Nat Geo for softer/smaller rocks.

[@MichiganRocks]

When you get a really thick slurry, it indicates that a lot of grinding has taken place. That's usually a good thing, as long as it happened without damaging any rocks.

[@zeichner42]

I've been using my National Geographic 3 lb. tumbler for a while now & have been getting good results in stage 1 (coarse grit) at the fastest speed. I make sure to have the barrel 3/4 full & add about 10% ceramic media of various sizes, to begin with. After about 4 days (which seems to be equivalent to 7 days on my Thumler) I check the barrel & add more media to make up for the loss to bring it back up to 3/4 full, and run it for another 4 days. After the first 8 days, I empty the barrel, wash everything & check all the rocks. Keeping it 3/4 full seems to be the trick for me, especially using media to fill the gaps & cushion the rocks. I'm not seeing any bruising & the rocks are shaped quite nicely after 12-16 days at the fastest speed (I'm doing mostly quartz, agate, jasper, & aventurine.) I try to always run rocks not only of the same hardness, but also of the same level of smoothing - never adding rough rocks to keep the barrel full. After stage 1, I keep it at the lowest speed & proceed as with any other rotary tumbler.

[@MichiganRocks]

I never use ceramics in my first stage because I don't want to wear them down. I also always add rough rocks as the rocks inside get smaller and I remove some. I'm curious why you don't add rough rocks to partially tumbled ones in the first stage. I've been doing it for ten years and have never noticed any problem. I'm generally using a much slower tumbler though. Do you do the other stages in your Thumler's tumbler?

[@zeichner42]

@@MichiganRocks Right now, I'm trying to "learn" the Thumler's, as far as how full & how much grit it needs to keep happy, so I'm doing additional stage 1 tumbles with it. Even though it's much slower than the N.G. tumbler, I can have 2 barrels working on rocks that are almost ready for stage 2. Now that I'm comfortable with how to use the N.G. tumbler for stage 1, I'm trying it on stage 2 (120/220 grit) on the lowest speed. As far as adding rough rocks to the partially tumbled rocks, I'm trying to keep the rocks together to better see their progress & I think I would have trouble remembering how long each rock has been in each stage. It just seems simpler to me to add some media (although, if I have rocks from different batches that have all reached the same level of shaping, I will mix them together to keep the barrel near 3/4 full.) I don't find that the ceramic media wears down very fast, certainly nowhere near as fast as the rocks. Plus, I feel that the media fills the gaps much better & helps the grit work faster.

[@MichiganRocks]

@@zeichner42 I use small rocks to get in the nooks and crannies. It the first stage, my rocks all go for as long as they need. Each rock is examined individually after each clean out. Some rocks from the same batch may be in for three weeks while others may be in for 12 weeks. By adding touch rocks, I'm not wasting any time in that first stage. The first stage barrel is a perpetual grinding machine. I take some out, add more in, and it just keeps going like that for years. You're right about getting different types of rocks mixed up. That's a pain. I try to put completely different looking rocks in the same barrels so I don't get them confused.

[@jimknarr]

What do the instructions say for Thumbler and National Geographic regarding pros/cons regarding high speed and low speed? Surely the manufacturers would have written up some situations in which they recommend using one speed over the other.

[@MichiganRocks]

The instructions say to run the first stage at the fastest speed and the third and fourth stage at the slowest speed. They don't say anything about the second stage. Most tumblers don't have speed controls at all. Rock tumbler instructions are notoriously bad. They almost all say to run the first stage for some set number of days, usually a week or ten days. It may be possible to get rocks to shine that way, but they won't look the way I prefer them. Other people may not care if there are cracks or holes, but I like mine perfectly smooth. I can understand why they don't tell people to run the first stage for weeks or months like I do, because many people are impatient. It would be nice if they at least gave the option of tumbling longer for better results. In National Geographic's defense, they do say that if you aren't happy with the results after the first stage, you can put them back in (with the same slurry) and run them for another couple days. The problem with that is that the grit is completely broken down by that point so there won't be much change in the rocks.

Vídeo lindo querido. Super top my dear a beautiful video. beautiful stones

[@nicblah8379]

I'm still new to this but I made a homemade tumbler with a 15 lbs octagon barrel and had troubles with rocks breaking at 60 rpm. I have slowed it down to 37 rpm. I'll have to wait to see the difference but it sounds way quieter so I assume the rocks aren't impacting each other as bad.

[@MichiganRocks]

Larger diameter barrels are usually run at slower speeds. My larger barrels turn at 28 rpm.

[@mysticalbeader2006]

Just wondering which tumbler to buy for best perfomance for the money. Any suggestions? I was looking at some for around 100 bucks. But wondered if they are worth it?

[@MichiganRocks]

My first tumbler was a Lortone 33B. If I was starting all over, I'd buy that tumbler again. The Rock Shed usually has the best prices. rockshed.com Lortones have been hard to get since the pandemic started, but send them an email and see if you can get on a list.

[@ingok1991]

Thank you very much for the great report! 👍👍👍👍👍 The slow motion recordings are particularly interesting. I didn't think that "slow" could be so fast.

[@MichiganRocks]

That National Geographic tumbler has three speeds and none of them are really slow.

