Adapting a power feed to the ST

[dahui]

Hi folks,

A general question for the resident experts. Has anyone adapted a power feed to the Shoptask? I'm going to be hooking up a VFD and will loose the ability to run both motors and hence the power feed.

My thought was to make some sort of powerfeed like you can put on a bridgeport type machine. However it occured to me that I might be able to hook up a servo motor (or other type) in the mounting spot for the CNC instead of hooking it up to the actual screw/handle end like on a B-port. What would you need to control the motor with a back and forth switch and a knob to adjust the speed? I've been looking on ebay for a cheapo Bport feed that I could tear apart and retrofit, but no luck so far.

I've also been considering hooking up a motor to adjust the column height and it would be great if I could set this up with a jog handle instead the adjustable speed. Then I would move my DRO scale to the column instead of the quill, and operate the column like a knee on a normal mill.

Any thoughts on either of these? Thanks in advance.

[Bloy2004]

Hi Jason,
Ah I see what you are wanting to do now.
I don't think you should consider this. By using it this way, the fifth column will always need to be unsecure and any cutting would be subject to flex and instability.
The quadralift is best used as only a positioner to get the bit within reasonable working space. Up for a clamp in a high vice, for example. Or low for a plate maybe mounted on the table...as an example.
This is a strong point for the 3 in 1 Shoptask..it's big incremental range in Z axis.
...just my feelings..

Hope this helps,
John (bloy)

[dahui]

Hi again,

Actually the "knee" idea was just something that popped into my head but I'll probably heed your advice and the motor wouldn't be suitable for this anyway...and I like motors. I suppose locking and unlocking the 5th column during operations would introduce some inaccuracy as well.

I'd still really like to motorize the column just because I find the constant cranking a pain. The first thought I had was to put a big ol hand wheel up there but the motor would be much slicker. Thanks for the info on that and the optical reader, I'll start poking around.

I found some ebay motors that are 24v DC/300 watts/2800 RPM and have built in speed controlers and a disconnect circuit. Of course I don't know what a watt means for torque. But I'm feeling after I gear it down it might do the trick...at least for the Y axis power feed. I'm not sure about the column. I was thinking I'd just mount it in the hole for the CNC servo and belt it up. I think with the disconnect I should still be able to crank by hand. The main issue is that they are 5" in diameter so I'll have to see if there is room to fit it with some stand offs. Thanks again for the info.

[lockeyone]

I used a garage door opener to power my quadralift on my 2003 unit. It was way better than hand cranking that thing. I just hooked it up direct, about 20 seconds top to bottom.