Speed control for a 110VAC spindle motor in 220V enviroment

[ftec]

Hi,

I'm planning to use a 600W Bosch router for the spindle and have it speed controlled from Mach. The 110V 1ph version of this Bosch router is sold in the US and Canada under the name Bosch Colt and the 220V 1ph version sold in the Europe (where I live) is called Bosch GKF 600 Pro and the price is almost double the US price. I was wondering if I could use an inverter to match the 110V motor into the 220V enviroment *without a transformer* and at the same time get the speed control. If yes, is there an inverter (suitable for the hobby budget) you could recommend?

Thanks,
Risto

PS. With inverter I actually mean a variable speed control (=variable frequency drive). If I have understood correctly in USA you may have 220V in industrial plants, so maybe there are controls intended for the industrial enviroment to power and speed control 110V motors...

[Al_The_Man]

The motor fitted to these are most likely Universal motors, if so the speed controls are most often simple Triac controlled type.
It may be feasible to use a 120vac model router off 240 with a Triac controller that has been tailored to limit the output power.
You will need some kind of speed controller anyway.
You would need to ensure the mean off load voltage did not exceed 120 as you will over speed the router.
Al.

[ftec]

Originally Posted by Al_The_Man The motor fitted to these are most likely Universal motors, ...

Al, thanks a bunch for your answer and for putting me on the right track; never knew of the type of motors used for these fast spinning hand tools. Here's something about the motor type if someone else is interested:

http://en.wikipedia.org/wiki/Electri...iversal_motors

... if so the speed controls are most often simple Triac controlled type. It may be feasible to use a 120vac model router off 240 with a Triac controller that has been tailored to limit the output power.You will need some kind of speed controller anyway. You would need to ensure the mean off load voltage did not exceed 120 as you will over speed the router. Al.

Ok, so it will require less tinkering if I fast a few more days and get the 220V version plus a 220V Triac controller, which I think I may find one with a 0-10V Input.

What comes to mind is that the spindle-rpm will be load dependent with a triac controller and even more so with a weakish 1 HP motor. This could be a problem if I want to mill aluminum too. The GKF600Pro (and the corresponding variable speed Colt version) has a speed adjusting knob and electronics to keep the rpm close to constant. Will that still work if there is an external Triac controller remains to be seen.

For those interested here is the single speed Colt ($79), the variable speed version is also available from Amazon.com.

Amazon.com: Bosch PR10E Colt Single-Speed Palm-Grip Router: Home Improvement

Amazon.com: Bosch PR10E Colt Single-Speed Palm-Grip Router: Home Improvement

http://www.newwoodworker.com/reviews/bcoltkitrvu.html

[Al_The_Man]

In almost all professional CNC type spindles, regardless of motor type, there is a feedback element of some kind to maintain the commanded speed, Tach etc.
Some time ago there was a Universal motor Triac speed control from a Treadmill that was sold on the surplus market, the motor had a simple prox. sensor and a toothed wheel on the armature fed back to the simple controller.
I used one of these on a band saw to good effect for speed control.
Al.

[ftec]

Originally Posted by Al_The_Man .In almost all professional CNC type spindles, regardless of motor type, there is a feedback element of some kind to maintain the commanded speed ... simple prox. sensor and a toothed wheel ...Al.

Ah yes, that is a good old trick, we used the same idea to measure paper reel speed to adjust it's braking torque. In this context a small Optoschmitt Sensor and a toothed wheel cut from thin film would probably work.

However, I ordered the 220V version and it's Constant Response™ Circuitry most likely uses something similar (see the newwoodworker.com link) and then the Triac controller can't be used. Probably made a mistake again Hasting To Wedding too soon.

PS. Unless I can get my hands on it's speed pulse and replace the functionality of the adjustment dial with 0...10V analog circuitry...?