[@markattardo]

I'll see your slomo and raise (or slow) you to .25 speed playback on youtube. Interesting to see that. Not sure what to make of it besides 2/3 full didn't appear to have as much tumbling action. Watching one rock "stuck" to the lid raised another question. Will that keep happening or will it eventually work down the barrel? Also high speed seemed to throw smaller rocks and chips.

[@MichiganRocks]

I filmed longer clips than what I showed. I watched one of those rocks stuck to the lid and after a few seconds, it got sucked into the center of the mass of rocks. I forgot about being able to slow the video speed on KZbin. Thanks for the suggestion.

[@markattardo]

@@MichiganRocks You're welcome. And thanks for answering the stuck rock question👍

[@SandwedgeMon]

Go Blue!!! My kids just got me this! So excited! Michigan is winning this !

[@MichiganRocks]

Go Blue!

[@allensaucier7071]

Recently purchased the NG tumbler in 2023, and not having the same experience. It seems that on slow speed it is running slower than my Lortone at 41 RPM. Could they have made changes to slow it down, or am I just lucky?

[@MichiganRocks]

I have no idea. That's the first I've heard of one going slower. 41 RPM seems like a decent speed.

[@gatchrocks]

I put a load on my Chicago electric and it wouldn't turn so I put an O ring belt on and now it's spinning over 60 rpm. I'm a bit concerned it may be too fast. It's probably around that 80 rpm range. I liked it when it was a bit slower than 60 rpm, but seeing here, I may be more concerned than I need to be. Any further thoughts on this experiment?

[@MichiganRocks]

I still don't like how fast this tumbler moves. I think it damages the rocks.

[@BlueSteelRabbit]

I was able to use a 6.0v power cord for my Nat Geo tumbler with no modifications and at speed 1 it runs at about 32rpm and at speed 2 it runs at around 41rpm all the test I did was with a barrel 2/3 full. :)

[@MichiganRocks]

That's great if it doesn't harm the motor. I'm not saying it will, because I don't know enough about motors to know if under powering them is bad for them.

[@nicolecarpenter1895]

where did you find a compatible 6v power cord?

[@cesarealessandrini9617]

hi Rob! a technical question: for phases 3 and 4 can I use airsoft pellets instead of plastic pellets? because in Italy they are more easily found

[@MichiganRocks]

I have heard of people using them. I don't see why they wouldn't work. MeMiner had an interesting way to obtain plastic pellets that might work for you. kzbin.info/www/bejne/r6qzoGufaseNb7s

[@cesarealessandrini9617]

thanks so much for the tips and tricks! you are a great jedi master of stones! 🤣

[@mdl1402]

Where can i find the rubber drums?

[@MichiganRocks]

National Geographic does not sell the barrels separately. The Rock Shed sells replacement barrels for Lortone and Thumler's. I much prefer the Lortone barrels. www.rockshed.com/product-category/rock-tumblers-supplies/rock-tumbler-parts/lortone-tumbler-parts/

[@mdl1402]

Thank you from central Germany

[@sparband]

That was really clever to use the glass to be able to see inside.

[@MichiganRocks]

This was not completely my idea, like most things on my channel. Rocktumbler.com has a similar video showing the difference between different fill levels. Jonathan, whose comment is pinned, gave me the idea to do this video.

[@christinekohnle2720]

I just bought Thumler’s tumbler model b (the 15 pound one) used from eBay. When I used it for the first time I thought “Wow! It’s fast”. I found out there are 2 different motors for that model, one is for rocks the other is for brass. I think the seller didn’t realize this and listed it as a rock tumbler.. I ordered the slower motor and now that I have it I’m thinking I like the faster one better but I’m not sure if the motor can handle the weight. So tempting.. it tumbles rocks half the time as the slower motor but man is it LOUD. I can’t find any information about this..

[@MichiganRocks]

I don't have experience with that tumbler, but lots of people love it. I'd suggest posting your question on the Rock Tumbling Hobby forums. I'll bet someone there can help you out. forum.rocktumblinghobby.com/

[@virginiarocks]

Fascinating. I like this experiment 🤩

[@MichiganRocks]

Yeah, I thought this was fun too.

[@SmallWonda]

Being impatient for shiny stones I'd probably want to try the NG tumbler - I'd think looking at the tumbled results would give more conclusive evidence if the Nat Geo Tum is tougher on the stones than slower tumblers? Can we see the end results? Thanks for demoing.

[@MichiganRocks]

The rocks that were in the tumbler for this demo are in the process of being tumbled. They're harder agates than the rocks that came with it, so they're taking longer. There will be a video when they're done. I have been working on it.

[@justinslife8898]

Howdy! Do you still own the clear lids??? A great vid would be seeing in both tumblers rough/smooth stone with ceramic/plastic media in clean water.... 2/3full and half full but filled with media to make up the difference. Maybe then we can visually see exactly how the ceramics behave opposed to the plastic that floats! Would be awesome!!

[@MichiganRocks]

I do still have the clear lids and think your idea is good. I'm putting it on my long list of future video plans. Thanks for the suggestion!

[@backroadsandotherstories4239]

Love this experiment! We are building a cabinet similar to yours and trying to figure out the speed that we will want to go with. This was fascinating to watch.

[@MichiganRocks]

I'm glad you found it helpful. It beats trying to imagine what's going on in there.

