Delta/Rockwell Radial Drill Press Speed Control

[Philip1231]

Decided I wanted better speed control on my Delta/Rockwell radial drill press. I ended up replacing the 1/2 HP original Rockwell (Leeson) motor with a 1 HP 3 phase Baldor. Driving this motor is a Lenze variable frequency drive. I modified the drive by adding a potentiometer to allow me to dial in any speed from 240 RPM to around 2400 RPM. 

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[tablesawtom]

I have been thinking about that for about 10 years.  Can you do instant reverse with your VFD? Where is a good source for the Lenze unit ?

Great job. I know you are going to love it.

Tom

[Philip1231]

I have been thinking about that for about 10 years.  Can you do instant reverse with your VFD? Where is a good source for the Lenze unit ?

Great job. I know you are going to love it.

Tom

Thanks Tom. It is capable of reverse operation but I don't have it set up with the typical forward/reverse momentary switches that you often see. I got the VFD on, where else: ebay. Just so you are aware: I went through a number of these units before I found one that actually worked: perhaps you will be luckier than me. I am also using a VFD rated motor. Strictly speaking, this may not be necessary for non-demanding applications where you are running the motor close to its rated frequency. However, if you plan on using the DP at the very low end frequency-wise, you would do well to search for a VFD rated motor and perhaps one with a higher HP rating than the one you are replacing. There is a lot of technical information on the web about this technology: I strongly recommend that anyone thinking about attempting this sort of setup does their homework and they should be comfortable with electrical/electronic projects.

[tablesawtom]

Thank you for the VFD rated motor tip. I am going to start asking at work tomorrow. And there is a motor rewind shop in a town 20 miles south of here I have done business with them before. I will do some checking. I just bought a Harvey sliding table for my saw so it will not be a real soon adventure but you have put the bug in me. I hate changing belts. Thanks.

Tom

[JDuke]

I achieved similar results using a DC treadmill motor.
And the DC motor has very high torque at low RPM for drilling metal.

The challenge these days is finding a treadmill with a nema 56 frame motor.

If you find an extremely old treadmill they can be had for almost nothing.

[MarkSingleton]

My metal shop drill press is a mid nineties Delta. Converted to a General Electric DC motor
that was originally intended for a treadmill. My buddy and I got several of them years ago
from Surplus Center and converted his DP and then mine. Best modification ever.
I can dial down the speed to VERY slow. High torque to boot. Drilled through half an inch
of armored steel plate once. Took awhile, but it got done.

[Philip1231]

I had briefly considered cannibalizing the DC motor from a not too frequently used treadmill. The one thing that has stood in the way is the fact that the treadmill belt runs smoothly by virtue of copious quantities of silicone applied on a regular basis over a number of years. Silicone and wood finishing just don't mix and I just didn't want to open up that can of worms.

[FrankAtl]

I've used Lenza VFD's a lot in my work. They are easy to program and in my experience, very robust. That setup should serve you well for a long time.

[Philip1231]

I've used Lenza VFD's a lot in my work. They are easy to program and in my experience, very robust. That setup should serve you well for a long time.

I stumbled upon this brand quite by accident: I recently acquired a lathe that used a Lenze controller and I was so impressed with it that I decided to explore the whole drill press project. The fact that it is made in USA is a bonus. They also have excellent customer support.