#29 Linear Sliding Rail Guide #29 / MGN12 / Dial Gauge Jig / Improving Movement / Butting Rails

[@auhopu]

I am not sure about the clones, but original Hiwin rails have a specific face that's precision grounded and marked with an arrow. This is the face you need to indicate off to ensure parallelism.

[@EducatingSavvas]

The clones trucks seem to have a mark on one side but the rails are the same on either side. I noticed that in some of the images online. Unfortunately mine are pretty cheap.

[@mattivirta]

but hiwin shit cost owerprice lot not newer buy owerprice parts.

[@3dprinting4life10]

One of the problems with linear rails is parallelism which you have found out, also the rails follow the contours of what it is bolted to and even extrusion is not always flat, If I was building a CNC I would probably apply the bearing 2:1 rule having two adjustable preload trucks on one rail and get them true and one non adjustable truck on the other rail, technically the rail with one on is just a guide and not as critical as the rail with two trucks on, regards RobUK

[@EducatingSavvas]

Hi Rob. Yes I was thinking something similar - I think. So fixed through holes on the plate for the bottom rail and slotted openings for the rail above. I think it can get the rail pretty parallel with the jig I built but I could also use slightly longer machine screws for the top so it doesn't tighten the plate against the trucks and the slots can compensate for any deflection in the rail.

[@serkanozkan8793]

Normally joining two piece of Linear rails should be with angle cut like 45 degree at least. Because if one side ball jump to next rail, other side afterwards, in this case slidely smoother jump.

[@waldvogelreview7755]

I actually have had this problem many times so i replaced them with better quality ball bearings from a reputable bearing company and i have had great luck. I havent noticed any play. It is on a 3d printer though, so that makes the forces at work much lower.

[@3dkiwi920]

Great video as always! I've ordered some g10 grade 3/32 chrome balls so we'll see if that helps any. Worth noting the little green piece is actually two pieces and can be opened and cleaned also.

[@BrianBoniMakes]

Found exactly the same things. My solution is to disassemble, clean and inspect all new trucks, they are all dirty. I've found bad bearings so have a very close look at them too, one side of the ball was flat and sometimes the trucks are missing a number of bearings. I gave up on trying to link the cheap rails, just buy them long enough.

[@EducatingSavvas]

Yeah I think long single rails is the way to go. It was just an idea and I realised testing whether it would work wasn't shared ina video. Hopefully it will answer some questions for people who are thinking of using the rails.

[@sinergiintanbrisena]

awesome sir

[@EducatingSavvas]

Taa!

[@ShopperPlug]

Want to build a small precision CNC bolted onto a precision granite surface plate for PCB laser etching/sensitizing. Need to check the rails for squareness.

[@vsasab607]

for this size you should use 1605 with MGN 20, Any size over 400 cm will have problems with T8 orT12 and inaccuracy at best , good luck

[@mr.es1857]

Hi, thanks a lot for your video, you really opened my mind for my project ... How and where can I look for those aluminum profiles to mount the rails, Thanks again!

[@TOM_78]

Do you experience any probems with the joints when temp changes ? Of course its not optimal to join rails, but how well does it work ? nice video and if you want it even smoother change the balls for chrome ones... I use them in my 3d printer and they changed the game by a very large margin, this way you can tune even aliepress linear rails to work rather well (of course in my case there is no real force applied to the bearings, because they are only used in a printer).

[@UberAlphaSirus]

You could print some felt wiper holders for the truck ends. Should stop any burnt cheese getting stuck on your greasy balls.

[@EducatingSavvas]

If I ever finish making this cnc machine and start selling them as kits, I'll provide a complementary cheese cloth to keep the rails nice and clean.

[@IceTurf]

You cleaned and replaced the balls, or just cleaned them?

[@EducatingSavvas]

Cleaned and replaced some balls.

[@julienhagen7411]

@@EducatingSavvas oh dude please don't do that.

[@turkayp]

Hi. MGN12 has 3.5mm holes but i see that you have had used M3 sliding nuts for mounting. Do you recommend M3 bolts for MGN12 or should i look for M3.5 bolts instead ? Thanks.

[@EducatingSavvas]

Mine used M3 machine screws but if you can find some with larger size it would help hold better. I'm in the process of upgrading to HGH15 ones now. Will keep the MGN12 for a drawings machine I want to build.

[@turkayp]

@@EducatingSavvas Thank you. I'm going to use M3 machine screws then. What head type do you recommend ? I'm thinking of using A2 head but they have cap diameter of 6mm and MGN12 has sink hole with 6mm diameter. It seems it's gonna be tight fit.

[@EducatingSavvas]

@@turkayp I can't remember the head size but if you look for the diagram for both the linear rails and machine screws you can work it out.

[@thirumenipharma2612]

Is that the 4080 C beam v slot

[@ltgengr]

Wouldn't it just be easier to 3D print a spacer block to adjust both rails to be exactly the same distance apart?

[@EducatingSavvas]

Unfortunately not, because you want the blocks to travel parallel but the rails might not be parallel. So the best thing is to measure form the set rail block to the free moving rail block - tightening it as you go long.

[@narcixxxxxx]

Hello, what's the name of the software you use for CAD?

[@EducatingSavvas]

That is Fusion 360.

[@johnfithian-franks8276]

Hi What are the groves for on the hammer?

[@EducatingSavvas]

Musical instrument. Lol.

[@TommyAventador]

I bet that ain’t no HiWin or NSK rail linear bearings. It sounded hideous when you first moved it.

[@andrewwaters2354]

Couldn't you have used a mag Base for the indicator?You must have had a reason for designing something specific

[@EducatingSavvas]

I just like 3D Printing stuff. Lol.

[@AnthraxVX]

just use a micrometer to sort them XD

[@nickoutram6939]

This is a very good video on linear rails and their associated bearing blocks, some of the problems with the cheap Chinese blocks and how they can be 'improved'; kzbin.info/www/bejne/oqCleYyZnsutiK8

[@marcus_w0]

Using a digital caliper for marking metal - I cannot respect you anymore.

[@johnlepkowski3831]

Those sound awful. Look completely dry. Real hiwin have matched bearings. And are buttery smooth from factory. China knockoffs are ok for home use but will fail in commercial use.

[@thebikeracer]

Or just buy Hiwin.....

[@EducatingSavvas]

I've learnt my lesson now - but they are so expensive...

[@thebikeracer]

@@EducatingSavvas The company i work for sells Hiwin and yes, they are expense.