Cheap Linear rail "review?": part 1 does it suck, and how to lube it.

[@ster9765]

Perfect. This is by far the definitive video on these cheaper pillow blocks. I appreciate the longer videos and explanations. Other folks just touch on the subject without reasoning or knowledge to back it up. Nicely done. Much appreciated.

[@Chaos_God_of_Fate]

Instead of a bowl a paper towel underneath or some kind of soft surface to keep any potential dropped bearings from bouncing/rolling away if they pop out. A good tip for dropping anything small enough to lose easily: don't try to save the drop and grab it as it falls, watch it until it stops moving and then pick it up- it's too easy to miss a falling tiny object and slap it to who knows where losing it even worse. Great Video, just got a Laser Cutter/Engraver with a super tight linear rail- got it soaking in Iso Alcohol overnight, then relubing it properly tomorrow! That's why I'm here. Thanks for the tips, I hope they work!

[@gumdamsniper]

I saw your unboxing of theses this morning. Not ten minutes after purchasing my own rails, I get a notification about this video. I expected a need to re-grease them upon arrival, but I couldn't have expected such an in depth guide to just drop into my lap. Thank you so much! I got a 1000mm rail for $38. I plan to make a long printer. Eventually, I might look into dual independent extruders, if it takes too long to print.

[@gumdamsniper]

@Wick I'm hoping to get by with one rail on the Y axis. I got an additional carriage to add to the rail and give more support to the build plate. If this fails then I'll have to bite the bullet and get another rail. Then, I have to avoid binding the two rails. I'll worry about it in a few months when the rails arrive from China.

[@terminsane]

first the logitech microswitch breakdown. now cheap linear rail review. subbed.

[@jirij]

Some time ago, after weeks of "research", I've settled on calcium sulphonate plastic grease of NLGI 1.5 as my "universal" grease that I use on guns and bearings. It's basically like lithium grease without any of the disadvantages (which need additives to lessen), it's food safe (NSF H1), it's "high pressure" (holds where any other grease got worn down), plastic-safe (as far as I was able to tell) and cheap, because it's usually sold in literal barrels for industrial use. ... And it is enough to make the 3/32" bearing balls roll, not just slide. :) I need only to tilt the rail by some 30deg before the carriage starts slowly sliding under its own weight, without noticeable backlash. However the thing that broke it for me was the rail being bent, even on 400mm length it slides well on 3/4ths of the rail, but catches on one end. Having experienced how the brand rails "feel", I would probably go for the HIWIN rails anyway - they're the low end of the rail market and the price is "just right" to offset your (well, mine I guess) time fixing / ordering multiple of the chinese rails (and they can take load smoothly given their 4-track ball design compared to the 2 of the clones, which grind with even slight load). Alternatively, the in-between option could be the chinese rails with black carriages and an oil nipple, often found as "TRH20" (and other sizes) - I still have to try those.

[@hv1461]

Once you got going, Brother, you did an excellent job and provided so much useful info. Highly valued.

[@mikedoingmikethings702]

haa! I exactly use 3-1 and occasionally CLP... the depth and analysis including editing of this video is superb! Thank you!!!

[@DavidMulligan]

I cannot count the number of times I have recommended this video to people using or wanting to know about cheap rails.

[@Cahuette98]

The best grease for linear carriages is actually semi fluid grease. I personaly work in heavy industry and have to use NLGI 00/000 type grease for open circuit carriage lubrication. Examples are elkalub GLS 381 or MOBILUX EP 023.

[@ikinkyxD]

I like the detail you put into the videos !

[@flypic1098]

That was fantastic. I'm looking at buying a Chinese CNC router and you've helped me understand a lot more. Thanks. Jim

[@BrotherEmmet]

Just what I needed! I'm designing a 3d printer based on those cheap rails and this video just about covered everything I needed to know, thank you!

[@BinaryBlueBull]

I am in exactly the same position, minus the "designing" part. Right before I looked up this video I had in my left hand a tub of white lithium grease and in my right hand a tube of super lube oil, with a wondering frown on my face. This video is gold. By the way, which cheap rails did you go for if I may ask? I'm not designing the printer myself by the way, I'm building a Voron 2.4 and went with CNA rails, a Chinese company that does have some repute among the cheaper brands, as it's the brand advised by the Voron designers

[@MegaMaking]

i am using these clones on a few of my printers for awhile now. I took out the balls, used 99% IPA to flush the carriages and "flush" again with wd40 dry ptfe spray, finally lubed with spray on white lithium grease. I don't quite get the reason not to use dry ptfe lube though. there is also another thing to lookout for, if you're planning to replace just the carriages or rails, just dont. you should buy them in set (both rail and carriages), they are usually slightly out of spec and vary from seller/manufacturer to seller/manufacturer or even batches to batches.

