Using the Wrong Tool to Balance a Grinding Wheel

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Today we're balancing a wheel for the surface grinder using an RC prop balancer. It's definitely the wrong tool for the job, but it might work anyway.
Tools used in this video:
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Bondhus Metric Hex Key Set (Amazon*): amzn.to/3eqZzwb
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Knipex Pliers Wrench 3-Piece Set (Amazon*): amzn.to/2ruzS8m
Noga MC1700 Mini-Cool Kit (Amazon*): amzn.to/2qgemiM
Raw Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 3.0 License
creativecommons.org/licenses/b...
00:00 Intro
00:50 Balancing hardware
04:38 Shopping for balancers
07:52 Prop balancer as a design pattern
12:10 Or maybe the prop balancer will work?
15:47 Test grind!
20:27 Inspecting the result
21:48 Wrap

[@DudleyToolwright]

Another nice video. Always well presented.

[@knowname23]

Nice set up

[@ElectricalInsanity]

I have hours of experience watching surface grinders on KZbin. Everything looks good to me!

[@mpioman9885]

Who said KZbin University isn't accredited?

[@ErikBongers]

In my case: days, so I have even more expertise, and I actually agree.

[@stephanc7192]

😀😁😂🤣😃😅😅

[@vincei4252]

@@mpioman9885 KZbin UNI is way more accredited than the Universities that used to be great that now pump out activists rather than useful members of society with actual skills.

[@wmweekendwarrior1166]

That’s funny

[@Preso58]

How fortuitous. I need to balance a cheap CBN cup wheel for my drill grinder. I don't really need another project so I'll see if i can get a Dubro prop balancer. Thanks.

[@vahpr]

Funny, I literally just 5 minutes ago minute threw that same balancer in a box of rc stuff to sell. Now thinking I should keep it for this purpose 😊😊

[@HaxbyShed]

A very useful review of the balancing stands. Thank you. Was good to see the range of prices. I have one which looks like the $629 stand, which I bought for about $20 at a flea market. Cheers

[@SethKotta]

The key to a good surface finish is to, before starting starting up the surface grinder, lean down and whisper "you can do it, buddy". The difference is like night and day.

[@markrainford1219]

Just remember not to do it AFTER you have started it up.

[@Bob_Adkins]

Or just tell it if it doesn't perform, you will ship it to ElectroBoom or AvE for a live post-mortem.

[@petercollins9682]

Peter again if you want better finish try on the spark out passes lightly run a 1200 die makers stone across the wheel face.

[@bh3141]

It's more in how you hold your tongue after you whisper.

[@ShadonHKW]

Your grind looks good to me. Fish scaling or scalloping: Sloppy spindle bearings (doubtful, yours is new) Cold spindle, a cold spindle will usually have about .0001 radial play until it warms up. Balance combined with cold spindle is also common. (Who wants to wait around for 45 minutes to grind for 10 minutes?) Stepover lines: Sharp leading edge of the wheel can create stepover marks, just touch the leading edge with a Norbide stick (after dressing) to make a slight radius, the leading edge of the wheel does the heavy lifting, the trailing edge does the fine finishing, grind either front>back or back>front, don't alternate. Welcome to the rabbit hole.

[@TheWidgetWorks]

agree 100%, make sure you take a well sighted in gun with you so you can get that dam rabbit if you ever find it;)

[@Clough42]

Thanks, Stan. I hadn't thought about warming the spindle. That's totally worth trying.

[@charlesstaton8104]

Assuming something is good because it's new, is pitfall I have to make a conscious effort to avoid. This goes doubly true for car parts. "It *_CAN'T_* be that sensor, I *_JUST_* replaced it." Uncannily often, it *_IS_* that sensor, off spec from the factory. I know it's not a sensor in question and this isn't car, but I've found the concept applies universally.

[@Clough42]

@@charlesstaton8104 ugh. I hear you. Starters and alternators are the worst.

[@boomermatic6035]

@@charlesstaton8104 This applies to so many things, in my industry $10,000-$20,000 power supplies have been bad right out of the box, $70,000 new out of the box radar simulators out of calibration, so cost and new don't guaranty accuracy or functionality.

