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Mantua General motor getting too warm (Updated) (Again)

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Mantua General motor getting too warm (Updated) (Again)
Posted by Wolf359 on Monday, June 1, 2020 2:17 PM

I recently acquired a Mantua General and four W&ARR cars a few days ago. The locomotive is DC with the motor in the tender, which turns the drivers via a drivesaft, universal, and worm gear. The loco had been sitting for a while before I got it, but I cleaned and oiled it, and made sure everything was working properly before putting it back together. The loco is in really good shape both cosmetically and mechanically, except that after about 8 to 10 minutes of running it starts to slow down and the motor gets really warm, or outright hot. The motor is original. The driveshaft and drive wheels roll smooth with no stiffness or binds when turned by hand, and there aren't any shorts either, as I have an MRC 2400 series power pack that has a circuit breaker that trips when there is a short. So my question is, is the motor going bad, or is there something I might be missing? Or, should I just look into putting in a can motor? Thank you in advance for any and all input.

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Posted by garya on Monday, June 1, 2020 5:13 PM

Wolf359

I recently acquired a Mantua General and four W&ARR cars a few days ago. The locomotive is DC with the motor in the tender, which turns the drivers via a drivesaft, universal, and worm gear. The loco had been sitting for a while before I got it, but I cleaned and oiled it, and made sure everything was working properly before putting it back together. The loco is in really good shape both cosmetically and mechanically, except that after about 8 to 10 minutes of running it starts to slow down and the motor gets really warm, or outright hot. The motor is original. The driveshaft and drive wheels roll smooth with no stiffness or binds when turned by hand, and there aren't any shorts either, as I have an MRC 2400 series power pack that has a circuit breaker that trips when there is a short. So my question is, is the motor going bad, or is there something I might be missing? Or, should I just look into putting in a can motor? Thank you in advance for any and all input.

 

I have a 1890 Rogers 4-6-0 that was doing the same thing.  I replaced the magnets, cleaned, and lubed the motor, but in the end I replaced the motor.  

It may be easier to find a small can motor that fits with a tender drive, rather than the narrow frame of these old locos.

Gary

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Posted by Wolf359 on Monday, June 1, 2020 6:11 PM

garya

 

It may be easier to find a small can motor that fits with a tender drive, rather than the narrow frame of these old locos.

 

I may just do that, because I put in a little Pittman motor that fits and that I had on hand, and while it runs smoother now, it still seems to be getting warm a little too fast. Maybe there just isn't enough airspace inside of it for open frame motors. Thank you for your advice.

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Posted by dknelson on Tuesday, June 2, 2020 10:12 AM

That engine's motor (tender shell) always did get hot because there was so little in the way of "air" around it.  It especially got too warm if you used "pulse power" which tends to make any motor warmer.  It sounds like you have already checked out the other common cause of overheating in The General and other Mantua locos, that being side rods that bind a little bit.  The original kit construction involved futzing and futzing with the side rods until the loco by itself rolled smoothly before installation of the drive train/tender motor.

I have some recollection that guys used to try to make the area above the motor (the "wood" load) opened up for a bit of venting.

It may be that the magnet is weakened as well but even with a fresh magnet the natural heat involved with the motor does not have anywhere to go in an as-built General.

Dave Nelson

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Posted by Wolf359 on Tuesday, June 2, 2020 1:29 PM

dknelson

That engine's motor (tender shell) always did get hot because there was so little in the way of "air" around it.

I was kind of thinking that might be the case, because I put in a Pittman motor, and it gets warm too. Just not as warm and not warm as fast, so I'm going to leave it in as it does run more smoothly.

dknelson

I have some recollection that guys used to try to make the area above the motor (the "wood" load) opened up for a bit of venting.

I was thinking about doing that as well, and reading that other's have tried it says to me that it's probably the right course of action. Thank you for suggesting that.

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Posted by Overmod on Tuesday, June 2, 2020 2:21 PM

I've been trying to respond to this post multiple times, but there have been 'gremlins'...

