View Full Version : successful treadmill conversion

Mike Amick
06-16-2012, 04:42 PM
Just converted my shopmaster 2000 to variable speed. I know a lot
of tready conversions have bugs .. but .. this one worked out pretty


06-16-2012, 06:55 PM

Nice job and neatly done! The low end power looks very good. When my AC China motor dies, this is the way I'm going.


06-16-2012, 09:15 PM
Nice clean motor conversion for what was shown. Good job!

Some "Rookieness" showing too. :D

Too much overhang on the stock. I could see the deflection.
NEVER clear chips with your fingers. Use a chipbrush or similar.

06-16-2012, 09:19 PM
Nice set up, thanks for posting this.

Forrest Addy
06-16-2012, 09:34 PM
Something to poit out. Notice when the feed was cut off in the first low speed "heavy" cutting test how the part relaxed frrom its deflected state?

Long extensions without support from the center pose deflection problems. Chances are had Mike continued his higher feed cut the full length there would be substantial taper.

BTW, that's electronic controlled feed? I wonder if there is a way to combine control of electronic feed with the DC control so if you change spindle RPM the feed per rev follows to stay more or less constant.

Anyway. Nice sanitary conversion. With a motor that powerful you may not have to sweat speed changes.

06-16-2012, 09:43 PM
you got a good radio voice OP, you could do commercials for tool manufacturers

Mike Amick
06-17-2012, 02:16 AM
lol .. thanx

I think "some rookieness" is a complement .. and a promotion to my
actual experence.

I do have a habit of leaving a lot of unsupported "hangout" .. my
usual indication of this is .. when I make a cut .. I usually don't
back off the cutter. If it cuts on the way back .. I figure it had
to be flexing ..

did you guys notice the tengential cutter ?

06-17-2012, 11:08 AM
What kind of cutter? The only guys I've ever met with THAT problem were wearing Bermuda shorts at the Salt Flats during Speed Week...

06-17-2012, 01:58 PM
Where did you purchase the speed control. Is it usable on other treadmill motors.

Mike Amick
06-18-2012, 03:02 AM
I had been hearing about this cutter .. its pretty neat .. and
dead simple to sharpen. Here is a pic of mine.

And here is a link to the company

The speed control is a Dart 250 series .. it will handle 3hp. I paid $40 for
it locally .. but ... I just bought another one (for the mill .. whenever) and
I paid 45 for it on ebay.

In case you are thinking about doing this .. remember that most treadmill
speed controls require you start-up in the 0 speed position .. then you can
turn it up .. in other words .. you can't start it with a speed already set.

Note that I said most .. I have a few controllers and one of them doesn't
require this .. so they are out there if you get lucky.

I just liked the Dart because it has adjustments for ramp-up of speed
and max speed and min speed etc etc

06-18-2012, 11:08 AM
Thank you, Mike.

06-18-2012, 11:41 AM
Looking over the manual for the Dart250 it resembles the KB/Baldor KBIC-240.
It also shows 2HP max.
Some of the differences are the Dart has a DC tach output and also includes the drive schematic.
Advantage to the KB is that the stop and restart allows the use of the accel/decel to be used, in the case of the Dart, the restart applies full voltage to the motor at the previous setting.
Also with the KB, if armature reversing is used, the inhibit can also be used to force the motor to go through decel/accel rather than putting the danger of putting full voltage reverse on if care is not taken.
The Dart warns about armature reversing without coming to a complete stop first.
Otherwise they appear fairly close. Both 2 quadrant SCR drives.

06-18-2012, 11:45 AM
Very nice job! I as well was most interested in the cutter. Besides being different and very interesting I noticed it seems very very much above center on the stock. Now I always put my tools at center just because that was how I was taught. Is there an advantage to having the tool above center for stainless or something?

Mike Amick
06-18-2012, 03:09 PM
Ummm .. I think it is just the perspective. It actually is at center line.