Reversing power drill’s rotation

Thread Starter

colhane

Joined Mar 2, 2023
7
I need help reversing my power drill’s rotation. I have installed a 6 pin switch which reverses the brush leaves for forward and reverse respectively. The problem is reverse is considerably slower in RPMs than forward and the upper of the two brushes is throwing green Sparks. I have checked to make sure the lead is not rubbing on anything. Can anyone help what have I done wrong?
 

MisterBill2

Joined Jan 23, 2018
19,466
Two possibilities, the first being that something is accidentally tied to the frame , causing a short circuit. The other possible cause is that the brushes are not positioned for optimum running in both directions. And there is a third possible cause, a wiring error excluding one of the field coils.
 

MaxHeadRoom

Joined Jul 18, 2013
28,830
Power drills come in two varieties, PM field for portable devices, and wound field for AC series Universal (mains) type motors, what do you have?
It is odd that it does not have reverse built in? All the drills of the above types I own are reversible? :(
 

MisterBill2

Joined Jan 23, 2018
19,466
If the TS has access to an ohm meter that has a low resistance scale then I suggest measuring the resistance between the mains plug pins with the trigger pulled to the on position. The resistance should be the same with the direction switch in either position. And check the resistance from either pin to the third pin, the ground pin. It should indicate an open circuit in all cases.

One more guess is that the brushes and commutator are quite worn, and have problems running in the opposite direction.
 

MaxHeadRoom

Joined Jul 18, 2013
28,830
We don't know the motor technology at this point, other than it has brushes, i.e. cordless/battery operated/mains etc?
A make/model would also be handy.
 

Thread Starter

colhane

Joined Mar 2, 2023
7
Power drills come in two varieties, PM field for portable devices, and wound field for AC series Universal (mains) type motors, what do you have?
It is odd that it does not have reverse built in? All the drills of the above types I own are reversible? :(
IMG_20230303_103551154.jpgI got this drill from my grandfather back in the '80s he was a machinist.
 

MaxHeadRoom

Joined Jul 18, 2013
28,830
Oh, one of the first of its kind, I can see why no reverse! o_O
There could be some issue with the GB not able to rotate as easily as in FWD?
 

Thread Starter

colhane

Joined Mar 2, 2023
7
Oh, one of the first of its kind, I can see why no reverse! o_O
It is strange that there is no reverse I never asked my grandfather why. But it does make it difficult because I assemble and disassemble many projects here at my shop. Thanks for your input
 

Lo_volt

Joined Apr 3, 2014
323
View attachment 288834I got this drill from my grandfather back in the '80s he was a machinist.
That's pretty cool. I have a similar vintage Milwaukee "Hole Shooter" drill that my uncle left behind. They're not meant to run in reverse. I use mine strictly for drilling. It's also single speed. When I got it, the cord was in pretty crappy shape and had only hot and neutral but no ground. I replaced it with a bright orange cord and grounded the case.
 

MaxHeadRoom

Joined Jul 18, 2013
28,830
I got this drill from my grandfather back in the '80s he was a machinist.
I am guessing that model dates alot earlier than the '80's!
I had a B&D drill in the UK in the 80's and it looked a lot more modern than that one, also had reverse.
Looks more like the early 60's.
 

MisterBill2

Joined Jan 23, 2018
19,466
Unless used in a Industrial arena, the typical home use drill never ever gets to that point as a rule.
Not in my many decades of owning them anyway. :cool:
I have worn out two of them, Max. One was used when I got it, though. I have worn out three electric (mains powered) mowers. But I have never cut a mower cord.
 

Thread Starter

colhane

Joined Mar 2, 2023
7
Two possibilities, the first being that something is accidentally tied to the frame , causing a short circuit. The other possible cause is that the brushes are not positioned for optimum running in both directions. And there is a third possible cause, a wiring error excluding one of the field coils.
Can you tell me more about your second possibility? (angle of brushes)
I was unaware the angle would be different for forward and reverse operation.
 

Thread Starter

colhane

Joined Mar 2, 2023
7
Unless used in a Industrial arena, the typical home use drill never ever gets to that point as a rule.
Not in my many decades of owning them anyway. :cool:
I have been using the drill without incident. I inspected the brushes and commutator as per your advice. Both are in good shape. I have since replaced the cord which was not as bad as it appeared
The RPM issue has since become less apparent, but the difference in spark color on upper and lower brush still has me puzzled.
 

Thread Starter

colhane

Joined Mar 2, 2023
7
I have worn out two of them, Max. One was used when I got it, though. I have worn out three electric (mains powered) mowers. But I have never cut a mower cord.
I dug this drill out of the bottom of my tool box out of necessity! My cordless drill bit the dust.
 

Thread Starter

colhane

Joined Mar 2, 2023
7
That's pretty cool. I have a similar vintage Milwaukee "Hole Shooter" drill that my uncle left behind. They're not meant to run in reverse. I use mine strictly for drilling. It's also single speed. When I got it, the cord was in pretty crappy shape and had only hot and neutral but no ground. I replaced it with a bright orange cord and grounded the case.
Thank you for your kind words. I have since replaced the cord.
I agree that this drill was never ment to run in reverse. I only put it into operation out of necessity! My cordless DeWalt bit the dust.
 
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