Variable speed drive control

We had a C&P press, and it worked with a variable switch from Grainger.

I’ve done this a number of times using variable frequency drives (particularly GE Fuji AF-300 mini models) and 3 phase motors (around 1/2-1hp, whatever is most affordable.)

It allows for:

Variable speed control
3 phase to single phase conversion
220 to 110 voltage conversion

I first did this in maybe 2009 to make C&Ps safer for students enrolled in workshops. They can slow down to probably 10 impressions per minute, slower than that and it’s hard to keep enough momentum/torque to keep the press running.

Hope this helps,
Bradley

This comes up every so often. Here’s the briarpress post that is, in my opinion, the final word:

http://www.briarpress.org/29788

If your Heidelberg has the original three phase 220 volt motor, you can control the speed by adding a variable frequency drive. The problem with reducing the press speed with a variable frequency drive is you also reduce the torque available from the motor so there’s a limit to how slow the press can run.

I added a variable speed drive to my 8x12 Chandler Price and I’ve found that at very slow speeds there isn’t enough momentum to keep the press moving through the impression. I’ve never run a Heidelberg but there’s a lot going on in that press — I believe it has a 1-1/2 hp motor vs 1/2 hp for a small CP.

If you want to give it a try, a great source for variable frequency drives (and motors, cables, how-to information and such) is automationdirect.com.