Supporting > Tooling & Machines

Stepper motor power feed for RF45 milling machine

(1/3) > >>

JCvdW:
I am currently busy building the MEM Corliss Steam Engine. https://www.modelenginemaker.com/index.php?topic=10004.new#new

I tried to fly cut some of the parts on my RF45 milling machine clone and struggled to obtain a good surface finish. What a good excuse to build an X-axis power feed for the milling machine!

What follows is not a detailed build log, but mostly photos to show the general idea.

Basic requirements for the power-feed were:

1. Variable speed setting with digital indication of speed, to allow repeatability.
2. Three way toggle switch to move in either direction, or stop the table and disable stepper motor driver.
2. Push button initiated rapid feed, to quickly move the table.
3. No end stops - to keep me awake while using the power feed.
4. Drive mechanism must not protrude above the table surface.
5. All electronics and mechanics protected from swarf.
6. Retain use of both manual feed wheels.

I already had a 2A Nema 23 stepper motor, a stepper motor driver and a 24V DC power supply. I decided to use this, as a more powerful motor can always be installed later if needed.

General approach:

1. Use an Ardunio Uno as controller.
2. Connect the stepper motor to the X-axis lead screw with a timing belt, with a 1:2 pulley ratio.
 

JCvdW:
First step was to determine how to control the speed of the stepper motor with the Ardunio Uno using a potentiometer as input. I found that using the Ardunio tone() function to generate a square wave works best. The frequency of the square wave can be set according to the voltage from the potentiometer.

First setup on the bench:

JCvdW:
I removed the dial ring on the end of the X-axis lead screw to mount the timing pulley in its place.



I then bored the timing pulley for a snug fit, and Loctite it in place.

JCvdW:
The controls consist of:

1.  A three way toggle switch to: feed left, off, and feed right
2. A push button to override the speed setting and rapidly move the table
3. A potentiometer to set the speed.

The controls were mounted on the side of the plastic box that houses the Ardunio Uno. Included in the box is a small DC to DC converter to convert from 24V to 5V required by the Uno.



First action:

[youtube1][/youtube1]

Admiral_dk:
Interesting project - but no video - error message
--- Quote ---#Invalid YouTube Link#
--- End quote ---

I'm not sure - but have you enabled / made the YouTube file Public ?

Per

Navigation

[0] Message Index

[#] Next page