5/9 Update: Fixed? PW engine runs OK, slows down, stops

Just curious Walt, is that a two or three position e-unit lever out the top? Had an MPC engine like this I gave away to kids and the darn lever used to move on its own.

It's 2.  Fwd and Rev only.  I can lock into one or the other if I want to .

walt

Walt:

Be advised that rather than post-war, that engine was made in 1979.

Having said that, I have never encountered that same problem on a post-war or modern Lionel locomotive.  It sounds like just normal wear which should have been corrected by the maintenance steps you have taken.

Sorry I can’t be of more help.

Bill  

That is what theirs had, with Sound Of Steam.

If is isn't the transformer or the e-unit, has to be the motor. Is it really hot when it stops?

FYI, that's not a PW engine, it was produced during the General Mills/MPC/Fundimensions era.

Is the engine very hot to the touch when it stops?  What transformer are you using to power it?

Are the brushes worn down?  Maybe new ones would help.

Walt,

That engine looks a lot like the old Lionel scout engines from the 1960's. Bill says it is newer, however I think that it may be shot, and the best thing to do is to look for another motor unit to swap it out with.

I had a Lionel 235 steam engine from the 1960's that died on me and I put a newer(1990) DC motor unit in it as the one I took it from the engine's shell was extremely damaged so I made one good engine from two.

Lee Fritz

When the engine stops, take the loco off the track and try and turn the drive wheels by hand. This will give an indication if the problem is mechanical or electrical in nature.

Larry

I am at the library reading this.  I will make note of things to try and when I get home I will try.

The engine gets warm but not so hot that I can't pick it up.

The brushes are 1/4" long, if not a bit more.  They are the old copper (?) type.

My parents bought me this engine in 197x (thinking 1977) so don' t know anything more about it.  I called it PW up front to be clear it's not a newer command control one.

I'll try when I get home.

thanks - walt

I have seen postwar engines do that when they have bad brushes. Your engine appears to have brushes.  Cleaning the brushes provide very temporary relief.
Try replacing the brushes. Clean the commutator again when you replace them.

(What are you doing to clean it?)

FYI; on brushes, most are made from lead as it conducts electric and won't damage the armature like copper will. If the brush has a scratch on the surface it can be filed down a little with a file or sandpaper.

Lee Fritz

I thought the brushes were carbon ??

Yes that aluminum-sided motor is a dead giveaway: Mid-1970s MPC production.

Chuck Sartor gave me a tip regarding these locos:  The brush SPRINGS can get weak or become annealed from the current, causing the brushes to lose contact with the commutator.  This will also prevent the loco from reversing reliably.

I'm pretty sure we concluded that postwar 2026 brush springs can be substituted (which DON'T have a history of weakening or becoming annealed.)  So basically, replace the brushes and brush springs, make sure there is enough spring tension, etc.

If you can reach it, I would also replace the pickup roller (collector) wire with a heavier gauge of wire.  The factory ones are kind of frail for the amount of current these motors can draw.

Before Chuck shared his wisdom, I had replaced the whole motor in mine with the motor from a postwar 249 plastic-bodied 2-4-2.  This motor has black steel sides and a 2-position e-unit with the lever in the correct position.  It gave very reliable operation.  Curiously though the MPC motor is MUCH larger.  It should pull stumps compared to the postwar motor and I know it has a lot more "coasting action" thanks to the large-diameter armature.  If you can't get your MPC motor to work the postwar version will bolt right in.

Good luck, let us know what you found out.  -Ted

one important precaution is not to put to much oil on the contact armature side as if it gets on the brushes can cause the motor to slow down and even run hot!!just one little drop of oil is plenty!i have seen many a older Lionel engine get ruined from too much oil on the brush and commutator !best of luck  !

Alan

As far as I know, there is no lead in brushes. Modern brushes are primarily carbon or graphite. Not all brushes are the same, they vary in hardness and wear characteristics.

Here is a site that may have more information: Helwig Carbon

And here is a Wikipedia article.

Point 1: tried to run it when I got home yesterday - ran VERY poorly for about 30 seconds and then died.  That was a first!  It didn't run long enough to see if it got hot or not.  As to the other test (mechanical  versus electrical) I turned the wheels by hand and they rotated freely.

Point 2: Ted said something very interesting "This will also prevent the loco from reversing reliably.".  That's exactly what started happening just about the same time as the engine started acting up!  It has always toggled properly until this week.  Thanks for mentioning that.