[@mattsaxey529]

First one of your videos I've seen. >SUBSCRIBED< great little demo, really like the tone of the video! looking forward to seeing more.

[@summerforever6736]

looks good from here

[@markschweter6371]

Those fancy hubs, with balancing weights aren't listed in the "tools used" section.

[@Andrew_Fernie]

Have you checked the balancing arbor for straightness ? Also concentricity and roundness of the badly fitting taper?

[@brandontscheschlog]

To inspect your true surface finish, take your precision ground stones and run them over your ground work. This will expose balance issues, wheel hop, step-over and any heat you may have put it the part from grinding. Use this to perfect your skills. You’ll be surprised at how much this will show you

[@LiviuGelea]

I saw a great tactic for balancing wheels. You use an accelerometer and a tachometer and connect the two to an oscilloscope. This way you can see the phase difference between the vibration and place you put the reflector

[@lannywestgard6131]

Accelerometer and Scope... That is right is James' wheelhouse.... I smell a follow up video....

[@gorak9000]

Was this on "The Gadgets Playlist" channel? He's done a number of videos on building balancers - pretty sure before he retired he used to do balancing professionally

[@LiviuGelea]

@@gorak9000 don't remember unfortunately

[@UncleKennysPlace]

"Real" aircraft propellers have relatively inexpensive setups to do this.

[@stanmacdonald1073]

​@@UncleKennysPlaceAviation and "relatively inexpensive "😊

[@mikebroom1866]

Looked like that worked perfectly. Don't fix what aint broke.

[@basiedp]

Hi. We have couple of these type machines. Each wheel that is delivered is checked in weird way by operator. He taps wheel with small hammer and sound has to be even all round wheel. If not he states wheel needs drying, it efects the balance. Also homemade unit for balance using tile cutter replacement wheels, same design as prop unit. The bed gets a very small grind after wheel has been done with diamond tip. Hope this helps🤷‍♂️

[@siimanderson4549]

Air bearings would be nice for balancing.

[@larrysmall3521]

Place a small clear plastic cup of water on top of the grinder cover and look at the ripples to check for vibration.

[@garychaplin9861]

Years ago I used the Du-bro type balancers for model prop balancing but then switched to a magnetic balancer, it was much more sensitive and settled quicker. Absolutely no friction or rolling resistance. When I got into larger models I made a bigger version. The only critical dimension is the concentricity of the shaft and mounting cones. With the rare earth magnets available today it should be easy to make one large enough to carry a grinding wheel.

[@Clough42]

I have never seen a magnetic balancer for grinding wheels. I agree it would be ideal, but that's a lot of weight to support, and very expensive it it slips out.

[@BNETT21]

Discs out of hard drives would work great for those large dia precision wheels.

[@MotoRideswJohn]

I still have my Dubro balancer from my RC flying days over two decades ago. I'm always finding new uses for it and it always continues to impress me.

[@Bob_Adkins]

The rolling type balancers shouldn't be underestimated. A good one with hardened steel rods is *very* sensitive. They are also very easy to make. It would take air or magnetic bearings and large wheels to be more sensitive. You prove they are accurate by flipping them around, just like calibrating a precision spirit or electronic level. Grinding wheels are funny things. Eccentricity makes them imbalanced. Balancing and dressing can throw them a little bit out of balance again, and they will dress a bit eccentrically again! It may take 2-3 sessions of balancing and dressing to get them close to perfect. Never use aluminum on any balancing device, it dents microscopically from weight.

[@philt214]

I agree with you and a balancer using even drill rod like the one I made seems to work very well. Getting the balancer level is of course very important so I use a precision machinist level. I am quite pleased with the results I get with my Harbor Freight grinder I bought more than 10 years ago. I can grind test blocks in 5 places on the chuck to within a tenth. This is more than good enough for a HSM.

[@Clough42]

I actually ordered a couple of HSS drill blanks to use as rails, and the ones I received were awful. The grind on them is so bad you can file your fingernails with them. Guess I need to throw a couple into my next McMaster order.

[@Bob_Adkins]

@@Clough42 Yikes, that must have been disappointing! In a pinch, I guess you could sand them longitudinally, which should make a smooth rolling surface even if it appears a little rough. I hope McMaster's blanks have a better finish!

