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Got a 2065 that’s ailing.  In Neutral it’s fine, but as soon as it come out of Neutral its a full blown short.  It’s a new to me engine.  I am beginning to think that maybe the armature is shorted out.  What is the best way to test it?  Is there an expected resistance that one could check for?

I haven’t yanked the e-unit out yet.  It’s pretty tight in this model and I don’t want to risk breaking any wires if I can avoid it.

Also, do I you have to remove a drive wheel to get the armature out on this model?  I had the armature completely loose and couldn’t wiggle it out.  Never pulled a driver, don’t have a puller (could get one) and no experience putting it back on.

Any comments or thoughts would be appreciated.  

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noswad posted:

My next step will be to remove the e-unit.  I’ve already looked for worn insulation everywhere the wires are exposed.  

 

Hi Noswad!  You have some pretty smart train men helping you, and I don't mean me!

Why not get a bit more information before you remove and disassemble your E-Unit, possibly to no good end, and with a lot of trouble. You have to remove the motor from the body of the locomotive anyway to get at the E-Unit. So why not put the motor's wheels on a section of powered track, work the E-Unit, and watch where the short occurs? You should know right away. 

You have wires both to the smoke unit and to the head lamp leading from the E-Unit on a 2065. Check their connections and insulation Too.  Please let me know how you do.

Good luck!

Pete

There are three wires that go from the e unit to the motor.  One goes to each of the two brush holders, the third connects to one end of the motor field. The other end of the motor fields is grounded to the motor frame. Disconnect the three wires from e unit to the motor at the motor.  These most likely will have to be unsoldered.  Then take a power lead from the transformer and connect it to one motor brush holder.  Connect the second brush holder to the disconnected field lead with a jumper wire.  The frame of the motor needs to be connected to the other transformer lead. The e unit is now out of the circuit. If the motor runs, problem is probably in the eunit. If the motor acts like it is shorted, the problem is probably in the motor. 

If problem appears to be in the motor, take the brush plate off by removing two screws.  Do not loose the brushes as they may jump out. Clean out the commutator slots with a tooth pick.  Wipe the commutator clean with a clean dry cloth.  Use an ohm meter to check the resistance between each commutator segment and every other segment. This should be three measurements. All three readings should be about 1.2 ohms. Check the resistance between each commutator segment and the armature shaft.  The resistance should be very high.  Thousands of ohms or higher. If any of these test fail the armature may have to be replaced, otherwise it is good.  The resistance from the field lead to ground should be maybe 1 to 3 ohms. If resistance is very low, there is a ground in the field somewhere. If the resistance is very high there is probably a broken wire in the field. If either of these problems appear look at as much of the field as you can see and see if you can find and repair the problem. If the problem is in the field, and it can not be easily repaired, that is probably the end of the line for the motor. But that would be rare.  To replace the armature one or two wheels will have to be removed. 

I haven’t yanked the e-unit out yet.  It’s pretty tight in this model and I don’t want to risk breaking any wires if I can avoid it.

I almost always unsolder the wires before removing the e-unit.
There isn't a lot of slack in the wire from the collector assembly to the terminal on the side of the e-unit, you might not be able to remove the eunit without unsoldering that one.

Before you remove the e-unit, checking the motor, as described in the first paragraph of David Johnson's post above  would be a good idea.

Last edited by C W Burfle

Thanks for all the info.  I’ve already had the shell off and looked for obvious shorts, including under power on the track with no luck, no visible sparking.  Next step will be testing the armature.  I know it’s the least likely but it is also the easiest, least destructive move for now.  More later. Thanks again to all who posted. 

If you have gator jumper wires, going to neutral and powering the motor via jumper wire would also point at the e unit if she runs jumped. Balance of an armature plates readings is more important than the exact ohms themselves though they can burn evenly too. The ohms would be more about torques & rpm per volts. With a bad armature normally one pole shorts to buried windings(offset reading), or cold shorts(0 ohm), or to the shaft. Be gentle on the wire in the armature gaps; I prefer a stiff brush but a toothpick works ok. Wipe brushes well of oils and clean tube walls. Spring pressure is important for good contact. Pressure vs resistance is proportional to all connections.

I forgot about the request.... Thanks Chuck.

Because there may be a short, keep the test connections off and connect as fast as possible; like just brush the wire to ground vs clip till you can tell if she wants to turn or not.

