When we got to the track Rich told me that the Club one-inch F7s were having a problem and we needed to get them repaired ASAP. What was happening was the "A" unit's front chain drive was rubbing on the chassis and the front unit seemed tippy. It turned out that the battery's weight was compressing the suspension springs. Our first inclination was to tighten the bolts that flank the suspension springs to decrease the tippyness but this decreases the "springyness" of the suspension. It also would not cure the problem of the drive chain from the motor to the gearbox rubbing on the frame crossbar. Then it became apparent that the solution was to raise the frame. This turned out to be relatively easy as all we had to do was unscrew the bolster attaching screw then insert a few washers under the frame lug that sits on the front truck. This gave us a about a 3/8" clearance between the chain and the frame. With the spacers the weight shifted a little and the rear springs seem to stabilize the tippy inclination. So the cover went back on and after testing it out we brought the F7s back out of the roundhouse for use during the weekend.
I had noticed the crossing lights were not going off after a train passed, they just stayed on continuously so I decided to check it out. What I found was that the heat (several days of high 80s and low 90s) was causing the rail to expand (positive temperature coefficient) and close the gaps between the isolated section and the rest of the track which apparently caused a ground loop through the connected track and turnouts. Tommy Cebulla had given me some track insulators made from fiberglass for isolating track sections so they act as fishplates and they hold the rail in alignment. I got an angle grinder with a 1/16" disk made for cutting metals and ran an extension cord to the location. After I cut the slot, I installed the new insulators and put a small piece of nylon between the ends of the rail as Tommy suggested. I wound up cutting two notches in the two locations at either end of the crossing block. It went pretty well except it was all in the bright sun and the temperature was close to 90 degrees. This seemes to have fixed the problem.
Next it was reported the semaphore at the roundhouse lead heading into Glacier was staying red all of the time. I checked and it was not a circuit board problem as the bias resistor was toasty meaning the track or the is wire from the track is shorted to ground. I removed the wire from the track and the signal bounced to green. Next I went from one end of the block to the other to see if there was some fault like a wire connecting from side to side and disconnected the opposing signal that feeds from the far end on the block. This did not fix the problem at the roundhouse lead end and the semaphore at Glacier car barn end then bounced green so the problem lies within the track. After considering that the block had worked properly for some time most likely the problem was thermal but the signal had acted up from time to time too. I started looking at the rail itself considering where the notch's were cut in the rails and suddenly it struck me the wrong rail was notched - the ground rail not the hot rail. I got going with Bill Schimmelman cutting more notches and installing insulated fishplates. Because the rail was butted up tight we had to drill new mount holes for the plates which slows the process. Finally after another hour in the sun we finished. The semaphores seem to be operating as they should and the first green in several hours was displayed. Sometimes problems can be knotty and you just have to work through them until you find the answer.
Sunday, May 30, 2010
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