Point 3: the brushes are nice and clean and SMOOTH - no scratches.  They have the color of copper that's why I assumed they are copper.

Point 4: Alan: I don't know what the "contact armature side " is.  The only part of the armature that I ever have oiled is where the non-gear side inserts into the little hole to hold it in place - I put one drop of oil on that because I've read that's a good idea.

Point 5: C.W. asked how I am cleaning the commutator face.  Well, at first I hit it with goo gone because it seemed pretty dirty.  I cleaned that off well with denatured.  After that was all good and dry I hit it with an eraser.  It's pretty clean.

Before I just give up on this thing, as Lee suggested that I might want to consider, I'll see about finding a pair of springs and new brushes even though I wonder if they're needed.  The springs seem to have plenty of tension on them.

 As always, thank you for the suggestions - walt

Ddoes this engine have a electronic E unit.  Maybe that is whats failing....

Marty

Isolate the motor from the e-unit. Disconnect the 2 motor field wires from the 2 terminals on the e-unit. Ground one field wire at a time by slightly loosening the screw holding the e-unit, slipping it under the screw, and tightening the screw. The loco should run in one direction steadily. Remove the wire, and do the same with the other field wire, and the loco should run in the opposite direction steadily.

If this works, then you have poor contacts on the e-unit and they need to be cleaned and burnished.

Larry

Walt,

With that type of motor, that's the nature of the beast. Think about how many years of service that you've received from a basic,"throw away" type of engine. That's pretty darn good!

If you do buy another engine, you know what to look for. It's been a long hard road for you. Remember, toy trains are an experience in happiness.

Larry: I can try but I pretty much stink at that kind of stuff - especially if solder is in the mix somewhere!

Pappy: My nature is to accept the challenge and try to fix what's wrong - if it's in my skill level.  Plus, since it was a gift to me by my parents only 1 year before my Father passed away, it's kind of a special engine set to me.

- walt

sHow well does it run with it on your test bench connectedd up with clips????

Marty

Walt,

I understand as I have more than a few left to me by my grandfather. I wish you the best.

Walt,

Now is the time to brush up on your soldering skills. The only way to get closer to a diagnosis is to isolate the motor. Lock the e-unit in forward, and look at the e-unit contacts and note which contact is closed. Get a short jumper wire and hook one end to that e-unit terminal, and the other end goes to ground, under the e-unit screw. You are jumping out the e-unit contact with the wire. Run the loco and see if it remains running. If so, the e-unit is at fault. If not, you have a power or motor problem.

Larry

Walt,

If you are unable to get your steam engine running. Please take it Robert Barth. His phone number is 724-736-0488. His address is P.O. Box 667 Perryopolis, Pa. 15473.

He is not far from you.

one other thought , what color are the copper windings on the field coil and the commutator which the brushes run onto, normally the winding are a red color, if they look brown or dark the windings might be cooked, or have shorted turns which will make the motor due as you describe and run for a short period and then  stop, and at that point the copper windings would be hot to the touch!  try running it again and then touch the windings quickly with your finger, quickly because i don't want you to burn your finger and then  get back to me.

Alan

Again to note, since I only have access to the forum from the library I am always on a one day delay in responding.

Larry: I looked at the e-unit and can't relate to what you are saying.  I'm sorry to say that because you're trying to help me.  For just one instance, I don't see a screw that you mention.

Jim: I have a Lionel repair guy in my community which I've used for non-command repairs.  BTW:  I handed my 2-year old Christmas tin-plate engine/tender to him at York for repair!!!!!!!!   He's got over 1.4 grand of my money on these MTH delicate trains.

Alan: I will look and report back.

I took it apart again just to see if I could spot anything.  Didn't.  I tried to increase the spring tension by expanding it and I thought it worked - the train ran really well for, as before, 3 or 4 minutes and then slowed down and stopped.  Maybe the springs loose their tension under heat????

Also, I touched the motor's outer housing and it was only luke warm.

Until I can figure out Larry's suggestion my next move is to pick up new brushes and new springs and see if that solves it.  I don't see mechanical as being the problem since it runs really well for a few minutes.

As always, thanks - walt

Walt, the screw I am talking about is one of the screws that holds the e-unit to the chassis. The screw is ground, so you can connect the wire under one of the screws, or anywhere else on the chassis. The entire chassis is ground; the e-unit mounting screw is just a convenient place to attach the wire to ground.

Larry

You should get someone to run a continuity check on the field coils and the armature. Especially the armature.

