What is in the black box, anyway?

So,

Long story short, the 18v right angle grinder stopped working, but bypassing the silver electronics module started the motor right up.

Therefore, what does that thing do?

I am guessing that some refer to a clutch in the tool, and not seeing one, the box may sense a near stall condition and lock out.

Thoughts?

WOW! Talk about a great conversation starter!!!! I wish I could help but when I saw the post my mind went to that dark place…. 😛

This guy tears down power tools and post on how the exactly work https://www.youtube.com/watch?v=NRxFn96XjOI&list=UUhWv6Pn_zP0rI6lgGt3MyfA It’s a really good youtube channel its worth subscribing.

Chris,

I’ve seen the one you describe. NO one will ever figure out how to make that one do your bidding… LOL 🙂

DR99,

Thanks for the link. I’ll buzz over there momentarily.

Shawn

Well,

No dice on the videos. The ones I saw, he was tearing down variable speed tools. This one has on and off.

I’ll keep looking, though!

Shawn

I’m talking out my ass here, but I’m guessing it’s probably overload circuitry. Have you tried to get it to cut out since you bypassed it?

It’s Pandora’s box, u do not wanna open that thing

LOL!

I think at some point I’ll pour some de-potter in there and see what they hid.

For now, though, it works just fine absent the magic box. Granted, I haven’t tried to cut 3/8″ steel plate with it, but I don’t envision that thing for that kind of work. Makes small quick cuts fine, no load sounds right and doesn’t overheat it. I dunno.

I am going to see if I can upload some of the pics I took to save you the trouble of breaking yours open… stand by

Ok,

well, there it is in all it’s naked glory!

It takes a Torx with the center hole (sorry, I forget the size) in every position EXCEPT the lower one in the base. It is one size smaller. Why? Who knows, but it certainly was frustrating!

To split it, you bust out all the handle screws, then the four screws in the angle head that point into the handle. These are tricky. Then pull the angle head off. The clamshell will then seperate fairly easily and nothing will pop out.

Be very careful, if you yank the brush holder off, you’ll need a pencil or something similar to depress the brushes to reinstall them.

Whatever that box does, it affects the ground side. I simply cut the box out of the circuit path, extended the black wire, and put it where the box terminated into the switch.

Now, on the newest Milwaukees, there is current needed on more than one terminal. I do not know which other terminals it is. I suspect there is a signal path for a temperature sensor buried in the lithium pack you’re supposed to use, but with the way mine is set up, I can’t advise.

Because that box is removed, you probably should be careful about duty cycle. That thing might prevent you from burning it up by too much torque (really getting into a cut or brushing) or running it too long without cooldown periods.

All I know, and my small contribution to this site!

Shawn

Not sure if this is the right diagram

http://www.ereplacementparts.com/milwaukee-268020-ser-b96a-cordless-volt-41234-cutoffgrinder-parts-c-131_4779_16337.html

electronics module assembly?  No Idea what it does.

Thanks for sharing, interesting view of guts

Yeah, that’s it. T20 Torx sounds right, too. I’m certain it does <i>something</i>, but outside of stall or lithium battery management, I couldn’t say.

Q; What’s in the Black Box?

A: If you have to ask you can’t afford it. 

Thanks for the follow up!

ChrisK1970 wrote:

WOW! Talk about a great conversation starter!!!! I wish I could help but when I saw the post my mind went to that dark place…. 😛

Do you know how a bottle blond is like a commercial airliner? They both have black boxes.

is this on the fuel or regular brushed? I wonder with their “new” fuel powerplant if the situation would be different, maybe it is something with overheating….unless ofcourse it remained the same after a cool down period?