[@AlexKenis]

That sounds like a pretty solid way to do it. As far as just using a dry ptfe film lube, i actually forgot to record a section of the video about heat and pressure vs load and running speed (I mentioned it in the section title and never filmed it.. oops) but the TL;DR is that you can displace the particles from pressure points under load, and also using an oil or grease also helps transfer heat away from the balls when they are running fast -- not that we usually run a extremely high loads and speeds in printers, but it is best practices. I imagine if there are large, fast, constant-uptime machines in the future, it will all become more important though.

[@TheGFS]

I am just starting a build , and have been wondering about wheels vs rails so i have both on the way , but this video was just awesome.. Love these very nerdy videos that dont just show a guy cleaning out the bearings and that's it, today this is by far my fav. 3d printing youtube chan :D

[@BischBaschBosch]

Just ordered a bunch of these for my manual cnc (ncnc?) sled/copy router type machine. Was using v-slot wheels but found them a bit sloppy. Hoping the linear rails will stiffen things up a bit. They might be cheap for linear rails by comparison but the full set from banggood for my set up was a around £190. Not a huge amount but not an insignificant outlay. This video has made me feel a little better about it and has some great tips. Especially the bearings. Many thanks.

[@MrDynamik1]

Great video and editing, I appreciate the effort and content. You covered all the material I've been going over the past few weeks with printer linear rail modifications and service.

[@Trunkmonkey916]

First Off, Well Done Sir. Very Informative like most of your videos.

[@3rd_Millennium_Engineering]

WOW! Fantastic video and has a previous poster had commented, a wealth of information. Thank you, Alex for taking the time in sharing this information with us. I am subscribing to your Patreon as you have helped me immensely.

[@ALex-qc4lf]

Hiwin says you should use EP2 grease on the rails. Also what about IPA that is 99.9% pure? Why is IPA not a "good" solvent?

[@zodak9999b]

Thanks to Google some years ago I found people (who knew more than me, not saying much tho) recommending Dow M-Kote 44 L. It's a NLGI #1 grease and my two homebrew Deltas with their cheap Chinese rails seem to love it. Being lighter, I didn't have the sliding bearing problem when I reassembled them. The bad thing is it's more expensive.

[@AlexKenis]

Never tried them. I thought all the MolyKote lubes had moly oxide particles, but at first glance apparently not all do, they just kept the name for the whole line.

[@RazzoAratey]

Dude!! Fuckin love your videos, ur homemade style is exactly what our community needs !

[@alanb76]

Misumi rails reportedly come with white lithium grease in them, and that is what it seems to be. They seem to move smoothly even though this grease a little thicker. They are higher grade rails and fit more precisely.

[@kazolar]

What I'm finding is trying to ensure tolerances on v-wheels is they get loose, or the bearing pop out just enough out of the wheel and they start to bind. Then having to re-tighten them or adjust them to eliminate the play -- ugh. On the other hand, I decided to give the "best" Chinese made rails a shot. I have a large format machine with 2 X carriages, 4 extruders, a total of 4 rails, 8 blocks. The issue I'm running into attaching a long rail to an extrusion and not have it bow or dip in the middle. I'm coming up with a jig to mount it. They're MGN15 rails a bit more robust than then common MGN12, so rigid sure -- but the slight dip -- .1mm or bow in the middle is pretty easy to get over the length of a 800 mm rail that would be with the rail mounter at a 90 degree to the bed surface. And as we know a dip or bow that much is enough to mess up a first layer.

[@AlexKenis]

If it helps, the openbuilds forum has a deflection spreadsheet for v-rails. I think you have to register to download, but the post was titled "Excel Sheet to calculate Deflection". When I have more room, I'll be working on a large format printer, so I'll probably run into the same issues when I get there, but I don't have any helpful hints at the moment

[@kazolar]

@@AlexKenis I made a jig (CNCed out of 6mm aluminium ) it bolts to the top of the extrusion with hammer nuts, and ensures 2.5mm of spacing down to the rail. I machined 3 of them, attach them at the edges and in the middle. Then use clamps to clamp the rail to the jig, and then tighten the rail to the extrusion. Ran some level calibrations and variance in 2 micron along a 600mm square bed, so that worked well. Without a jig like this, there is no way to ensure consistent spacing as the rail will sag or bow as you tighten it to the extrusion. I can then run the jig along the top of the extrusion and see that the rail is actually pretty consistent.