[@billdoodson4232]

Ha haha! "Some aluminium that came out of the scrap bin". I wish I had a scrap bin like that.

[@Piasecznik72]

Arrow inspector (for spinning arrows and checking its straightness has same parts.

[@michaeltornero9220]

Thanks for the great video! I’m exploring different options on balancing slot car motor amateurs and wheels. Looks like what you did should work great for grinding wheels. Wanted to offer my opinion about your surface finish. First let me say that getting a good ground finish on mild steel is tricky and yours looks acceptable. If you wanted to improve it, I would try switching to a non porous Norton 60 grit wheel or equivalent. The Radiac wheel you're using is a porous 46 grit wheel. Porous wheels grind a little cooler than non porous wheels and can be used without coolant in some cases. Since you have a coolant setup, I’d try a non porous 60 grit wheel, balanced with your method, and it should improve your finish.

[@bowez9]

In my former Die Shop we never balanced the wheels. We did dress new wheels as soon as they were installed. Think about it as you dress the wheelthe balance changes. We would also flood with Fuchs coolant. We ran a 60+year old Thompson and 30 year old Chaviler grinders.

[@jimcoleman52]

I was sitting here thinking about where I can source nice discs and bearings, and it occurred to me that I might be able to use 4 old spinny hard drives for hubs, bearings, and thin nicely concentric discs all in a convenient little package.

[@Scumbagthings]

i used to do tool and die, never seen or used cooling mist on surface grinders....

[@aly-tek7190]

Looks good from here ;)

[@GT40Nut]

Thanks I've needed to build one of these for a while.

[@robertginther9248]

1. Anderson balancer is the ONLY way to go to get a good balance. (The one shown in your video for $1925.00). I looked for 4 months & found a used one for $250.00 & it's perfect. They are available. Even the guys @ Anderson told me not to change the wheels: each wheel has a precision bearing & is balanced @ the factory. Wheels for my balancer, (which will hold a wheel up to 22" in diameter & 10 inches wide), sell for over $200 each. Spin a wheel with your finger @ it will spin for about 2 1/2 minutes. 2. Make your own test shaft--I did. Between centers & taper of 1/4 inch to every inch of width. Simple to set up & turn. 3. Wheel goes on test shaft & tap shaft on solid surface to seat. Test your shaft with machinist blue to check contact. It will stay easily if the shaft is correct. 4. Every time you mount your wheel in machine, true it. Diamond tip should be about 3/4 inch behind center to make it be about 15* angle of contact. Too close to center will wear the tip off of the diamond. 5. Your finish grind shows signs of hopping. Look @ the reflection & you can see it. Slow your pass, decrease step over until wheel grinds very smoothly. Watch for loading. 6. My finish pass with an 8 inch Radiac ceramic wheel, 36 grit, on 55 Rockwell steel is .000025 inch to .000050 depth @ .005 inch step over & it produces a mirror finish that you can shave with. Try it & see. I can't even get that good a finish with my 150 grit diamond wheel, no matter what I do. 7. Check out Steve Barton @ Solid Rock Machine Shop on KZbin. He's the best I've found. Works within 50 millionths of an inch & his products are unsurpassed in quality & accuracy. Sorry this was so long....

[@Maskinservice]

My experience of the Du-Bro balancer is that it is very, very good for balancing lighter stuff like propellers for model air planes, which is its purpose. It is also suitable for balancing heavier stuff like grinding wheels, but it seems like the friction in the bearings somehow increases with the heavier load. The bearings might not be premium class, but who could ask for that when the complete balancer cost less than just one premium class bearing? But still, the Du-Bro balancer is extremely good for its price and it is good enough for most of us. But I would recommend removing the grinding wheel from the balancer when moving the weights, simply because the balancer isn´t meant to be used with the weight of a grinding wheel. Add to that the forces that you inadvertently add to the balancer when working with the grinding wheel and you might stress those tiny bearings even more. Anyway, good video, thumbs up! Cheers from Sweden.

[@guywihn1658]

When I'm balancing most things in bearings I'll always ad vibration to overcome the last little bit of bearing friction.

[@Clough42]

Oh, that's an interesting idea.

[@notsonominal]

So electric pre-heater with wifi and smart home integration for the grinder next?

