I was trying to get my 3D finder concentric (and managed to ~5µm) but while I was doing it I noticed a lot of movement if I did anything other than spin the spindle, so thought to try and measure the machine’s rigidity.
With the DTI held in a vice to ensure it doesn’t move and held parallel to the 3D finder (which has an admittedly extreme ~55mm stickout), I saw that when I applied some light pressure to the collet nut with my pinky finger, I could easily move it 10µm (~1/2 a thou) in each direction. With my thumb and a bit more effort, I could move it 100µm (~4 thou) in each direction.
I thought it might be a loose spindle but I made sure it was tight and that made no difference.
I was also able to apply torque to the Z-axis carriage by hand to get a similar (but slightly lessened) effect.
Is this much movement expected for the Nomad?
I have a feeling this might be a factor in my issues with cuts with high axial engagement but low radial engagement. e.g. I have a 6x15mm 3-flute finishing endmill with a manufacturer recommendation of 12mm axial, 0.1mm radial at 10kRPM and 450-500mm/min. When I try that on the Nomad, despite seeming well within specifications (HSMAdvisor says this cut is 0.006Nm of torque and 0.006kW of power), it makes a ton of noise and appears to deflect from the wall. This can be seen visually, as if you let the endmill “rest” in a spot with the spindle running, it’ll cut itself a little “dent” in the stock.