[@tlk13ns]

Hi I have a nat geo tumbler the same as in yr review its been running pretty constant fr about 10mnths . It just started act up would stop spinning I took a toothbrush an cleaned all the blk rubber stuff that wore of belt that didn't fix it then I put new belt on an it ran fr a couple dys an stopped again an I don't believe it's over weight

[@MichiganRocks]

It has a two year warranty, so email their customer service. They should send you a new one.

[@tlk13ns]

@@MichiganRocks well I got ahold of natgeo an I'm having issues because I live in Canada an I guess our Amazon doesn't have any an no idea when they will get any. They offered me the hobby one with extra grit an extra rocks but I just don't see that being a good thing too small not crazy about their grit an the rocks that came with professional tumbler were not impressive either but I really liked it

[@MichiganRocks]

@@tlk13ns That's a bummer. I'd ask them if you can hold out for a professional model. You could also ask if they have the three pound model that they could upgrade you to.

[@tlk13ns]

@@MichiganRocks I ended up getting my money bck I didn't think about upgrading didn't know they had one an they didn't offer just offered smaller hobby one with extra grit an rocks but I wasnt crazy about their grit or rocks trying to find a double barrel but Amazon only has a Chicago one an it's a plastic barrel

[@tlk13ns]

@@MichiganRocks do u know if its possible to get a motor fr the nat geo tumbler the same as yrs or suggestions on what I can use to replace it

[@wyomingadventures]

Is it me or do the NG tumbler seem to be not real round. Looks like the barrel hops alittle. I don't know anything about tumbling but I would think the rock hardness would have something to do with it also. And it looks like the slower the speed the more the rocks move over each other. That probably sounds weird but when it's going fast it's like the force throws the rocks to the side of barrel. Not sure if the rocks are rubbing against each other as much as slower speed. I'm probably wrong about all of it. But it's interesting seeing rocks tumbling!

[@MichiganRocks]

The barrel seems round enough. The rollers have a seam that I should have sanded off. I think that's where the jumping comes from.

[@jalilfarhat6740]

I have the national geo with 1 speed tumbler ...as I count I feel like I'm at 160 rpm seems way to fast

[@MichiganRocks]

Yep, slow and steady wins the race. I think that might apply here.

[@Woodjunkie]

I will keep my NG rotary on slow and 50%+ full. I also have a HF rotary. I plan to round rocks in the rotary and finish with Lot-O-Tumbler once It arrives this week! This video saved me some time, and rocks, experimenting. Thanks!

[@MichiganRocks]

That's what I do. I have all of my rotary tumblers working on the first stage and the Lot-O does everything else. You'll love your Lot-O.

[@Woodjunkie]

@@MichiganRocks you get all the credit for my new way. I learn a lot from your videos. Thanks for all the help!

[@MemeDaddyTaco]

I know nothing about tumbling rocks, but it does seem like the nat geo is too fast. The rocks sorta crash together instead of roll and slide across one another. Seems like the other tumbler would yield better results, though it may take a bit longer.

[@MichiganRocks]

That's my initial feeling too, but I'm trying to keep an open mind while I try using this tumbler with my own methods.

[@TheJustindragoon]

Have any of you tried using fine play sand as your grit?

[@MichiganRocks]

Sort of. I just made a video about tumbling glass that hasn't been released yet. I used beach sand in an attempt to make beach glass. The first round, the sand didn't even scratch the glass. Then I made some adjustments and got it to frost the glass. Glass has a hardness of about five on the Mohs scale. I imagine sand has a lot of quartz in it, so it's probably has a hardness of about seven. Silicon carbide (first stage tumbling grit) has a hardness of nine. It also is brittle and breaks into smaller, but still sharp fragments as it tumbles. That makes it very effective as tumbling grit. Sand wouldn't do much good on harder rocks like agates because it's about the same hardness.

[@TheJustindragoon]

@@MichiganRocks thanks I didn't know any of that.

[@TheJustindragoon]

I also sent the images of the agate to your Instagram

[@TheCaptainShow]

Hi, Rob, great video, Ive build my own tumbler which is running around 12/15 rpm and it works well, I'm new at this , so still learning very happy with my results you can seen them on my channel, but will be upgading my tumbler in the next few weeks, by adding another set of roller with a bigger cog making my second lot of barrel run faster , I think that its the stones that say what speed to run at, harder stone can go faster , putting galena type rock in a fast speed will end up one big lump of lead lol, will be filming my results later and using different types of rock and methods , seen someone using saw dust for softer rocks no water, so I think its horses for course , thing, thanks again great video

[@MichiganRocks]

Larger barrels usually turn slower than smaller barrels. Because of the difference in circumference, the action inside can be the same at different RPMs. I'd say that either way, yours is turning a bit slower than necessary. I have never used sawdust, but I have tumbled Petoskey stones in dry corncob media with good results. kzbin.info/www/bejne/naO2nY1uaJqJetE

[@justinslife8898]

Im currently pondering the idea of a pulley swap🤔 diffrent size/ratio to reduce rpm

[@MichiganRocks]

That's one way to go. If you read through the comments, you'lll also see a lot of people who used different power supplies to slow it down.

