Heisler Pickup Problem

[naptowneng]

Hi All

Chapter two in the faulty pickup adventure (there are 4 chapters...;(  )

My Heisler, not sure how old, but had little running, had been fussy as the rear truck would stall now and then.  I finally put it on the bench, and using the power supply determined that rear truck was not operating properly. The truck is suspended under the bunker with a screw into a rod, and there are 4 contacts two for motor and two for pickups.  These use copper strips on top of motor block and a system of 4 pins, two brass ones which I think are pickup power up and two gray metal ones which I think are motor power down.  They contact a set of 4 thin copper strips under a plastic piece in the bunker.
This allows the truck to swivel and tip. Well, the 4 screws that hold the upper contact plate in place had unscrewed themselves (?) but somehow due to residual magnetism, were still hanging around.  So I put them back, cleaned both contact surfaces and put it back hoping for a cure, but, still having a contact problem.  Testing seems to indicate power from the board to the motor is present, but I am having a loss of power to the motor from where the gray pin contacts the upper copper strips.  I do not see where to go from here as the upper copper strips seem intact.  The gray pins do not seem to drop down and up as freely as the brass looking pins that conduct power up from the truck.  I would welcome any thoughts on this issue
Thanks

Jerry

[Joe Satnik]

Hi, Jerry.

If I recall correctly (IIRC), most have given up on the contact plate and directly hard-wired the 4 wires,

or used a 4 pin connector set somewhere along the 4 wires.

Others more knowledgable, please chime in.

Hope this helps.

Sincerely,

Joe Satnik

[mickeykelley]

Are the springs in the plungers working?  Maybe try a drop of electrical contact oil.  That setup sounds like the one used on the newer Climax.

[naptowneng]

Mickey- ? If you mean the pickups on the wheels, they are fine.  The problem is the "pins" that carry power to the motor that rub on the plate on the top of the motor and on the copper strip above the truck.

I determined by appplying power with probes that the connection to the motor from the board is broken at the upper copper strip that the gray pin is supposed to be touching

Thanks

Jerry

[mickeykelley]

I'm talking about this part:Model: 824XX-G821X-00B01-2 which is actually for the new 3 truck Shay but is very similar on the Climax. I had one prong that had a dead spring in it and would not make good/full contact. A drop of electrical oil and it stopped sticking and started working again. Just a suggestion.

[naptowneng]

Thanks Mickey- I need to do some more exploration of why that contact is bad and what it would take to hard wire the truck into the circuit board

Regards

Jerry

[Loco Bill Canelos]

Hi naptowneng,

While have not hardwired the Heisler, I have done others. Like Joe, I strongly recommend hardwiring especially if you will be using track power. 

The reason is that when a short occurs the first item to heat up is the spring in the plunger.  The heating weakens the spring due to the short.  If you run a lot on track power eventually after several shorts the springs seem to fail.  My experience is the plungers that press against the wheels are better (fail less often) than the ones between the truck and chassis which are the weakest. Sometimes in a single severe short a spring can weaken to the point it will not function as designed.   The advantage of battery power R/C is that the shorts which weaken the springs do not occur.

Conductive oil while it may help in the short run on a weakened spring, is generally not a long term solution.  Replacement of a failed spring is recommended if you run track power and have a weakened spring.  Regrettably I do not know of a suitable replacement spring.

Bill

Hope this explains why the springs often fail. 

[naptowneng]

Thanks Bill appreciate that wisdom
While the pickups against the back of the wheels have springs, there appears to be no springs on the pins that transmit power from the truck to the copper strips on the bottom of the bunker.  It seems to just use gravity the push the truck up against the pins and the copper strips. Sorta amazing it works at all!

While I have 6 or 7 battery locos, be a long time before I get to doing battery conversions on all the fleet, I hope you can appreciate   

Jerry

[Loco Bill Canelos]

Jerry,

I can't tell anything from the diagrams, but I am thinking gravity would not work at all. Can you get into one of them to verify the method? 

I definitely appreciate the situation on battery conversions, I am in the same boat, and even have a priority list.

[mickeykelley]

Pretty sure all 4 pins use springs.  Missing or damaged springs is my guess.