stress relieving cnc frame

[Farzad]

Hi, my name is Farzad and I am from Iran.
I am building a DIY CNC machine for myself, and my goal is to make money with it.
I designed it in SolidWorks and bought the necessary items (I also made some purchasing mistakes).
This is my design (it’s mostly inspired by a YouTube channel not an engineer).
The design is simple and is made from a 250mm × 250mm × 1300mm iron box with 8mm thickness. The material is called ST37. I am going to reinforce it with some + shaped plates and weld them inside the iron box.
For the linear rail placement, I bought some 35mm ST37 plates that I am going to attach to the main iron box using bolts and epoxy.
These plates were cut from a very large plate with a torch.
Stress relieving these parts is costly in heat treatment furnaces.
Can I use VSR instead of an oven?

I asked ChatGPT about it, and it suggested that I can grind off the torch-cut areas first and then use VSR on them, because most of the residual stress is concentrated on those cut edges.

[Clive S]

Looking good and very strong. Keep the pics coming.

[routercnc]

Hi Farzad,

I'm not aware that anyone on the forum has used the Vibration Stress Relief process, but I could be wrong. There is an abstract to an article here which suggests it gives similar results to Thermal Stress Relief: https://journals.sagepub.com/doi/10....44089241286271

Another option is just to build it as it is and monitor the squareness periodically and then shim the column to base joint as required if anything moves?

For the design it sounds like the materials have already been built but I would have considered extending the side plates on the column down to the clamping interface plates. Same on the lower base section - extending the side plates back to the interface joint plates. This way there is no real change of section as you transition from the base to the column. But I'm sure it will still all work as a milling machine as there are large sections and thicknesses used in the design.

Good luck with it!