linear bearing maintenance
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- เผยแพร่เมื่อ 24 ธ.ค. 2020
- When i leaked a few ball bearings from the carriage of a Chinese import HGR15 style linear rail i couldn't find many useful resources on exactly how to fix them. Since i have a brain like a sieve i thought i'd leave some notes here. Maybe they'll help someone else too.
I presume the process will be similar for HGR20 and larger rails too.
Apologies for the poor camera work; Blame holding a phone while fiddling with bearings. I think you can see what's going on though.
Although the size of my rail is 15mm, the bearings themselves are imperial sizes. I need to order 1/8 inch for these.
Note that with a fully populated carriage there is still a small amount of space in each race. It would be possible to install one extra ball without realising.
These are the exact rails:
www.aliexpress.com/item/10000... - วิทยาศาสตร์และเทคโนโลยี
you are an ANGEL. i was sitting here in literal tears staring at my 3d printer's linear rail that just exploded in a mess of bearings, i'm so relieved that all i need to do is just order some more 😮💨
LIFESAVER! you are in my prayers tonight
It might work for awhile but factory tolerances are gone, just order a few new linear bearings, they're not that expensive at all. You could damage the rails doing it this way.
Your rail will have it's model on it and so will your linear bearing block.
Lol you made it look difficult. 😁
Respect for holding the phone in one hand and fiddling with tiny bearings with your other hand.
You need a gap of one ball bearing
Original Hiwin have a gap
yes. these (non-original Hiwin) ones have that too.
You can see where i say this at 6:26.
I have a question regarding MGN12C rails. The maximum size that I can get is 1000mm, is it possible to mount them end to end and extend the range? Say if I mount two 1000mm rails end to end, I can extend the range to 2000mm
I've never seen the MGN12C variant of these so can't say fro sure but i think it would depend on how accurate you need the transition from one to the other rail to be. I think without very careful grinding of the ends and alignment there will always be some vibration during the transition.
While 1meter is the standard upper length for these, i've seen lots of sellers on AliExpress advertise custom length on request. Maybe they can do longer rails if you ask them?
@@DuncanLaw I tried it out, and yes there is slight vibration even the carriage moves over the joint. Do you think it will affect the life of the ball bearings? I have to design an automation system that will be in use constantly. I asked my supplier, 1000 mm is the max possible with these rails. However he suggested WEDM technology for cutting the rails, he says joints will be better, any idea what WEDM technology is?
@@arbjful Wire Electric Discharge Machining. en.wikipedia.org/wiki/Electrical_discharge_machining
I've never used it but it should leave a very square cut with no burrs.
From there is all about how precisely you can assemble things.
Hi, i have lost some ball bearing from my hg20 block, can i change new ball bearing and will they not come out from rail ? please let me know thanks
i don't own any HG20 bearings.
try it and let us know.
I wonder if it would be worth swapping the bearings with ceramic balls instead.
It would definitely be possible but i'm not convinced you would gain much performance.
These carriages aren't exactly high quality to start with so the bearings are not the weakest link.
If you need the high precision or low friction provided by ceramic bearings, i'd advise you to start with higher quality (ie: more expensive) carriages and rails.
That said, if you had some ceramic bearings sitting about anyway, and a few hours free one afternoon, it would be an interesting experiment.
Ceramic Si3N4 bearings very expensive. I believe most generic linear blocks use stainless steel G25, just get some chrome steel in g5 or g10 grade will be plenty upgrade.
@@DuncanLaw did you know that the code of the bearing block specifies also a preload? I bought the heaviest preloaded ones as I need rigidity for the lathe they go on. If you need free movement for a 3d printer for example (which those don't offer for sure) try the lightest ones. The codes can be found in Hiwin website on some spec sheet or something and are the same for the chinese hiwin copies. At least the aliexpress sellers had the preload codes and no explanation for them so that a buyer who buys randomly doesn't know what is getting.
@@MF175mp Interesting. Thanks for the info. I'll look into that more if i ever buy these again.
I suspect the average cheap versions of these do not have sufficient repeatability for the numbers to be meaningful though. Mine are at the upper end of the cheap range and preload still varies a bit between units which come from the same batch.
I would advise anyone who actually needs the precision these numbers imply to buy better quality (more expensive) bearings than i did.
On the other hand, if high precision is not critical, i'm very pleased with the value of the ones i got.
@@DuncanLaw I'm sure the ones I have will be sufficient for a diy lathe in terms of precision. The mounting slot precision would be the most important thing as the rail is pulled straight by the means of that slot if it has any slight bow in it. Also it's pulled crooked if the slot isn't perfectly straight or has some dirt in it. What's nice is that this cheap rail offers the possibility of upgrade, if you want to go with more precise Hiwin rails they would bolt right on.
how much ore is there in total?
zabardast
do the maintenance on a large cookie sheet to keep track of your balls
I got step one mastered😂🤌🏽👍🏽