There are only a few correct ways to wire a motor.  Incorrect and it usually just won't work, no damage(knock knock)The possibility of a short always makes me more cautious, logical or not

OK guys.  I think I know what is wrong, but would like some of you to hear what I found and see if you support my conclusion.

I popped the e-unit open.  The drum was a little dirty, but there is NO sign of any arcing or heat damage what so ever.  There is no sign of arcing or heat damage in any of the wiring. 

I measured the resistance of the field windings from the e-unit finger to ground and got around 3 ohms (my meter isn't supper accurate, I suspect it needs new batteries). 

Then I measured the resistance between one of the brush holders and the armature shaft while I rotated the armature by moving the drive wheels.  For some of the rotation of the armature (like maybe 100 degrees - just guessing as I couldn't actually see the armature) it varied between 2-8 ohms.  For the remaining 200+ degrees it measured open circuit.  I think this tells me that one or more of the armature windings has shorted to the shaft, and therefore to ground.

I think I need a new armature?  Opinions please.

It sounds like you left the motor wired to the e-unit. If so, seeing 2-8 ohms between a brush holder and ground might be ok. Seeing open circuit for part of a revolution of the armature is not. You may have an open coil.

If a winding was shorted to the shaft or ground, you would see zero ohms.

Retest by removing the brushplate and recheck by touching your probes to each individual commutator segment in pairs and each one against the shaft. Each pair should be about the same. Each segment against the shaft should be infinite ohms (open).

Unfortunately, if your armature is bad, some of the wheels will need go be pulled to remove it.

CW, the e-unit was totally dis assembled so all the wires coming into it were not connected to anything.  

And, I misspoke in that the 200 degree reading was in fact 0 ohms.  I mistakenly reported that as open circuit.   Sorry about that confusion.  I know better.  

I hope that makes things clearer?

 

CW, I appreciate your patience and advice .

OK, now I have super confused things.  I’m using a digital ohm meter and it reports 0F on open circuit.  When I cross the ohm meter leads it reads 0.001 ohms.  So to try again,

e-unit was dis assembled so all leads into it were dead ends. 

Measuring from a brush holder to shaft (ground) was 2-8 ohms for at least 1 commutator, and open circuit for the other 2 commutators.

 

As several posts have stated. You really need to check the armature directly. That is, with the brush plate removed.
You should also clean the copper segments of the commutator plate. I have seen plates so dirty that no reading could be taken. (and clean out the gunk between the segments)
As I have already written, use your probes to check pairs of segments. One on each segment. There are three combinations. All three should get about the same reading.
Then check each segment against the shaft. Again there are three tests. Each test should get no reading. (There should be no continuity).

As far as meters go: I like my analog meters. There isn't ever any confusion about the readings. I have an inexpensive digital meter, I think it was recommended here. Don't really care for it. It seems to hunt for the correct value quite a bit.

Last edited by C W Burfle

Well, I'm pretty sure I'm beating this one to death.  I don't fully trust my ohm meter.  I think that one of the leads may be slightly loose?  That said, I did remove the brush plate and measure the resistance between pairs of commutators.  Got around 2 ohms on each or the 3 pairs.  Then from each commutator to the shaft.  All 3 were open.  So, maybe I'm barking up the wrong tree with the armature. 

Next I'm going to physically remove the e-unit completely and jump the motor and see what happens.  That may take a few days as I'm waiting for a new soldering station to arrive.  Then if the motor runs I'll start digging around in the wiring and the e-unit.  I had the e-unit fully apart and it looked OK but . . . perhaps not. 

Thank you all for your kind, generous and knowledgeable inputs.  This is a great forum.  I have used it for problems several times and always received top notch input.  When I get more information I'll post again.

They sell just the leads.   I often make or repair my own leads too. The tip may screw out of the handle to access the connection, and Banana plugs often fit the sockets to replace molded ones oone to crap.  The meter sockets are semi-universal, only a few variations are usually used, gaurded and ungaurded male portion is the norm. gaurds trim away easy.

I'm glad you decided to pull the plate, my posts backing the other requests seem to have failed. 

When some digital meters hunt, going blank is a norm. I avoid those, always testing before I buy. Others are just that sensitive; static from introducing sunlight suddenly even showed on a nice Fluke I once had . And some can have stablized readings, peak holds, zeroing, inductive reads(no leads, a wrap instead), logic, capacitor, transistor, and diode check sockets and other cool features. I bet you could drop a grand easy on a really good one now.

