All steel, no welding, 2000x1300x250mm

**Wal** · 27-08-2015

Yep, It's not just achieving the consistency in your method that'll give you a problem - the height of the rail will also depend on the torque of the bolts - as such it's going to make measuring for the ball-nut bracket fitment a real pain... You need to be designing around what you know - data that is readily available, not "Oh, I'll just put these rails in using the maddest method I can come up with and then see about my ballnut bracket later.."

Heh, the rails will probably resemble a roller-coaster by the time everything's torqued up anyway. Using this method the ballnut might just move smoothly along a couple of inches of track...

Honestly, don't pursue this inviable method..! It'll be a waste of your time and money. Enough said.

Wal.

**D.C.** · 27-08-2015

Eurikain,

Listen to the sound of bearings moving in this video:

http://www.youtube.com/watch?v=bGbWBDtzydw

It sounds bad.
Very bad.
Very, very bad.

I'm guessing this video or something like it is where you got the idea for DIY supported rails.
It is a bad idea.
Very bad.
Very, very bad.

The reason why everyone is giving you negative feedback is because it is a bad idea, so ditch it and move on. If it helps any, hiwin rails from hobby machines have a good second hand market value. When you outgrow your machine you can recover a lot of the price by selling them on.

PS I'm the resident village idiot, annoying people with my hair-brained ideas, even I figured out that DIY supported rails was a non-starter.

**eurikain** · 29-08-2015

Hi ! Sorry for the late reply, I've been a bit busy :)

I hear you all, and I will take your advice. I know, DIY supported rails are not the way to go. I hear you. Even if this is not going to work, I think that the profile method was going to work, just not with steel, or made differently with short pieces. I think DIY rail is possible, but you need to get the supports milled from ALU or steel and then tap them. What I am just explaining here is that ROUND fully supported rails don't seem efficient to me cost / strength wise. I've run a couple simulations in SW and that confirmed my idea. You could semi-support a round rail with at least 1/2 of the material used in fully supported chinese rails. Of course, getting those parts machined may be expensive, unless you've got a CNC within hand's reach, or know someone that can get them milled.

That said, supporting the rails with bolts is a silly idea, I agree.