speed controller plans

J.McDonald Knives

J.McDonald Knives

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Jan 28, 2007
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anyone know where i can find plans online for a speed controller? my 1x30 with 5" disk has a 1/3hp motor. i would like to build a speed controller for it and im good at soldering electronics. im sure i can find all the parts at radio shack or one of the electronics stores in san antonio. if i can build one for alot cheaper than i can buy one ill do it.
 
You could use a variac. (variable transformer)

That's what I'd do. No soldering involved. Definitely an Ebay or Pawn shop item.

BTW. My post last night regarding your frequency was not meant in a negative way. Not sure why I typed it.

Hope you have a good day.

BJ
 
im trying to find plans to make something to control the speed of the motor. id rather spend $20 in parts than to spend $100+ on buying one.
 
There's a 120V 15A variac ending on Ebay in 2 hrs. It's going for $5, currently. There are many variacs listed on Ebay for cheap that you could easily mount in a project box from Radio Shack.

What's you desired max current rating?

That's how I built one for my father in law. Total cost was around $20.

:)
 
i want to be able to control the SFPM of the belt. i just want to be able to grind on a blade without burning any belts.
 
dennis, which one did you get? really all im looking for are just plans. i still want to take a look at those.
 
Guys

If your motor is a universal motor (it has a commutator and brushes) you can use a router speed control. Harbor freight sells them for $24.95 and throws them on sale about every other month for half price.

The problem with using a variac, which controlls the voltage, it that Power is equal to voltage squared divided impediance. When the voltage drops to half your horsepower drops to one quarter (roughly, there are other factors at work also).

I believe the router controllers just chop up the wave form and doesn't change the voltage.

Jim A.

http://ww2.harborfreight.com/cpi/ctaf/headsearch.taf?function=Search
 
PimpinSquee,
If you were asking me about knife making I would not even reply....
Electronic manufacturing......I'm game.

I looked at the circuit. As a major electronic manufacture (I could get these puppies out of China cheap), I decide not even to waste my time soldering this circuit together.

Call Beel! Johnathan is excellent and will walk you through the installation. Not really much to install. Like I earlier typed, should instal in a hour.

I will let you know more when the controllers arrive. I got my first 1 hp DC motor today. The other motor should arrive tomorrow along with my drivers.

I just requested the final quote from Norm Coote today for my grinder.....WOW.

Dennis
 
keep me informed about how well they work. they seem very reasonable in price. take a pic of it when its done.
 
A variac connected to a single-phase AC motor will not give you speed control.

You might be able to control the speed of a DC motor by rectifying the output of the variac and connecting that to your motor. You do run the risk of burning out your variac, after a while, with the starting surge current of the motor.

You will not find the neccessary components to build a DC motor drive or three-phase VFD at Radio Shack. Designing a motor drive (AC or DC) that works reliably and safely is no trivial task (my last job) so just go buy one. The second one that Dennis linked to (SMC-N412R) would be the better choice. It has an NEMA12 enclosure meaning that it is dust proof. It is not easy to install a drive in a dust tight enclosure and make it work reliably. The SMC-00 model is meant to be integrated into a larger machine that has an enclosure to protect it from the environment, and you from the lethal voltages present in it.

Phil
 
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