  But the low buck units often work out fine with some minor human logic thrown in.  ".00-whatever" is more normal than 0.0000". It's often just the meter measuring the leads and/or connection resistance.  I think I paid $60 for an old Sears Craftsman unit I use most.

First check your field coil, look for a short to the plates/chassis/etc., then jump it.... wipe your brushes very clean, clean, inspect underside of plate, that the armature shines, etc  (pencil erasers was a decent cleaning method not mentioned that polishes well.)

It's an electro magnet. A caveman approach is metal being drawn to it. isolate the field. 12v to the field and a nut/nail on a string near the inner radius, (or steel keys on a ring, etc) and they will be attracted and swing out of plumb; "defying gravity" ( ? weak? fair? ferris hrdwr?) or pulling like mad (definitely good) (works on a cars alternator too )

  Sliding the tip acoss it's magnitized plates the right way can create a homemade magnetic screwdiver vs the pendulum way if your bored and want to play with the magnet, or just need one, or just can settle for feeling the pull by hand  

I make my own leads too. I picked up spools of quality test lead wire years ago, and have a supply of banana plugs and test clips. My favorite analog meter is the Simpson 260.

That is a model that has been on the market many years and has undergone lots of revisions. The oldest ones that I am familiar with have pin jacks. Then they went to banana jacks. The newest model I own uses reverse banana plugs. I haven't made any leads fot that one.

The meter I have out for daily use has banana jacks.

Gee CW, what kinda tech dinosaur would still have anything to do with equipment that old? You cant even jam a loose piece of wire in a pin socket half the time. I finally broke my original common pin just recently.IMG_20180825_232926~3

With 'nanas you can often fold the stripped wire at the bad plug end back over the insulation and cram it in the socket to continue in a pinch.

Would you like any/many pictures of the manual CW?

Last it got professionally calibrated for work was in 1990. But the previous paperwork comments just read "in tolerance", so I don't think a thing has been swapped out or adjusted internally before I got it either. Dead on till I'm dead is likely

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Would you like any/many pictures of the manual CW?

Thanks, I have a manual.
I also have a set of the "add-a-tester" adapters that attach to the bottom of the meter to expand the functionality.

It's my impression that the 260 is still being made.
I read somewhere that there are certain applications where an analog meter is preferable. But that was some time ago. Maybe whatever those applications were, today's digital can do it.

There are usually lots of 260's on EBay, should anybody want to pick one up.
I've paid as little as $5.00 for one at Estate sales / flea markets on more than one occasion.

Yea, once you know the needles sweep rate I guess you can notice rates ramping up/down but I'm not super clear when or to what it might be applied to today other than maybe logics, where general variables aren't seen as clear. E.g. with analog, & say, a shark fin wave,  you could more easily note a  ramping difference or the greater side of the curve being at the begining or end of a wave cycle, than watching the rate of digital numbers changing on screen.....like an osiliscope with just a dot, no wave trail, & no frequency controls; the eye and brain fill in some missing action info while watching.

An analog curve is always better. A digital version isn't really a curve, but a whole lot of short straight lines that aproximate a curve. Thats why many audiophiles usually returned to analog recordings after a fling with CDs. The strentgh in digital was noise reduction was easier and it is a cheaper process for the media industry to use.  I.e., the industry tricked us with showy but inferior tech in ways (that count for sound) and we bought it hook, line, and sinker, with us paying more for the privilege too, lol.

 Had we bought into the 64b rate vs 32b rate our general music quality would be twice as good...but still not an analogs equal. Frank Zappa and some others tried their hardest to get us to buy and demand the 64b quality as a minimum. But would we listen?.. Noooo-ooo! It was the 80s, the rebirth as Ummmm-erica and full embracing of the cheapest tossable was well in hand... Man do I miss real quality built into my stuff.. like some original versions of music, NOT the remastered versions. (some changed things to make the best out of what 32b digital could actually reproduce well and dropping levels on what it couldn't; the ambiance was lost in some conversions imo.)  The first CDs I bought were 64b... then they vanished except for special production disks pushed out by certain artists. I had found about 20 discs total I've wanted in 64b... just 2 drops a big bucket.

Lol, then came MP3 for another hit to quality in the name of tech...sigh..

  I'm pretty sure even some of our trains sounds can be heard at a 64b now to give an idea what we COULD be using daily elsewhere if we had any sense.  Thank god this is a republic or we might be even worse off

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