[@JohnK8]

I have that same balancer and was going to try the same thing. Glad to see that it worked.

[@Ale_Lab]

I was looking at the same cheap propeller balancer for my small surface grinder. Thank you for trying it out!!!

[@kimber1958]

nice job James very clean very clean work thanks for sharing the time with us

[@1960fl]

I always perform balancing and trueing in a regressive manner, balance then dress repeat at least once. If you balance then dress you removed material that may affect the balance etc. I always do this on a fresh-mounted wheel.

[@SolarMillUSA]

I painfully went down this same rabbit hole a few months ago. Static balancing is good, but the king of balancing is dynamic balancing. You identified the core problem, overcoming static friction. If the magnitude of imbalance is below the amount of leverage needed to overcome the friction, it doesn't move. Or it settles into a position that is not truly indicative of the imbalance. Dynamic balancing can reveal greater detail, below what is needed to overcome the static friction. All one needs to do it install a reflective sensor on the mounting wheel for phase, as well as a *very* cheap accelerometer, and then run those two signals into a pocket oscilloscope and you can balance in place on the machine. :D

[@ralphpavero7760]

I hope you don't mind if I copy those clamps great jobi really do enjoy all the videos thank you

[@jefffromjersey52]

As soon as I saw the Bearings model, and he says it did not work because of Friction. Immediately I thought of CERAMIC.. We use them in Fishing Reels, and they are very very fast , and extremely low Friction. Any Oil in a Bearing will slow it down somewhat .

[@harry8506]

looks good to me

[@sl_st]

Prieolnoe video. I'm wondering, what about magnetic suspensions for bearings? Something with a needle stopper on the end. Of course, it is difficult to comprehend the necessary supporting ability, but still interesting.

[@sierraspecialtyauto7049]

Steve Summers put up a video several years ago about using the DuBro balancer for grinder wheels in the shop. He says it works great. I got one for my balancing needs and agree with Steve. Just handle it carefully and be gentle. It should last indefinitely in the home shop.

[@Clough42]

Ha! I didn't know that.

[@tonyray91]

Well done for remembering who it was.

[@samrodian919]

@@tonyray91 it wouldn't be hard if like me you are an avid follower of Steve's channel. I visited his shop last year when on a trip to the states from England. A really nice bloke and very humble.

[@tonyray91]

@@samrodian919 Yes, I know he has to follow the interst but a bit of a return to machining would be welcome.

[@Mike-ff7ib]

Finally, a long awaited episode that delivered pure entertainment. I look forward to the next release! Looked like a nice grind to me but I'm not a grinding expert.

[@Clough42]

I might be being too particular. That happened that one other time. :)

[@mazchen]

​@@Clough42 YOU!? No way! 😂

[@subuser9627]

Nice job, careful with that yellow cloth and a still rotating grinding stone...

[@kevinkoller8493]

Hi. Great video. Do you have any links or information to the supplier of the the balance arbor? I can’t seem to find them for typical US style taper spindles. Thanks!!

[@wb8ujb]

Started this video and you spoke of making a balancer for the arbor. I stopped the video to find a link to the one I have used for many years. Came back and continued your video. :) you brought forward the very same one I've used forever with my R/C planes. You got this, those things will last forever. Like all precision machines even the smallest need care. Good job, appreciate the video and the time you put into it so we can enjoy it.

[@davekerr6614]

I'm no expert but got about 15 years as a tool and die maker at a bearing manufacturer, got a few things that will help you.. that coolant isn't going to work. It's not directly in the cut, you need to flood that right in between the wheel and the job. Don't get truing the wheel confused, when you mount the wheel you true it first to balance. Dressing exposes new grain structure to allow the wheel to cut. Now I always worked on Jones and Shipman surface grinders which don't have an Arbor just like yours and we always mounted then trued up the wheel to balance and was always good, I know wheels are never consistent but it worked fine and what I was taught to do as an apprentice. Not sure on the colour coded you have in the US but that wheel would be softer here. I would probably grab an aluminium oxide wheel. To grind mild steel. As they are generally harder acting. Best truck to check for true to is to grab a wooden brush handle and just touch it against the surface of the wheel, you will feel any vibration through that and it won't bounce like steel. A wheel never cuts at its best straight after a dress, generally it's just to Sharpe and you need to grind a couple of parts... That's more of a general rule.. The last thing and probably the most important. When you mount a wheel and start the spindle you dress it and then don't stop the spindle. You leave it run, spindles could be on for days... Oh and don't forget to ring test a new wheel and let them dry for 10 mins if using alot of coolant. 👍