[@AlexKenis]

sounds like a good way to do it. I'll have to make a note of it for future use so that I dont forget and then have binding when I get to the large format design

[@kazolar]

@@AlexKenis funny enough, you won't get binding, the variance is literally a couple hundred micron over nearly a meter of rail, it's enough to throw of level, but not enough to bind.

[@ahmedal-modaifea4457]

I have been wondering, these are salvageable from some machines that are already in the market. Stencils for example. would it be viable to check them out. Hmm i bet size would be a bit iffy and probably worn out.

[@DiscoverRajivVlogs]

This is how to convert Chinese rails to HIWIN rails. Thanks a lot for a really detailed video.

[@Trikkie87]

Hiwin rails actually suck when used in parralel. As a hobbyist you will be throwing away money for worse performance and you will not get warranty from hiwin (it specifically states it in the manual). The tolerances are to tight. If you want to use hiwin you need to make sure one rail can be floating.

[@HannesMrg]

What about dry PTFE without any oil/grease?

[@diggraph]

Great video. Thanks. Is it possible the bearings are metric size and not 3/32"? (A bit oversize for 3mm though) I don't think you mentioned how often a relube would be needed?

[@heninugraheni3950]

holy mama. At first I was overwhelmed by the talking :-) Almost skipped the video. But, being an engineer I am amazed about the depth of the research on only some linear rails. Thanks you so much to put so much effort into this ! I need these rails for my CNC project, still gona buy them from banggood

[@billgilbride7972]

Very informative. Makes me wonder if it comes to change, would stepping up to the next better bearing be a longer term solution. Now if you would do a video comparing the different bearings to show if all it does is make it bigger not better or bigger and better. THANKS again!

[@wiradharma7030]

You could smooth the surface and quench the bearing and the bearing housing(not the rail, it will bend for sure). You could use gas stove to heat it up, after it start glowing dark red quickly put it on running tap water. If you heat it too much let it cooled down a bit, you want dark red. If you not used to, do it on a dim lighted room. You could also want to cover anything except the gutter where bearing sit with clay. I do not recommend quenching the bearing if you are not used to quenching. For the rail itself, you could use carbon fiber to add stiffness. I am gonna use this for mine. And, i think we do not even need precision bearing for our aplication. Just my 2 cent.

[@christopherrumford]

Another great video Alex I follow the exact procedure per your video. I use these cheap rails on all of my delta style 3d printerrs. Much better than using wheels on the aluminium v slot. In my last order from china I ordered x3 rails with matching carriages. Two of the rails were great,however on the third rail the carriage was binding up.i solved this issue by swapping the carriage from a free moving rail.i now have three free moving carriages. Just proves the non exact tolerances between rails even from the same batch/supplier's. Lastly some of the M2.5/M3 mounting holes on the carriages are not threaded full depth,using bolts that are ever so slightly too long will result in the carriage twisting and binding up on the rail.

[@AlexKenis]

Good to know! I didn't think to check screw depth, so i'll keep that in mind. THanks

[@olafmarzocchi6194]

I wonder whether an ultrasonic cleaner filled with isopropyl alcohol can better clean the bearings before greasing. Would it damage anything?

[@Adam-qr4jj]

Awesome video! Great content, got a new subscriber right here! Currently I'm creating a custom cartesian printer, re purposing a old Wilson Prusa i3. In process of finalizing my design, but here is what im using for linear guiding--> I'm using 2020 extrusion & MGN12 for my X-axis, 12mm OD x 8mm ID carbon fiber tube (With polymer bushings) + T8 leadscrew for my Z-axis, 10mm hardened shaft and linear ball bearings. Extruder is a hybrid dual hotend utilizing geared drive and bowden (1 motor on x carriage) Currently working over geometry to reduce moments and increase rigidity. This video was super informative, thanks for making it! Starting to rethink my decision on the 12mm z axis tubing and go with 10mm hardened rod and bearings, I dont know, thought the carbon fiber rods would be cool and different. I have to decide on keeping my eye out for a good used Japanese rail to pop up on Ebay or impatiently pull the trigger on (US warehouse) Chinese bearings and G25 balls!

[@jmtx.]

Thanks for a greatly detailed video on linear rails. Time to check my rails for wear since I definitely didn't care for them all that much during installation.