[@LivetolearnMama]

I wonder if cushioning the rocks is what those black foam blocks that these tumblers come with is really for. I have some softer rocks that I tried to tumble in my Nat Geo Hobby tumbler, but it didn't work well. They did get nicely shaped, but not nearly as shiny as others have been able to get theirs. The hobby tumbler doesn't come with that weird black foam, but now I'm wondering if it actually would have helped. 🤣

[@MichiganRocks]

I got some good results from this tumbler without using the foam cubes. I made two videos showing how. One was with beach rocks and the other was with rocks I purchased. How to use a Nat Geo Tumbler: kzbin.info/www/bejne/eaS3lGShjbqohtE Tumbling Beach Rocks: kzbin.info/www/bejne/lYfQnmVqe8hqoJY

[@baron8463]

Thanks for the interesting video, as someone who enjoyed the old school rock tumbler when I was a kid, I bought this as an interesting toy to play with and make cool rocks. I think they give out the same pamphlet with all the rock tumbler models they sell, and seeing as how this one is much faster my first batch of rocks got reduced to almost nothing, and so did my second. My third batch came out a little bit better but I cut the times down to one day for the first and two days for medium and I can't remember how long I polished them for but they still need more polish. Have you tried running it really really full? my current batch is almost completely full and I am on second day of pre polish. My main issue is I don't know which rocks are soft and will get eroded away faster, I just kind of pick out the rocks I want to make look pretty and load them up. I noticed in your videos that you also use less water then the Nat Geo Instructions say to use, have you tried the Nat Geo one with a little bit more water? Also the Nat Geo model I bought came with these little sponge things to help polish the stones up after the last polish do you know if that really helps or is soap better? Anyways I have only had it for a short while and I am still figuring it out, my main complaint is all the stones get so much smaller, but since I cut the times down on the corse and medium they are not getting whittled away as much, I will try my next batch on the slowest speed and see if that helps. Also response to the point of the video it seems to me that the more mass and water the more you get that centrifugal force, I bet if you had more water and just the right balance of stones you would see the stones stop moving in a tumbling motion and move with the container, then it would just be the water moving around the rocks with the grit polishing them. Also Last question one of the grit refills I bought came with plastic does that help protect the rocks? I know I have to reuse the same plastic with the same grit, which is a little bit of a pain, do they help at all?

[@MichiganRocks]

I see that you've watched a couple of my other videos since making this comment, but you haven't watched the one where I got good results from this exact tumbler. Here's that video. I think it will answer a lot of your questions. kzbin.info/www/bejne/eaS3lGShjbqohtE I have used both plastic media and ceramic media. I prefer ceramic. It can be moved along with the rocks unlike plastic and I tend to get better results with it. Both types of media protect your rocks to some degree, but the plastic also slows down the grinding action. You shouldn't use either kind in the first stage. Those little foam cubes didn't do anything in my opinion. I contacted the company and found out that they contain no abrasives of any kind. I won't use them again. You make a good point about using more water. That might be a good idea.

[@claudine1220]

Did any of your rocks sustain damage from the faster tumbler? I can't be certain but it looked like tiny chips were in the mix although they could have been bubbles! Also it would depend on the rock types and how fast they degrade in a tumbler eg those strange little black sample rocks in the review video all but disappeared but others you can bash around for 10 days with little to no change! There's too many outs to compare accurately but I feel the slow way is the best way. Hands down :)

[@RufotrisRootedRockhound]

Agreed. Using hard rocks it’s not a real problem soft rocks can chip and break up and I have definitely found a lot of small pieces in the end of my tumbling runs and it broke one of my favorite Tigers eye pieces in half so the Nat Geo can definitely be a bit aggressive on softer rocks but in a batch of quarts I just did I don’t really see any fragments

[@MichiganRocks]

It's hard to tell until I'm finished with the batch. There are a few small pieces that came off of one particular rock that was fractured before I started. It's not at all unusual for that to happen even in a slower tumbler. I chose rocks that should be pretty durable, but more fragile rocks might not do as well. I really don't know at this point.

[@mike-indiana6643]

I have never tumbled rocks. My thoughts are low on the ng for the first grit. That should work fast then maybe over fill it say more than 3/4. An slow again. Just my thoughts.if it's not got much room then less chipping.

[@donnalantz7981]

Interesting. That's about all I can say about it. The nat geo seems to be a bit louder as well . Thanks for sharing.

[@MichiganRocks]

You don't need to have an opinion. I'm just glad that you found it interesting.

[@deenomad1975]

Love this! I always wondered what it looked like in there during tumbling.

[@MichiganRocks]

Wonder no more!

[@markreetz1001]

What a great idea. There sure seemed to be some centrifugal action going on. I think there was some motion that would save some wear on the rocks.

[@MichiganRocks]

Saving wear on the rocks is not what I want. I think the slower speeds on the National Geographic are the way to go.

[@webcompanion]

I don't know how to judge this. It seems like there was not a lot of water in there and the barrels were only about 1/3 to 1/2 full. We load ours up and I have no idea what it looks like inside. However I think a slower tumbler would be better with a pre-polish and final polish step compared to the Nat Geo running at higher RPM.

[@MichiganRocks]

I put in about as much water as I usually do, a bit under the top of the rocks when the barrel is in the position for filling, resting on it's round base. I won't know how this performs until I get another batch run through it. For now, I thought it would be fun to see what's going on inside.

