i have this electric die grinder http://www.harborfreight.com/c...44141


and it only has one speed and max on the description is 25000rpm. so this must be what it runs at.

its 4.5amps, 60Hz, and takes 110volts single phase motor. BTW

i need less than half power, about 10-12k rpms. what sort of electrical device could i rig to make this happen. i can solder etc. i was thinking a few resistors with a switch or something? could i resist it to like 2.0 amps and be done with it, with a switch?


Modified by hybridvteceg at 12:30 AM 3/12/2004

 

I'm assuming it's not a variable rate item. The resistor idea should work, in fact you can rig up a series of switches if you want to make the speed fully adjustable. You'll have to experiment with exactly how much resistance to use though.

 

wow. never heard of a variable resistor before? goto rs and buy one, it might be called a pot. either way it will make the speed adjustable with the turn of a ****

 

ok im going to take it apart, just resist the main power wire to the motor right? and not a variable resistor, i dont know whatd itd actually be called but thats the best way to describe it

 

potentiometer? rheostat?

 

right but run it inline with the power to the motor right?

 

Go to your local sewing machine repair shop/thrift store/garage sale/Good Will/mom's sewing room and get a sewing machine foot pedal. Cut off the wierd sewing machine plug and screw on a Home Depot/hardware store plug eng. Plug in grinder. Use foot pedal to control speed. Works like a charm. This is what I used to control the speed on my ancient Sears Craftsman "Li'l Crafty" electric grinder to do head porting and it was MUCH easier using a foot pedal than some **** or button. Now I don't know if this will work for ALL kinds of electric motors so don't sue me if your house burns down, but it worked for me.

 

can you go more in detail about that, its hard to visualize, any pics too? what plug from home depot, and screw it in?

 

???

 

Make the output from the sewing machine pedal a standard 110v plug instead of the flat plug the sewing machine probably uses. Then just plug the grinder into that and use the pedal to control your speed. It's perfect for your application since it is a variable speed controller for a motor about the same size as the grinder so it won't overheat or burn out.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hybridvteceg &raquo;</TD></TR><TR><TD CLASS="quote">can you go more in detail about that, its hard to visualize, any pics too? what plug from home depot, and screw it in?</TD></TR></TABLE>

Most sewing machines have some oddball kind of plug where the cord for the foot pedal plugs in. Useless for anything other than a sewing machine. What I meant was, cut off the end of the foot pedal cord that plugs into the sewing machine. Go into your local Home Depot/Lowes/hardware store and say to the nice man, "I ruined the female end of my extension cord and I need to fix it. Do you sell replacement ends here?" and he'll show you where they are. You usually screw your bare wire ends onto two terminals and then screw the two plastic halves of the plug together. All you need is something that you can plug your dremel into just like a wall socket. (truth be told, the first time I tested this idea with my wifes sewing machine foot pedal, I plugged Li'l Crafty into the short end of a ruined extension cord and just pushed the bare wires into the end of the foot pedal cord. Shhhh, don't tell anyone.)

 

here is what you really want http://www.mlcswoodworking.com....html

This is just one manufacturers version. There are many out there.

If you use a resistor the speed will be very sensitive to load.

 

some say "if it's not on mcmaster, then it doesnt exist" so...

"Light Duty Variable-Speed Foot Switches
Vary the speed of fractional horsepower motors while keeping your hands free. These AC speed controls have solid state circuitry and are designed to work with small fractional horsepower AC motors. Connect the foot switch to your power source and then connect your switch to the motor. They're made of a polymeric material that won't rust or corrode. Size is 6 3/4" Lg. x 4" Wd. x 2 1/4" Ht. UL listed.
"

40$, but its load is only 6 amps. so ill probably get the woodworking one on the link aboe so that can control my cheap one speed chop saw, and my dewalt angle grinder. thanks for posting that BigMoose

 

Or a light dimmer reostat fm Home depot.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DonF &raquo;</TD></TR><TR><TD CLASS="quote">Or a light dimmer reostat fm Home depot.</TD></TR></TABLE>
Exactly what I was going to say. Easy and cheap

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DonF &raquo;</TD></TR><TR><TD CLASS="quote">Or a light dimmer reostat fm Home depot.</TD></TR></TABLE>

Thats how I have mine setup. Works great.

 

i just ordered the mlcwoodworking.com one so we'll see how that turns out. plus i can quickly plug in my chop say and other stuff to it since it can handle 15A