Chinese ball nuts & screw on Ebay

[Matt McColley]

Has any body out there used hardware from this outfit.....
http://stores.ebay.com/linearmotionbearings

They advertise their ball screws as C7 and they certainly look ground, from the photos.

I'm curious just how they are getting the "anit-backlash" features in their ball nuts, as their 16mm nuts only measure ~1-3/4" long (with the flange). Is that long enough to get two seperate tracks? Or are they likely just oversizing the balls?

Limited experience here.....

[rwestbr]

Originally Posted by Matt McColley Has any body out there used hardware from this outfit..... http://stores.ebay.com/linearmotionbearings They advertise their ball screws as C7 and they certainly look ground, from the photos. I'm curious just how they are getting the "anit-backlash" features in their ball nuts, as their 16mm nuts only measure ~1-3/4" long (with the flange). Is that long enough to get two seperate tracks? Or are they likely just oversizing the balls? Limited experience here.....

I have recently purchased and installed these ball screws on my x2....they are awesome!!! They are replacing the NOOK setup I had previously They are not ground but precision rolled....they get the anti backlash from offset ball track inside the nut, instead of oversized balls...works very well and should last longer than one with oversized balls.

I am very very pleased!!! with the price,service, communication (excellent English) , shipping time (under 1 week, they ship EMS) and defiantly the product,it is 1st rate.But remember these have flanges and it takes a little effort to adapt them to the X axis on the X2, but totally possible.I cut one side of the flange off and milled some material from inside the sadle where the ball nut mounts.

I ordered 3 ballscrews and nuts with machined ends for under 300$,they thew in 2 motor couplers for Free.

Hope this helps..

Robert

[tumutbound]

I have some of their ballscrews (1605) Good people to deal with, quick response to any questions and on time shipping. Freight can be a bit high but that applies to most stuff from China
As C7 grade, I doubt they're ground..

I can;t comment on the backlash as I haven't used them as yet. I bought them to build a CNC router but have been sidetracked with a recently bought X2 mill.

[tumutbound]

rwestbr,

What size ball screws did you put in your X2? Did you get the supplier to machine the ends to your requirements (apprently he'll do this for a very reasonable rate)

I was planning to CNC an X2 once I get a bit of manual experience with it. nook screws seem to get the most mention where the X2 is concerned but the stuff from lineramotionbearings is better priced - for me in Australia anyway.

[rwestbr]

Originally Posted by tumutbound rwestbr, What size ball screws did you put in your X2? Did you get the supplier to machine the ends to your requirements (apprently he'll do this for a very reasonable rate) I was planning to CNC an X2 once I get a bit of manual experience with it. nook screws seem to get the most mention where the X2 is concerned but the stuff from lineramotionbearings is better priced - for me in Australia anyway.

I got the 16mm screws with 1605 nuts, Yes they machined the screws on my request, to my specs. And YES VERY Reasonable...All 3 for under $300USD Shipped....

I'm no Expert, but i cant measure any backlash... the spec I believe is <.015 millimeters = 0.000590551181 inch Backlash.But you can E-Mail them to confirm this....

Robert

[tumutbound]

Originally Posted by rwestbr I have recently purchased and installed these ball screws on my x2....they are awesome!!! <snip>.But remember these have flanges and it takes a little effort to adapt them to the X axis on the X2, but totally possible.I cut one side of the flange off and milled some material from inside the sadle where the ball nut mounts.

Robert,
I've been going over the various commercial offerings for X2 cnc conversions to get ideas on doing my own.
I've love to see any photos of your X2 conversion and any details of what you had to do to fit the ballnuts.

[rwestbr]

Originally Posted by tumutbound Robert, I've been going over the various commercial offerings for X2 cnc conversions to get ideas on doing my own. I've love to see any photos of your X2 conversion and any details of what you had to do to fit the ballnuts.

I will have to disassemble the X axis....give me a few days and I will show you...but keep in mind that I had to use a cheap drill press to mill out the clearance (not pretty), however it works and is out of sight. I also made an end support with a pressed in 3/8 id bearing for the X axis (a must have!!!)
Here are some pics in the mean time..

Robert

[ellik]

These seem to be the same ball screws and nuts Homeshopcnc is selling. I would be very interested in seeing how you fit these nuts on your X and Y axes, how ugly it might be

EK

[rwestbr]

Originally Posted by ellik These seem to be the same ball screws and nuts Homeshopcnc is selling. I would be very interested in seeing how you fit these nuts on your X and Y axes, how ugly it might be EK

They look similar, but my flanges have 6 holes instead of 4....The Y axis is simple, the flange is long enough for the set screw to engage. The X is more difficult but not that bad.I will get some pics and post in a few days.

Robert

[Hirudin]

I bought some ballscrews from them (I left them their 14th feedback) and as far as I can tell the screws and nuts seem like high quality. Unfortunately I didn't have them machine the ends so they've just been sitting on my shelf since they got here.

[Hirudin]

This same company is selling spindle motors on eBay and there's a thread discussing the quality of the spindles. From the little bit I skimmed it looks like people are happy with 'em.

[renatopub]

Originally Posted by rwestbr I'm no Expert, but i cant measure any backlash... the spec I believe is <.015 millimeters = 0.000590551181 inch Backlash.But you can E-Mail them to confirm this.... Robert

I have those screws fitted to both X any Y on my X2. I measured 50um backlash with the dial indicator. Absolutely no way these screws can get down to 15um unless you use 2 nuts with pre-load. Where do they state 15um?

I had to take one of the nuts out to get the screw machined, amazingly that was not so difficult to get it assembled again. And it was interesting to see the insides of the nut, looks very good as it is precision ground (the screw is just rolled though). There are 3 raceways with one turn each.

It was a pain to machine the thing in my mini-lathe, but it felt good to do it myself. Next time I would order it alredy machined though The outer 3mm shell of the strew is hard as stone, I had to sharpen my carbide tool every 30 minutes.

I will try to post some pictures today. There was some grinding work to get the Y axis to fit, but it looks good now