Hello Robert,
Thanks for your opinion. I actually have the same concern on rigidity. I'm not expecting to run it on steel, just on aluminum - see #5 above.
What I can also do to improve the rigidity:
1. I have one more HRW35 slide, so I could mount the milling head on two slides; I would lose ~4" of Z-travel in this case.
2. I can reduce the offset of the milling head by ~3", and I would lose ~3" of Y-travel. See picture below.
3. I can do both 1, 2 one-by-one to see the effect after each step.
I don't think I can make a better Z-column mount. I hope the steel angle plate I'm using is solid enough.
I think I should continue with a mill as is, and start implementing points 1-3 only if I'm not happy with the results.
Ivan.
It's looking good but my gut feeling is you're not going to have much rigidity with this machine. It will be interesting to see how it does with aluminum. I suspect it will be similar to my Sherline. That is to say it will cut aluminum but your depth of cut will be very limited. Since it is CNC you may not care if you have to take a lot of small cuts since the machine can run in your absence! Nice work! You may inspire a whole set of people to make their own CNC shop toys.
Robert