[@C-M-E]

It's probably worth a laugh at this point, but I modified a du-bro to balance my first 254mm compressor section for an axial jet engine built from a cornucopia of other jet engine parts. Did the job, but I started banking out for professional laser balancing when going larger than that. Peace of mind at 85K rpm is certainly worth something.

[@rkoellner63]

I'm also new to surface grinding and learning every day. One thing I did learn was, after you balance a wheel, then dress it. If you put it back on the balancer, it show out of balance. So, I've had the best luck and the best finish, if I balance, then dress, then balance again, then dress again. It's a little longer process, but way better results.

[@petermetaxas9696]

It's the same logic when balancing tires. Mount them on the machine, balance them then loosen the tightening mechanism then move the wheel/tire 15 deg or more then re-balance it. You may or may not see any changes but it's worth the extra 60 seconds. Probably 20 minutes on the grinder.

[@elgandos2]

Honestly, I never balance my wheels. I give em' a ring test, throw them on the arbor and just dress it true. Never had an issue...

[@oldfarthacks]

Well, do you first dress your wheel in drag? Now here is a question, could you make up a balancer that uses air bearings? Using a close fitting slot on both sides and supplying compressed air to levitate the wheel.

[@MrBuck295]

try bluing that arbor to find what the fitment problem is , small burr or wrong angle taper

[@MrRbtgold]

Hello….I not only use the same Dubro balancer for my RC props, but also for my lawn mower blades. So far it works great!

[@oldschoolman1444]

I have one too, works great.

[@joeldriver381]

I had the really simple prop balancer that just held the shaft between magnets. Excellent idea!

[@MichaelStevens-pl5iv]

I think you may have a few things that are contributing to the surface finish that you are getting. I have been in the trade for 30+ years now and a couple of things.. First the type of coolant is very important, we always used grinding coolant as apposed to milling coolant. My experience has shown that if you are using a milling type of oil, the wheels would tend to clog , and this led to poor finish and even burning of the part. This leads me to the second point. You really need to use enough coolant to really keep everything really cool and theotetically you should not see any sparks, especially on light cuts. Also bear in mind that the coolant is also there to clear the wheel in operation. The other thing that I have experienced is that some of the modern import grinders don't seem to be as rigid as the old school (Cincinnati for example) machines and I found that I just couldn't get the same quality finish unfortunately. Hope this helps for what its worth.

[@bengrogan9710]

Adding to this statement "You really need to use enough coolant to really keep everything really cool and theotetically you should not see any sparks, especially on light cuts. Also bear in mind that the coolant is also there to clear the wheel in operation" The coolant we used in my parents shop for the cylindrical and surface grinders was the same overall coolant from Rocol, Just at a radically lower concentration - recommending 20 to 1 for cutting and 60-80 to 1 for grinding One part that needs to be considered is that mist coolant may cause more problems than flood coolant - Just like a whetstone, The wheel will be absorbant and swell until it is saturated - with mist I doubt you will reach that point and will be loosing some accuracy: but we are talking a few tenths of a thou here

[@paradiselost9946]

i dug an old TOS tool grinder off a pallet, cleaned the dust off it, set it up, ground a few chunks of carbide for a job. boss whinged and whined that i "wasnt a machinist, it wasnt economical". i got the effin job done. along with several others... he sold it. $500. glad i pinched the magnetic chuck. same job(s) comes up. cant do... "why not?" sold my grinder, you wanker. (ad verbatim) "it wasnt worth the time..." so youre telling me its more "economical" to now send the carbide away to get ground the same way i did? FFS... never got them jobs again. lost a big contract for FAE... those forestry mower things. i left. paid a visit one time. oh my... a new surface grinder hiding in the corner... not even a shadow against that TOS. chinese rubbish. can you tell it still hurts me?

[@MichaelStevens-pl5iv]

I feel the pain!

