I am looking at getting some track roller bearings to run on thompson shafting for my linear ways, it would be similar to what shopbot uses, but for round rails, I am looking at either the lv 202-41zz which is a v bearing with 120 degree angle so that it works with the round shaft, or lfr 5301-20 npp which is the gothic arch bearing, both of which are suited for 20mm shafting, which isn't all that expensive. I am looking at getting these bearings from http://www.track-roller-bearings.com/product_appliactions.htm
I have heard good things about there bearings.

Would anybody else like to go in on some bearings with me so we could get a quantity discount? If we get 100 they are just $10 each, and could be great for a relatively low cost linear solution with zero play, good tolerances and good load ratings.

Does anybody see an advantage to one type over the other? Has anybody used either of these bearing types?

Just in case this helps, my plans with the bearings were to use 3 per side for the gantry support bearings, and for the y axis I would use a total of 4, they seem like they would be a lot easier to mount than pillow blocks. it seems like the angled ones could be used for rods that were bigger than 20 mm as well as smaller.

You can buy double linear bearings mounted in a aluminum housing for 20mm shafting from Misumi for around $40 per assembly, at this price it makes it hard to beat you should take a look.

http://www.misumiusa.com/PDFViewer.aspx?Metric=true&Page=177

For the open single size in the 20mm they are $64 each, and I would need a total of 8, so that adds up quick, for the open double, it is $121 a piece. I wanted an 8" span on the gantry support bearings, so I would need 2 of either of those. It seems like for closed bearings they have great deals, but for open they are comparable to thompsons, thompsons just have a much higher load rating.

I was looking at these bearings for a simple way build the machine, that would have adjustable pre-load, be reasonably priced, and have great load ratings. one of the vee bearings has 2x the load rating of the misumi double open bearings, laterally and like 3-4x the load rating radially. If I don't end up using these I will go with the thompson super smart and build my own aluminum housing.

Thanks for the link though, they seem to have very reasonable prices on the square style linear bearings and will be a great resource to have.

Yes the open style in consderable more expensive, I wish it were the otherway around. I am using the 25MM closed style on a light duty machine that I am building and they are quite nice. If you need to span a long distance or need high ridigity, the open with supported shafts are muuch bettter. I wish I could find a good supporded bearing or rail system that was cheap. I want my cake and eat it too :)

That was kind of the idea with these, but there doesn't seem to be a whole lot of interest, so I will probably just end up using thompsons instead.

[Would anybody else like to go in on some bearings... ...$10 each]

Bruggles,

I strongly suggest you try inline skate bearings. In your application you are not running these at breakneck speed. Skate bearings are about $1 ea. (or less). At this price it makes it hard to beat, you should try it.

Rance

$8-$10 bearings? One man's ceiling is another man's floor. :)

These might suit you. You can buy small quantities.

http://www.cadcamcadcam.com/index.asp?PageAction=VIEWPROD&ProdID=107&strVarSel=&strCompare=

Thanks Harry, that seems like a great price on those and the tracks are reasonable as well, that was basically what I was trying to accomplish anyways.

You may be able to get them for less here:

http://www.superiorbearing.com/docs/guidewheels.html

someone ordered a set from china not too long back if memory serves me. anyway think they said it ended up being 5 bucks a pop for a bulk of 100. but dont go off my memory

I recall seeing that as well, but I think that they were a smaller size.

While I have never bought anything from these guys, they have been mentioned before on the site for cheap V-bearings. They also sell 120 degree angled bearings for riding on round shaft:

http://www.yi-tong.com/yi-tong/W-Guide-Wheels.htm

I think that the two are the same company, which seems a little odd to have to different pages with almost identical content. Both are the Yitong company and unless there are two companies with the same name in china that do the same thing, they are the same company.

Everyone, Yes, http://www.track-roller-bearings.co...ppliactions.htm and http://www.yi-tong.com/yi-tong/W-Guide-Wheels.htm are the same company. So if you are interested, please send email address to get offer and more information, market01@yi-tong.com will give you a reply within 24 hours. The contact name: Anna Gong