I’ve noticed that the bed of my Pro XXL flexes when I lean on it gently. It looks like my table surface is slightly warped so it’s no fault of the Pro.
I’ve seen people talk about adding foam beneath the cnc but I’m concerned that the foam would only half solve the issue - foam is compressible after all.
I’ve considered a thick sheet of plywood but I figured that would warp to match the table bow.
I have a few questions:
does the foam really work reliably long term?
could I bolt the pro down to a sheet of plywood; does it have fixing holes?
would plywood ontop of a sheet of foam be the best combination? Foam would absorb the bow and the plywood would distribute the weight over the foam, reducing the compression in the foam.
My Pro is on a pair of tables, and I didn’t quite manage to get the two level (or one sunk deeper into the carpet after first setting things up), so the foam is taking up the difference — the distribution of weight seems to be keeping the machine from distorting and things still seem quite level/even, w/ surfacing of the MDF taking similar thicknesses across all the slats.
This weekend’s project is attempting to level the surfaces of the tables to each other again, then rechecking calibration/squareness.
Not knowing how your table is constructed I’d first start by asking how the bow in the table got there in the first place. If the table surface is made of materials (thin, not structurally rigid/strong enough, …) and cannot sustain the weight then it may be worth addressing this first. For example maybe the table needs a bit more support in the center to bring the surface back to a flat surface and then if still needed add some materials like the plywood as needed. On my table I went down the path of building a torsion box design that sits over a frame.
On the other hand if the table is built like a tank and it simply has a bow in the surface and will not move anymore then I wonder if epoxy is fluid enough to act like a self leveling concrete? That said I’ve never work with the stuff (yet) so would wait on someone else to comment if this would be a good approach or just asking for trouble making the surface worse then it is.
In my case even if my surface seems to be fairly flat I still added a rubber exercise mat (dense rubber / heavy) under the machine to help with any small imperfections in my table surface and also because the added benefit of helping to absorb much of the vibration/sounds that come with this hobby.
I guess your height difference is a straight line through the middle of the machine then and not a bowl shaped dip in the middle. Perhaps that’s how you’ve gotten away with it so far.
Do you know anything about any mounting holes on the Pro?
Unless you have a verified flat surface like a granite surface plate, I would not mount your machine to anything. It will warp and flex your machine to match whatever you mount it on.
I dont have a pro just a Shapeoko 3XXL. The 3xxl has a steal beam that runs across the middle of the base. That beam sags. I put the rigid foam under it and solved the saggy middle. I also built a torsion box for my table and put the foam on top of that.
There are holes, please don’t bolt the machine to anything which would distort the base of the machine out of flat.
The height different is a dip off one table (there’s a half of a ping pong table) onto a narrow slightly lower table — I just want to get the machine back to level.