[@remcovantriest4357]

That's exactly what my professor told me, start the machine let the coolant fill the grinding wheel fully. He always told us to be keen on not seeing sparks. He did have a similar idea on the oil, he was also very keen on the mixture to avoid inverted emulsion.

[@samrodian919]

@@paradiselost9946 good call leaving the wanker! Even though you used the dollar sign, you sound to me like you're a Brit, (like me) working in the states or Canada maybe?

[@bh3141]

Grind with piece at about a 20 deg angle.

[@gamezxtrem3348]

2 strings hanging from the ceiling with hoops at the ends to hold the wheel shaft in the air, just need same length strings. I would think this would work with out being a money sink.

[@Zeusspupp]

Your balance looks good, the chattery finish is a sign of a dull diamond or too slow a dress. Softer material=harder wheel, softer also likes a more open grit structure.If the wheel is "bouncing", its to hard, out of balance or needs more dressing. Coolant(especially oil based) needs to be mixed lean, think 5%, I have found synthetic best for grinding. Consider putting your part at 45 deg on the chuck to limit heat build up. .001 is an ok ruff cut, on soft ,a big cut loads the wheel, on hard material, it wears it. Ruff , redress, then .0005 and sucessive .0002 finish cuts and spark out passes. On CRS, Id use a J or K wheel, a porus wheel would be best. Also, tighten the nut on the wheel adapter as tight as you can, loose wheels slip and will be out of balance again in addition to being out of round. I mount, dress, balance and dress again. Some grinders are more fussy about balance then others.

[@Clough42]

Thanks for the tips. This is an open structure wheel, but it's a G. I have a K, but was getting similar results. The soluble oil coolant is mixed at 20:1, which is the 5% you recommend. I've done more balancing work since and have some better results. Video coming soon.

[@memegusta42]

I think the wheel/material combo you're using is the main hindrance to finer surface finish. When grinding vanilla 1018 CRS and I want "wringable" surface I usually use a 32a120-kvbe with a closed dress for my finish passes. I've also had a great time with straight AlOx wheels (pure white in color). I think a longer warm up will help too. These tips worked on a full wet grinder instead of mist cooled, so you might encounter burning with a wheel that hard? Hard to say.

[@memegusta42]

I should clarify, by "wringable" I mean I could wring them to a clean granite surface plate, but If I had 2 workpieces treated in the same method they wouldn't wring together without lapping

[@snakezdewiggle6084]

Fluid vs Gravity... kiss tech is your friend. ;)

[@robertlunsford1350]

I have a couple prop balancers. I actually grabbed one identical to yours that was behind me while watching the video. Great idea.

[@TheAyrCaveShop]

Looks like a win / win.... cost / performance

[@GMCLabs]

RC tires can get pretty big and heavy, so if its designed for wheels and props, it should be good.

[@mark111943]

Good work James, I found this interesting even though I can’t use the knowledge, yet. For friction free bearings the first thing that came to mind was some kind of air bearing. Maybe others who have used such things can chime in.

[@DonziGT230]

You can remove your doubt about the balancing arbor by rotating it and re-inserting it in the wheel, if the balance remains the same then it's good enough.

[@gilcd85]

Great content! Keep'em coming

[@fuzzy1dk]

add an accelerometer to the grinder and maybe a laser pointer to show the high spot, make it its own balancer. Too bad the weights aren't accessible from the front

[@YaBoiTogashi]

That ring paper that goes between the hub and grinding wheel. What’s that called and where can I buy it? I damaged Norton.

[@AmateurRedneckWorkshop]

Very interesting video. Thanks for the video keep on keeping on.

[@JanBinnendijk]

When balancing a Grinding wheel, Start off with all the balance weights removed, so you can find the "Heavy point of the wheel".. then Mark and mount the first weight directly opposite of the heavy point, that way, the center of mass is on the line between the heavy point and the first weight. Keep that first weight where it is.. and place the other 2 weights symmetrically, you then have to move the both of them up or down to properly balance the wheel.. with some experience it can be done in 5 minutes.. i Used this method for years, and colleagues always turned to me to balance the grinding wheels..because it would take me 5 minutes..

