[How do I?] Speed Control.

Sorry to say but your chances of controlling that motor's speed are bleak. I recommend trading it in for a 3 phase motor and then buy a cheap VFD. Or a DC motor and drive.
 
There are some single phase VFDs out there, I have bought some on Ebay, and they work. They are made by Minarik. If you have to buy one new, it is more cost effective to get a 3 phase motor and VFD, as they are expensive. I got them dirt cheap on Ebay, but they don't come up all the time, so you have to be willing to wait.
 
Hi Bob, I've been through this recently and have dealt with the Australian pricing phenomenon of chinese vfds being similar in price as decent quality.
Have a look on ebay then have a look on rs components aust. You can get a new teco 1.5hp motor for under $300 and a abb or parker vfd for similar. Last i checked you are paying over $250 for a chinese vfd. Not worth the trouble imo
Are you on single or three phase?
 
I wired my $5.00 FVD (220 AC) to my 1/3 horse band saw. There was no slowing that sucker down, even a the lowest setting. The band saw has a two prong plug, so I wired the FVD to a duplex outlet (independent of the house current) and plugged it in. So much for cutting steel with that band saw.
 
Str8jacket said:
Hi Bob, I've been through this recently and have dealt with the Australian pricing phenomenon of chinese vfds being similar in price as decent quality.
Have a look on ebay then have a look on rs components aust. You can get a new teco 1.5hp motor for under $300 and a abb or parker vfd for similar. Last i checked you are paying over $250 for a chinese vfd. Not worth the trouble imo
Are you on single or three phase?
Click to expand...


Thanks for response I have ordered a cheap $3.00 PWM type controller from china on ebay, it's rated a t 2000w, so I'll wait and see. I do have 3 phase on the premises but chose to go with single phase because the model lathe I am buying it's extra to have 3 phase and I didn't think I'd need it. plus I'd have to have the 3 phase wiring extended to where the lathe is going. The only reason I want to lower the speed is Id like slower speed for some screwcutting jobs that are critical my lowest speed on the gear box is 60 RPM and for most times that is enough but I can see that there will be times when about 30 RPM would be nice.
 
Hi Bob,
you may have to make some concessions if the motor you are trying to put the PWM controller is a capacitor start and/or capacitor run motor.
the centrifugal start switch will be trying to put the start capacitors' charge into the motor's start windings anytime the motor dips to around 80% of it's rated RPM.
this means that you'll need to wire in a momentary start switch circuit for starting, and disconnect the centrifugal switch.
you should start the motor with the PWM at the high speed end of the speed pot's travel to avoid high current draw.
most motors don't like operating over 12Khz, you may wish to avoid that as well.
i hope the information is useful :)
 
Ulma Doctor said:
Hi Bob,
you may have to make some concessions if the motor you are trying to put the PWM controller is a capacitor start and/or capacitor run motor.
the centrifugal start switch will be trying to put the start capacitors' charge into the motor's start windings anytime the motor dips to around 80% of it's rated RPM.
this means that you'll need to wire in a momentary start switch circuit for starting, and disconnect the centrifugal switch.
you should start the motor with the PWM at the high speed end of the speed pot's travel to avoid high current draw.
most motors don't like operating over 12Khz, you may wish to avoid that as well.
i hope the information is useful :)
Click to expand...


hi, thanks for your words of wisdom, i had not thought about that. I'm not sure which type it is but it does have two capacitors one for forward and one for reverse, beyond that I don't know, I'll have to check it out. But as I said its not critical I will only want to reduce the speed occasionally for some sensitive screwcutting jobs , where I feel my lowest gearbox speed is a bit fast at 60 RPM and at that it will be very low load, I would just like to be able to cut the speed to about 30 RPM on the odd occasion.

I intend to set it up with a bypass switch so that it will always start by passing the speed control then if I need to I can flick the switch and run through the speed control. If it doesn't work I'll have to think of something else.

Cheers,

Bob.
 
I re-studied my band saw set up, 'Seems I'd plugged the Dremel tool into the controlled breadboard, the band saw was not in that circuit on the previous test.

With the band saw plugged in, I had to open up the speed fairly high to get it to start, it would then slow down, but not enough to cut steel, and kept wanting to keep slowing until it stopped, It didn't seem to want to run consistently.

'Twas only by way of experiment, anyway.
 
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