If you can find 20mm for not much more then go with those has the slightly larger height and bearing size makes things a bit easier.
Thou 15mm will be fine but you'll need to put raiser blocks between back plate and bearing to give clearance between front and rear plate for ballnut. 20mm mean you just machine a shallow channel in plates for clearance.
Mart....try these people NSK LS20 Linear bearings & rails L400mm cnc thk router | eBay. Both Wobblycogs and I have had rails off them and they came quickly and seem genuine good quality although they are used. I also got some rails from YASKAWA, MITSUBISHI items in PK-USEDPARTS store on eBay! these people, ordered Thursday received Monday.Neil...
I think Dean means the spacing of the Y rail mounting bearing mounting blocks horizontal should be spaced wider ..Clive
Here is a "right " place to buy everything. The guy is called Fred , here is his email. Very helpfull and good price. I bought last week from him rails and ball screws and am waiting for them. Apart from the ball screws being the cheapest around./when making big order/ he can provide you with 3 types of supported rails and carriages:
1.LG /chinese/ cheapest, the minus is that they don't have long bearings like Hiwin
2.TBI , same like Hiwin, more expensive than Chinese, have long cariages, no dedicated double lip dust seals
3.Hiwin/more expensive than the before mentioned, from EU can be bought the dust seals/
I bought all ballscrews+Hiwing long carriages and rails + shipping+ customs???, a bit cheaper than the Hiwin would cost me here in EU.
Still waiting for the rails, but some guys here bought before from him.
After his detailed offer about your specific need, you will have much clearer view about everything. If cheap is what you search, i believe going with the chinese square rails is better idea than going with round supported rails
I have cut a bunch of steel meanwhile. And started laying out the bed frame yesterday evening.
In other news, I have to find a new job soon, so it might put everything on hold for a little while.
And if anyone has any leads on a mechanic / fitter / fabricator line of job, I might be interested :)
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