Merry Christmas everyone! My 2037 is acting up. I recently went through the motor (cleaned & new brushes/springs) and disassembled the e-unit (cleaned & polished drum, contact fingers, and plunger). The loco runs great & smokes terrific. The e-unit cycles perfectly until the loco is run for a couple of minutes then it won’t even buzz. If I let it sit for, say, an hour or so it might work fine or still not even make a sound. I can get the drum to change by turning the loco upside down so I don’t think the problem is mechanical.
I took the shell off & set the motor on my test track & of course it worked just fine. Tried tweaking the wires and nothing appears to be loose, though I suppose I could have a poor solder joint somewhere. Could the e-unit coil be going bad or is that something that either works or doesn’t work?
I’m having problems with three of those old e-units. On my 2035 steam locomotive, sometimes it sticks in reverse, sometimes it works ,sometimes the engine just buzzes. When that happens it kicks in if I switch the e-unit off, then back on. The one on the old 1110 does the same thing. Lubricating the drum on my 601 diesel seems to have fixed it.
These things are so old, I’m considering taking mine to a pro to have the locomotives refurbished.
I know there are others out there who know a whole lot more about these units. Good luck.
It may be that there is a break in the coil that is sensitive to heat. But there is also a possible mechanical problem. The next time it happens, shut off the power and give the locomotive a good whack on the top with your hand. If that gets it to step, I’ll give you the details of a fix.
Bob, I got a chance to try your suggestion today…a good “whack” was all it needed.[bow] I actually got to try this method twice and it worked both times. Please share your “Fix” details.
For the life of me I cant remember the fix. But Iam willing to bet Bob is going to say the plunger is magnatized. And I would have to say he is correct. He will be on sooner or later with the fix.
What happens is that the mechanism sticks in the upper position, even after the coil is shut off. Whacking it knocks it loose.
Some folks believe that the sticking is due to the e-unit’s becoming permanently magnetized. This seems to me very unlikely, since the demagnetizing process is to put the object in a strong alternating magnetic field which is then gradually reduced to zero. Because the e-unit coil is an electromagnet, this means that you are demagnetizing it every time you use it. Another clue is that they don’t stick on DC operation any more than on AC.
I believe that the sticking is mechanical. If you were to examine the drum, you might find at the crotches between the teeth, notches worn by the tip of the pawl as it pulls upward to turn the drum. If you are careful, you can smooth these out with a narrow wood chisel without disassembling the e-unit. Scrape toward the crotch along the long back side of each tooth until it is smooth.
I recently discovered what I think is another problem area. There is a tang on the top side of the pawl which limits its upward travel. It digs into the surface that it hits and roughens it up. I tried putting a small brass cover on the tang. It is a piece of 5/32-inch tubing about 3/16-inch long. I slit it along one side with a razor saw, opened it a little, and filed a V into the end of the slit to ease it onto the tang. I disassambled the e-unit but think it could probably have been installed with small long-nosed pliers. To immobilize the tube for slitting, I put a length of 16 AWG wire through it and clamped the ends of the wire in a vise with the tube pulled down against the top of the vise jaws. I straightened the bend in the middle of the pawl somewhat to compensate for the change in its angle due to the tube.
Adding to Lionelsoni’s comments, I have occasionally found the part of the pawl that engages the drum will have a burr which may be the cause of (or exacerbates) the wear he describes. I routinely check that whenever I find a worn drum and smooth it up as needed. I tend to agree with Bob regarding the “magnetized plunger”; I think it is nonsense. Cleaning up the “crotch” has worked for me 100% of the time, but maybe I’ve just been lucky. Also, try to salvage the original drum whenever possible as the repro drums available these days are mostly crap (but that’s another story)
Had a chance to do some investigating today. I took the e-unit out of the motor frame, leaving the wiring intact. Holding the e-unit upright to simulate running conditions, I “grounded” the unit & touched the the other wire from my test transformer to the loco roller. If I apply/remove power quickly it works perfectly. However, if I apply power & leave it (simulating the loco running?), within 5 to 10 seconds the buzzing will cease. Now when the power is removed, the plunger/pawl is stuck & does not drop down.
Maybe the “quieting” is normal [%-)] but I’m trying to provide any clues I can. Also could be that the quick bursts don’t allow the pawl to embed itself into the "crotch"and get stuck. Regardless, it looks like it is coming back apart to check the pawl & clean up the drum. Thanks guys!
I think I found the problem & you were right Bob, it was mechanical. After disassembling the unit & checking for burrs, smoothing the “crotches” on the drum, cleaning the coil sleeve & plunger assembly,and putting it all back together, the plunger was still sticking.
It seems that the plunger/pawl assembly was binding. I could predict the bind when testing since the e-unit would always get quiet. I surmise that when the plunger jams the clearance in the coil sleeve is gone & thus no vibration. If I shut off the power & tweaked e-unit frame a little, the plunger would free up & drop down.
I decided to try a plunger assembly from a spare unit & this seems to have solved the problem. It feels a bit looser than the other one did, too. Not sure if the problem plunger was original or a repro since it came with a used motor that I picked up. However, the pawl is different from all the others in my locos. There is a tiny hole stamped (or drilled) in the pawl just below the bend. All the others I have are solid.