[newpatch]

HI All,

Today I received my order from linearmotionbearings2008. It took 8 bus days from the time I paid him.

Thought I'd share in case everyone is wondering about the quality and service..

I got:

2 1250mm, 2 800mm, 2 400mm rails with 4 bearings each.
2 1300mm, 2 850mm, 2 450mm ballscrews with nuts
3 bk12 bearings
3 bf12 bearings
3 flex couplers


Here's some pics and a little causualties....



































You'll notice that the rails don't have mounting holes??? Maybe it's better that way since you can now drill the holes so they'll fit SAE extrusions....Normally they are 30mm apart. I also have issues getting the bearing blocks on the ballscrews...it's tight, but I think I can fix that with some 600 grit sandpaper..

Also those measurments are approx values...although the ends are 10mm and 12mm in diameter.

I think the quality is pretty good considering....

newpatch

[Walky]

I got a package quite similar to yours a couple of days ago (it must be my 7th or 8th purchase from Chai so far).

My rails are also not drilled (this is the first time they come like this). I actually like it, and the reason for me not asking for it before was the fear of a misunderstanding resulting in me getting "blank" rails too (I don't have the proper equipment to drill and tap such rails). The rails supports and blocks are a little damaged (only the aluminum parts), but not much. I noticed that this time my 16mm blocks came with two set screws (top and side), while a set I got a couple of years ago only had one on top.

Ballscrew machining is amazingly smooth as always, and apparently according to specs.

I bought 14 blocks this time instead of 12 (I want to use 3 on each gantry side to help reduce racking), but I got 12, I think it is an understandable mistake considering that's what must people buy. I notified Chai, he apologized and the next night I had the tracking number for the missing blocks at my inbox, nice!

It's pretty common for the screw's machining to be a tight fit on the blocks, I use some wet sandpaper and they work great afterwards (maybe they can just be pressed in with the proper equipment, without sanding). I'm perfectly fine with oversized diameters, since undersized diameters would be a PITA to fix.

Some BK blocks can have internal play sometimes, it can be easily fixed by adding a couple of shims to create preload. I usually disassemble the blocks to check that the bearings at actually back to back, add some grease and shims if necessary.

IMHO, it's really great stuff considering the cost. Not perfect, but I'm willing to spend a few hours or days tuning things up if that means not having to pay way more than twice for the "real" thing. I'd love to see picture's of the facilities where they do the machining of the ballscrews.

BTW, if you need wider hole separation you can ask Chai for TBR rails (similar to SBR, but the support's base is wider).

This is what I got:

[SixOfOne]

I also have issues getting the bearing blocks on the ballscrews...it's tight, but I think I can fix that with some 600 grit sandpaper..

I think the quality is pretty good considering....

I had the same issue, 600grt wet/dry paper. Cut a piece about 1" x 3" (didn't want to mar the threads), wrapped it around the section that was tight and twisted the screw by hand for about 20mins, cleaning it off then checking fit then repeat (while I watched tv of course). Once I got the screw buffed down so the bearing would slide on I had another issue. The locknut binding on the rubber seal. Lou suggested a socket that's the size of the seal and press it in further which helped a lot (at the time I didn't realize they can be pressed). I hadn't used my cheapo arbor press in ages, it was about time it earned its keep.

And I agree (not that mine has seen a nano-second of use) they seem great for the price and the wait isn't long at all even for custom sizes.

[port_huon]

It's good to see that his quality hasn't declined with popularity. I first bought some ballscrews from him about 4 years ago.

I wish he'd stock flangeless ball nuts though.

[newpatch]

My bearing blocks also have 2 set screws....

Hey sixofone.....that locknut your talking about that goes on the ballscrew do your have set screws on the corners??? Mine do but if you look on the inside the hole the set screws are not drilled all the way through??? Is it supposed to be?

"Ballscrew machining is amazingly smooth as always, and apparently according to specs."

I agree Walky...yesterday I held the ballnut on one of my ballscrews, and the ballscrew started twisting off by itself very smotth...my other ones need some minor cleaning to get the film off....



Also, since I won't use this parts for a while, what oil do I use on the rails, ballscrews, etc., so that they won't rust or pit??? I read somewhere here someone used air tool oil?? I have plenty of it...

newpatch

[HorridHenry]

Is this new stuff or discount?

can't say I would be happy with some of the components you have there.

