Analia Posted November 21, 2022 Report Share Posted November 21, 2022 I recently acquired an old electric pottery wheel that runs on an AC motor. The wheel has no way of regulating the speed of rotations, so it just goes at one set speed that is too fast to do anything with. I tried using a variable voltage controller to reduce the current that reached the motor, with the hopes that that would slow the rotations of the wheel. At lower voltages the wheel would just stop, and once the voltage was just high enough (180V I think) the wheel would spin at full speed again. Any ideas on how to reduce the revolutions of my wheel? Thank you! Quote Link to comment Share on other sites More sharing options...
Dick White Posted November 22, 2022 Report Share Posted November 22, 2022 It is probably an alternating current motor which sets its speed according to the 60 (or 50 depending on where you are) cycle utility alternating current. It will work at that set speed as long as there is sufficient voltage to start it turning. When the voltage drops below that, it just won't start. As voltage increases above the threshold, it starts again at the same set speed. Current models of wheel typically have a direct current motor, the speed of which is dependent on the voltage sent by the controller (which in turn is based on input from the foot pedal). There are expensive devices, such as an inverter or a pulse-width-modulation device that can change the frequency to change the motor speed, but those may not be practical. If belt driven, you can change the size(s) of the pulley(s) to change the ratio of the wheelhead speed to the motor speed. Quote Link to comment Share on other sites More sharing options...
Analia Posted November 23, 2022 Author Report Share Posted November 23, 2022 On 11/22/2022 at 1:43 AM, Rockhopper said: Is it belt-driven, cone (or wheel) driven - or directly attached to the motor ? Posting some pictures will help get you a more specific answer - especially if there's a name-plate with brand-name and/or model # - but it will depend entirely on how the wheel-head is connected to the motor. Hi, Thank you for your response. The wheel is driven by two belts. I attach some photos. Thanks again! Quote Link to comment Share on other sites More sharing options...
Analia Posted November 23, 2022 Author Report Share Posted November 23, 2022 On 11/22/2022 at 2:24 AM, Dick White said: It is probably an alternating current motor which sets its speed according to the 60 (or 50 depending on where you are) cycle utility alternating current. It will work at that set speed as long as there is sufficient voltage to start it turning. When the voltage drops below that, it just won't start. As voltage increases above the threshold, it starts again at the same set speed. Current models of wheel typically have a direct current motor, the speed of which is dependent on the voltage sent by the controller (which in turn is based on input from the foot pedal). There are expensive devices, such as an inverter or a pulse-width-modulation device that can change the frequency to change the motor speed, but those may not be practical. If belt driven, you can change the size(s) of the pulley(s) to change the ratio of the wheelhead speed to the motor speed. Yes, what you say sounds like the situation that is happening. I am worried about changing the sizes of the pulleys to change the ratio of the wheel head, because that would still result in a wheelhead that spins at a fixed speed - albeit a bit slower. Furthermore, I am not sure I could fit a larger ratio into the wheel I have (See photos attached on my other comment). The current method of controlling the speed is by loosening or tightening the belts - so at the "slowest" setting the belt slips more. But I find this method ineffective. I will look into the frequency inverter, since I think that could give me a bit more control. Thank you for the suggestions! Quote Link to comment Share on other sites More sharing options...
Bill Kielb Posted November 23, 2022 Report Share Posted November 23, 2022 54 minutes ago, Analia said: I will look into the frequency inverter, since I think that could give me a bit more control. It’s a 1/4 hp motor, so given the cost of a frequency drive or speed control and torque at low speed you may find all this very costly. Maybe even more costly than replacing with a dc motor and new drive. I helped a friend setup a new minarik drive last week, I think he paid 150.00 for it. Rae Reich 1 Quote Link to comment Share on other sites More sharing options...
Hulk Posted November 23, 2022 Report Share Posted November 23, 2022 I'm still curious what "...to B.S.S. 170/39" means; I've looked! Those Hoover motors were used in lathe, drill press, and many other types of machines. Quote Link to comment Share on other sites More sharing options...
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