Possible Servo Motor Conversion?

[ahooper]

First up I would like to apologies for a cross posting however after some searches found that my most really belonged here and not where I had posted it.

I was looking at building a CNC router and while hunting around my workshop remembered I had a box of wheelchair motors. I was thinking about converting three of these into servo motors by adding an encoder and circut (maybe even a soft start speed controller).

Each motor has a gearbox and the motor is coupled to this using a worm gear however i'm not sure of the ratio and have not yet counted the teeth. However as you can imagine these things are real work horses.

I have cobbled together a simple PWM speed controller to see how slow I could rotate the motor without it stalling. and i managed to get about 1 revolution every 3 seconds. I am not yet sure of the upper speed. There also seems to be no backlash in the gearing system.

24V DC at 8A continuous
50Nm stalled torque
120 rpm

Each motor also has an integrated brake that is on unless you energise it with 24V This however can be removed and would allow me to insert the encoder on to the read end.

I originally thought that i could split the motor and Box but after pulling most of it apart it seems that the housing will not allow them to be split into two pieces unless I make a few major modifications.

Do you think converting these is worth while or should I start hunting around for other options?

Regards
Andrew Hooper