[@Koto-Sama]

on my kp3s the linear rails started binding and add layer shifts. i will try this. hopefully that will fix them

[@SkewedVisionsGames]

Fantastic video, earned a Sub. Special shoutout for the Wawa pretzel and the shot with The Boyler Room in the back.

[@CDN_Torsten]

Fully agree that these low-cost rails need cleaning. I typically fully disassemble them, and then clean all parts in an ultrasonic cleaner using 99% IPA as solvent. This method will release a disturbing amount of particulate which would have shortened their life or impacted their movement quality.

[@rdpeake]

Would you do anything differently with these if they do have the grease nipple on them (and similar question with ball nuts for ball screws with grease nipples)?

[@Sment1337]

Ευχαριστούμε ρε Αλέκο!!

[@mostafaalabd3629]

I have problem about ends of block made from plastic easy to broken do you have solve this problem

[@geldan]

There are two core xy projects that I know of that source these cheap rails in their BOMs with excellent results: voron and railcore. Voron even goes so far as to recommend a particular ali vendor.

[@wesc23]

I purchased from the voron recommended vendor, cna mechanical. 17/20 rails are unacceptable.

[@alianildinler]

Thanks mate, i have learned the hard way by experimenting myself for my case; ethyl alcohol as cleaner and light oil works best and you will be quite suprised after cleaning your cheap chinese linear carriages and see them work perfect.

[@Core3DTech]

Great video! I've used Linear rails on all my printers. I used to buy, used ones (IKO/THK) which are great but pricey (even used). When I started designing printers for thingiverse (for others to build) I've since bought several of the cheap ones and have had very mixed results. It's not uncommon to receive rails with over 10 balls missing. I've also received some that would just stall (I think due to that ridge inside the block). There are two sizes of blocks the one with holes spaced 20mm x 20mm and the smaller ones with 20mmx15mm spacing. The latter seem much smoother (unless I just got lucky with those). I've also gone through replacing the balls with McMaster Car ones but found a lot more play between the block and rail so that kinda defeated the purpose, the balls might have been better, but accuracy was out the window. I would recommend going on ebay and checking out brand rails that have been salvaged from machines which for some reason seems to happen a lot in Korea. On my last printer, I've used 15mm THK SR15 1638mm long (total overkill, I know) but I couldn't pass up these rails for $450 when new (3 rails with 2 blocks each) these would have cost about $2500. You're definitely right about the cost to value. I probably tipped that a little.

[@AlexKenis]

Yeah, the price is what kept me away so far, but those IKO/Nippon/etc rails are really nice. I almost bought some nicer used rails for $50 a piece, but I decided to give the cheapies a whirl. Just took a look at your project and it is similar to one I have been working on. I'm going to try the heavier-duty dual row budget-rail carts for the Z axis though, just to see how well it holds up... fingers-crossed

[@Core3DTech]

@@AlexKenis make sure there some "break" mechanism on the Z-axis. The problem with belt driven Z axis with rails is that once the motor loses power, it comes crashing down. On an earlier printer I had to change Marlin, end of print/pause/stop code to bring it home nicely. That won't help in case of power loss. Good luck and thanks for the in-depth videos.

[@cellularmitosis2]

Exactly the video I needed!

[@bakaneko718]

i must have restarted doing 6 different carriages. each one is just binding too much no matter how little or how much grease and lube i use. i double checked the bearings and ensured i used new ones and they look like they go through the channels fine. it is turning into more trouble than it is worth at this point. i spent 10 minutes cycling the cart on the rail back and forth hoping that it would loosen and cycle.

[@travisr.3667]

Hoping you still read these comments or someone else can tell me! You mentioned using Krytox lubricants, I actually have 205g0 and 105 on hand for my keyboard switches. Would either be good for lubing rails like these?

[@AlexKenis]

Still read them when they bother to send a notification... anyway, 205 is a bit thin (and expensive), you can certainly use thinner stuff, but since the bearings are not sealed you'd have to apply it more often, and that can get expensive. Id save that for your keyswitches since it would be a bummner if you needed it and had to order another tub. On the kp3s printer, I ended up using superlube grease on the rails and that has been fine for a couple hundred prints so far. I used thinner greases and oils on the other ones, and they work fine too, but as expected, they get dry a lot faster.

