Large Scale Central

ACCUCRAFT Goose #2 Shorting out

Problem Solving
#1

I have the Accucraft Goose #2, a very nice brass model. It seems to be a simple engine, with a pickup for the engineers side on the pilot truck and a pickup for the fireman side on the powered truck. The pickups are simple wires touching the axle.

I will be running this unit on track power and it will suddenly stop, and I find the 10 amp fuse on the track side Train Engineer blown. Usually this only happens if I manage to derail on a switch and short out the tracks.

So I took off the cargo compartment and checked the resistance for the pickups and all seems to be isolated properly. But as I jiggle and push on things I may get a very quick momentary twitch on the ohm meter.

But no obvious cause for this, thus I suspect an intermittent short somewhere. Quite frustrating of course. Next step is to run it on rollers and see if I can observe anything, but I don’t have much hope of being able

to spot the problem

Has anyone run into this before with this unit, and have any suggestions?

Thanks

Jerry

#2

Derailing on a switch normally shorts the rails together through the loco, usually through pickup wires. In many locos the internal wiring burns up or blows/trips an internal fuse.

But failing that, your 10 amp fuse should INDEED blow in your power supply, it’s there to handle a short.

You should count yourself lucky that an easy to replace fuse went as opposed to destroying internals.

The picture below is the main board of an Aristo loco that derailed on a switch and the short went through the loco:

The suggestion is to put PolySwitches on the track pickup wires, which are effectively self-resetting circuit breakers. This not only will avoid blowing the main fuse, but protect the loco internals.

Greg

#3

I’d look for the rims touching the frame, or wear in the journals, has the lateral travel increased with wear? Does a hub rub?

This is assuming the wires are sound.

#4

I’ve never had this problem with my goose.

Did you know that you can get an additional pickup for the rear to put on the other side and make a simple pick-up for the other side of the front and double you contact area?

Accucraft sells the rear pick-up.

I made the front pick-up by soldering a “brass wire” to a brass “tab,” with a piece of wire electrial wire soldered to that, to conduct electricity to a cental location. A piece of vinyl electrial tape goes around the brass tab and this is “sandwiched” into the truck frame by loosening/retightening the factory screws. The brass wire rubs on the back side of the front wheels.

My goose also has ITT sound (idling and running), smoke from the rear stack, and steam from the radiator cap. You can see the steam in the pic. (http://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-wink.gif)

#5

Gents-Thanks for the replies. Yes Greg, a polyfuse in the feed wires would be a good idea, I have a bunch from earlier troubleshooting

John- There is little wear, not run much. I may add styrene shim stock between wheels and rim, see if that helps or tape here and there

Todd- Good idea to add additional pickups, but need to find the problem first, the wires are all in good shape

Jerry

#6

On the PolySwitch (that’s actually the brand name, goofy that it is not ~fuse) you can get them pretty cheap, I use the 3 amp ones, like Aristo used, which basically should “hold” 3 amps and trip at 6 quickly. Since they work by heat melting and recrystallizing, they are not immediate, but fast enough in most cases to avoid damage.

I got the name brand ones for about 50 cents each, either Mouser or Digikey.

I put one on every pickup wire, it may sound like overkill, but that will protect from ANY and ALL combination of shorts “though” the locomotive wiring, except between wheels on the same side of the same truck, which is really rare.

Putting in one or two is really not sufficient. By the way, that board above is mine, and burned it up twice. The trace that burned was from the front to the rear, the typical situation.

The picture below pretty clearly shows that the power between the trucks indeed goes through the main board, this is a typical setup. Roasting a circuit board, especially from a company out of business is not fun.

Regards, Greg