[Walky]

Hey sixofone.....that locknut your talking about that goes on the ballscrew do your have set screws on the corners??? Mine do but if you look on the inside the hole the set screws are not drilled all the way through??? Is it supposed to be?

If you check the internal thread, you'll notice the thread directly under the set screws is a different color/material, that's because the set screw will actually press those thread sections against the screw (this prevent damaging the screw's thread). I guess (haven't confirmed it, though) that those pieces of thread might fall off if you turn the setscrews without the nut being installed, so I'd be careful not to do that.

[ger21]

Is this new stuff or discount?

can't say I would be happy with some of the components you have there.

New, direct from China. here in the US, you can buy the same chinese parts from a reseller for 50-100% more. Or buy higher quality for 5x more?
You can't have your cake and eat it too.

[bel630]

New, direct from China. here in the US, you can buy the same chinese parts from a reseller for 50-100% more. Or buy higher quality for 5x more?
You can't have your cake and eat it too.

sorry to say... but I'm thinking, higher quality product actually not from US made...

[HorridHenry]

New, direct from China.

According to their feedback....damage is a constant thing....dang! I wouldn't worry about the damage I'd be more worried about the poor quality of the material.

[HorridHenry]

I think the quality is pretty good considering....

pmsl

[abender]

Thanks for all of that information and pictures!

[newpatch]

No problem abender,

The communications with them/him is outstanding....even after the sale is made...


Does anyone have any suggestions on what oil to put these parts so they don't pit or rust by the time I start putting together my cnc?

newpatch

[joshendy]

Great to see your glad with his products, very nice write-up. I was worried a little before about the quality due to how affordable his products are.

Just to double check the round linear rails absolutely don't come with the mounting holes drilled? Or would that be a paid extra to have him do?

I'm fine with the mounting holes the way they are in the specs and would rather not have to do them myself.

Cheers,
Josh

[Walky]

Great to see your glad with his products, very nice write-up. I was worried a little before about the quality due to how affordable his products are.

Just to double check the round linear rails absolutely don't come with the mounting holes drilled? Or would that be a paid extra to have him do?

I'm fine with the mounting holes the way they are in the specs and would rather not have to do them myself.

Cheers,
Josh

For the last couple of years they always came predrilled, no extra charge mentioned, they just came that way every time. I don't know why this time they didn't. Anyway, the holes were hand drilled so they were not perfect, close to specs but not perfect. I think it'd be better to ask Chai directly if you're not sure about what you're going to get.

[Walky]

Oh, the irony...

Today I was placing marks for the mounting holes and noticed a "detail" just like yours, not only that, but it actually made the rail bend, and now it's 2-3mm off at one side when put near the other rail. I sent a message to Chai, I hope he'll be willing to send a replacement, as I have a customer waiting for his machine (and another, potential customer waiting to see this machine to decide if he'll get one too).

I know this has happened before to some people, but for me it's a first.

Oh well... :violin:

(I'd check your rail's straightness if I were you, that damage seems like it could have cause a bend too)

[newpatch]

I would check the rail also...and I'll check mine tonight just to see....

I'm starting to wonder if something like this could happen while shipping.....

The items were well packaged.....and I didn't see the box damaged. It takes a lot of force to do that on a well packaged part.

newpatch

[Walky]

I would check the rail also...and I'll check mine tonight just to see....

I'm starting to wonder if something like this could happen while shipping.....

The items were well packaged.....and I didn't see the box damaged. It takes a lot of force to do that on a well packaged part.

newpatch

I'm pretty sure it happened before shipping, that's not the kind of damage you get from shipping, and it's even more unlikely considering it's not an isolated case and the packing material (which is quite thick) was not damaged. It looks like someone dropped the rails from a considerable height against another metal. Actually, it looks like someone dropped a whole bunch of those, because I don't think a single rail's weight would cause such a severe impact. Or maybe it's the other way around and they dropped something over the rails, or some guy got fired, went nuts and started hammering stuff

[HorridHenry]

This is not down to transit,its down to the place it was bought.

[praneetn7]

I just got my rails a couple of days ago and they were in perfect condition. I haven't checked the straightness yet but there was no dents or any damage at all.

There are a few scratches and stuff but who cares about that anyway.

Chai has been very good to talk to and reply's to emails very fast. I will definitely buy from him again f i build another machine.

Praneet