Dapol motor overheating, surging and slowing - cure?

[Dr Al]

Hi,

 

I've still been having trouble with slowing and surging of my first Britannia, and with more and more people reporting similar, I finally got the opportunity to test a hypothesis of the cause last night.

 

The symptoms are - running fine it'll suddenly slow to about 1/2 the speed it was running at. Watching the ammeter, the 100mA or so it was drawing suddenly jumps to 180-200mA. It would do this intermittently. With this doubling in current (and therefore quarupling of the power dumped in the motor) the heating effect is much greater which can't be good for the motor long term.

 

I'd been pretty sure that this could only be caused by soft brushes or brushes made of not quite the perfect material, such that the commutator was getting prematurely clogged up with brush dust which in turn was semi-shorting out the commutator, by filling up the segments.

 

After some hunting I finally found a pair of Bachmann Farish motor brushes (from their 5 pole skew wound motor, used in the old tooling 37,47,50,52,55 etc) which seem to fit the Dapol motor ok (albeit being slightly shortened).

 

Doing this seems to have immediately eliminated the problem and the loco ran last night for 1/2 hour after changing the brushes with no problems towing 7 Dapol Gresleys and 3 Farish staniers no problem, drawing 90mA at 60% power on my standard Gaugemaster controller. Immediately before changing them performance was erratic.

 

Whilst I can't be sure this won't come back, the signs are encouraging. The only problem is these Bachmann brushes aren't available as spares so unless a source can be found....

 

Cheers,

Alan

[Andy T]

Hi All

 

I have also suffered for the first time Surging on a Dapol model ( Maybe my fault !!!!) on one of my Dapol 86's last night i was running a test run over a new section of track when it slowed on half power and cut out causing a short on the controller . So i lifted the body off ( As you do to check what was wrong ) to find that the motor was " Red Hot " so to speak . so i left the " 86 " overnight to cool down and tested the model this morning before leaving for work to find out that the headlight at one end had overheated and now dont work but the model runs with no aprent problem ( Has any one else suffered this???) but as i have said this is the first ever problem i have had from a Dapol model and i have many of their models ( Well over 50 )

And this has not put me off at all ( Might be my fault or not)

Cheers

Andy T