Hi Dan:
Thanks for the close up pictures of the gap filling process. Every bit helps.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
If anyone is still following this, I just did another one of these mods tonight on a motor, just to see if I remembered everything correctly.
Work over a clean shallow box or lid. Don't lose the thrust washers:
Note, It is difficult to get the commutator end of the motor back in place. It just is. Make sure the motor frame isn't bent outward before you go to assemble. Also, yes, dipping the end of the plastic into a dab of superglue will be needed. The plastic wont stay in there without it. When superglued in, it only takes a dab on the end, it is strong. Here I am actually holding the whole motor by the plastic slip in the fingernail cutters that I'm about to snip with. Look closely, you can see the plastic sticking out of the commutator. That, you have to carve down to below the surface of the coppers, as I 'splain below the picture. Also, When it's all back together, you actually have to get the surface if the plastic slip just below the surface of the copper. Otherwise when the motor stops with the brush on the plastic, it wont start. I did this by using the point of a #11 blade and scraping it along the gap until the plastic is below. Tuning is time consuming!. It takes patience, and bench running and stop-start-stop-start until you're finally sure you got it. The way to tell which gap is not correct is when the motor stops and wont restart, it's the gap UNDER one of the brushes... the other 2 gaps will be visible. Lightly scrape away at the gap some, and keep tuning. This is not an anyone-can-do-it remedy. I think this procedure is for those who don't mind spending the time to get a locomotive running even when there are better locos to be had, who enjoy the challenge of "micro surgery" and know there's the risk of botching a motor. Like some hard core critter fans...
Note, It is difficult to get the commutator end of the motor back in place. It just is. Make sure the motor frame isn't bent outward before you go to assemble.
Also, yes, dipping the end of the plastic into a dab of superglue will be needed. The plastic wont stay in there without it.
When superglued in, it only takes a dab on the end, it is strong. Here I am actually holding the whole motor by the plastic slip in the fingernail cutters that I'm about to snip with. Look closely, you can see the plastic sticking out of the commutator. That, you have to carve down to below the surface of the coppers, as I 'splain below the picture. Also, When it's all back together, you actually have to get the surface if the plastic slip just below the surface of the copper. Otherwise when the motor stops with the brush on the plastic, it wont start. I did this by using the point of a #11 blade and scraping it along the gap until the plastic is below. Tuning is time consuming!. It takes patience, and bench running and stop-start-stop-start until you're finally sure you got it. The way to tell which gap is not correct is when the motor stops and wont restart, it's the gap UNDER one of the brushes... the other 2 gaps will be visible. Lightly scrape away at the gap some, and keep tuning. This is not an anyone-can-do-it remedy. I think this procedure is for those who don't mind spending the time to get a locomotive running even when there are better locos to be had, who enjoy the challenge of "micro surgery" and know there's the risk of botching a motor. Like some hard core critter fans...
When superglued in, it only takes a dab on the end, it is strong. Here I am actually holding the whole motor by the plastic slip in the fingernail cutters that I'm about to snip with.
Look closely, you can see the plastic sticking out of the commutator. That, you have to carve down to below the surface of the coppers, as I 'splain below the picture. Also, When it's all back together, you actually have to get the surface if the plastic slip just below the surface of the copper. Otherwise when the motor stops with the brush on the plastic, it wont start. I did this by using the point of a #11 blade and scraping it along the gap until the plastic is below. Tuning is time consuming!. It takes patience, and bench running and stop-start-stop-start until you're finally sure you got it. The way to tell which gap is not correct is when the motor stops and wont restart, it's the gap UNDER one of the brushes... the other 2 gaps will be visible. Lightly scrape away at the gap some, and keep tuning. This is not an anyone-can-do-it remedy. I think this procedure is for those who don't mind spending the time to get a locomotive running even when there are better locos to be had, who enjoy the challenge of "micro surgery" and know there's the risk of botching a motor. Like some hard core critter fans...
Look closely, you can see the plastic sticking out of the commutator. That, you have to carve down to below the surface of the coppers, as I 'splain below the picture.
