Mystery Short

[jonathan]

Because I have a garage layout, I can't run trains in the winter.  So my winter project has been building a Pennsy G5 (4-6-0). The shell and chassis is Bowser.  The tender is Penn Line.

This morning I installed the motor (skew wound DC-71) and did a test run.  The engine shorts out on right hand curves (22" radius).  It runs fine going straight or left.  I have all wheel pick up in the tender, so I didn't wire the motor to the loco frame.

At first I thought it was the pony trucks, so I removed them and ran the engine... still shorts on the right curve.  However, if I lift the front of the engine a little, it begins to run again.

223 pieces of the loco are metal.  The only plastic parts are the tender trucks and tender axles.  I'm no electrician, so I'm at a loss to solve the problem.  My gut says either the front drive wheels or the pilot is bridging the tracks somehow.  Is there a simple test to find the short?

Thanks for reading this.  Will post pics when I get this last bug out of it.

Regards,

Jonathan

[jonathan]

Here's a few pics with the pieces test fit.

[BaltoOhioRRfan]

Please tell me you don't have that Pennsy engine on the Belt Line through the Howard Street Tunnel :-P

anyway, see if you have any metal(Frame included) touching the wheels, sounds like the drivers might be coming in contact with something. turn the loco upside down and replicate the right turn and see if anything is touching the wires.

If possible, take leads from the track and hold em against the pickups while replicating the turns.

[pdlethbridge]

 another option would be to wire it like bowser suggests and see if that works. That's a great looking engine. I'm building the bowser light USRA mike and setting it up for DCC. Both brushes are insulated from the motor frame. Do you have the 2 wire motor or 1?

[jonathan]

PD and B&OF,

Thanks for the tips.

I have the two wire motor.  It is new.  It also the last DC-71 Motor that Bowser had.  There will be no more.  I plan to reconnect to the loco frame once I find all the little bugs.  I think that will lead to a smoother ride.  On perfect, level, straight track, the engine is as slow and smooth as my Spectrums, but the Bowser is completely unforgiving of imperfect curves and turnouts.

I am quickly discovering that many adjustments are necessary when building a Bowser loco.   Here are a few:

The pilot is causing a short when it hits the left rail.  The engine is finding two minor humps in my trackwork I was unaware of.  I am filing down the cowcatcher as much as possible to solve that.   Will revisit these invisible humps. 

One of the crankpin screws was a hair long and touching the brass driver wheel holding plate as it went through its revolutions.  Caused a short when turning right.  Filed down the crankpin screw AND all sides of the driver wheel holding plate.

Pony trucks will derail on one curve on my layout... only one.  Since it is the only engine that behaves this way,  I will try to add weight to the truck.

Anyway, I've been building this for about a month.  Can't complete the final appearance, until I spend some time making it run right.  I believe I can get there.  It's going to take a lot of patience and minor readjustments for now.  I hate this part...

Regards,

Jonathan

PS,  tried the "Blacken-it" on the drive mechansim.  It certainly looks weathered, but it wasn't the effect I was going for.  Live and learn...

[pdlethbridge]

As long as you're us old DC, using one wire to the frame from the motor is okay. But if you are doing DCC, DON'T DO IT. You'll fry the decoder.
Bowser engines are tough to build but yield a nice product when done. When people see the engine and say, nice, you can say, I built it myself. Between my brother and me, there are a ton of the old locos kits like that. From Mantua there are as follows. 0-4-0t, 0-4-0, 0-8-0, 2-8-2,and a 4-6-2. from Bowser we have a 4-6-2 k4, 2-8-2 USRA light mike and a 2-8-0 old lady. 2 weeks ago I cleaned the wheels and tested the 0-4-0t, it ran like a charm. All the engines except the 2-8-0 and 0-8-0 are old DC. Remotoring thr rest at this time is not in the budget. And as a note for endurance, the 0-4-0t was acquired in high school so that makes it at least 45 years young.

[Woody Elmore]

Those old Mantuas will run forever with a little maintainance.

