As I posted in another thread I picked up a brass Shay loco. It ran fine for awhile then just shut down and stopped working. I took the body off and connections from the motor to the trucks and they seem fine. I did clean the wheels and the wipers against the wheels. I did put power to the motor directly and one time it ran and another nothing happened. There us also a third wire that was just under the gear box doing nothing, could that be for grounding purposes or maybe for the headlight installation? I think the problem is in the trucks but really have no idea what next. Any ideas or advice would be appreciated
You really start with getting the motor running consistently with direct power to the brushes and work back from there to the pickup at the rails.
If the motor doesn’t run properly and consistently when powered directly by the throttle you are using then the locomotive just won’t run properly.
Re-motoring isn’t particularly difficult according to many threads on this forum. Often the new motor will be an upgrade and draw less current developing higher torque, a win win.
Once the motor issues have been solved then you work from those brush terminals down the wiring to the wheel pickups, finding and fixing any continuity problems. That’s when you’d also fit your decoder and speakers…
I have two of these and have taken them apart a few times. It sounds like someone modified this engine. The original engine only had one wire - that provided power pickup from one truck to the motor. The other truck basically provided prower directly to the frame. A simple power arrangement, really. So many modelers add wipers to provide 8 wheel pickup (instead of 2 - 2). That might be your case. Lights were inexistant on these models, to my knowledge.
So the issue could be mechanical or electrical. The motor is unlikely to be your problem, especially if you got it to turn as some point. Try to figure out the wiring, using an ohm meter, and look for loose wires or wipers that may be either shorting or not providing power. That loose wire is probably the problem. From a mechanical perpsective, the motor is easy to remove (if it’s original). But before doing that, try to spin the motor shaft with your fingers to see if the shaft can actually make the gears and wheels turn (do not try to do the opposite - push on the engine to make the motor turn from the wheels). This engine was very well designed and it’s probably fine from a mechanical perspective. But if there is a bind when trying to spin the motor shaft with your fingers, then you
I can turn the motor by hand easily and if I connect my transformer directly to the motor it will run. There are three wires from this motor one wire to each truck and the third just laying under the gearbox seemingly doing nothing. When I put it on the track it sits there and the transformer acts like the loco is shorting out. I had disconnected the trucks to clean the wipers etc and the washers that were on the screws got away from me and hiding on the floor. I did have some brass washers and wondering if when I put them on they might be causing the problem? Should I maybe using insulating plastic washers?
Somewhere you need power from each rail to reach only one of the two terminals on the motor. One motor terminal needs to be connected to one rail andvthe other motor terminal to the other rail. There are two common ways of doing this. The most common is to have the frame powered by one rail and the motor connected to the frame (not the best for DCC) and the other rail power connected by a wires from at least one truck directly to the motor connection.
Those two wires on your locomotive, one to each truck, are they both connected to only one pole of the motor? Or does one wire take power from the left side of one truck to one pole on the motor and the other wire from the right side of the other truck to the other pole of the motor?
My guess is that those two truck wires are connected to each other and then both are connected to only one pole of the motor. That loose wire is probably the other rail connection and needs to be attached to the other pole of the motor.
I don’t know that but from the photos on the internet it looks like the geared end of the drive axles is insulated. That implies that one rail power gets picked up from the truck wheels on that side. The other rail powers the entire frame and there should be a wire connecting the frame to the other pole of the motor.
One thing for sure is there ought not to be a third wire not connected to anything. Two wires are needed to get power from each truck to the motor. Either those two wires are connected together and feed power from only one rail or that third wire shouldn’t be there.
I took a closer look at the motor and one pole has two wires connected to it each going to each of the trucks. The other pole has the wire that is not connected to anything
OK, my guess is your locomotive has been remotored.
The loose wire is probably supposed to be connected to the frame somewhere, anywhere in fact.
Try this: put the chassis on the track, put power to the track, just touch the bare end of that loose wire anywhere on the frame. See if the motor turns.
clearly show that one pole (brush) of the motor is powered from the frame and the other from the wheel pickups on each truck. You can see the white nylon (or maybe hdpe) insulating motor mount in the photo. The other motor mount is brass and electrically connected to the frame.
Possibly the locomotive you bought was halfway towards a remotor, all-wheel pickup DCC conversion project.
Just btw that PFM model is really lovely and a very good Shay model. There are a number of less than stellar Shays out there but you’ve found a very good one. It’s well worth tracking down this issue and fixing it.