[@travisr.3667]

​@@AlexKenis I didn't see this response until just now! One of the side effects of my keyboard addiction is having stupid amounts of 205 around so I'm not exactly worried about running out, but I took your advice and ordered some Superlube grease that I'll be using anyways. Thanks for the reply, I appreciate it very much!

[@iuppone]

Hi, i saw somewhere, i don't remember where, changing the balls with ceramic one's. What's your idea about it?

[@sfcoawol6273]

I've been looking into these rails lately but I have no hands on experience to make a decision. I'm planning on building a cnc for milling aluminum and maybe steel on occasion. not planning on having a mill volume more than 12x12x6. would you recommend the linear rails like you are showing in this video? or should I get the v rails? I imagine that it will get pretty messy with aluminum flakes but just not sure if the linear rails would hold a more accurate cut than v rails or if the difference would be insignificant.

[@AlexKenis]

I have not done any CNC testing, but I imagine V-rails would be the simpler solution. Try looking on the openbuilds forums at the projects and discussions there and see if you can get a better picture. Im sure there are folks that have tried both over there

[@cri8tor]

You just got another subscriber. Long video, but full of very useful details. Cheers

[@italosoares69]

holy shit! thank you so much, i got more information on rails on this video than in my 5 years graduation lol

[@Anjfyi]

Currently building a Voron v2.1 with these linear rails and I have a Kossel Linear Plus. I've had to replace the ones that came with the Linear Plus, one of the rails weren't moving at all. I disassembled, cleaned thoroughly and tried to put in another carriage on the rail but it seemed that the rail itself was the issue and was too wide. In Voron discord and forums, people have been using white lithium grease and apparently it works better than super lube, I'm not sure of the details though.

[@AlexKenis]

I'll be putting up a part 2 soon with superlube tests that may help clear thing sup (spoiler alert: I like PTFE lithium grease slightly better)

[@jsimmonstx]

I just got a set of rails (Inverntech MGN12 off amazon), and when I pulled it out of the box, the carriage would freely travel the length of the rail under its own weight. I cleaned it up, lubed it wit SuperLube grease, and went ahead and replaced the bearings with the G25 bearings. When I got it re-assembled and put it back on the rail, the fit is much tighter - not so tight that it wouldn't go, but I had to be very careful about sliding it back on the rail because the bearings wanted to stack up on me at the end of the carriage, and pop out of the race. The carriage no longer slides down the rail on its own, but when I turn it over and observe the bearings, they are turning when I slide the carriage, and it travels smoothly the entire length of the rail.. Should I be concerned? Should I put the original bearings back in?

[@jsimmonstx]

UPDATE: Since I had four more carriages to clean/lube, I decided to do the rest without replacing the bearings. It seems that the Super Lube grease is so thick that it tightens up the carriage to the point that it won't slide under its own weight. At this point, I'm gonna go with it this way. It makes a little less noise and there's absolutely no slop in the carriage at all, and it moves very smoothly (just not as free-wheeling as a non-lubed carriage. Comments?

[@Timj27]

@@jsimmonstx I’ve got exactly the same problem right now, I replaced all the bearings with g5 ceramic replacements but it’s made the carriage too tight. Not sure whether it might loosen up over time or if I should put the old bearings back In!

[@alanartt3138]

Nice informative video. I think your rail is an MGN12 type. Just for info if anyone has the smaller MGN9 rails then use ball bearings that are nominall 1.9844 mm in size or 5/64"

[@AlexKenis]

Good call. I don't think I specified, yes they are the 12mm clones

[@DJSolitone]

Thanks for the info. Are you sure MGN9 use 1.9844mm or do they use 2mm (metric). For the life of me I cannot find any reference chart online referencing nominal ball sizes for miniature linear rails.

[@DJSolitone]

Ok after measuring on my rails, ball size is confirmed to be 1,98mm on mgn9h with 34 balls per side so 68 per slider block. Measured with Mitutoyo slide ruler. I am considering to upgrade to ceramic balls for my Voron V2.1 build. It comes to about 10 USD per rail for G5 grade ceramic balls.

[@enrilopez]

Any updates on this lubrication process? I'm trying to redo the linear rails on my resin printer i would love your input thank you

[@user-lx9jm1wo3h]

I know this video is old, but hopefully you still read comments here? I am wondering if 12mm is any better than the 9mm rails? If the rails are mounting on a solid platform such as aluminum extrusion and not supporting anything really heavy, is there any point in using 12mm over the 9mm width? I thought about upgrading but I'm not sure if I should go with lighter 9mm instead of the heavier 12mm ones.