I can attest to the fact that Jon's G-5 was a basket case a month ago. He didn't mention that he scratch built the under running board piping himself rather than get a Bowser kit.

Jon's engine is a product of skill, effort, patience and time. We now have a shake the box crowd who will vilify Bachmann if a coupler is too low. These folks will never know the satisfaction of tinkering with something (especially a basket case) and then seeing it operate.

Kudos to Jon!

[pdlethbridge]

Yes kudos to Jon. I never had an easy time building those engines, it was always something, but the satisfaction of getting it working, and working well is great.

[jonathan]

Thanks for the kind words, guys.  Really my thanks goes to Woody who sent me this "basket case."  It really wasn't in that bad of shape--a few bumps and bruises here and there.  I felt like I was over the hump once I got the drive mechansim turning freely.  He also sent some brass detail parts which really enhances the appearance.

If I understand the theory behind these metal kits, the whole loco is designed to pick up current from the right rail.  So anything that contacts the left rail (or wheels) would cause a short.  Following that logic, I wonder if an application of this "bullfrog snot" stuff, to the left driver wheels, would prevent a lot of shorting possibilities.  Not that the engine needs more traction.  It weighs in at nearly two pounds.  It feels like lead in my hands.

As to my skills, well this may be the last steam kit I attempt.  It's really a lot of work (60+ hours so far).  Plus, my eyes and hands aren't what they used to be.  A magnifying glass and tiny tweezers will only get you so far.  In the end, one can spend as much working on a kit as buying a RTR.  I do agree it will be quite satisfying when I get this puppy rolling true. 

Regards,

Jonathan

[pdlethbridge]

Yes, they are not 'shake the box' ready. They do require a lot of work. The bull frog snot wouldn't help because the rim might be touching, not the tread. You might try a fiber shim on the axles if the wheels are moving too much side to side. It wouldn't take much. This is on the side with the insulated drivers. They should be kept from touching anything metallic. Even a piece of electricians tape or very thin plastic sheet cut to fit on the side of the frame might solve the problem. The loco picks up current on one side and the tender on the other side.

[Woody Elmore]

Yes, a shim behind the drivers might definitely help. The fireman's side drivers have insulation between the tire and the wheel casting so technically they are insulated and shouldn't cause a short unless the flanged tire is touching something.

The Bowser engines are a lot of fun but they can be very frustrating when little shorts occur (as Jon is finding out!)

[jonathan]

PD,  you caused an 'AHA' moment!

I could cut a slit in a few fiber washers to fit over each axle, and if I need to, I could sneak in a little glue to hold them to the frame.

Brilliant!

udaman (text speak for thanks a million, friend)

Regards,

Jonathan

[pdlethbridge]

I     hope that will fix it.

[jonathan]

OK, I was able to cut a slot in the fiber washers and 'snap' them into place between the wheels and the frame.   Easier than I thought.

Initial test shows my only grounding left is caused by the pilot touching the left rail in two spots on my layout.

I have since filed down the pilot.  The bottom rung looks like a razor blade!
I also put a fiber washer between the pilot and the bracket that holds it.  In all I have raised the clearance a little more than 1/32".  Haven't had a chance to test it, but if there is still pilot grounding, I think it will be a case of humps in the trackwork that I need to fix. 

I should mention, there is no problem on my outer loop, which has a minimum 24" radius.  The inner loop is 22" radius minimum.  This loco is suppose to be able to run on 18" curves, but I'm not going there.  Don't need to get to that tolerance on my mainline.

I think I'm ready to get back into the final assembly and addition of a few more superdetail pieces.  A little touch up, and I'll be ready to show off my newest baby.

Thanks B&OFan, PD and Woody for helping through the tough part.

Regards,

Jonathan

[Woody Elmore]

Jon: That Cal Scale brass pilot is similar to but not exactly the same as the Bowser die cast one that came with the engine. Perhaps mounting it a tad higher would work better than filing!

I can't wait for your final pictures.