[BrassBuilder]

Got a couple of questions for mounting THK linear rails before I screw it up.

Looking at the THK literature for mounting their rails, they mention a "referencing surface." It appears to be a lip milled for the rail to push against to make alignment easier. How important is it to have this lip milled into the surface? The literature also says "most" rails are mounted this way (or words to that effect). This alludes that not all are.

Next...the rails (SR25) are being mounted on 1" thick aluminum 6061 stock. My plan was to drill through the 1" and then bolt, lock washer and lock nut the rail to the aluminum. I prefer this over drilling and tapping 32 holes as tapping 32 holes through 1" aluminum by hand is going to take forever and I also have concerns about breaking a tap having to tap that many holes.

These are for a lathe conversion if that makes any difference and will be mounted on top on a machined surface. We will only be able to machine half the mounting surface and then we need to move everything over and machine the other half. Having to get everything aligned for the second half, while not impossible, is time consuming.

Advice is greatly appreciated!

Mike

[RICHARD ZASTROW]

We've milled a key way full length then put a key in the slot for a "reference surface". Never had to move the part, however.

The slot was as accurate as the machine putting the slot in. The inner edge of the slot can be manipulated by hand finishing before installing the key or adjust the surface of the key itself.

Dick Z

[BrassBuilder]

We've milled a key way full length then put a key in the slot for a "reference surface". Never had to move the part, however.

The slot was as accurate as the machine putting the slot in. The inner edge of the slot can be manipulated by hand finishing before installing the key or adjust the surface of the key itself.

Dick Z

I understand milling the slot in the full length, but I'm not sure how the key works with this. The slot that I need to mill in is around 40" long and then push the rail against the edge of it.

What I plan on doing is milling the top of my two aluminum mounting flanges flat to each other (with no lip), place where I need my THK rails, drill the holes, and bolt them down. Although now I'm thinking I might be better off to drill and tap them instead of drilling them for bolts and nuts.

Thanks for the reply.

Mike

[adam27]

probably a little late but if you look at 5bears website under cnc mill he explains about mounting the rails with regard to using a milled edge for the master rail

[BrassBuilder]

probably a little late but if you look at 5bears website under cnc mill he explains about mounting the rails with regard to using a milled edge for the master rail

That is exactly what I ended up doing. I had found a good manual on the THK site for installing rails and they had various procedures listed. The reference edge is the way I went. Getting the reference edge milled within a couple of thousandths over 36" of the centerline of the lathe....that was the hard part.

Mike