[@robertwalker7834]

respects. great video. one small point fadal cnc mills that use linear bearings do have some play in them. the ones with box ways that have been adjusted right are better. they use a light wax free oil and it is pushed into the bearings then left to circulate with the coolant. point being their could be a recirculating system with these bearings. why did you not use a white honing stone and rub the bearing grooves and run bigger balls. great information. im building a scalar fdm printer with a 12*12*24 capacity. im down to purchasing linear rails. and ball nut lead screws.

[@williamcase426]

YOU RULE DUDE

[@gmagician3135]

Hi, this tutorial is really detailed and complete, thank you very much Since I'm a noob about these arguments I have some question. Once followed the whole procedure open + degrease + flush + lubricate + close (I'll use grease because I'm lazy and I don't want to lubricate often) I'm wondering... a) subsequent lubrications what has to be done? open + degrease + flush + lubricate + close again? only open + lubricate + close? only lubricate? and in latter case may be done through th central hole? b) When a new lubrication is needed? What are the thing that say you its time to repeat? c) In my country Super lube is not sold. Is there a "viscosity" index to compare to that let me choose another brand? What is the "best" formula..PTFE needed? something else needed? Maybe you already said that in video but different language doesn't help, even if "subtitles" are helpful

[@AlexKenis]

Lube is tough to talk about in detail because is depends on environment and use conditions, but heavy machine oil or light grease of various types seem to work well as long as they are compatible with the seals and not too heavy or too light. If you have to relube more often, oil may be better so that you don't have to remove the cart to repack, but grease makes for a quieter-runnning bearing and less maintainance. If you dont have super lube, the greases I have tried have seemed like they were between NLGI Grade 1 and grade 2 in consistency, so Im sure there is a brand of silicone synthetic grease with teflon in a similar grade that you can find

[@Waltkat]

Great info. I bought one of the cheap knockoff rails for my printer just to try it out. I did clean all of the stock oil out and lubricated it with 15wt pure silicone oil. Seems to be working well. I do have a tube of that Krytox but it's a very thick grade so probably not a good idea. Also, 3 in 1 also sells a thicker oil (SAE 20) called 3 in 1 Motor Oil. Comes in the same size cans as their regular oil.

[@davidhaney1394]

it wont work well for long .

[@Waltkat]

@@davidhaney1394 It's been 3 years and it's just recently been exhibiting a little bit of slop. I'll have to take everything apart to be sure it's the linear rail that's the cause of the slop, but even if it is, for the price I got my use out of it. I'll just replace it with another one or go back to the POM wheels since I haven't noticed any improvement in print quality with the linear rail.

[@AndrewAHayes]

I think it was Micheal of Teaching Tech who changed out the roller wheels for linear rails on an Ender 3 and they were worse on that machine, although I can't remember for sure if they were Hiwin

[@Pocketninjanight]

Makes a lot of sense, I was wondering if using a rail vs v slot was a better choice vs weight.

[@Trikkie87]

Good video. Only comment i have is that these cheap linear bearings are actually waaaaaay easier to put parralel when compared to hiwin rails. Like hiwin rails in parralel need to have very tight(insanely tight) tolerance specs on the construction for hiwin to give warranty on them when used in parralel. The cheap linear rails have much more leeway in bad aligntment because the tolerances are pretty bad and the balls are too small. Like about 150% more leeway than the hiwins. In other words: when you use these puppies in parralel, the cheap chinese linear guides will actually have smoother performance and higher life, all other things being equal. Now i personally would recommend to make one of the linear bearings floating . Slightly loosen the bolts on one side of bearing, spray a hit of silicon oil under the contact area and make sure it stays in place by using a bit if loctite.

[@TonyRios]

I'm using the Finish Line Extreme Fluoro on my z axis and white lithium grease on my x and y axis

[@hesperaux]

Wow. Extremely awesome video. Many thanks.

[@SyFyBry]

How much difference in friction or drag was there? Was it noticeable at that two viscosities?

[@millpreetk1406]

does anyone know how to clean rail or if there's little noise only on small part of rail. Is the rail need replacing? seems to work fine for now

[@vasyapupken]

yes Hiwin says that particle grease is not good for they high precision C5-C3 linear bearings but in case of yours cheap ones with it's bearing races already damaged some kind of NLGI-2 moly grease might be a good choice actually ))

[@daveklingler820]

I haven't gone through all the comments yet, so someone else might have posted it, but Amazon sells Finish Line Premium Grease, mit teflon, so it's still being made.

