Broadway Limited Imports ''Sharks'' A unit shorts out

Model Railroader General Discussion (Model Railroader)
1

Well here I am again with something interesting about this model. As you may know my DCC board smoked it’s self right after maybe two hours of mostly forward running time. I sent the board back to BLI and received a new board, the service was great and turnaround time was wonderful. With the new board installed, shell on, cab address #3, running factory settings, here we go. This loco has some very good weight to pull a train.

Now on to the next problem with this loco. Every thing was going great forward, then when backing aroung a left hand 22’’ or 24’’ curve pushing cars the engine would stop dead on the track but the lights stayed on, no motor humm, no wheels turning, no smoke, no system shutdown. Ok, dirty track, out comes the cleaning crew.

Lets try this again, in reverse same thing, stalls, wait lets use more speed. Woops, to much speed. Crashed in to a few cars in the yard. Now the Kadee #5 on the rear has a smashed (compressed) knuckle spring. So lets change that out.

But it still stalls in reverse on the left hand curves pushing cars. Off comes the shell and lets see what is happening.

Aha, there is the problem, the trip pin tip swings out and catches on the outer rail. I did notice the loco. would stall on a turnout at times.

Ok check the height of the coupler and trip pin. That’s strange, it’s spot on. So now let’s run it in reverse without cars though that curve again. All’s good no stalling. Let’s try it with cars, aha, there it is.

All that drama to get to the point…

With the loco (A unit only) in reverse, slowly pushing cars around a left hand curve, the rear coupler will swing out and down slightly and the tip of the trip pin touches the outer rail, yep there’s the very tiny spark that stalls her out.

That rear Kadee #5 metal

2

I found some arc/shorting out marks on the frame…so far.

Front truck left side, where the black pickup wire is soldered to the tab of the brass axle bearing side plate. That solder joint/blob will just skim the frame.

Ok, at the front truck right side on the frame, I see a slight scrap mark on the frame from the gray wire’s soldered joint to the brass axle side plate.

Three choices, #1) The tabs need to be pushed down some, #2) grind out some frame, #3) remove some of the solder blob. Looks like #1 gets my vote.

I hope the folkes from BROADWAY LIMITED IMPORTS get wind of this.

3

They won’t if you limit yourself to just telling us here. Call them or email them.

Rich

4

If the frame is hot, then you should replace the coupler with an insulated shank version, because sooner or later this would come back to bite you anyway - say two ynits coupled together tail to tail. If the frame and coupler box are live, the only way the trip pin could short out like that, then you not have a dead short through the couplers. Same issues go back to the AThearn BB days, and the choise was either install a coupler in Kadee’s own insulated box, or use an insulated shank version of the coupler which they also make.

If you don’t use magnets for uncoupling, just bend the trip pin up slightly. Might even still work with a magnet, you don’t need much, just enough to keep it from touching the rail. Even if it didn’t short, catching on the rail will likely cause the loco to derail.

–Randy

5

I agree with Randy. You should use couplers with insulated shanks. Since you said you’re using Kadee #5s, I suggest changing them to #28s. They’re the same thing only with an insulated shank. I recently put them on an MDC two truck Shay and two MDC 2-8-0s, and they work great.

6

I also agree on using the Kadee insulated shank couplers. The plastic they use is very tough, and the finish they put on looks so much like the standard metal that there won’t even be a visual difference.

I’ve also had good luck with McHenry scale size couplers.

7

Thank you guys for your highly respected response’s. I went down to the train room to look for some Kadee #28 couplers which I would have bet that I had none in stock. Well I have one pack of Kadee #28 at $3.35 date stamped 12/26/96 with a description on the bag ‘‘Talgo-Truck Adaptor Kit’’.

I will mount this #28 (insulated shaft, metal knuckle, coupler only) on the rear of the A unit Shark. BUT this is not a One-and-done fix. The problem is still at the front truck, the GRAY and BLACK wires that are soldered to the top of the tabs on the brass axle bearing side plates. The clearence is to small at this soldered point and can scrape the frame and arc (I can see the marks on the frame) causing a short. If both GRAY (right) and BLACK (left) wires touch the frame at the same time (ouch, I’ve been bitten). So I still need to make adjustment/repairs to this front truck pick up wire/frame area.

The Kadee #5 style metal shank, head and screw in a plastic socket are factory installed equipment on the rear of the Sharks.

I do not think the frame is supposed to be hot. All wires from both trucks go to the DCC board.

I have always tried to used Kadee’s insulated coupler boxs on the Athearn BB’s. I think I drilled and taped the metal frame and screwed them down.

8

Here is what I did to correct the arcing/shorting out problem created by the front truck pickup wires where they are solder to the top of the tab of the brass side axle bearing plate. Both of the wires/solder connection would lightly touch the frame and sooner or later scrap the black paint off then arc and shut down the motor, but the lights would stay on. I can’t say what the sound did because it was turned off at the time of the troubles.

What I did was… unsoldered the black and gray wires from the brass pads, (after disassembling the truck side frames of course), removed the solder blob from the top and cleaned up the BOTTOM of the pad. I soldered the wires to the BOTTOM of the pad. Plenty of clearance now.

So far she runs great.

The rear truck has not giving me any trouble.

For the record, this is a Stock #5752 BLW BF 16A, PRR 2011A, Paragon 3 Rolling T., Sound/DC/DCC, Black Box Lid, date stamped 13 Aug 2019.