Model Power Pacific 4-6-2 Improvement: Fixing a Disaster and making a Pearl

[mmagliaro]

Runs great, Ron!  Yep, can't have a bind like that if you want it to start up and creep.  Very nice work.

In record time, I got 6 of those motors from China (courtesy of Ali Express) that looked similar to the Model Power motor.
Remember, the ones I was buying for their armatures that looked EXACTLY like the MP motor are no more.

Out of the 6, one is a klunker and the other 5 run great.  They will all start under 2V, draw only about 40 mA all the way up to 12v,
very quiet.   The photos don't show it well, but these ARE skewed-armature 3 pole motors.  The klunker runs, but it starts at a higher
voltage and sometimes won't start.  I have seen this before, and it's probably just some cement or other residue on the commutator surfaces that needs to be cleaned off.

I don't really know how much power they have, but just gripping the shaft with fingers, they seem to be about
the same as any conventional-armature motor of this size.  Here's a photo montage from the internet (but this is really how the motors look). 

I find it very interesting that the 3 poles on the armature are actually labeled in Sharpie, by hand, with "1", "2", and "3".  This
makes me wonder if somebody balances them by hand.  (There are blobs of balancing epoxy on them)

The only issue may be the short motor shafts.  4mm or 5mm might not be enough, but it might work.  I am going to take the klunker and see if I can push the axle shaft through to get one longer shaft out of one end.  Sometimes you can do that.  Sometimes, all the coil and comm assemblies are so tight to the shaft that you can't get away with it.

[u18b]

Max,
Thank you for posting this.   You're the second person who let me know that there is a direct replacement for the Ajin motor (I'm sorry I didn't post that earlier when I meant to).

However.....  even if I wanted to do that (say because of the heat-deterioration of the plastic around the brush holders),  I can't imagine how I would deal with the flyworm.

I wouldn't even know how to get it off of the old motor, nor how  to get it on the new motor (esp without damaging it).

It is (I think) one solid piece of brass.




And that includes the tip.  It is brass, not steel running through the whole.



In fact, I'd be happy to send you the motor above (from the third trashed loco) as an experiment to show how it can be done- if you are intereted.

[peteski]

I find it very interesting that the 3 poles on the armature are actually labeled in Sharpie, by hand, with "1", "2", and "3".  This
makes me wonder if somebody balances them by hand.  (There are blobs of balancing epoxy on them)

That is not uncommon. I have seen this in 3- and 5-pole motors used in model locomotives.  I also see small chunks of what I assume epoxy putty stuck i the windings near the armature. I have also seen similar slivers of stuff stuck in flywheels which have grooves in them. Yes it is likely for dynamic balancing.  One such example was the motor in the FVM Hiawatha. 

I don't have a photo of the numbered poles, but here you see the blue putty used to balance the flywheel and armature. There is also a black line on the flywheel (likely used in the balancing process).


I would love to see how such a small balancing machine looks like.

[peteski]

Ron, if you have a good motor, you should be able to swap just the plastic end which holds the brushes.  First remove the brush holders, then open up the small metal  tabs crimped onto the plastic end, then you can slide the plastic end off the motor frame.

Do the same with the new motor and swap the plastic ends.  Then you can solder wires to the brush holders while they are out of the motor to avoid any heat damage.

I have done this successfully on various motors (like this one or the Kato-style motors).

If after the replacement the parts are not perfectly aligned, I fix that by banging the motor flat against the workbench. That lines everything up    I usually check how freely the shaft spins before installing the brushes.

[u18b]

Pete,
Yes.  That makes perfect sense.
A good option.

Since these two locomotives run almost perfectly, I think I'll let them be for quite a while.
 

[u18b]

@kiwi_al is the one who mentioned this to me first.

Here is a link he sent me.   Worth ordering.

https://www.aliexpress.us/item/3256805282690630.html

[u18b]

Been working on an LED headlight.
Results have been challenging and mixed.

I'll post more probably next week. 

Problems I'm encountering:
all metal boiler (challenge to hide and route wires)
nose light pipe is awful- so even a REALLY bright LED is not looking great.

More experimentation to go.

[mmagliaro]

@kiwi_al is the one who mentioned this to me first.