[@en2oh]

static balancing a dynamic wheel? Does that lead to the best outcome?

[@stanmacdonald1073]

What a perfect opportunity to try your hand at making an air bearing. Have you made any air bearings? How could you let this opportunity sit a moment longer? Oh, and speaking of rabbit holes this would ...

[@michaelrobinson9643]

I've been balancing RC car wheels on such a device for years. Easily built for less than $10 :P

[@snappers_antique_firearms]

Have you thought of the magnetic style bouncers. I use them for rc props and they seem to be far more sensitive. They also will never wear out. You would obviously have to build a bigger one to hold the weight.

[@Clough42]

I had a conversation with someone about those this week. I suspect it would work great, but would also require very powerful magnets.

[@stanmacdonald1073]

They also sag so the wheel spindle may not be horizontal. Does this matter? I don't know.

[@snappers_antique_firearms]

@@Clough42 i figured it would need large magnets. I am curious of how well-balanced you can get a wheel and doesn't make a massive difference. if the regular rolling style balancers are good enough then i would think what is ever. Cheaper is best

[@cameronwebster6866]

My first thought for this went to graphite air bearings, which are surprisingly easy to make. Virtually no friction, and by carving the channels after assembly you can get rid of almost all misalignment. You could also add a feature to the part of the arbor that goes in the bearings, such as a flange, and a corresponding feature in the bearings, you could "key" the arbor axially, while still allowing free rotation.

[@4GSR]

I don't claim to be an expert at surface grinding. I've been using a similar Radiac wheel on my grinder for several years now. I don't use it that often. Started out with a 8" OD wheel now around 7"- 7-1/4 OD. Have never used a balancer to balance the wheel. Does leave a nice finish most of the time. I noticed the last time I used it, it started to leave a ripple like you had shown before balancing the wheel. Time to try your balancer and see if it makes a improvement in the quality of the finish. Your grind sample looks very nice! Thanks for the video, Ken

[@turtlemann14]

im surprised noone uses air bearings for this.

[@JoseAguiloworkshops]

Great video! Do you use .6 nozzle for your 3d prints with carbon fiber? A what layer height, temp and speed? That prints looks beautiful. Thanks!

[@ftownroe]

Another great video James. If it works or works well enough for your use it is an excellent use of existing tools to meet a purpose as opposed to purchasing an expensive tool that would have limited use.

[@Sausketo]

What are those parallel jaw tongue and groove pliers?

[@goodstormsgames9744]

Hey get a silver marker and mark that nut in the direction to loosen it. Arrows will save you headaches. :)

[@trollforge]

Well James, at least no one can say that's not a "Prop"er balancer... ;)

[@JesusvonNazaret]

you could dress the side of the wheel to get it balanced even better (before adjusting the balancing weights)

[@lindsayfog5246]

put the dresser on the far left to avoid gritblasting your mag chuck

[@hasanzakeri8708]

Thanks for the video! It would be nice to hear your thoughts on dynamic balancing too (not just for wheel; but in general)

[@chrisburbank6484]

slower on the passes and .001 is a pretty heavy cut depth for a 6x12 grinder , generate alot of heat/ distortion . another slow spark out pass wouldn't hurt. wheel choice looks good . a dressing before the balance gets it round sorta, then balance, dress again . if you really want to get picky balance again . the out of balance pulls the wheel off concentricity a bit. this shows more on bigger wheels like 20 inchers

[@joewhitney4097]

Great video, I think the simple little prop balancer worked fine. It worked to do the job and I think you can build one that will work for heavier and/or larger wheels. The finish appeared very good. I think it worked great. Thanks for sharing.

[@gjkozy]

I had made the exact same style of balancer for my grinder, I used small bearings but their was too much friction, then I tried larger bearings which helped but still not satisfied. I was considering using the round stock or putting a inverted Vee on the top of the side pieces and getting rid of the bearings all together. I had operated a Berco crank grinder and a large surface grinder and both used the large wheels for balancing. I deduced that you need the fulcrum effect that the wheels provide with the low friction of small bearings. Now you have given me another consideration. Machining the tapered disc's and keeping it all concentric was a concern.

