Triang Blue Pullman - is there a way of adding a 'shock absorber' or suspension to allow smoother running / less juddering?

[drt7uk]

Hi everyone,

 

I've got a Triang Blue Pullman, the motor of which has been serviced by a professional to it's best possible condition, but there is still a juddering as it goes around the layout. I think it is partly the way it is designed, with the motor being attached to the chassis towards the top of the cab, rather than the running plate at the bottom.

 

Is there any way to add some sort of shock absorber to it? Or some kind of suspension? Would need to not restrict it's ability to turn freely of course. Scratching my brain a bit with it, and may be there is no solution. I can live with that, the judder is relatively minor and I quite like the growl of the thing. Just keen to know if anyone has any ideas!

 

Of course, if anyone knows where I can get one of those replacement (Beetle?) motor bogies then I'd be very grateful! But they appear to be sold out / no longer produced.

Thanks in advance,

David

[Chrisr40]

Would one of the current Hornby motor bogies do the job ? Likes of which are in their railroad diesels. They are smooth and quiet plus cheap.

https://www.ebay.co.uk/itm/Hornby-X137179-Class-66-Drive-Motor-Bogie-Complete-/333864913320?var=0&mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338268676&toolid=10044&customid=Cj0KCQjw38-DBhDpARIsADJ3kjlbshHZkbZrHpODE0FHiBxJRe4GQmBAFbyYAA-td-gUV361Mgvgpj8aAlw0EALw_wcB

Edited April 12, 2021 by Chrisr40

[Les Bird]

Is it one of the early ones with serrated wheels? If so, changing the wheels may help.

 

[33C]

Are the 2 rectangular weights present in the black plastic, chassis moulding? They matter, also, is the motor mounting hole worn oval? If so, sleeve it to take up any slack, which should dial out the judder! 

[The Johnster]

A simple bodge solution might be to place a block of foam rubber or sponge between the top of the bogie and the roof of the power car; if it works, you can make a permanent job of it by glueing to the roof. 

[DCB]

The Triang Power bogies need a bit of TLC to run nicely.  The wheels range from awful to really awful but the Blue Pullman can usually be persuaded to run reasonably well by adding shim washers between the wheel backs and the chassis or between the worm wheel and the chassis to restrict side play and then adust the back to back to about 14.5mm.   Likewise the rear bogie benefits from having the back to back around 14.5mm, standard is about 13.9mm.  a small washer between the wheel halves sorts out the trailing bogie on most of these Triang Diesel chassis.

The wobble is accentuated by the top mounting of the bogie, extra weight low down helps, but unfortunately the power bogie is at the frong and they run much better power boge trailing.

I would cram as much lead flashing as possible well forward and low down.

The real thing was also addicted to bad riding so maybe its just Triang making ther models super realistic.

[GWR-fan]

My experience with these bogies is that they either run well or they misbehave no matter how much money and time you throw at them.  Critical is the amount of wear in the axle cutouts in the drive block.  Also relevant is the wheel tread surface,  some are smooth, others very coarse and of course the serrated treads.  Out of nearly twenty of these Blue Pullman drive blocks I was only really pleased with four of them,  getting them to run as smoothly as any more recent motor bogies.  The others I tried new brushes, shaft ball bearings and felt pads, carefully aligning the magnet carriers and aligning the brushes with the commutator.  I even tried neodymium magnets with no joy (they would just bend the armature shaft).  I finally gave up and sold everything.  

[drt7uk]

Thanks everyone for your tips!

 

I did replace the serrated wheels a while back and had the motor serviced so unfortunately I think it runs as good as it's going to.

 

Thanks @33C I got rid of the gap and thus the wobble you mentioned, used leftover plastic windows from a super quick model, which I hole punched to make washers. The smooth plastic means it turns no problem.

 

Unfortunately I've now determined that the issue is the motor and as people have pointed out, it is what it is. Like I said it has been serviced by a professional so it does run well. Good idea to experiment with a bit of sponge instead, might try that!

 

I also discovered that whilst it runs well, it wasn't starting or braking smoothly. So today I added some pickups I made out of copper strip to the back bogie and works really well now!

Edited April 17, 2021 by drt7uk