OK, so the problem sounds electrical. I looked at one of my Shays this morning. Power pickup on mine is: front-right, rear-left. The rear truck is isolated by a fibre bolster. Both trucks have a brass washer. If you lost yours, you should replace it. Your’s might have additional wipers installed… See my previous post about that.
It sounds like you have a can motor. If this is the case, you should have one wire from the rear truck going to one of the motor power lead, and one wire going from the frame to the other motor power lead. The front truck is not isolated from the frame and power goes through the frame. The previous owner might have soldered a wire from the front truck to the motor for power. If there are indeed wipers, then wires would need to route from there as well.
So you need to figure out your wiring. If there is a 3rd wire dangling, and there is a short, make sure that is not the source of the short. If you don’t have wipers, I would just cut that wire off. So then you would be down to two wires to figure out, as I explained above.
Also, make sure you did not reverse the wheels when you reassambled it. That can be easily checked with an ohmeter (I strongly recommend you get one if you don’t have one). The front left wheels should be isolated, and back right wheels as well (I think I got that right [*-)]).
Oh, and if you need to remove and reassemble a truck, one trick I use is that I put a small dab of silicone on the side of the screw, underneath the head, to “hold” the spring in place while you install it. Nothing worse than looking for a loose spring on a shop floor…
Is it possible a PO got partway through modifying this to left side/right side all wheel power pickup? I understand this is a popular modification and especially if planning to also install a decoder.
Is the brass washer on each truck where the power wire would be soldered?
The second pole of the motor needs a connection to power. From the factory this comes directly through the frame, no wire is needed. Power to the frame comes directly from the truck although it’s hard to understand how that could be done without a wire from the truck to the frame.
Check for power at the motor connection with the disconnected wire. Touch the bare end to thevframe while the Shay chassis is on track.
If the motor always runs when powered directly at the brushes (contact strips at the motor) and the Shay is not on track then you can’t have an internal short in the actual locomotive. If the motor sometimes runs and sometimes doesn’t when not on track and is powered directly and only at the motor contacts then likely you do have an internal short or a loose connection to the frame/truck pickup. That would indicate an intermittent short.
If you place the locomotive chassis on track and apply power does your powerpack indicate a short? Can you run another locomotive on the same section of track when your Shay chassis is also on that section of track but not moving?
If the motor always runs when powered directly and does not run when on track but other locomotives can run while the Shay is on track then the Shay has a power connection fault between its trucks and the motor but no internal short.
i did attach the loose wire to the frame and put it on the track and it just sat there. later today and tomorrow I will putter around with it using the suggestions you guys have offered. Wish me luck, I would like to get this going again.
Sorry I missed the above comment. One motor pole should connect to one truck, and the other motor pole to the other truck. If you have wipers, there might be other wires.
I did change the wires around so each truck is connected to a poll on the motor and the loco still sits motionless on the track, the third wire is both attached and loose. I think the trucks are the problem. They are both attached with a screw with spring. Should there be a washer between the truck and frame and if so should it be metal or non conductive type. I did have brass washers there. Also the wires are connected to a wiper setup, not sure if they are original or custom made by the former owner. should there be any washers underneath the unit and if so what type and I have a brass washer on the screw as the hole in the wiper unit was larger than the screw head. would that be ok or should I change to a plastic type?
You will need to put your detective hat on to see. Since the Shay did run on your track at some point, it appears that you did something while reassembling it. The washer does not isolate the truck, not on mine anyway. It is a strip of material under the rear truck. One thing you can do is put the loco on the track, put something under one set of wheels to lift it above the track, and see which is the offending truck. The wipers might have been affected by the cleaning procedure.
I have done just that with the trucks. For awhile I thought it was the rear truck then it reversed itself and it seemed that the front truck was the culpret. Now if I hold the unit in my hand and connect power directly to the motor it runs but not if I put it on the track it shorts out. Also sometimes it requires the loose wire to touch the frame and sometimes not. Wonder if I should rewire the darn thing?
Thats key information. Somewhere between the motor connecting tabs and the trucks you have a short.
My guess would be the trucks are not isolated properly.
As originally wired these had one truck power one pole of the motor and the other truck power the frame which powered the other pole, according to information in this thread and other places on the internet.
Someone altered this original wiring. Possibly during the remotoring.
At this point you would benefit from using a multimeter or other circuit continuity device to trace the fault. You’re looking for a short inside the locomotive wiring.
Truck or motor mounts would be my first investigation.