[@ErikBongers]

If you want a balancer with 2 horizontal rails, you might get some inspiration from "Adam the machinist". He makes high precision jigs with....3D printed plastic and carbide rods. He shows that plastic differential adjustments are surprisingly effective.

[@Clough42]

As a matter of fact, I have already 3d-printed something like what you describe. :)

[@OhHeyTrevorFlowers]

I’m glad to see other fans of Adam. His channel is under appreciated for the quality of his work.

[@HolmesHobbies]

Adams channel is amazing

[@thisoldphoney3448]

Love Adam's work. Up the Robin and Stefan

[@risfutile]

Hi James. I'm wondering about re-dressing the newly balanced wheel. Wouldn't dressing introduce new unbalance? It feels to me like one of that multi-iterative processes that influence each other. In the same way that bumping in square stock on the lathe chuck concentric *and* perpendicular influence each other and have to be done multiple times in a row.

[@Junkboy888]

Some RC props are over $150 and what is what we use.

[@court2379]

I don't understand why vibration isn't used more in balancing. A super low friction balance isn't needed if you overcome the friction by vibration. It should greatly increase the accuracy.

[@JeffSearust]

You could make a balancer to the accuracy of your surface plate, but I think you're still constrained to a guestimate of accuracy in placing the weights.

[@brendanshorter5550]

Perspex cover?

[@steamboatmodel]

One of my uncles worked for Liford grinding X-ray photo plates, they used two devices for balancing the wheels, the first one for initial balance had two parallel knife edges as sharp as razor blades, the second used air bearings on the shaft and flashed a dot of light to show were to add weight or remove it. My Uncle said the balancer machine cost as much as a grinder and him and another guy were the only two in the shop certified to use it. the machine reminded my of a tire balancer refunded and shrunk.

[@melgross]

I buy a fair amount of Starrett hardened, precision ground stock from McMastercarr. All of it over the years has slight undulations running down the length of the stock, almost like what you see on windy beaches. It’s it a lot? No, but can be a tenth. Often maybe half that. Sometimes less. This is Starrett folks. Supposedly they have very expensive computer controlled equipment, excellently maintained and adjusted. But nothing is perfect.

[@FrancisoDoncona]

Bought the Tormach arbor, its threading is too short to actually use.

[@Clough42]

Hehe. Same here. I made a recessed nut. Video coming soon.

[@nickp4793]

I've designed infant pendulum swings for 15 years that rocked infants to sleep. We paid a lot of attention to bearing decay, as the lower the friction, the better they would work. One year instead of a hanging pendulum style seat, we made a curved track and wheel system for the child's seat to "rock" on. I was in charge of the drive and track system. I prototyped many different track, wheel, wheel cross section, ball bearings, plain bearings, etc. And counted the system decay on each one. What that meant was putting a 20lbs weight in the seat, pulling the seat to the hard stop of the track, and counting how many cycles it went until it stopped. It ranged from about 8 cycles to 70 cycles, with all the different combinations. This is all very relevant to the balancer you showed. What I found was the following: The smaller the ID of the wheel, the better. So if a plain bearing, a shaft diameter of 1mm worked better than a shaft dia of 4mm. If a ball bearing, a shaft dia of 4mm worked better than a shaft dia of 8mm (608 skateboard bearing). In all cases, a ball bearing worked better than a plain bearing, even a small plain bearing compared to a larger ball bearing. Next was the wheel diameter that the bearing was mounted inside. The larger the diameter, the better it worked. A 2" wheel was much better that a 1" wheel, etc. Last was the cross section of the wheel and how it contacted the track. In general, the smaller the contact area, the better it worked. I had about 100 data points on all the variables, and plotted them all out, and that led to the mass-produced product that we sold tens of thousands of. So in my experience, if I was to make a wheel type balancer, I'd use a much smaller bearing than a 608. Something with maybe a 4mm ID from McMaster. Get the FAG brand that's what they sell if you get their Japanese bearings, and they are very high quality. (sorry, this was 10 years ago, I forgot the bearing trade numbers now). Then use a large diameter wheel. Maybe 2-3" in diameter. Turn the wheel on the lathe and bevel its edge to maybe a flat about .050" wide. Smaller would be even better, but I think the risk of it getting dinged will override the decay advantage. IMO:)

[@mp6756]

Yes