Help please with a troublesome LGB Mallet

[whatlep]

Chaps/esses

I have a problem with an LGB Brohltal Mallet. If left to run continuously, it runs fine for a while, then stops dead and appears to have shorted out the entire layout as all other locos/ stock stop too or lose their lights. After 15 seconds or so, the Mallet will usually start again and then run for a while before the cycle repeats. Typically, if the cycle repeats several times, the Mallet does not recover and needs to be removed (as if it were cooling down or resetting something). If I run the Mallet only for short periods, the problem does not occur.

All other locos work fine and use exactly the same chip as this Mallet (Massoth XL). Logic suggests I have a duff connection somewhere which is heating up and making/ breaking. Could it be one of the motors? How can I probe without getting into destructive testing?!

All help gratefully received!

 

[mike]

motors overloading, build up off heat excpands the windings, jamming motor causeing a short.. 8|

 

[mike]

sorry should have added do a amp test on the individual motor blocks, set multimeter to read milly amps.. inline on one feed to one side (wheels) track power to other side, run loco.. it should read 0.5 if new.. worn its ok to 0.7.. 0.8 pushing it.. when your on 1 ....

 

[Spule 4]

Peter-

On one of the fourms there was someone else with a dual motor locomotive with the exact same situation, one bad motor, you can chase it down with Mike's method.

 

[minimans]

Check the smoke unit these loco's had a habit of leaking smoke fluid straight down on to the motor!! ( I don't think it is the smoke unit itself leaking more the "owner" overfilling!)

 

[stevelewis]

It could well be an overload on a motor, which is causing the Decoder to cutout as it senses too high a load, it then resets as the motor overload is removed cools down,

I have had this problem with USA trains diesels in the past.

Re the Mallet many years ago 80s I bought a S/H mallet which had a visibly SLOWER wheelset the front one,

I removed the motor and ran it NO Load and it was drawing much more current than another similar new motor I had spare, so I simply fitted the new motor,

The cause was eventually tracked down to a faulty smoke unit which was leaking into the motor block and hence the motor.

I had a similar problem with a V51 fitted with 2 decoders ( MTS2) one decoder kept cutting out after a few mins running, the cause was again a duff motor, in this case it was pinpointed to over zealous lubrication by a previous owner, the motor was 'full' of oil!

Hope this helps!!

 

[Steve]

Brilliant Thread .

I to have a mallet with the exact same problems as Peter`s.

I am having the motors changed but if its the smoke fluid causing the problem on the front motor can the motor be reserected or is it pooped..

Cheers

 

[minimans]

Brilliant Thread .

I to have a mallet with the exact same problems as Peter`s.

I am having the motors changed but if its the smoke fluid causing the problem on the front motor can the motor be reserected or is it pooped..

Cheers

I cleaned mine out with brake clean and it ressurected itself although I still have it as "spare" I've not needed it yet!! and yes my smoke unit didn't leak I kept overfilling it and it would drain the excess down the chimmny.....................

 

[Steve]

Brilliant Thread .

I to have a mallet with the exact same problems as Peter`s.

I am having the motors changed but if its the smoke fluid causing the problem on the front motor can the motor be reserected or is it pooped..

Cheers

I cleaned mine out with brake clean and it ressurected itself although I still have it as "spare" I've not needed it yet!! and yes my smoke unit didn't leak I kept overfilling it and it would drain the excess down the chimmny.....................

Paul

Yep thats what i have done over filled the smoke unit many many times .

 

[stevelewis]

I have found that the motors can be cleaned up to a point but they never seem to be as good as they should be,

Re smoke units I stopped using smoke units years ago, there was quite a bit of publicity about the the affects on health of inhaling smoke ( especially children) it was stated that the smoke was many times more dangerous than cigarette smoke, For quite a while exhibition managers banned the use of smoke units!
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IT is not too difficult a job to access the Mallets motors.

 

[Steve]

Guess now i have stopped smoking i will have to have a word with me locos

 

[whatlep]

Thanks everyone. Looks like we're all agreed it's probably one or both motors then! Definitely not a case of smoke unit overfilling as I don't use them (and isolate them when fitting a decoder.

I shall take the Mallet apart and see what I find. Any results will be posted here.

 

[stevelewis]

Another point I have thought of:

Is the decoder hard wired and the original LGB PCBs totally isolated or removed?

If not it could poss be that a component could interfere with the decoder, a capacitor for example?

Steve

 

[Philbahn]

Chaps/esses

I have a problem with an LGB Brohltal Mallet. If left to run continuously, it runs fine for a while, then stops dead and appears to have shorted out the entire layout as all other locos/ stock stop too or lose their lights. After 15 seconds or so, the Mallet will usually start again and then run for a while before the cycle repeats. Typically, if the cycle repeats several times, the Mallet does not recover and needs to be removed (as if it were cooling down or resetting something). If I run the Mallet only for short periods, the problem does not occur.

All other locos work fine and use exactly the same chip as this Mallet (Massoth XL). Logic suggests I have a duff connection somewhere which is heating up and making/ breaking. Could it be one of the motors? How can I probe without getting into destructive testing?!

All help gratefully received!

My money like Mike is in a motor, while doing one why not replace both. Not much more work and the jobs done. And you have a spare motor to use again when you've identified the bad one

 

[mike]

as phil says its much, much better to bite the bullet, and replasce both motors if ones gone, i do, with my mallets/twin motor locos.. if you dont, you will notice one motor block running slower, via the vale gear, due to wear.. 2 new motors, it will be like new!!

 

[whatlep]

A brief update after spending a rainy afternoon productively. Both motors removed and checked for current draw:
Front: 65-130 milliamps (dead slow, minimum volts to 24 volts DC analogue)
Rear: 80-140 milliamps
Those readings look pretty reasonable to my eye, but I'll accept guidance.

However, the previous owner must have had shares in Castrol. Both gearboxes were swimming in lubricating grease, to the extent I needed kitchen towels/soap/water to remove the gunk and clean my hands!

I also noted that the Massoth XL decoder had shifted off its sticky pad and could possibly have been making contact with the lead weight. Lead weight now covered in insulating tape and decoder better secured in place.

Too wet to do an outside test this evening, so another update when it's warmer and drier. Fingers crossed!

 

[stevelewis]

Must have been the same previous owner of a V51 I had as mentioned in a previous post!!!!!

Its highly likely that the lubricant has found its way into the motor(s)

 

[stockers]

Bugger - My Mallet ran great yesterday - today it does 12 inches - stops, starts does 12 inches. Looked at the Navigator read out - its pulling 4 amps. So it look very like I too have a dead motor - again in a Brohltalbarn Mallet.
Only put the massoth XLS in it a couple of weeks ago!
Smoke oil was not a problem then, so it looks like high mileage - it has been round my layout a fair few times.