Also, When it's all back together, you actually have to get the surface if the plastic slip just below the surface of the copper. Otherwise when the motor stops with the brush on the plastic, it wont start. I did this by using the point of a #11 blade and scraping it along the gap until the plastic is below. Tuning is time consuming!. It takes patience, and bench running and stop-start-stop-start until you're finally sure you got it. The way to tell which gap is not correct is when the motor stops and wont restart, it's the gap UNDER one of the brushes... the other 2 gaps will be visible. Lightly scrape away at the gap some, and keep tuning. This is not an anyone-can-do-it remedy. I think this procedure is for those who don't mind spending the time to get a locomotive running even when there are better locos to be had, who enjoy the challenge of "micro surgery" and know there's the risk of botching a motor. Like some hard core critter fans...
Also, When it's all back together, you actually have to get the surface if the plastic slip just below the surface of the copper. Otherwise when the motor stops with the brush on the plastic, it wont start. I did this by using the point of a #11 blade and scraping it along the gap until the plastic is below.
Tuning is time consuming!. It takes patience, and bench running and stop-start-stop-start until you're finally sure you got it. The way to tell which gap is not correct is when the motor stops and wont restart, it's the gap UNDER one of the brushes... the other 2 gaps will be visible. Lightly scrape away at the gap some, and keep tuning.
This is not an anyone-can-do-it remedy. I think this procedure is for those who don't mind spending the time to get a locomotive running even when there are better locos to be had, who enjoy the challenge of "micro surgery" and know there's the risk of botching a motor. Like some hard core critter fans...
If a motor is needed, ebay and Bachmann still sells the motor with worm.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
New episode of Model Railroader: The Trouble with Critters.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Good and timely info. I am in the middle of repairing a very old verticle shaft motor from a GHC 0-4-0 Camelback. The commutaror was broken, but continuity was still there from all pieces. I managed to super glue the pieces back in place but one is slightly out of place and has a gap larger than the rest and catches the brush periodically. I will try and fill the gap and see if the problem is corrected.
George In Midcoast Maine, 'bout halfway up the Rockland branch
Dan,
Thanks for sharing this interesting and useful info.
Mike Lehman
Urbana, IL
SouthgateNow you have no 'scuses...
Yes Ricky Ricardo, uh oh sorry, yes Dan we have no 'scuses'!
I'll have to dissect another 44 tonner to get the plastic filler. I have to admit that I feel a bit guilty when I scrap a perfectly functioning locomotive but then I remind myself that it is all for a good cause, i.e. the proliferation of critters!
Kinda sounds like that Star Trek episode where they were being inundated with little fuzzy creatures. Darned if I can remember what they were called, but it was one of the less memorable episodes. I'm sure several of you will remind me of their name.
That may well have been me.
Yes, the idea is to smooth the gap, and not allow room for the carbon from the brushes to fill the gap and cause a short between the commutators.
Playing around with it now that I'm poking around in the parts stashes, I just discovered something pretty cool, too; Bachman provides the very plastic you need, already in the 44 tonner! There's a clear plastic strip between the circuit board and the cast metal frame in the top of the engine. EXACT FIT! May not need super glue, since the centrifugal force would be minute in that small of a radius. That gap is deeper than you'd think, too providing a good area of squeeze in the filler. I measured the plastic with a micrometer, .0095... Basically .010, ten thousandths.
Now you have no 'scuses... Dan
Hey Dan!
Thanks for posting this thread.
So, if I understand what you are saying, you are essentially filling the gaps between the commutators to provide a smoother running surface for the brushes. Have I got that right?
Based on your method, I thought about simply using epoxy to fill the gaps but then it dawned on me that the heat would mess with the epoxy and it wouldn't stay in place.
I seem to recall that this advice or something similar about filling the commutator gaps was posted a few years ago. Was that you?
Anyhow, thanks for the tutorial!
(edited in)I added more info in additional replies to this thread, which I think may help those who wanna try this...
By request by Mike and Dave, here's a mod I found to help the little 44 and 70 tonners with dual motors run better. And this IS about the MOTORS, not the gear problems associated with these guys.
My little locomotives were acting up, overheating and dying. I discovered that the gap between the commutator surfaces was scraping carbon off the brushes, filling the gap, and shorting.
The solution was to take (find first) a slip of plastic that will just fit that gap. I used a clear plastic from a sheet for windows. (Acetate I think.
Edited in: the clear plastic insulator between the circuit board and the cast metal frame is a perfect fit. See my reply to Daves reply below...
