Can anyone explain why a loco runs perfectly when I place a wire on to the wheels whilst it is in a cradle but it sometimes needs a push when it is on the track. I cannot believe that there is no contact between the wheels and both rails especially with the weight of a white metal bodied loco. The wheels are clean and the track is clean.
Tony Clarke
Perhaps check the pickups that touch the wheel? The may be touching fine, when upside down in cradle, but may lose good contact when right side up.
Another reason to go RC :)
Jim F
Certainly the picks-up are the first thing you should check.
I would also place the loco on a flat glass or metal surface and check that the chassis is set nice and square - and does not rock.
Having been the service engineer in a well known model shop for many years, I have come against this problem a number of times, and unfortunately it can be a difficult one to cure.
If the problem still persists after carrying out the previous suggestions and ensuring pickups are making good contact with the wheels when the loco is standing on the track, then it is probably a problem within the motor itself, either the carbon brushes not making good contact with the commutator due to a build up of carbon dust and general grott in the brush holders, ( if they are of the type held in a 'tubular style holder'), or, if the motor has been lubricated, the brushes and commutator could be contaminated with lubricant, and therefore the motor will require stripping and cleaning thoroughly.
Just to explain, if any of these conditions are present, the action of gently pushing or tapping the loco when on the track, moves the motor armature fractionally, (through the play in the gearing), just enough to make the initial contact to allow the motor to start to turn, and once turning it will continue until the speed drops to a level where contact is lost again.
These conditions are usually indicated when a loco requires a lot of coaxing with the finger when attempting to run at very slow speed, typically when shunting.
I hope this is of some help to you.
When the 'new' Minitrains Plymouth was first released the first one I had had a similar problem when the spring at the top of the motor went. A bit of blu-tack in the body pushed it down and solved the problem. Since it was a new RTR loco I simply swapped it for another but the bodge with the blu-tack might help.
Danny
Thank you for the replies. It gives me some things to investigate
Tony
What chassis are you having problems with Tony?
Brian Meldon
Brian,
The following give me trouble:- Fleischman Piccolo, Minitrix 0-6-0 which fitted an old GEM Varikit and Bachmann 0-4-2 which fitted an equally old Roxey Mouldings LOK3 Hampton
Tony Clarke
I will start with the Minitrix 0-6-0.
It is quite common for these chassis to get worn out quite quickly. You may well find that the axles and gears become very lose in the slots in the cast chassis block. The result is that when power is applied they twist to one side. When the loco is upside down it does not matter but when it is on the track with the weight of the white metal body the entire loco is lifted as the power is applied needing more power from the motor to get it going. Also, the axles tend to sit at different angles to the track as they twist in their slots causing one or more wheels to lose contact with the track. The motors can also give problems on their own some need the controller turned up higher just to get them moving without any load from the chassis.
The last version made has brass
The Fleischmann 0-4-0 is usually quite a good chassis.
There are two versions, one with a metal chassis block and the other with a plastic chassis block. The metal ones are better as I have known the plastic ones to suffer from worn axle slots causing one wheel to lift off the rails when running.
However the most common problem with these is the contacts, not only on to the wheels but also where the contacts touch on the motor brush holders.
However in general these usually have very few problems.
Brian Meldon
What controller are you using?
The reason I ask is that these older type chassis do not work so well with some modern pulse controllers that work well with modern chassis with modern coreless type motors. They run better with older type controllers.
Brian Meldon
I am using a Gaugemaster Model W handheld controller.
Thank you for all the information. These locos are very old and do not stand comparison with my newer ones from either the detailing or running characteristics. I may well pension them off.
I will strip the Fleischmann one and clean it up. This is a much better chassis as you say. It also has sentimental value as I bought it at the Beds and Bucks group sale of Mark Howe's stock just after he died
Tony Clarke
Quote from: Tony Clarke on March 16, 2018, 16:03
I am using a Gaugemaster Model W handheld controller.
Thank you for all the information. These locos are very old and do not stand comparison with my newer ones from either the detailing or running characteristics. I may well pension them off.
I will strip the Fleischmann one and clean it up. This is a much better chassis as you say. It also has sentimental value as I bought it at the Beds and Bucks group sale of Mark Howe's stock just after he died
Tony Clarke
Model W should be fine. However they do suffer from dirty control pots. (Just like old transistor radios!) The way to test them is to turn it on one direction without a loco on the track and turn the speed up and down slowly. If the 'track' light flickers then the control pot has a dirty track. Do not worry as Gaugemaster offer a lifetime repair service so just send it back and they should fix it for free and send it back.
Brian Meldon