Foredom Pedal With Dumore Drill Press?

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SteveHGraham
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Foredom Pedal With Dumore Drill Press?

Post by SteveHGraham »

Some time ago, I got a Dumore sensitive drill press from some guy whose company threw three in the dumpster. I don't use it. I bought it simply because it was a great deal.

I am thinking of making it part of my indoor work area, but the drill press has an issue. It only runs at one speed, which is something like 10 million RPM's. I forget the exact figure.

Dumore makes a speed pedal for it. It's a steal at $300.

Here's what I'm wondering: can I put a $40 Foredom pedal on this thing? I don't see any reason why not. They work with Dremels.
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John Hasler
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Re: Foredom Pedal With Dumore Drill Press?

Post by John Hasler »

Size, ratings, and type of motor? Looks like the $37 control is rated for 1/6 hp motors.
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BadDog
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Re: Foredom Pedal With Dumore Drill Press?

Post by BadDog »

17k rpm, 1A @ 115V, 1/16 hp.

I've got one too, almost never used. My Pratt Whitney "sensitive" (at a feather weight 80+lbs up to 1/4" bits) is far more useful for anything except TINY drills. But I am vaguely interested in the possibility of using one of those pedals...
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SteveHGraham
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Re: Foredom Pedal With Dumore Drill Press?

Post by SteveHGraham »

Foredom makes two pedals. One is plastic. The other is metal.
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Rich_Carlstedt
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Re: Foredom Pedal With Dumore Drill Press?

Post by Rich_Carlstedt »

I checked my Dumore control (OEM)
It has no rating printed on it but when you first depress the pedal , you get maybe 100 RPM
The control shows 1000 Ohms at that point, and fully depressed (max RPM ) the control shows 75 Ohms
When not touched, the Ohm meter displays-- infinity for resistance
I would think a sewing machine motor control would also work ?

Rich
John Hasler
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Re: Foredom Pedal With Dumore Drill Press?

Post by John Hasler »

Rich_Carlstedt wrote: Mon Jul 02, 2018 10:43 pm I checked my Dumore control (OEM)
It has no rating printed on it but when you first depress the pedal , you get maybe 100 RPM
The control shows 1000 Ohms at that point, and fully depressed (max RPM ) the control shows 75 Ohms
When not touched, the Ohm meter displays-- infinity for resistance
I would think a sewing machine motor control would also work ?

Rich
That's just the potentiometer. The electronics must be in the motor.
Magicniner
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Re: Foredom Pedal With Dumore Drill Press?

Post by Magicniner »

John Hasler wrote: Tue Jul 03, 2018 7:59 am That's just the potentiometer. The electronics must be in the motor.
No it's not, and no they aren't :D

Old sewing machine controllers were a stack of carbon discs which the pedal compressed via a spring to give variable contact pressure and thus variable resistance.

A Potentiometer is a resistor with a movable tap allowing the potential applied across the resistor to be divided in a variable manner.
John Hasler
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Re: Foredom Pedal With Dumore Drill Press?

Post by John Hasler »

75 to 1000 ohms is not going to work as a rheostatic speed control. You need zero ohms for full speed. A carbon pile pedal control has a set of contacts that short out the carbon pile when the pedal is fully depressed. Before that it needs to get much lower than 75 ohms to get near full speed.

If you want to get pedantic a potentiometer is a device for comparing an unknown voltage to a standard cell.
Magicniner
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Re: Foredom Pedal With Dumore Drill Press?

Post by Magicniner »

John Hasler wrote: Sun Jul 08, 2018 2:00 pm If you want to get pedantic a potentiometer is a device for comparing an unknown voltage to a standard cell.
With how many connections?
John Hasler
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Re: Foredom Pedal With Dumore Drill Press?

Post by John Hasler »

Two to the unknown voltage source and two to the standard cell.

The term potentiometer has been abused, though, first to refer to a resistor with a movable tap used as a voltage divider and later to refer to any low power variable resistor. It has also been shortened to "pot".
Last edited by John Hasler on Sun Jul 08, 2018 4:13 pm, edited 1 time in total.
Magicniner
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Re: Foredom Pedal With Dumore Drill Press?

Post by Magicniner »

A potentiometer has 4 connections? :D
John Hasler
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Re: Foredom Pedal With Dumore Drill Press?

Post by John Hasler »

The instrument does, yes (unless you consider the standard cell part of the instrument, in which case it has only two).
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