Giving details in case anyone is interested.  Sorry to be so long though but want to be thorough in what I report.

I took it to an authorized Lionel repair shop - the guy's been doing repairs for 33 years so I would say he knows his stuff.  I took the engine with me. Without even removing the shell he looked at the part that holds the brushes and after a very short test with clips determined that it was indeed the brushes.

I brought up about the springs and he said that they are fine - he said that when they overheat to the point of failure that they have a blueish tint to them and mine certainly don't.

So I bought 2 brushes and 2 springs anyways.

I think it's fixed.  Why just 'think'?

I'll provide some details just in case anyone is using this as a learning expedition of sorts.  Not to bore you!

I installed the 2 new brushes and only one of the new springs.  Why just one?  Because one wasn't soldered in place and the other one was so I just replaced the easy one - I gave consideration to the repair guy saying the springs are OK.

Put it on the test loop and it ran like crap!!!!!!!!!  DARN - are you telling me that it wasn't something as simple as the brushes?????

Since the shell was off I look at the e-unit and tried to relate to Larry's suggestion.  I found the screw holding it on.  It was just a hair loose but I didn't think anything of it at the time.  Not real loose, just a hair.   Remember, I have no experience with an e-unit.  So I removed the screw and saw how the e-unit was now free to remove except for 2 wires soldered to the top of it. 

Again, not knowing anything, I held the e-unit away from the frame and applied track power.  Of course it didn't move but then I remembered Larry's comment about how the frame acted as ground.  So I just laid the e-unit on the back of the frame and applied power.  It ran beautifully!!!!!!!!!!

Now I was really confused.  I ran it for 8 minutes and it stayed perfect.

Re-attached the e-unit and put the screw securely in place.  Ran sans shell for 11 minutes and it was fine.  Nothing got hot and not really all that warm either.

Put the shell on and ran it another 16 minutes and it stayed perfect the whole time.  Again, nothing got hot.

So digesting the above you can see why I said I THINK it's fixed.  If it was the brushes why did it run like crap after I first put them in?????   I really didn't do anything to e-unit except remove and replace it.

But it's running.  Still, I would love to know what fixed it.

I will continue over the next 2 weeks or so to be running it because I'm testing a track configuration using this engine.  I'll check back in after a while either way, good or bad.

Again, thanks to everyone for all of the suggestions.  Without being able to personally inspect the engine each of the above suggestions was surely a probable cause so thanks for offering them.  I will keep this thread in mind for future reference since I also have another engine similar to this one.

thanks again - walt

I have seen locomotives with grounding problems, but they ran poorly all the time. Since tightening the e-unit screw resolved the issue, that had to be it.

I've been repairing toy trains for a long time too.

Something tells me it was the screw.  The brushes definitely needed replaced but since it did run well sometimes it leads me to wonder.  The old brushes were 1/2 the length of the new ones.  I'm not a repair guy so I can't draw conclusions as to whether that short length is unreasonable or not.

Thanks C.W.

walt

The loose e-unit screw prevented the e-unit, and thus the motor, from getting a good ground. The motor is grounded through the e-unit contacts, which are grounded through the e-unit frame through the screws to chassis ground.

The loco should run properly now.

Larry

Walt,

Congratulations, my friend! I read over the earlier notes. What I did not see was,"Lock-Tite". I do not know how Larry or CW feel about it. I would put a drop on the threads of that pesky screw. Just a thought. 

Some e-units are mounted with an external toothed lock washed under the mounting screw. If e-unit don't have one, it probably would not hurt to add a lock washer.
If the engine is already together I wouldn't bother.

Just remember the fix for the next time, if it ever comes.

I have a couple of different types of Loctite in the shop. They don't get used very often.

CW is right, IMO. Loctite is not often used, I only use it on MTH locos that have the crankpin screws that have a habit of coming loose, especially on articulated locos for some reason. Sometimes when you replace the brushes, they have to "run in" so the miniscule grooves on the commutator wear into the brushes a little. I think you have it taken care of, so enjoy it!

Thank you guys for the positive 'fixed(?)' replies.  I do really appreciate them.

Don't know what a loctite is but if this screw is loose if I ever experience this problem again then I'll find out what it is and use it.

Luke: thanks for the comment about brushes having to get broken in - I was kind of hoping that was what the problem was after replacing them but had no idea that it is a known thing

As always, thank you guys - walt

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Thanks Dave.  Earlier I was thinking it was some type of specialty washer.

Now that you posted the info, yes, I have heard of it.  DUMB!

- walt