N00b question about EBay item

[mrogowski]

Hi Guys,

I'm looking to build a router with a 4ft X and 3ft Y axis, and am currently examining linear rails. I keep seeing this product on EBay and am wondering if anyone could tell me whether or not it is worth using for the X axis. It's quite cheap compared to the flat rails I see posted elsewhere, so I am thinking there are trade-offs involved:

http://tinyurl.com/3yt9s9

Best regards,
Mark

[daedalus]

its pretty standard round linear rail, there are several companies that make it, and its fine for light loads. If you search for the product code in google you will find other suppliers / manufacturers. The stuff you linked to is continuous supported, which is beneficial for long axes, where a bar supported only at the ends would deform.

The Flat rails you mention support significantly greater loads, and deflect less, in a smaller area, and that is why there is such a price difference between thk flat rails and these. There are also companies that do lighter duty flat rails which are significantly cheaper, IKO and Hiwin are worth checking out.

[mrogowski]

Ok, thanks a lot. I guess what it is I'm doing would be considered light loads then.

I will certainly check out the others.

Best,
Mark

[fatal-exception]

Those should work fine if mounted in the right configuration.

Paul

[LeeWay]

If I had to do my router over again, I would consider those for X and Y and even Z. I would only consider unsupported rails for Z, but with all the smaller THK rails available at a decent price, they are much more attractive for the short axis.
The key when using those is spacing the blocks as far as you can from each other and still get the travel you are looking for.
The wider the stance on those, the less chance for flex.

[mrogowski]

Thanks for responding guys. Things are still pretty much a pipe dream, but I am looking to acquire parts slowly.

I was looking at the IKO flat rail units (1" wide, 55" long) and they are about $210 each plus a shipping charge with two blocks. So, these are looking rather attractive.

Best,
Mark