lucky find...decision time

[KTP]

I just bought about 22 feet of THK HSR-35 rail with 4 carriages brand new for $100. One piece is 72 inches, the other 2 pieces are about 98 inches.

Now, I have been toying with the idea of building a mid-size gantry out of 80/20 and linear shafting, or maybe IGUS rail, or even drill rod/skate bearings, but I just placed a piece of 1515 80/20 on top of this rail and it is a perfect fit...even the mounting holes on the rail are a perfect fit for the 5/16-18 bolts used in the 1515 8020 t-nuts I have.

So...Do I close my eyes and cut a piece of the 98 inch rail in half to make the x axis of my 4' x 2' router? (I have some much larger rails and carriages if I ever want to build a 4x8 router). It seems almost a crime to cut such nice long rails, and they are a bit stout. I almost wonder if the 8020 is worthy of such rails

Would 1 carriage on each side of the gantry on the x axis be sufficient since they are such large carriages?

Opinions?

[damae]

There's no shame in cutting them. After all, what would you do with just one 98" rail? On the other hand, I suspect those rails weidgh more than the 8020 they'd sit on.

Yes, it'd be sort of a waste to underbuild the framework, but on the other hand, it's DIY and your hobby. If you look at it the other way around, you're building a just right frame and doing overkill on the rails, then it sounds a lot better! If you need some 15mm rails that are "just right" and the right lengths, I'll gladly trade you for mine and save you any anxiety about having such big rails!. =)

If you do build a mill, i'll follow your thread...

[JRoque]

Hi. I got myself into a similar predicament when I first got long pieces of 8020. I decided to buy rails to match them and ended up with a 5' by 5' of cutting range. If you use the 98" rails for Y and buy another 72" for X you can end up with a machine that could easily cut everything up to full size doors, etc. On the other hand you might not have the space or be willing to spend the extra money on the 8020 frame. The THK rails I bought were a tad longer that the 8020 frame I had and I also thought it was a crime to cut the rails. I punched a hole through the axis end block frames for the rail to go through.

Things to consider also include the longer screws you'd need to buy and that's exponentially more expensive with the longer axis. A smaller frame usually means a tighter machine which otherwise requires extra frame supports. All that said, I couldn't go back to a smaller machine now. I got used to throwing large wood panels and making just about anything.

If you're looking for votes, count me 1 for keeping the rails and building a big machine around them.

JR

[vacpress]

yeah.. it will be really hard to find such a deal on rails that size ever again.. if this isnt the case, let me know how to find some!

you have, it sounds like, 5k of percision rails... imagine the router you could make with those...

but like stated before, i wouldnt put those rails on 1515!!! at least order a few pieces of 3030 to put them on! sure it will cost more, but the 1515 is... its designed to hold up 50lbs of part bins.. those rails sound like they must weight something like 2lbs/inch....

nuts.. i wish i had rails like that! i am all happy i got 4 12" THK 21mm rails with 4 blocks, new, for $130~... your find is truly amazing...

good luck!

[ballscrewed]

I have two blocks to fit those rails but I have no rails. mabey we could work something out.
Aaron

[gbowne1]

I might use some THK rail on my V mill. $100 is a good price new.. where'd you get it?

Greg