Z Stiffness question

I’m getting close to convincing myself to add a SO3 to my collection. I’ve had a Nomad for some time. Maybe some of the S03 experts can help me out. I’ve seen several people comment that the Z axis on the S03 isn’t as stiff as they would like. Are there recommendations for how to improve this? I’ve seen some comments about the new Z-axis plate being better but does the beam need stiffening as well?

The new plate is a huge improvement, and would be hard to improve upon.

For the beam, the Z-axis extrusions seem essentially inflexible at this scale and these forces.

The one upgrade which has been considered (arguably bandied about, and I’m the one doing all the trouble-making) is an Acme screw for the Z-axis, replacing the belt — I’m hoping to assemble a spare machine out of spare parts in the near future and will use it as a test bed for such ideas.

If by beam, you mean the unsupported X-axis, then we’re good on that front as well — it’s hugely over-engineered at this size — @chamnit did FEA which proved it out as suitable for unsupported spans for a 5’x5’ machine (so by extension, all we need for a machine to do 4’x8’ full sheets of plywood are a suitable table, a suitable frame, a suitable drive system, and maybe some side supports along the Y-axis — anyone got a spare line of credit I can use to build my dream workshop?)


The new design for the z-axis plate is a vast improvement on the original flat plate design and nearly removes all the flex that the shapeoko 3 used to have in that axis. However, there is still some flex which I think is coming from the x-axis carriage v wheels. Not sure if upgrading these to metal v wheels would help, perhaps the carriage just needs more wheels?

I completely agree with the replacing the Z-axis belt with an Acme screw. The belt tightens when I raise the z-axis then when lowered the left side of the belt loosens and gives me trouble. I’ve looked to see if I did something wrong when setting up the machine but everything looks perfect. The X and Y axis are accurate enough for my needs but the Z-axis need much improvement.

Please contact support@carbide3d.com and send in some photographs and a step-by-step depicting your difficulties — hopefully we can puzzle this out.