Wednesday, November 27, 2019

Controller Solutions

It was cold and very windy today, but a few of the regulars were hard at work as always.  The first truck for the Cleveland PCC is finished, so the other one has been put in its place.  

Gerry and Chuck went over to Barn 6 to finish installing the pilot braces on the 460, but I didn't get a picture of this operation.  In any case, it's much appreciated.  And Tim was working all day on seat frames.

Here we see Jack Biesterfeld working on windows for the 109, and in the background Buzz is making good progress on the velocipede.

He had to replace several spokes in the wheel.

And the main lever for propulsion is nearly done.

I haven't noticed much work on the Multi-Purpose Building lately, but several new piles of bricks and blocks showed up recently across the street, so that's a good sign.

And it looks like they're working on the HVAC system inside the building.

As for the 451, there are a couple of electrical issues to be addressed.  It turns out that while the MG set was running, it wasn't actually recharging the batteries.  The problem was traced to a broken mounting for one of the relay contacts, as seen here.  Thanks to the second shift for looking into this for me.  I removed the two pieces of bakelite and took them home to be epoxied together.  That should work, but if it doesn't I can probably fabricate a new one.

The bigger problem was with the controllers in the 451.  These are much more complicated mechanically than the older type, so I was busy trying to figure out why they didn't work.  This is a spare which I started disassembling in the shop.

One thing I hadn't known is that these controllers were equipped for a floor pedal connected to the deadman mechanism.  It's the long rod sticking out of the bottom of the case, above.  I don't know if the 450's ever had these pedals installed, and the deadman feature was removed from service almost immediately.  So that's only a matter of academic interest.  But the normal operation of the controller is still sort of mysterious. 

I went over to the 460 again to observe the operation of a known-to-be-good controller, and finally figured out what was wrong.  I can't explain it in words, but the basic problem is a design flaw.  If you remove the controller handle, as we sometimes do for safekeeping, the shaft is no longer centered and can be moved back and forth.  And this allows a large coil spring to come loose.  Getting it wound up and reset is difficult, but not impossible.  Identifying the problem was the main challenge.

Controller in the 460

And by the end of the day, I had the #1 controller in the 451 operating correctly, at least by observation.  I decided to quit while I was ahead, and wait until next time to start electrical testing.  

#1 end of 451

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