[@hisuiibmpower4]

actually for small stroke application cross roller way unit is the best，it‘s not that expensive when u find the right retailer

[@martijnellenbroek6448]

The b and c in hardness rockwell mean hrc= hardness rockwell cone and hrb= hardness rockwell ball

[@intelli07]

Very detailed information! Thanks Alex!

[@wernerboden239]

I often use thinner to clean things, but I think there are plastics that could melt with that. I'm told that petrol is a good cleaning agent as well. But there's also petrol with 10/20% oil in it for mopeds, so when you clean with that, would that be good, or bad thing ? Since it will leave thin film of oil on it. Rearding rails: I bought 4 of these MGN12 rails L700, with 2 carriages each, for $125 or so. Quality is pretty good; no noticable play there. Seems to me, chinese products have become a much higher standard, these past few years. Some of them still deliver crap. So, it's a good idea to just buy 1 rail, first (and check user reviews). I checked the mounting holes on these carriages as well and they are spot on, to specs. Some have pretty huge deviations; so when you drill holes for the gantry (in this case 20x20mm), you could find out, the carriages won't fit. And yes .. I intend to slide an 8mm aluminium strip into a v-slot profile, to mount them (leaving a little room to make adjustments), and wire tap them (I think it's M3)

[@AlexKenis]

I think this is the last of the comments that got caught up in the filter (sorry, my boot drive died the other day, so I have been re-installing and have not caught up on comments. I have used petrol quite a bit for old oil and grease, especially if there is a lot of dirt or dust mixed in. It works well as long as there is no pertol soluable plastics (I tried to dig up a chart to post but couldn't fin it). I'm not sure that 2-stroke/2-cycle oil would leave enough film for lubrication, but maybe enough to prevent corrosion for storage? I really couldn't say. As far as rail, buying a single first is probably a good idea. I grabbed mine together because they were on 'super sale' and they all ended up having some play. Tha'ts okay-ish for some cases, but it was not great for my Y-axis, so I had to do a work-around that I mentioned in the linvestream

[@gregjenkins5258]

I use royal purple motor oil on my skate bearings once the factory grease wears off it works really well but I do have to disassemble and reoil more frequently. Also a note on cleaning the best method would be to sonicate everything starting with acetone, methanol, alcohol, lastly water of course all would have to be reagent grade. Thanks for the great video.

[@ameliabuns4058]

have you tried robotdigg ones? people say they're far better, but it still seems like unless you get preloaded rails at 35$ for something near 350mm you're gonna have play :(

[@m3chanist]

Excellent video Alex, well done. And yeah, Ive never seen cages on carriages down at this size, a bit hard to get reliable flex cages at that size.

[@vonyolo420]

Does anyone know if it is possible to "pop" the carriage off of the rail (ie twisting it off)?

[@Zigge]

Thanks for the video. Can you explain how to choose between grades of these cheap rails if I want to use something a little better / more expensive?

[@AlexKenis]

I wish they did have a grading system, but the cheap ones seem to vary wildly. I posted a link in the description to some rails on amazon that are supposed to be better quality and better bearing tolerance (at 2x the cost though), but I have not used them myself. The main concerns I had with the super-cheap rails I got seem to be the bearings and the quality of the rolling surface on the cart, so presumably you can swap the bearings and use a decent lube and they should be "okay" albeit with a less smooth action and lower bearing life. I'll be swapping the bearings on the third rail so I can see how well that holds up in comparison since I'll probably be using them on a daily basis.

[@kazykamakaze131]

@Alex Kenis Hey bud, you can remove the static noise using Audacity. Just select beginning of your video where you don't speak then apply noise cancelling to the rest of your video. This should sort all static out of your videos. Hope this helps!

[@JoergGebhard]

i also but some MGN12 from Banggood, they also got some play, the additional Carriages i bought are fine, till now i could not find a decent trader for the bearing balls

[@AlexKenis]

I grabbed some of the bearings i linked from amazon and they are pretty good. my 3rd rail came in, so I'm going to put up a part 2 with superlube and those bearings probably later tonight or tomorrow. For high-tolerance parts, I usually go through mcmaster carr since they are quality and close by, but I don't know their shipping policies

[@nickoutram6939]

The difference in sound of oil vs grease is amazing, I wouldn't have thought it made that much difference. I think the big take out of this video though is that although China has undercut on price it has hugely undercut on quality of fabrication which is only apparent on deeper inspection. "You get what you pay for" has never been so true. Now for the hobbyist with some knowledge and extra maintenance work it is possible to have cheap and 'better'...