[@4loops43]

I use my nat geo for stage 1 on high, stage 2 on high for 1 day, then 2nd for 2 days and low speed to finish the stage then use a traditional tumbler for step 3 and 4.

[@MichiganRocks]

I think that sounds like a good way to use it, although I’d always use it on the slowest speed. I just used mine for a first stage tumble.

[@azdigger4843]

I really like your videos. I noticed my AR-1 the barrel tends to walk one way or the other, so I called True Metal Products and they told me to just make sure the bottom of the barrel was against the guide wheel in the direction it traveled. They said to spray some lubricant on the bottom of the barrel and that will prevent chafing. Seems to be a non issue. And the tumbler is tumbling away just fine. They seem like friendly people, and told me I can call any time with questions, comments or concerns. As for the speed, I am still learning, but it just seems the Nat Geo is spinning too fast, and the rocks don't seem to be getting a good tumble. I would say it's like a good BBQ. Low and slow. Is the way to go.

[@MichiganRocks]

I agree, this is not a hobby for people in a hurry.

[@mutahmarriagecounselor2272]

Late to the party... but what kind of lubricant would be good to apply that won't degrade the barrel?

[@wooferhound7571]

I feel like the most effective tumbling action is accomplished when the rocks are sliding against each other while spinning. The higher speeds on the Nat Geo seem to throw the rocks across to the otherside of the barrel avoiding most of the sliding action that I want to see. The low speed seems to do the Slide very well. The faster speeds have less sliding action and plenty of impact action.

[@MichiganRocks]

I agree. Sliding seems better than flying. I'm running it at the slowest speed.

[@paigelee6321]

Interesting experiment

[@emdee7744]

Very interesting to get a look at the world inside. I don't know enough about tumbling to really have an opinion.

[@MichiganRocks]

I know a fair about about tumbling, but I'm not sure that I have an opinion yet.

[@Rookie_Rockounding]

Man Rob this is really interesting man! I reckon it’s probably not making as much rubbing contact with the other stones on the fast speed one. But I genuinely can’t say I know what I’m talking about haha. Either way I loved this!

[@MichiganRocks]

I'm not sure that I know what I'm talking about either, but the more stuff like this we look at, the more knowledgeable we'll both be. I thought this was a fun little experiment.

[@jeanbendallart]

Interesting video. I'm new to rock tumbling and really enjoy your channel. I particularly liked your review on the national geographic tumbler, and look forward to seeing a video on how you would use that tumbler for better results. although you did give clear instruction on the review video of what you would differently (which I really appreciate and will be following your instructions). I started my very first tumble yesterday. 😁 wish me luck. and thank you for sharing your knowledge.

[@MichiganRocks]

Good luck! The rocks in this video are partially tumbled. When they're done, I'll post a video showing how I did. Hopefully I will be successful so you can follow my method.

[@wintuwarrior5266]

I'm not to concerned about the speed as I turn my barrels around everyday, so sticking grit isn't a worry for my loritone, I'm pretty sure it would work for the nat geo as well

[@MichiganRocks]

I'm not sure what you're saying. I don't know what you mean by "sticking grit". My concern is chipping.

[@wintuwarrior5266]

@@MichiganRocks I was just responding to others that commented on grit, if you're wanting just comments on the nat geo, then I wouldn't want a tumbler that makes the rocks jump.

[@PotooBurd]

Love your work! Comenting for the algorithm 🌻

[@MichiganRocks]

The algorithm and I both appreciate that!

[@JamesJones-tu4pq]

So I would think that with the faster tumbler, if you used a rock that was'nt prone to chipping then I'd say it would be fine, but like trying to do agate, or quartz, or something along those lines but if you where doing jasper or a soft rock, or one that tends to want to fracture then I would go for a slower tumbler.

[@MichiganRocks]

I agree with you. I'm running some Bahia agates right now to see how they do. I think they should be fairly durable for fast tumbling.

[@paulcockfield6037]

Brilliant stuff. No ceramic mix... both seemed a bit crashing. I was expecting more of a concrete mixer tumble, perhaps the sludge and ceramics would slow the tumble of the rocks. I prefer the slow tumble 2/3 full with ceramic mix replaced with rubber bands on last polish, avoid crashing use your ears you can hear ithe perfect mix. Awesome video

[@MichiganRocks]

I will be adding ceramic media in the stages after the first. I never use ceramic in the first stage because of the wear on the ceramics. It's hard to say what a thicker slurry would do, but my guess is the same as yours. I think it would slow things down and make them stick together a little better. Doing this experiment with slurry would make it hard to see through the glass.

