N Gauge Forum

Your Layout and Models => Train Surgery => Topic started by: daftbaker on July 11, 2018, 10:30:39 pm

Title: Class 33 not picking up power.
Post by: daftbaker on July 11, 2018, 10:30:39 pm
I have changed the gear cogs including new drive axles and pick ups on a Class 33. The motor runs but not by picking current up from the wheels, only if I put the wire to the brass or copper strip underneath and the outer chassis. The wheels turn around if it is on its back. But if you put it on the track, it will not pick up power. Any suggestions? Thanks.
Title: Re: Class 33 not picking up power.
Post by: Newportnobby on July 11, 2018, 10:41:38 pm
Hi Daftbaker, and welcome aboard :wave:
I'm sure someone will be along to help very soon.
Title: Re: Class 33 not picking up power.
Post by: ntpntpntp on July 11, 2018, 11:10:55 pm
OK, so not being familiar with this particular model I don't know the pickup design.  Is it Dapol or Farish?

Does it have wiper pickups on the backs of the wheels, or does it have split axles and pass power through the axles?

Do the bogies have wiper contacts onto the chassis, is it a split chassis? 

Any of the above could be the problem, you need to trace through the pickup path.  Have you tried feeding power to various wheels via a pair of wires while the loco is upside down?  When the loco is on the track does it cause a short circuit (this can happen if the model has wheels insulated on one axle only and you've put one or more axles back in the wrong way round)?
Title: Re: Class 33 not picking up power.
Post by: daftbaker on July 12, 2018, 04:09:27 pm
It is a Farish model.

If I touch the wires on the wheels the motor turns and the gear cogs operate as they should. If I stand it on the track, it doesn't  work. Other locos do work on the track so that is fine.
Someone posted a pretty comprehensive service article for the loco, which I have followed. I just can't understand why there is a problem between track and wheels.

Thanks for your ideas.
Title: Re: Class 33 not picking up power.
Post by: Chuffington on July 12, 2018, 04:32:14 pm
So the motor works when you touch power to the wheels when the loco is upside down - have you checked the motor runs from every possible wheel combination of applying power ? Front bogie & rear bogie ?
Possible that you have an internal short which only shows up when both bogies are on the track ?
Check the contacts on the bogies where they touch the chassis to ensure they are only making contact in the correct places.
Title: Re: Class 33 not picking up power.
Post by: Steven B on July 12, 2018, 04:59:28 pm
The Farish model uses a brass sprung contact to get power from the bogies to the chassis block. One or more of these isn't making contact. Take the body off, and with the loco on the track look between the bogies and chassis. It should be clear which contact isn't making contact.

Steven B
Title: Re: Class 33 not picking up power.
Post by: daftbaker on July 13, 2018, 12:29:15 am
Thanks.

The comment regarding putting the wires to all wheel combinations might be the answer as it works when the wires are touching different bogies along one side only.

I will check this out .
Title: Re: Class 33 not picking up power.
Post by: daftbaker on July 13, 2018, 10:05:50 am
Thanks to the help.

It was a pick up problem. Reviewed the Farish shed servicing article and I had four alike connectors where two each should bend differently.

Problem now resolved.

Move on to the next problem loco now.

Class 159 just won't go, think it is something to do with the long spring that goes front to back.

Dapol class 67 hardly done any mileage, been in store. Just sits on the track, not even the lights come on.

Any ideas?

Thanks again from a happy old man.
Title: Re: Class 33 not picking up power.
Post by: Chuffington on July 13, 2018, 10:26:35 am
Good to hear you got the 33 running again  :claphappy:

159 : Can you give more into as to the chassis type ?

67 : Assume this is 'DDC Ready' ? If it has a DCC chip in it and you are using DC most likely nothing will happen.
If you are using DC and there is no blanking chip in the socket this could also cause nothing to happen.


   
Title: Re: Class 33 not picking up power.
Post by: ntpntpntp on July 13, 2018, 10:59:00 am
67 : Assume this is 'DDC Ready' ? If it has a DCC chip in it and you are using DC most likely nothing will happen.
No, by default decoders will work on DC unless specifically disabled by CV programming or it is one of the few cheap decoders which don't support that functionality.

Could be the decoder (or blanking plate) has worked loose?
Title: Re: Class 33 not picking up power.
Post by: Chuffington on July 13, 2018, 11:12:04 am
67 : Assume this is 'DDC Ready' ? If it has a DCC chip in it and you are using DC most likely nothing will happen.
No, by default decoders will work on DC unless specifically disabled by CV programming or it is one of the few cheap decoders which don't support that functionality.

Could be the decoder (or blanking plate) has worked loose?

I bought some s/h locos which had DCC chips in - didn't realize at the time - tried them on a DC layout and nothing happened, removed the DCC chips and replaced with blanking chips and they all worked fine - even got a few 's for the DCC chips !
Not sure what brand the DCC chips were though. 
Title: Re: Class 33 not picking up power.
Post by: Dr Al on July 13, 2018, 12:39:54 pm
Class 159 just won't go, think it is something to do with the long spring that goes front to back.

Almost certainly split gears on the 4 wheelsets locking it up - extremely common.

Dapol class 67 hardly done any mileage, been in store. Just sits on the track, not even the lights come on.

Most common faults on 67s are dodgey PCBs, or broken connection to the motor. Worst case would be a duff motor.

Cheers,
Alan