Craftsman 109

I currently run a hp treadmill motor on my 109 it works very will, I also run a 2 hp on my mill drill. I feed them both off of the same speed control and tach. the control selects which machine i'm running and forward or reverse. I can also look at either machine from the tach.

If you look at the treadmill or any dc motor the rpm normally is way higher then a induction AC motor. so when you are running at the same speeds as a AC motor the delivered HP is far less. For example at full speed my lathe motor turns 4800 Rpm and draws 19 amps AT 90 Volts That is 1700 whats and 2.28 hp. but at 1200 rpm the current is 9 amps at 35 volts .425 hp and 300+ watts. most of my usage on the lathe is less then 1500 rpm and when i'm in back gears for threading and die work i rarely run it above 1000 rpm so that 2 hp motor is realy working at about 1/4 to 1/3 hp and ideal for a 6 or 7" lathe.

The real advantage i have found is on the mill in that i can power tap and not worry about breaking taps off because it just stalls the motor if the tap bottoms, on aluminum it will tap through anything up to about 5/8" on steel it will bind and I just reverse it and go again . on a 1/2 hole 3/4" deep it might stop twice . Full variable speed is also a great big advantage.

My mill drill is a fully modified 17" drill press with angular contact bearings and gibbs on the spindle, a fine feed on the spindle and Gibbs on the column. It also has a powered Z axis of 7" + the spindle travel of 4" this gives me 11" Z axes travel I use ER25 Collets and a lock pin on the MT2 adapter. The X Y Table is one from about 25 years ago and not asian made. I have about 225.00 in the mill, A good functional light mill drill can be made from a large drill press if all the issues are addressed.

Art
 
I was all so thinking about3/4 variable speed sero motor like in sewing machines .
 
The sewing machine motor is still a dc motor and has the same low speed issues but a 3/4 when slowed down would only deliver about 1/5 to 1/4 in the operating range that you would be using that isn't enough power to thread or take a descent cut with. My original motor on my 109 was a 1/4 hp 1125 rpm motor and i stalled almost every time i tried to take any kind of a cut.

I have used the treadmill motors on a lot of what would have fractional hp motors I also used it to convert my 12" wood verticle bandsaw for ferrous metal cutting and have cut 3" round stock with it. The problem with wood saws are that they are moving the blade about 4 times to fast for cutting ferrous but with a 2 hp treadmill motor runinng at 800 to 1000 RPM it is delivering a solid 1/2 hp which is enough power to run the saw. When i want to cut aluminum which is what i cut normally I just run the speed up and i'm ready to go. No pully changing etc.

I also use link belts on all my machines as they deliver power through a small motor pulley without taking a memory that causes vibration issues.

I also have gotten all my treadmill stuff off craigslist as free treamills. I get one within a month when I start looking. The older or high end treadmills have good dc motors that deliver the HP.
 
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