[@vance7354]

We have a tumbler Similar to the Nat Geo tumbler. There is some Debate between me and my girl on the speed Issue. Link to the tumbler at the end of this post. My question is this, If you are running at a higher speed, could this not, at least in theory, reduce the time needed to get through each stage? Example, the directions in the book say Stage one for 4 to 6 days with the included package of 60 grit SC. The issue is not if it smooths the rocks, but rather we lost a fair amount of size on the rocks running it for 5 days dead middle of the instructions. She says we should run it at the lower speed where as I say run it at the same speed just for less days. Example, Run stage one for 2 or 3 days instead of 5 but stay at the fastest speed. My question is this, Would it be possible, At least in theory, to control the amount of cutting done not with the speed, but with the amount of time? Also A second question on the Grits, The kit came with a starter grit enough for 1 batch, it included 60SC, 150SC, 600 SC Pre Polish, and 1200AO Polish. Is it possble to get a super shine using just those grits? I have watched a number of your videos and I saw you say that your Polish grit was over 8000? When we go to order grits I want to order from rock shed and she wants to just get a poly plastics kit off amazon that is similar to the grits that came with the machine, which way should we go?Thanks for your time and all the great videos! Here is the link to the tumbler we have. www.amazon.com/Professional-Polisher-Tumbler-Lb-Barrel-3-Speed/dp/B09PYR2RRT/ref=sr_1_7?crid=2ZN0L9Z4JGQT0&keywords=rock%2Btumbler&qid=1661290662&smid=A2219247NDSR1I&sprefix=Roc%2Caps%2C113&sr=8-7&th=1

[@MichiganRocks]

Hi Vance. I have never used that tumbler, but it appears to be made by whoever makes the National Geographic tumbler. I would guess that it turns about the same fast speed. By tumbling faster you will grind faster too. The problem is that it can beat up the rocks in the process. Some rocks that I tumble lose a lot of size, but my goal is to get my rocks as smooth as possible, with no holes left in them. Depending on how deep the holes are to start with, they can get just a little smaller or a lot smaller. I run my first stage over and over, removing rocks as they get done and replacing those with other rocks. If you want to keep your rocks larger, and aren't concerned about removing every hole, then just be careful to clean out those holes very, very well between stages to avoid trapping grit in them and moving it to the next stage. Another factor in size reduction is the hardness of the rocks you're tumbling. Harder rocks will wear away slower. Soft rocks lose size quickly. Agate and jasper are good rocks to start with because they're hard. Harder rocks are also much easier to get a good shine on. I would definitely suggest getting good grit from either the Rock Shed or Kingsley North. I'm sure there are other great suppliers, I am just not familiar with them. I think you could probably get a good shine with 1200 aluminum oxide, but I'd suggest running it for a longer time to accomplish that. I have such good luck with the polish that I use that I can't imagine using something else.

[@joshuajones6113]

Purely in terms of physics, if the rocks are moving faster then that means there is more force. You've seen evidence of bruising and chipping with the nat geo...that seems to correlate. It is interesting though that the motion of the rocks at the higher speeds and at different levels of fill is clearly different. Smaller rocks are going to the outside and presumably encountering less friction. Rocks in the middle of the tumble are spinning without necessarily tumbling over each other. The question remains if different types of motion results in different qualities (or styles?) of polishing. What a great experiment. I guess you will need to do MORE TESTING to see if the actual results of one speed/fill would be preferred over the other!!! :D :D :D

[@MichiganRocks]

I am of the opinion that slower is better. This tumbler is good at getting results quickly which is a good thing for the impatient, but at this point, I’m pretty patient.

[@patriciamckean4186]

Cool look inside 😎

[@GREEKEXPLORERS]

Congratulations on the amazing video!!

[@MichiganRocks]

Thanks!

[@JeffWeymier]

That was a cool experiment.

[@MichiganRocks]

I'm glad you liked it.

[@wolverine1623]

This is a great video which explores the mystery inside the dark drums! I would say the faster speed is much more aggressive maybe good for the hardest of rocks idk. My thought is I wouldn’t want to tumble softer rocks like Petoskey Stones at this speed! Also just a thought…you can buy electrical dimmer cords which reduce power primarily for the use of dimming lights. I’m not an electrician but am wondering if this type of application could slow down the fast action of the NG barrel? Great video Rob!

[@MichiganRocks]

I'm not an electrician either, so I don't know if it would slow it down or not. Most people aren't going to buy one of those and I have plenty of tumbling capacity at slower speeds, so I'm not going to bother with that either. I'd recommend just buying a slower tumbler to anyone who hasn't already purchased one of these.

[@hobbyhacks]

It comes with the switching type power adapter, so it would not work. Also lowering the voltage puts strain onto motor, and reduces torque.

[@ReiDaspedras]

👏🏻👏🏻👏🏻 show muito bom 👌 valeu like no vídeo 👍🏻

[@milesnn]

Awesome awesome video fantastic getting that glass cut to sure this personally to fast doesn’t give a even grinding and will cause chips to happen but that’s me awesome thank you

[@MichiganRocks]

We shall see how they do. I'll be posting a video about this batch of rocks when they're finished.

[@matthewkite5110]

I've had my 2 lbs nat geo for 2 years. And after the very first batch was complete. I bought a 6 lbs double barrell leegol. Once I noticed that the speed was faster, i relegated the nat geo to stage one only.

[@MichiganRocks]

That seems like a good move.

[@matthewkite5110]

@@MichiganRocks next I go full pro and get a vibe tumbler. Do you have any suggestions. My plan is Nat geo phase one. 6lbs barrell the phase 2 and 3. And then Vibe for polish. Just don't know who makes a vibe comparable to the loritone for barrels.

