Need wiring diagram for electric drill

[David Nebenzahl]

This is so simple, I feel kind of foolish posting it, but here goes:

I need a wiring diagram for my garden-variety 3/8" variable-speed reversible drill. (It happens to be a Craftsman, but is the same as hundreds of other similar tools.)

Years (decades, actually) ago I replaced the speed control which I got from Sears. The drill has worked since, but not correctly, so evidently I screwed up when I put it back together. I think I had to resolder some wires to the reversing switch, which is where I think the problem is.

Here's the deal: it works, but not like it used to. At slow speeds, it feels like it's "chugging" or cogging. No sparks from the brushes. At medium speeds it runs a little smoother with minimal sparking, about what you'd expect. At high speed, it runs with a lot of sparking, more than it should.

The commutator is in good condition: I cleaned it and scraped out all the built-up crap between the contact bars. Brushes are in good shape. Field and armature coils are all good (tested with ohmmeter).

So I'd sure appreciate it if someone could post a (link to) a wiring diagram for this tool. Like I said, any similar variable-speed reversible consumer-quality drill will do.

Please resist the urge to post if you want to tell me

• to buy a new tool (this is my favorite drill)

• I ought to learn a whole lot more about electricity

• I should leave this kind of repair to "professionals"

• I should have noted the wiring when I first opened it up.

[buffalobill]

[David Nebenzahl]

buffalobill spake thus:

Further info: the drill is wired so that the field and armature are in series. (The reversing switch flips the polarity of the armature with respect to the field.) Is this typically the way these drills work?

[tom________]

Just buy another drill. They're cheap.

If you insist on doing this repair, you really should learn more about electricity before you tackle the job. You could be electrocuted. Spend the winter going to a technical college. Since you obviously lack that knowledge, dont touch it until you get an education on electricity. Otherwise, take it to a professional repair shop, but be prepared to pay more than the worth of the drill. But you reap what you sow. If you had left the pros do the job in the first place, or at least labelled the wires, you would not have this problem now. I hope you learned from this mistake.

If by chance you figured out how to procreate, you could always send the drill to your sons Junior High School for their electricity classes. They'll take it apart, learn from it, and then repair it for you. (for free).

Tom

---------

[buffalobill]

[HeyBub]

Why buy another? It's a Craftsman. Take it back to Sears and they'll replace it.

[dpb]

David Nebenzahl wrote: ...

If it runs and variable speed is functional, it isn't a simple wiring problem. The spitzen-sparken and erratic running at low speed is indicative of the brushes not fitting correctly. I'd hazard a guess the combination of "cleaning" the commutator and perhaps turning the brushes around or otherwise getting them mis-aligned is the primary problem...

[krw]

The Craftsman "lifetime warranty" is only on hand tools. Read the information that comes with the power tools and you'll find the warranty more like a year.

Buy another, but not from Sears.

[David Nebenzahl]

dpb spake thus:

Then you'd guess wrong.

Reread my original post. The drill runs without *any* sparking at low speeds. At medium speed it runs with the normal amount of sparking expected from such a motor. The brushes are clean and fit the commutator well. It only sparks at high speed.

At this point, my question is a simple one. I direct this to ANYONE WHO ACTUALLY KNOWS THE ANSWER AND CAN GIVE IT MINUS A LECTURE ON LEARNING BASIC ELECTRICAL PRINCIPLES (which I do know):

Are drills like these wired with the field and armature in series (as it is now) or in parallel? Simple question. (Sorry for shouting above!)

[David Nebenzahl]

buffalobill spake thus:

[propman]

David Nebenzahl wrote in news:4571ce59$0$5806 $ [e-mail]:

And maybe you should check what you originally wrote in your initial request...to whit:

"So I'd sure appreciate it if someone could post a (link to) a wiring diagram for this tool. Like I said, any similar variable-speed reversible consumer-quality drill will do."

Seems to me that his site referal fufills the second statement........ :-)

[David Nebenzahl]

propman spake thus:

You meant to type "to wit", no?

Have you checked either of the sites he sent links to? Neither has wiring diagrams for *anything*. I checked. Nada. Zip.

Lots of exploded parts diagrams, though.

[buffalobill]

[Charlie Morgan]

Beggars can't be choosers, and your behavior does not inspire anyone knowlegeable to help you. Next time you want to ask a question on usenet, I suggest that you don't tell people whjat answers are unacceptable, and thank everyone who makes an attempt to help you whether the information is helpful to you or not.

CWM

[dpb]

...

It also runs (as the _retained_ quote _from_ your original post shows) poorly. A very good description, in fact of what poorly fitting brushes or damaged/rough commutator edges act like.

Was simply trying to point out an area that seems more likely than miswiring, but if you know better then fix it as you see fit.

...

Then you obviously must know how motors work and have the answer to your question available by applying same.

[David Nebenzahl]

dpb spake thus:

I know how motors like this work *in general*, but obviously I don't know this specific detail--whether the field & armature should be connected in series or parallel. That's why I asked the question. If you know the answer, it would be appreciated.

[Rick]

Google "universal motors"...

[propman]

David Nebenzahl wrote in news:457240a3$0$5782 $ [e-mail]:

$5806

Nope.........asshole!

statement........

Wrong again, asshole.......it clearly shows wiring DIAGRAMS.......if you want the SCHEMATIC then you should have asked for the SCHEMATIC!

Take your f****ng attitude and shove it where the sun don't shine.........

[David Nebenzahl]

propman spake thus:

What's the problem--got a low threshold? off your meds?

[Camperken]

MOST power tool motors are wired in series. Heavy sparking at high speed is indicative of bad brushes or loose comutator bars, One loose commutator bar will not have to move much at the speed these armatures rotate to cause arcing.

John Normile