This motor has had it done already, I'll try to describe the procedure. I didn't take pictures when I did these, so I'll do my best.
Get your best magnifiers out! You have to take the motor apart. VERY DELICATE stuff here. First mark the top of the motor, cuz if you put it back in upside down, it'll run backwards. Also note and mark the magnets so they go back into their location and position You need to bend the brush spring retainers upward just enough to get the springs and brushes out. Take whatever precautions needed not to lose them. (if you do, I think Kadee knuckle springs work) Then you can pry the metal frames open enough to pull the commutator end out. If you have gotten this far, I'll assume you have the plastic needed to make the gap fillers. You can do that with the motor assembled. Cut a tiny slip of plastic as long as the gap, and wide enough to stick out of the gap, to hold it with tweezers. With a micro dab of superglue on the plastic, slip it into the gap. Let dry. Then with a new exacto blade carve it down to where its just even with the commutator surfaces. Then file it flat across the gap. If it can hold the brush just off the commutator surfaces at all, the motor won't run. the brushed have to be able to contact BOTH commutator pads even after the gap is filled. The plastic, and probably the superglue have filled the gap so carbon can't fill it. Even after the motor is assembled, if it stalls, you can gently scrape away at the filler to get it tuned in. Be aware, these little open frame motors can attract junk. Tiny chips get stuck on the magnets and the armature cores and cause mechanical binding, so work clean and check for chips during the whole process. Dont forget a little dab of Labelle oil on the bearings too. Hope this helps. Having seen what you two; Dave and Mike, who requested this info have done, I think you can handle it.
Get your best magnifiers out!
You have to take the motor apart. VERY DELICATE stuff here. First mark the top of the motor, cuz if you put it back in upside down, it'll run backwards. Also note and mark the magnets so they go back into their location and position
You need to bend the brush spring retainers upward just enough to get the springs and brushes out. Take whatever precautions needed not to lose them. (if you do, I think Kadee knuckle springs work) Then you can pry the metal frames open enough to pull the commutator end out. If you have gotten this far, I'll assume you have the plastic needed to make the gap fillers. You can do that with the motor assembled. Cut a tiny slip of plastic as long as the gap, and wide enough to stick out of the gap, to hold it with tweezers. With a micro dab of superglue on the plastic, slip it into the gap. Let dry. Then with a new exacto blade carve it down to where its just even with the commutator surfaces. Then file it flat across the gap. If it can hold the brush just off the commutator surfaces at all, the motor won't run. the brushed have to be able to contact BOTH commutator pads even after the gap is filled. The plastic, and probably the superglue have filled the gap so carbon can't fill it. Even after the motor is assembled, if it stalls, you can gently scrape away at the filler to get it tuned in. Be aware, these little open frame motors can attract junk. Tiny chips get stuck on the magnets and the armature cores and cause mechanical binding, so work clean and check for chips during the whole process. Dont forget a little dab of Labelle oil on the bearings too. Hope this helps. Having seen what you two; Dave and Mike, who requested this info have done, I think you can handle it.
You need to bend the brush spring retainers upward just enough to get the springs and brushes out. Take whatever precautions needed not to lose them. (if you do, I think Kadee knuckle springs work)
Then you can pry the metal frames open enough to pull the commutator end out.
If you have gotten this far, I'll assume you have the plastic needed to make the gap fillers. You can do that with the motor assembled. Cut a tiny slip of plastic as long as the gap, and wide enough to stick out of the gap, to hold it with tweezers. With a micro dab of superglue on the plastic, slip it into the gap. Let dry. Then with a new exacto blade carve it down to where its just even with the commutator surfaces. Then file it flat across the gap. If it can hold the brush just off the commutator surfaces at all, the motor won't run. the brushed have to be able to contact BOTH commutator pads even after the gap is filled. The plastic, and probably the superglue have filled the gap so carbon can't fill it. Even after the motor is assembled, if it stalls, you can gently scrape away at the filler to get it tuned in.
Be aware, these little open frame motors can attract junk. Tiny chips get stuck on the magnets and the armature cores and cause mechanical binding, so work clean and check for chips during the whole process. Dont forget a little dab of Labelle oil on the bearings too.
Hope this helps. Having seen what you two; Dave and Mike, who requested this info have done, I think you can handle it.