Good morning. This motor is on a long arm sewing machine. It currently has a rheostat and a separate on/off switch. I'm wanting to replace the on/off switch with a variable speed switch. I know that is what the rheostat does however, I am short and the rheostat location is not in a convenient location to operate while my machine is in motion. Due to the setup and the machine itself a foot pedal would not work.
On a previous long arm I had I was successful in wiring a variable speed switch from an electric drill to the handle bar to control the speed. But I'd like to do something a little more permanent with this setup. The motor is an ac/dc brushed motor. Please see photo for tech info. My question is (and I know it sounds far fetched and ghetto):Is is possible to replace the on/off switch, leaving the rheostat where it is, with an ebike thumb throttle? Or would I just be constantly frying the switch?
I've searched online for switches and nothing else comes close to what I am looking for. The thumb throttle is similar in operation as a foot petal which this machine was never equipped with, the harder you press the faster the motor spins, you let off and the motor slows which is what I am looking for. If this is not possible do you have an recommendations? Machine photos are also attached. One showing location of the rheostat and one showing location of the on/off switch on the handlebar. I am looking for something small that i can add to the handlebar.

 

The old reostat method is a little inefficient, a Triac (Dimmer) may be the better solution, also use a bridge rectifier after the Triac will make it a little more efficient.
I take it you would like the same action as a foot pedal, i.e. self returning to off?
You also need something that is insulated according to 120vac.
Max.

 

Our friends at GRAINGER offer motor controls that will do exactly what you are asking for. But they have a knob, not a pedal. So you may need to do some mechanical work to make it function with a pedal. They may also offer a pedal operated version, it is several years since I installed a knob version device. But if you are willing to experiment a bit there are slider type controlled light dimmers that ought to work and will only need a pedal added to operate the slider. And they are cheaper.
Max reminded me that a spring return knob would be preferred, and so if a dimmer would work all you need to add is the spring return to the knob.

 

The way I read it a foot pedal is not preferred with the preference being a automatic return rotary knob!
Max.

 

Our friends at GRAINGER offer motor controls that will do exactly what you are asking for. But they have a knob, not a pedal. So you may need to do some mechanical work to make it function with a pedal. They may also offer a pedal operated version, it is several years since I installed a knob version device. But if you are willing to experiment a bit there are slider type controlled light dimmers that ought to work and will only need a pedal added to operate the slider. And they are cheaper.

I’m actually looking for something similar to a thumb throttle on an ebike. A rotary switch would require construction of a box to added to the handlebars. The foot petal was a reference as to the function of the switch I am looking for.

 

The old reostat method is a little inefficient, a Triac (Dimmer) may be the better solution, also use a bridge rectifier after the Triac will make it a little more efficient.
I take it you would like the same action as a foot pedal, i.e. self returning to off?
You also need something that is insulated according to 120vac.
Max.

Yes the same action as self returning to off when I release pressure. So the ebike thumb throttle will not work? I’ll check out the triac and bridge rectifier. Thank you