Bob Engelhardt wrote:
On 6/7/2015 11:42 PM, pyotr filipivich wrote:
DIY often means "We could have bought it for less ... but it was
the process which was why we did it."
...

I heartily agree! Not only the process, but the continuing
satisfaction when using the product of our own doing. However ...
when the results of doing it ourselves are not what we expected, there
will be
disappointment; directly proportional to the time, effort and care
that we put into the project. Snag is putting a lot of care into his
project and there is the potential for a lot of disappointment.

I see the drill motor & PWM drive as the weak link, especially
regarding constancy of feed. For a powered feed on my lathe, I used
a servo amp with tach feedback and it's amazingly constant:
http://www.mwdropbox.com/dropbox/ServoPowerFeed.pdf
Buying the servo amp might be less satisfying than building your own
PWM drive, but I still get a REAL NICE feeling every time I use my
power feed.
Bob

The way this is designed , I can change the power source if the need
arises - and I did consider using one of the stepper motors I have , but
they're not powerful enough for this task even with the torque
multiplication from the reduction gearing . Several pieces were cast in my
aluminum foundry ... if I could have found a "real" power feed unit for less
than a quarter of the cost of the mill itself , I would have bought one . I
toyed with using a wiper motor , but the ones I have available all have
stripped worm drives .
--
Snag
And hey , if it doesn't work out as well as I want ,
I still have a really nice reduction gear set .