[@MichiganRocks]

@@matthewkite5110 I love my Lot-O. The only thing I do with my rotaries is the first stage (with a couple exceptions). All other stages are handled by the Lot-O. I can do everything after the first stage in seven days. The Rock Shed usually has the best prices, although it's hard to find tumblers right now, so I'm not sure if they have any in stock. There's a link for The Rock Shed in the description of this video. Check out this video: kzbin.info/www/bejne/oaTVnqOGj9d0q7c

[@tlk13ns]

I have a nat geo an I love mine the 3spds definitely makes tumbling quicker I recently got leegol electric as a gift boy is it slow 2wks at least fr final polish where as the nat geo 5to7dys also nat geo u can use it an frgt the leegol u have to oil it once a mnth an check it fr over heating daily my only an the lid is very hard to get off. My only complaint about nat geo is barrel size its only 2lbs but I plan on get a couple more lol

[@MichiganRocks]

Thanks. I have never used a Leegol tumbler. It looks like a rebranded Chicago Electric/Harbor Freight tumbler.

[@tlk13ns]

@@MichiganRocks using it just for final polish gonna take a good 2wks b frst batch in it geo is quiter at speed3 leegol seems to make a higher pitch sound probably cuz its metal

[@miltonwinslow2976]

Has anyone looked at a wat to reduce the speed of the tumbler down?

[@MichiganRocks]

Someone told me that they 3D printed a larger pulley. Others suggested using some sort of a rheostat or something to slow it down electronically.

[@miltonwinslow2976]

@@MichiganRocks For a beginner, is the Nat Geo tumbler a good tumbler or is there another tumbler that you would recommend? Thanks

[@MichiganRocks]

@@miltonwinslow2976 I much prefer Lortone tumblers. The 33B doesn't cost much more and has two barrels. The 33A has one barrel. I bought the 33B as my first tumbler and never regretted it. I have links to the Rock Shed and Kingsley North in the description of this video. They are both great places to buy one. They're in short supply lately, but ask one of those places to hold one for you when they get some in.

[@ed98027]

Wow watching the video does give me some concern about Nat Geo tumbler seeing how the rocks crashing and bouncing into each other. However, in real life I haven't experienced too much of rocks cracking with them. Maybe one unlucky one in the entire batch each time.

[@MichiganRocks]

I've heard from enough people who have had good luck with this tumbler, I'm beginning to wonder if it's not as much of a problem as I think it is. I still haven't been convinced not to use the slowest speed. Even the slowest speed is a very fast tumble.

[@Indyanas_ocean_view]

Wow, cool experiment. Very scientific. 😍🥰😇👍🏻👍🏻👍🏻

[@MichiganRocks]

Sort of scientific. It's not like I actually measured anything. Fun to observe, anyway.

[@Indyanas_ocean_view]

@@MichiganRocks It was interesting to observe what happens inside the tumblers. 😍🥰😇👍🏻👍🏻👍🏻

[@renegade5748]

good information based off of your video i think mine runs just over 33 at 1 and about 100 at 3

[@renegade5748]

but mine is a different brand

[@MichiganRocks]

There are several brands that seem very similar.

[@EDLaw-wo5it]

I am afraid I would stick with the slower speed of the Thumbler. I think someone else mentioned that when the slurry gets thick, as it sometimes does, it would stick to the sides of the fast tumbler. Maybe the NG has it's place but I haven't had enough experience to know. Good vid. Havagudun Rob.

[@MichiganRocks]

I don't have enough experience with it to make a judgment yet either.

[@EDLaw-wo5it]

@@MichiganRocks WAnt to ask Are the Thumbler barrels the same size as the Harbor Freight or do you know. One of my barrels is starting to deteriorate and wanted to replace it with a tumbler or other brands.

[@MichiganRocks]

@@EDLaw-wo5it I know the Thumler's is a larger diameter than the Lortone. It won't fit in a Lortone base. I don't have a Harbor freight tumbler, but it looks like a copy of the Lortone, so the barrels might be the same size. I don't like Thumbler's barrels because they leak. Lortone barrels don't leak.

[@EDLaw-wo5it]

@@MichiganRocks Thanks. Idon't have anyone close so I can compare. I may try a Lorotone and if it is too large return it.

[@davidhile5363]

@@EDLaw-wo5it I recently replaced the lid gaskets on one of my H. F. tumbler with Lortone gaskets. They fit a little snug but will work just fine. The next time I do that I think I’ll chuck the stem of the inner metal lid in my cordless drill and spin it while holding a file against against the edge of the lid to reduce the diameter about 1/32 of an inch. But they will work without doing that, they just fit a little tight. I’m surprised your barrels wore out. I had a problem with a hole wearing in the center of the lid gaskets after about 14 months of use. That doesn’t cause them to leak but grit gets trapped between the gasket and the inner metal lid and then you have to remove the gasket and clean it out, especially if you’re changing grits. I guess what I’m saying is that the Lortone and H. F. barrel parts are interchangeable. Also the Lortone drive belt will work on the H. F. tumbler according to the Rock Sheds web site info.

[@davidhile5363]

With the National Geo running at fast speed and in slo-no the rocks didn’t appear to have much contact with each other so you would think that the grinding process would be much slower. Another thing that might be going on at high speed is possibly the grit is clinging centrifugally to the I. D. of the barrel and more wear is occurring where the stones are contacting the barrel wall as opposed to most of the grit being suspended in the slurry. Also when the barrels are 2/3 full there seems to be a lot less bouncing around going on. Another thing that I noticed is the Nat. Geo. tumblers rollers seem to bounce around a lot more that the Thumlers. You were late I was beginning to think I had fast forwarded to Wednesday. Ha Ha !!!

