Bearing for optic travel

[KevinH673]

Could anyone recommend a good bearing manufacturer for tight tolerance applications? I have a metal optic holder(CAD drawing picture provided) holding an optic. I would like to use some linear ball bearing to slide this metal optic holder on rails that would eliminate almost any "wobble" down to the micron level. Is there a manufacturer that comes to mind that offers a tolerance this tight? Say bearing size is about 1/3" or so, optic is 1" diameter.

http://img526.imageshack.us/img526/3772/opticholder.png

 

[caoimhin1]

Difficult to see what you are doing, but if you are designing with linear guides, all bearing companies that make linear guides do versions which are preloaded, so in theory no wobbles. Various accuracy classes will also increase precision. Have a look at the linear guide sections on NSK, THK, SKF etc websites for more details.

 

[KevinH673]

caoimhin1 thank you for the help, I will look into this.

 

[unclesyd]

As posted above there isn't enough information to define your exact requirements. The numbers you posted are very small.
I would give Steinmeyer a call with your exact requirements.

http://www.steinmeyer.com/content/cnt_cnt/docid_629/iso_en

 

[KevinH673]

Could I possibly make some design that would use O-Rings, or maybe some spring washers, that would use three ball bearings. Two with forces in one direction, one with a force in the opposite directin, to try to make any play almost zero?

Also drew a possible V design, but I'm leaning more towards the opposite force design...

 

[MikeHalloran]

Get the ball bearings out of your head. They will give you problems with brinelling, and with trajectory errors associated with ball rotation and with race finish.

You can make nice long sliders on v-flat ways, and put a little grease on them, or make them of dissimilar materials if grease is not allowed.





Mike Halloran
Pembroke Pines, FL, USA

 

[KevinH673]

Mike, thank you for the suggestion. I cannot use grease, because the optic will be in a sealed, vacuum tight chamber where any dust or dirt getting in would cause big issues. Would I have some "shaving" if I use dissimilar materials? What would you recommend ?

 

[MikeHalloran]

Is the chamber subject to a high temperature 'vacuum bakeout' also? The service temperature range affects the material selection.



Mike Halloran
Pembroke Pines, FL, USA

 

[Clyde38]

Take a look at:

http://www.micromo.com/n112710/n.html

[link

http://www.linkedin.com/in/clydehancock

]

[/url]

 

[KevinH673]

Thanks for the link, Clyde. Do you know the tolerancing/precision on these? They don't seem to list it. I clickd on one of the products to get more detailed information on sizing, etc. They list property dimensions by assigning them a letter, but don't seem to list an illustration showing you what they correspond to. Also, I click on linear bearing, and they show me a ball screw.

http://www.micromo.com/servlet/com....255&sprachid=1&htdigurl=/n112710/i404856.html

Have you ordered from them before? Are the tolerances/precision high enough for optic use?

 

[Clyde38]

Sorry, the link that I sent is the US link. Their (Micro Precison Systems AG) direct link is:

http://www.mpsag.com/n379202/n.html

http://www.mpsag.com/n358418/i359041.html

[link

http://www.linkedin.com/in/clydehancock

]

[/url]

 

[KevinH673]

Clyde, thanks. I gave them a call, they're going to get back to me with radial tolerance/play figures.

Pretty pricey, though I suppose you have to pay to get precision parts. They quoted me at $91.10 with a minimum purchase of 10. Do you guys have any other recommendations? I'd like to try a few other places to see if I can get price down a bit.

 

[KevinH673]

Can anyone recommend a high precision rod manufacturer to accompany these bearings? The bearing company recommended one to me, but when I contact them, they only do custom orders.

 

[EdDanzer]

You have a significant problem. Any metal rolling element bearing either needs lubrication or there will be metal flaking off from brinelling. You may be able to use softer polymer rollers without lubrication and preload.

Ed Danzer

http://www.danzcoinc.com

http://www.dehyds.com