Etch a Sketch style power feed

I see these pwm motor controllers on eBay that have a dial for speed control and a switch for forward and reverse. I'm wondering if they make one, or if one could be modified, to function in a way that the dial controls forward and reverse as well as the speed.

Since I'll still.be manually milling I'll still handle backlash and positioning the way I always would.

And I suppose I can actually achieve close to what I want by replacing the toggle switch on the pwm controller with a 3 position on-off-on momentary switch. All I would loose is the dynamic speed control.
 
Here you go.

I can confirm that these three items will give what you've asked for, I've bought and used them all together.
Although from what you asked I think you're looking for something to control your existing auto feeds. I doubt they're steppers but I've never taken one apart and don't know if they would be easy to modify.

Amazon.com: DC 5-12V/15-160V Stepper Motor Drive,PWM Adjustable Stepper Motor Controller Signal Generator Speed Regulator: Home Improvement

Amazon.com: DC 5-12V/15-160V Stepper Motor Drive,PWM Adjustable Stepper Motor Controller Signal Generator Speed Regulator: Home Improvement
www.amazon.com

Quimat TB6600 Upgraded Version 32 Segments 4A 40V 57/86 Stepper Motor Driver: Amazon.com: Industrial & Scientific

Quimat TB6600 Upgraded Version 32 Segments 4A 40V 57/86 Stepper Motor Driver: Amazon.com: Industrial & Scientific
www.amazon.com

Stepper Motor DC 24V, 4 Leads 2.2" Long, 4 Channels, Single Shaft - - Amazon.com

Stepper Motor DC 24V, 4 Leads 2.2" Long, 4 Channels, Single Shaft - - Amazon.com
www.amazon.com

But you might as well do CNC by that point IMHO.

Cheers,

John
 
All you would need to do is change the PWM controller for a motion control breakout board and you have computer control of the whole thing. With Mach 3 or 4.

With Mach you have all the things you want like backlash adjustment, detailed motor tuning, precise speed control

Mach also has some canned cycles like round or rectangles. You would need to change z depth manually.

Then it is essentially a CNC machine and that is good.
 
Assuming that you don't think you can cut diagonals this way this gets easier. That is you would only really be cutting in one Axis at a time. This seems like just bringing two power feed controls in to one control panel with two pots on it. Not a bad idea.

The obvious thing that happens next his feature creep. If you are building the power feeds then why not use stepper motors, stepper motor controllers and an Arduino or Mach as suggested. At that point you start to think 'hey, I can get this setup to cut circles' and away you go.

I am planning on buying a much bigger milling machine soon (MH 28V) but it's head crank is up at the back. The setup I will ultimately use should mean that I never try and crank the head up and down by hand. Its design, when i do it, would be a reasonable starting point for this sort of thing too. I will probably use a stepper motors and want some sort of remote knob on the bottom right of the machine, either jog or speed, probably with a covered on/off switch. Stefan Gotteswinter's quill and cross power feed is a way to go instead of stepper motors. He uses a geared motor and I assume he is confident about feed rates on the basis that its speed is more or less impervious to load. Easier if you can do without a feed rate display.

Hope this is some useful brain grease, I like that phrase.

First post :)
 
if i go cnc then i wont be able to mill manually anymore will i? and perhaps once i go cnc i'd never want to go back but i enjoy cutting the parts. i'm afraid i wont get the same satisfaction from cnc. i do recognize that cnc opens the door to a wide open world..
 
Driveslayer45 said:
if i go cnc then i wont be able to mill manually anymore will i? and perhaps once i go cnc i'd never want to go back but i enjoy cutting the parts. i'm afraid i wont get the same satisfaction from cnc. i do recognize that cnc opens the door to a wide open world..
Click to expand...

There are many ways to use a CNC converted machine with manual control. If that's what you want you can build it that way....

I'm thinking that controlling two axis with motor drives simultaneously will be beyond challenging where as programming a CNC to do so is just normal function. I'll be using LinuxCNC but there are many other programs out there suited to a hobby user.

One exercise to try would be to draw out a part you think you would build with your system and try drawing it on an etch-o-sketch. Then try to make it on your mill using the existing set-up. Think it through and I bet you'll decide to either stay manual or go CNC.

Cheers,

John
 
Driveslayer45 said:
if i go cnc then i wont be able to mill manually anymore will i? and perhaps once i go cnc i'd never want to go back but i enjoy cutting the parts. i'm afraid i wont get the same satisfaction from cnc. i do recognize that cnc opens the door to a wide open world..
Click to expand...

When the power is off to the steppers or servos they free wheel. So as long as you leave a handle on you can use it manually.
 
I think most of you guys have overlooked the point that most power feeds for mills use a gear drive that engages the motor to the screw, as well as a switch. The feed lever mechanically engages the gear and also energizes a micro switch for that particular direction.
 
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