a/c motor speed control question

davidh

davidh

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I need a bit a knowledge here.

the picture is of a 1/15 HP 110VAC gear reduction motor that reverses.
can I use a incandescent light control switch for speed control or do I need a "router" type speed control ?

next, do these small enclosed motors heat up bunches when they are run at low speeds ?

you can most likely guess what I would like to do with it. . . . but, without the above knowledge I hate to ruin it after making the necessary modifications....



screwjack.JPG

screwjack.JPG
 
Generally AC induction motors are speed-sync'd to the line frequency. That's why they use VFD's (variable frequency drives) on AC motors. By reducing the voltage...light bulb or dimmer...you can slow the motor down due to rotor/stator slippage. But, at the loss of torque and excessive heating.

Ken
 
If this is an a/c induction type motor, then no router controllers or light dimmers won't do it. You can only use those with a/c d/c universal motor as found in most power tools etc.
 
after total disassembly of the motor & gearing assembly, its double reduction plastic but the armature output shaft looks like a variable speed Milwaukee drill output shaft. . . ok, ugly a marriage that that could be it might be a basic start or. . . hummmm not giving up yet.

oh boy here I go shopping again.

maybe I should stick with getting rid of all my drills and stuff. . . .
 
davidh said:
after total disassembly of the motor & gearing assembly, its double reduction plastic but the armature output shaft looks like a variable speed Milwaukee drill output shaft. . . ok, ugly a marriage that that could be it might be a basic start or. . . hummmm not giving up yet.

oh boy here I go shopping again.

maybe I should stick with getting rid of all my drills and stuff. . . .
Click to expand...

David since you took it all apart, does it have brushes in the motor?


David
 
no brushes. . . the armature shaft pressed out pretty easy too. nice looking steel. the gearing is plastic with some bushings and some bearings. . . .

I figured if push comes to shove I'll add some bearings instead of the bushings that are there now and do a belt drive. I don;'t know, maybe its not worth the effort.

on a different note, I understand the ---- of a round column mill. they got to be tight as hell or they will rotate when feeding a little aggressively on the "x". its a learning curve all over again.
I still have my PM30 on order, just in case. . . ..

I wish I knew more about electronic controls. . . it would make this idea much easier. I cannot wrap my head around ohms and stuff.
 
Also...linear drives like that are commonly used on things like recliners and hospital type beds. Because the motors are pretty well sealed up with no venting they heat up rapidly. The motors generlly have a very small recommended duty cycle...like 10%. :(

Ken
 
very limited for sure. I think the tag said 1 min on and at least 8 minutes off. these are raising and lowering treadmill platforms. nice looking little gear cluster stuff. now for a motor. what about a windshield wiper or window winder or even a power seat motor ? I have a bunch of that stuff. of course its all 12 volt but that's easier to control speed with I think.

I will carry on. . . I just can't justify the three / four hundred bucks for a power drive on a low cost mill yet, maybe. . .
 
I would go with the windshield wiper motor since that one will be continuous duty.
 
davidh said:
I wish I knew more about electronic controls. . . it would make this idea much easier. I cannot wrap my head around ohms and stuff.
Click to expand...
Ohms law is such a simple formula, but I get tangled up with it every time I try to use it too. I have cheated on occasion and used internet calculators to avoid having to do the math, but being able to use Ohms, Thevinin, and others will make understanding schematics almost second nature. I have been studying basic electronics now for over 2 years and I STILL get hung up all the time. Fortunately there is a great forum for learning all about electronics. I go to All About Circuits.com and they have just about the smartest bunch of folks I have ever encountered with very little hassle or headaches. Their texts are first rate and they have a very active forum for Q&A and other discussions.
Bob
 
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