[@MichiganRocks]

I noticed the lack of contact in the slow motion video too. I'll tell you that it does grind fast enough to completely break down 46/70 grit in three days on the slow speed. The slow motion video was with the barrel only 1/2 full. I have been running it 2/3 full.

[@lynettepavelich7540]

From someone with zero experience, I’m feeling like, the while the Nat Geo would obviously produce results faster, the aggressive speed could be detrimental to the softer varieties of stones. I feel like I would have more overall control of the results using the slower procedure.

[@MichiganRocks]

That's about how I feel too. The hardness of the rocks is not as important as how fracture prone they are.

[@anthonysees5015]

Looking at the comparison, I like how the faster speed of the National Geographic grinds the rocks. To me, it looks like the rocks in the National Geographic tumbler are more comprehensively tumbled. It looks to me that the rocks are moved through the group more thoroughly on the faster speed. Of course, more fragile rocks shouldn't be tumbled in this.

[@MichiganRocks]

I'm excited to see how this batch of rocks turn out. I suspect that these Bahia agates will be tough enough to survive the faster tumbler. I wouldn't want to try tumbling something like obsidian in the National Geographic tumbler though.

[@invictusfarmer7188]

gravity saved the nat geo tumbler. im testing one right now and with my rpm meter i got 90 rpm. my thumler is more like a hit and miss tractor and the nat geo is a mustang lol. being new im not sure what i like better but i can certainly see why gentle would make more sense. wonder if i can tweak the speed on that motor lol.

[@MichiganRocks]

Look through the comments on that video. A guy posted and linked to a video he made of changing the speed of his tumbler. I think he used a combination of changing the pulley and doing something to slow the motor itself down. I don't remember the details, but he made a good video explaining what he did.

[@invictusfarmer7188]

@@MichiganRocks awesome! ill check it out. you really have built a wealth of information on this channel. thank you so much for that

[@MichiganRocks]

@@invictusfarmer7188 You're welcome!

[@RockhoundTreasurehunt]

I infact have both types of tumblers. I have 2 Nat Geo and 2 of the traditional that hold 2 3lb barrels on each. I use the exact same grit and polish in both types. I run both types the same amount of days. I also adjust the Nat Geo speed control for the proper running cycle. Of course the speed and amount of days is personal preference. When all tumblers are completed on the same day they are all very shiny. They all have the same look. ( extremely polished ) You're doing your tumbling wrong. You have no spacing material to minimize the material from crashing into other material so violently. Use ceramic pellets. Air soft bbs or rubber tile spacers. Something as such to help minimize fractures. Also, it doesnt look like you're using enough water but that might just be the view. There's really no difference when done correctly. At least i see no difference. They all turn out beautiful. Rock on!

[@MichiganRocks]

That's good to know that you are having success with both tumblers. I hope to have success with this Nat Geo tumbler too. We'll see. You say I'm tumbling wrong. Have you seen my results? I do use plastic or ceramic media. I prefer ceramic. I never use any plastic or ceramic in the first stage thought. Plastic really slows down the grinding action. Ceramic gets worn out much quicker with coarse grit.

[@RockhoundTreasurehunt]

@@MichiganRocks I've seen your specimens. Great job! Excellent channel! Keep it up

[@margaretlynch1494]

I think The faster Centripetal force is more likely to crash the rocks.

[@RenSauceMan]

It seems like for the fastest speed the rocks are making less contact with each other.

[@MichiganRocks]

Yes, they are flying around a bit more. At the slowest speed on the Nat Geo, the rocks make good contact and still move around a lot faster than in the much slower Thumler's.

[@dawnmorning]

Slow video to .25 speed to slow movement down. Nice

[@dalevandenbussche5004]

With the nat geo I would think you would have to use more water then you normally would !!!!

[@MichiganRocks]

Why is that?

[@dalevandenbussche5004]

I would think it would make up for some of the action caused by the speed!!

[@MichiganRocks]

@@dalevandenbussche5004 That makes sense. Extra water for more cushioning.

[@jonathanyoung7785]

Dale, that's what I do with this tumbler and I think your observation / recommendation is spot on.

[@captpaul8827]

Nothing really to add here, I just find the rocks that go into a tumbler..... ;-)

[@MichiganRocks]

Bahia agates in this one.

[@captpaul8827]

@@MichiganRocks Thought those looked like Bahias

[@manapgemstonebatuakikgarut9151]

Nyimak ka

[@steveswhirld]

that was farout , to see ,, ive never tumbled rocks, from what i can tell tho 'slow and steady wins '

[@MichiganRocks]

That's how I feel about it.

[@williamscoggin1509]

To me that seems like a waste of time, the true test is the quality of the stones when they finish tumbling., Not just spitting around a little bit and some water at different speeds.

[@MichiganRocks]

I thought it might be fun to see what was going on inside. Now we don't have to wonder. Of course, it might look a little different after a slurry forms, but that would be hard to see with the glass all mudded up.