As I recall there was some discussion of this on the Civil War Railroads Yahoo group (now on groups.io).  The idea is to make a wood load from stock wood, with an open 'weave'; you can use dark mesh or fabric underneath if anything 'shows'.  Best to put some holes/slots in the chassis for through-ventilation.

Overheating the motor has probably had a progressive demagnetizing effect on the motor, and I wouldn't hesitate to change it out for a high-strength replacement (which will reduce the current passes through the armature to make torque at low speed, and so contribute to reduced heating).  Periodically check to be sure the new magnet is retaining its strength...

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Posted by Wolf359 on Tuesday, June 2, 2020 3:12 PM

Overmod

I've been trying to respond to this post multiple times, but there have been 'gremlins'...

That seems to be happening a lot lately. I have that issue about once a month or so.

Overmod

As I recall there was some discussion of this on the Civil War Railroads Yahoo group (now on groups.io).  The idea is to make a wood load from stock wood, with an open 'weave'; you can use dark mesh or fabric underneath if anything 'shows'.  Best to put some holes/slots in the chassis for through-ventilation.

Thank you for the good advice. I've replaced the fake wood with real wood on most of my other wood burners, so I'll definitely be putting in some vent holes before I add the wood load. It will look a lot better too.

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Posted by Darth Santa Fe on Tuesday, June 2, 2020 5:49 PM

Do you have an ammeter to check on current draw?  When one of these is running smoothly with no binds or tight bearings, it shouldn't use more than about 0.35A with the old motor.

When I built my General kit, I ended up replacing the motor with a coreless one that fit nicely into the tender.  The current draw is so low that it can run all day without even getting warm!

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Posted by richg1998 on Wednesday, June 3, 2020 10:23 AM

Some years ago before Mantua was bought out, they had motor upgrades for the General and I bought one. I think it was a flat can, abut 27mm x 15mm x 12mm.. 1.5mm shaft as I recall. You should find near equivalent on ebay.

I found near the same for my Bachmann in old CD drives a few years ago.

I keep a dial caliper handy.

Rich

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Posted by Wolf359 on Wednesday, June 3, 2020 11:32 AM

Darth Santa Fe

Do you have an ammeter to check on current draw?

I don't have an ammeter, unfortunately, but I should probably look into getting one.

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Posted by Wolf359 on Wednesday, June 3, 2020 11:36 AM

richg1998

Some years ago before Mantua was bought out, they had motor upgrades for the General and I bought one. I think it was a flat can, abut 27mm x 15mm x 12mm.. 1.5mm shaft as I recall. You should find near equivalent on ebay.

Thank you. I'll have to keep an eye out for that.

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Posted by garya on Wednesday, June 3, 2020 12:45 PM

Wolf359

 

richg1998

Some years ago before Mantua was bought out, they had motor upgrades for the General and I bought one. I think it was a flat can, abut 27mm x 15mm x 12mm.. 1.5mm shaft as I recall. You should find near equivalent on ebay.

 

 

Thank you. I'll have to keep an eye out for that.

 

There are a huge number of inexpensive motors available on eBay, Aliexpress, etc.  You could look around for those aproximate dimensons.

Mel (@RR_Mel) is very knowledgeable about motors; he tends to model big stuff (cab forwards), but he may have a suggestion for you.

Gary

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Posted by Overmod on Wednesday, June 3, 2020 12:57 PM

Wolf359
Thank you. I'll have to keep an eye out for that.

If $50 is a reasonable budget, you might google 'MRRHQ General CanDrive' and see what develops...

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Posted by Wolf359 on Thursday, June 4, 2020 12:11 PM

Overmod

 

 
Wolf359
Thank you. I'll have to keep an eye out for that.

 

If $50 is a reasonable budget, you might google 'MRRHQ General CanDrive' and see what develops...

 

That's something I'll have to bear in mind down the road.