Here is a link he sent me.   Worth ordering.

https://www.aliexpress.us/item/3256805282690630.html

Yes, those are the same ones I got.

As far as getting that worm off the old dead motor,  I'll give it a go.
Go ahead and send it to me.

Rivarossi did some like that too, on their E-8 and C-liner motors.  I get those off by just driving a wedge
between the back of the brass flywheel and the motor face.  Sometimes, that ends up destroying the motor, but since
we don't care about saving the old motor, that won't matter.  Using the tip of the flyworm as the bearing surface is a really
awful design, for this reason among others.

And in fact, from what I saw of your photos in the engine, that brass tip isn't running in a bearing anyway.  It just spins free in an open
hole (unless it's out of whack and binds against the hole, which you had to fix).  Confirm to me that this is true.  Because if it is,
then why even keep the tip at all?  I could cut the tip off flush with the worm,  put the flywheel portion in a lathe, and then bore into the end of the worm until I reach the motor shaft.  Then the shaft could be pressed out the normal way with a gear puller or a long punch.

Getting it on the new motor is the easy part.  The motor has a back shaft peeking through a rear bearing.  You just have to set the motor into a vise with that back shaft against one jaw, and press the worm onto the other end by closing the vise.  Unless you get it started really badly, the shaft will follow the hole right into the worm.

[u18b]

No, the tip does run in a bearing, albeit a plastic one.

The one in that photo.



And in this shot, the blue is touching the black bearing.

[mmagliaro]

Okay, Ron. I didn't see that plastic bearing.  So the brass nose has to stay.  Still okay.  I'll get that worm off
if you want me too.  But no guarantees I can preserve what's left of the motor.

[nscaler711]

So, dumb question time, does any of the issues occur in the latest runs of these Pacifics?
So far after installing a Soundtraxx decoder in one I haven't seen or heard anything like you all are describing. Granted, I have not done anything to the locomotive itself.
Though I will say I think my version (ATSF 1369) has an LED. Maybe this was done under MRC?
Honestly my only issue is the locomotive has found a "dead" spot which no other locomotive has caught, and the sound light and movement cuts out for a second which so far I'm assuming its a pick up issue.

[u18b]

So, dumb question time, does any of the issues occur in the latest runs of these Pacifics?
So far after installing a Soundtraxx decoder in one I haven't seen or heard anything like you all are describing. Granted, I have not done anything to the locomotive itself.
Though I will say I think my version (ATSF 1369) has an LED. Maybe this was done under MRC?
Honestly my only issue is the locomotive has found a "dead" spot which no other locomotive has caught, and the sound light and movement cuts out for a second which so far I'm assuming its a pick up issue.

If you have a good one.... I would do nothing.

But Spookshow says the later releases look about the same.  So not sure what significant differences there are.
I have early and mid.   I don't own a late.

[garethashenden]

It was ages ago, but I think I removed the flywheel/worm piece by sticking a flat screwdriver in there and prying gently. This thread is making me think about the pile of pieces in a bag that is that locomotive. Not sure its worth saving though.

[mmagliaro]

It was ages ago, but I think I removed the flywheel/worm piece by sticking a flat screwdriver in there and prying gently. This thread is making me think about the pile of pieces in a bag that is that locomotive. Not sure its worth saving though.

Yes, sometimes you get lucky and this works if the worm isn't pressed on too tight.  That's why my wedge trick sometimes just harmlessly pops the thing right off.   I have had good luck with this on some Rivarossi E8 and C-Liner motor worms.  But sometimes, they are so tight that I have to just rip the whole thing apart, grip the back of the armature shaft in a vise, and drive the worm off "the old fashioned way" (with a hammer and a small screwdriver).

[craigolio1]

Yes, sometimes you get lucky and this works if the worm isn't pressed on too tight.  That's why my wedge trick sometimes just harmlessly pops the thing right off.   I have had good luck with this on some Rivarossi E8 and C-Liner motor worms.  But sometimes, they are so tight that I have to just rip the whole thing apart, grip the back of the armature shaft in a vise, and drive the worm off "the old fashioned way" (with a hammer and a small screwdriver).

Could you put a mini torch on just the worm and heat it enough to expand it without destroying the motor?