[@wizrom3046]

Shouldnt use teflon grease on rolling balls it is too slippery, same with most silicon lubes. The risk is that because it is so slippery the balls will slide and gets flat spots instead of rolling. A better lube is a tacky oil, like a thick gearbox oil. My preferred lube is the red Lucas oil stabiliser, it can be used neat and is clingy so it has high retention, and is tacky so balls and rollers roll well.

[@claws61821]

This reminds me of something I read about on Machine Design when I was studying up on screw drive mechanisms a while back. Do you know much about nesting or movable support blocks? I've tried to find them on KZbin and a couple of other places to get a better look but haven't had much success.

[@AlexKenis]

Like telescoping blocks? Unfortunately I don't have any experience with them.

[@claws61821]

Something along those lines, yeah. Alright, thanks anyway. Always good to see a new video from you.

[@puha666]

Thank you Sir for sharing your detailed knowledge in a pleasant way. Liked and subbed.

[@whatevernamegoeshere3644]

Can we like cut this into 5 parts so we can like all 5? This has more info than an entire series on another channel

[@SpaceraverDK]

+1 for Superlube... It's my go-to for anything that needs lube thicker than household oil.

[@christophergrove4876]

Yes... THK's "SSR" rails' bearing blocks do have a flexible "caged" bearing arrangement. Nice... an' 'spensive!!! I know this because my Roland Large-Format printer (2D) has them.

[@AlexKenis]

Ah, I thought someone might have gone that route. Yes, they are expensive as heck!

[@thebeststooge]

I despise the wheels and wish I could move away from them but been using them for 5 years now. On my laser it uses 2nd hand rails (from the manufacturer they used 2nd hand Chinese rails) they are so much better than wheels but were pricey. My CoreXY I need 3 500mm rails and 3 blocks which was 100-200 dollars just two years ago and I would still need to print an adapter but once done no wheel system can compete with a linear rod. Of course the linear rod is unforgiving so if everything is not perfect you will know fast. Btw, which rail to use on a V-Slot (real V-Slots not knock offs) is to be used as I would T-Slot them on?

[@ameliabuns4058]

i just finished my printer using one mgn12c on the x today! and honestly mine is great. it doesn't wobble a tiny bit and the rigidity/weight is great compared to rods. without the wear of v-slots (I hope) but i'm not sure if i just got lucky or not. plus v-slots hvae a nicer rigidity/weight ratio anyways. I was wondering if they're just underrated? everyone I meet hates v-slots to death for some reason EDIT: I got play now after a few months

[@AlexKenis]

Nice! I'll show the more recent rails in the final kingroon printer video, they are much better than what I had in this one. They actually bothered to polish the inner surface, and the tolerances were much better

[@ChazzDerby]

Really great video. Looking forward to see you try the 2.38 balls. A kind of modification i would do.

[@GregTheroneggythetech]

So can you prep LM8UU's the same way?

[@frederikdehn8576]

All the info I needed!

[@payton1284]

Love you dude, Somebody who knows how to talk XD Thanks man

[@hisuiibmpower4]

cross rollers guides themselves aren't that expensive,but cross rollers translational stages are due to precise machining required to make them

[@007Mofro]

That's some good knowledge right there, thank you

[@avejst]

Thanks for sharing😀👍 One guy sad that you can use SKYDD (protect) mineral oil from IKEA, because it is clean, as oil in rails..😀

[@Woyta]

What about silicon oils for RC shocks? There is high variety of viscosity you can order. And it is not expensive.

[@joshuabroussard8838]

This video has killed any desire I had to convert my printer to rails.

[@chuuba_lover]

IKR

[@DARKredDOLLAR]

Mine was reinforced lol I've been putting rails on cncs for a while, they'll benefit my printer. (wheels just suck)

[@aaronhambek6362]

I know this is ancient but v wheels aren’t better, you just don’t know all the things that can damage them or make them wear faster. Linear rails are fine

[@emaayan]

what about "WD-40 anti friction dry PFTE lubricant? "

[@mechanicallydev4536]

I bet the best lubricant would be spray canned lithium grease, as its not as thick as the squirt version.

[@AlexKenis]

Agreed, the spray foam lithium would probably work really well.

[@mikem8145]

I don't thing HIWIN MGN series rails have 4-row recirculation ball bearing guide. Only on bigger series.

[@tareql1906]

Excellent research! thank you.