[ixoreak]

Hello,

I have the next DIY machine




but now I would like to improve the rigidity of my Z axis replacing the 20mm bars with prismatic 30mm guides, like this



the tool will work nearer of the X axis and the rails look solid, but i don't like the Z axis plate. Although will be 10mm thick of steel and I'll take advantage better the travel of this axis, this plate looks the weakest point. How are reinforced the Z axis in industry models. I thought to add an aluminum "T" profile to each side, like so



would it be enough? I would like to run a FEA analisys, but I don't know the cutting force values I could use for a router of 1530W, 8mm end mill, cutting 4mm depth of cut on hard wood.


Thanks in advance

[pippin88]

Add steel stiffeners to the side, essentially making it into a bit C channel

[ger21]

There's no reason to use 30mm rails. They won't be any more rigid than 20mm rails.

A bigger improvement would probably come from replacing the rounds rails on the gantry, or making the gantry beam taller and spreading them further apart.

[ixoreak]

For now I just want to improve the Z-Axis. I need to new plates and I would like to have a good design so I can send the files to being machined.

It's true the prismatic guides won't add too much more stiffness to the axis, but the current design moves the end mill too far from the gantry. Apart of that, I don't like the clumsy bottom plate, specially for roughing 3D models with end mills not so long as 3D finishing ones.

I've found a some cutting force values in an old post of this forum and I've runned a FEM analysis. The T reinforcement profiles and the 30mm guides are more than enough, but i don't want experiment if not, learn some "industry stardard"

I'll keep in mind the gantry issue for the next upgrade, looks a good idea to replace the 40160 profile with a taller one. Any other recommendation?

[pippin88]

15mm linear rails would be more than enough.

Linear rails should not be used to add rigidity. The structure must be rigid.