1ph motor

[knowot]

Hi all,
Just wondering if it's possible to control the speed of a 1ph motor as its the only way i can get my boxford vm20 mill working as the expanding pulley that adjustd the speed has been smashed beyond welding.

cheers Adam

 

[shenion]

Not practically. There are supposedly VFD drives for single-phase motors but i never have seen them available.

3-phase motors are cheap and there are deals on VFD modules. I did my lathe for about $100 with a drive/motor (1/2HP.) That was some lucky deals though. There are surplus places for motors and ebay.

My lathe has a variable pulley and I have seen them available. However, it is "fixed" at one diameter when used. I assume the mill has something lever-operated that allows changing from the front panel.

Maybe you can have someone remake the pulley setup on a lathe. I made a regular one for my lathe.

 

[gridley51]

VFD`s for small three phase motors are quite cheap.There is a guy often advertising them on this site.
www.homeworkshop.org.uk
Mark.

 

[tigler]

To vary the speed on a single phase motor use a light dimmer. It's not perfect as at very low speed the torque will be limited but over a reasonable speed range it works fine.

 

[shenion]

On an induction motor you will find a light dimmer will just vary the torque. Speed stays near the same then it just stops.

Motors with brushes can use a dimmer circuit although they tend to be unstable.

 

[tigler]

It should just vary the torque but I have used the dimmer method on a number of induction motors and it does vary the speed.

 

[Wedg1e]

Have a rummage on Ebay (or elsewhere) for a Boxford VSL lathe being stripped for spares; I believe the expanding-pulleys speed control on the VM30 used the same components.