Milwaukee Mag Drill Help

[bartels_metal_works]

I am in need of help with my old mag drill. It is a Milwaukee 4231, with a Milwaukee 4262-1 3/4" Drill. I bought this for a song a while back, but knew it had an electrical issue. It appears to just need a "rectifier assembly" (23-38-2760), but it has been long since discontinued and I can't find any old stock either. It is extremely simple, but I need the values of the 3 components. I believe it has 2 diodes and a disc resistor. Mine only has the leads, but the components are missing.

If you have one of these old mag drills, and are willing to take some pictures of the wiring on the back of the button plate, I would greatly appreciate it!

 

[Zebu Fellenz]

I might be able to help you out. Is the button plate on your mag drill (F/N/R for the drill motor) and (Off/On/Lock for the magnet)? Single speed?

 

[bartels_metal_works]

I might be able to help you out. Is the button plate on your mag drill (F/N/R for the drill motor) and (Off/On/Lock for the magnet)? Single speed?

Thank you for your willingness to help me, I really do appreciate it. Here is a picture of the controls on my drill.

 

[Zebu Fellenz]

Thank you for your willingness to help me, I really do appreciate it. Here is a picture of the controls on my drill.

I think we have the same control. I'll pop the cover off mine and get you a picture, probably will be tomorrow night before I get a chance.

-Cheers

 

[bartels_metal_works]

I think we have the same control. I'll pop the cover off mine and get you a picture, probably will be tomorrow night before I get a chance.

-Cheers

That would be fantastic, thanks! Hopefully there are legible markings on the diodes and resistor.

 

[captaindiode]

I don't think that is a resistor. It looks like it could be a disc capacitor, a MOV, or some type of PTC thermistor. I have never seen a resistor in that type of package.

 

[bartels_metal_works]

I don't think that is a resistor. It looks like it could be a disc capacitor, a MOV, or some type of PTC thermistor. I have never seen a resistor in that type of package.

I was only taking an educated guess, to be honest. I believe this is a half wave rectifier, so going off the generic diagrams I have found, it appears to be a resistor. When I searched for "disc resistor", I guess I was seeing varistors and thermistors (which if I understand correctly, are forms of resistors). I may also be talking out my hind-end...

 

[BukitCase]

This
https://www.google.com/imgres?imgur...YjlAhWOvp4KHRvmAPcQMwh8KAswCw&iact=mrc&uact=8

is more likely what you have - doesn't help with YOUR actual values, but what's labeled Rl may be replaced with the inductance of the mag coil - that would work with that small a capacitor to smooth out the peaks of that (FULL wave, but not Bridge) rectifier.

If that's what they did, the cap value needs to be known but nearly ANY diode that's big enough NOT to burn up could be subbed (provided it FITS physically)... Steve

 

[Zebu Fellenz]

I was only taking an educated guess, to be honest. I believe this is a half wave rectifier, so going off the generic diagrams I have found, it appears to be a resistor. When I searched for "disc resistor", I guess I was seeing varistors and thermistors (which if I understand correctly, are forms of resistors). I may also be talking out my hind-end...

Got the cover off and took some pictures. Hopefully the link works for you.

https://photos.app.goo.gl/t3FVsGh9pz9bfyAm7

 

[bartels_metal_works]

Got the cover off and took some pictures. Hopefully the link works for you.

https://photos.app.goo.gl/t3FVsGh9pz9bfyAm7

Holy damn batman, that is EXACTLY what I needed! I was able to get the part numbers I need to proceed, but that varistor sure is a pain in the *** to find... I can't find a single datasheet for that exact part. By logo, it was made by Matsushita which is now Panasonic. Parts are on order!

Thank you to all that replied, you took time out of your day to help me and I truly appreciate it!

Nick

 

[captaindiode]

The MOV appears to cross to NTE2V130 if it is 14mm in diameter or less. If it is 20mm it crosses to NTE524V13.

 

[bartels_metal_works]

I ended up ordering the Panasonic ERZ-V14D201.

 

[Zebu Fellenz]

Holy damn batman, that is EXACTLY what I needed! I was able to get the part numbers I need to proceed, but that varistor sure is a pain in the *** to find... I can't find a single datasheet for that exact part. By logo, it was made by Matsushita which is now Panasonic. Parts are on order!

Thank you to all that replied, you took time out of your day to help me and I truly appreciate it!

Nick

Happy to help, let us know if you get it working when the new parts arrive. Good luck!

 

[bartels_metal_works]

Well, the mag drill lives again! It still needs a good cleaning and a handful of replacement parts, but at least the magnet and drill both work. Thanks again for the assistance.

Nick

 

[GMC]

Glad to hear the drill works again. My father is trying to replace the same part, would you happen to have the specifications for the diodes you used?

-Matthew

 

[sthompsn]

I know this is a very old thread. However, it is the best information I have found. A coworker has the same 4231 Drill that he is rebuilding, and it suffered a catastrophic electrical event. The Magnetic Base Switch is toast and no longer available as far as we can tell.

I am trying to design an alternative, but because the Switch is so badly damaged I can't tell which Contacts were closed/open in the three positions.

Does anyone have a operational schematic of the Magnetic Base Switch operation or no where to get one ? Thanks for any help.