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Posted by Wolf359 on Thursday, June 4, 2020 12:25 PM

Update: As per Dave Nelson's and Overmod's suggestion, I removed the tender shell and drilled eight or nine vent holes in the top, and then disguised them with a new wood load and it seems to help quite a bit. It still gets a little warm, but not as warm and not as fast. I should also mention that the weather has been on the hot side lately, and I live in a 112 year old house that doesn't have airconditioning, so that may be a contributing factor. Thank you, everyone, for your helpful tips and suggestions.

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Posted by richg1998 on Thursday, June 4, 2020 5:26 PM

Wolf359

 

 
Darth Santa Fe

Do you have an ammeter to check on current draw?

 

 

I don't have an ammeter, unfortunately, but I should probably look into getting one.

 

 

I have used meters since 1955.

 

The past ten years I have used the below and put the expensive ones away.

I have four of these.

http://www.trainelectronics.com/Meter_Workshop/index.htm

I keep one in the garage for the car. I have different clip lead sets. One is for a DCC amp meter.

Rich

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Posted by Alantrains on Friday, June 5, 2020 5:21 AM

Sorry to hijack this subject, but with the number of people contributing I thought I'd ask, where do you get replacement traction tires for the Mantua General? Mine have perished to the point where they are unuseable. Also I'm in Australia.

Alan Jones in Sunny Queensland (Oz)

 

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Posted by T.C. on Friday, June 5, 2020 8:35 AM
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Posted by Alantrains on Friday, June 5, 2020 7:32 PM
Thanks TC

Alan Jones in Sunny Queensland (Oz)

 

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Posted by Wolf359 on Sunday, June 14, 2020 1:10 PM

richg1998

I found near the same for my Bachmann in old CD drives a few years ago.

If may revive my thread one last time, I just remembered that I have an old CD drive from a retired computer in my garage. Is there anything I need to be cautious with when taking the CD drive apart, or can I just have at it and get the motor out?

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Posted by Darth Santa Fe on Sunday, June 14, 2020 5:28 PM

Wolf359

If may revive my thread one last time, I just remembered that I have an old CD drive from a retired computer in my garage. Is there anything I need to be cautious with when taking the CD drive apart, or can I just have at it and get the motor out?

Just have at it!  If you don't care what happens to the rest of the drive, you can cut away parts that are snapped together and hard to get apart.  You may have to unsolder the motor contacts from the PC board.  You may also be able to get some decent gears out of the tray ejection mechanism.

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Posted by Wolf359 on Monday, June 15, 2020 12:42 PM

Thank you. I did after seeing your reply and got two nice motors out of it! One is a Mabuchi that's shaped like a cylinder with flattened sides, and the other is a Mitsumi that's shape like a hockey puck, (but a lot smaller than one). The Mabuchi might be a good fit if I can figure out something to make the driveshaft fit the universal type socket that goes on the end. (The motor's driveshaft diameter is too small and the length of the shaft is too short). I'll have to go through my parts and see what might work, or I can save it for something else. Either way, I got two motors out of it!Big Smile

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Posted by richg1998 on Monday, June 15, 2020 2:09 PM

Some years ago I got one thta I would call a flat can motor with a 1.5mm dia motor shaft. Same diameter as the standard motor. Works fine.

Did it with two Bachmann tender drive steamers.

Put N scale decoders in all three. Lead shot for weight.

Put pickups on all tender wheels and opposite loco wheels. Ran one more wire as a hose to the tender.

Did an IHC tender dtive 4-4-0 but kept the larger motor. It workerd fine.

HMinky had great ides for pickups using kadee springs.

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.

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Posted by Wolf359 on Friday, June 19, 2020 5:00 PM

Good news. I figured out how to make the Mabuchi can motor from the CD drive work, since the open frame motors kept overheating. I found a short metal shaft that fit in the end of the universal type socket, and attached it to the motor's shaft with a small piece of surgical tubing and a tiny dab of CA on the shafts. After a little bit of fine tuning, it seems to run a whole lot smoother and cooler. I've got to do more testing, but I think the can motor cured its issues. Thank you, everyone for all of your help.

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