Building small vertical CNC mill

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
 
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.
IMG_20200717_110232387_upd.jpg
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.

rwm said:
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
Click to expand...
 
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Ivan, I think you should move forward without any radical changes. It does not sound like you had any expectations that it was going to rival a heavy iron mill. Build it and see how it performs. Then take what you learn from actual use to make improvements, either in this one or in a version 2. Keep up the work and keep sharing your progress.
 
Here's how mine is set-up, multiple bearings and solid pieces of aluminum.

complete.jpeg

The bearings are mounted on steel.

John
 
This is exactly my plan :)

Boswell said:
Ivan, I think you should move forward without any radical changes. It does not sound like you had any expectations that it was going to rival a heavy iron mill. Build it and see how it performs. Then take what you learn from actual use to make improvements, either in this one or in a version 2. Keep up the work and keep sharing your progress.
Click to expand...
 
Hi John,
How's the column mounted to the base?
I decided to use cylindrical rails because 16mm rails have the same height as supports for 1605 ball screws. Wanted to avoid these risers underneath the rails.
Your steppers look small. Don't they lose the steps?

matthewsx said:
Here's how mine is set-up, multiple bearings and solid pieces of aluminum.

View attachment 330881

The bearings are mounted on steel.

John
Click to expand...
 
r3292c said:
Hi John,
How's the column mounted to the base?
I decided to use cylindrical rails because 16mm rails have the same height as supports for 1605 ball screws. Wanted to avoid these risers underneath the rails.
Your steppers look small. Don't they lose the steps?
Click to expand...

I recently upgraded to 425oz steppers.

The column is something I found on Craigslist, probably out of an optical comparitor. The base is fabricated from steel and has a heavy square tube sticking up which the column slides over, that way I have some adjustment for tram.

Here it is up close.

DSCN1341.JPG

Another angle showing how the column is mounted, the bearings are in the steel piece that slides vertically on the column.

testz.jpeg

John
 
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