Time for a look at the trouble I had with shorting pick ups and (still) dragging brakes yesterday. I'll get the images uploaded first and add text as the evening progresses - in between casting some resin items, "A Matter of Loaf and Death" and some Great Expectations later on - so if it doesn't all make sense at first, give it time....
That first image simply shows how the outer keeper plate (modified by me) carrying most of the brake gear comes off when un-screwed, releasing the two contact strips that lie beneath making contact with studs on the inner keeper plate. That plate is wired through to the motor - unless, like mine, it breaks off as soon as you touch the thing!
You can see here how very little free motor lead projects out of the bottom of the chassis, and as I've mentioned on another thread, it had previously proved impossible to pull any more of it through without at least loosening the mountings of the motor - even then it didn't free up very much so I wonder if you have to take the motor (or something else) right out? Anyway, this time around I was trying to confine activity to a "brief simple job" without even taking the loco body off yet another time, so......
I thought I could get more space in which to position the inner keeper plate, the wire, and a soldering iron if I undid the rear crankpins and put aside the rear wheelset. That worked fine for soldering, but the presence of the tight-fitting keeper plate and the wide Cartazzi unit (another item I didn't want to remove as that is a body-off job too) meant that I couldn't then sneak the wheelset back in under the keeper from front, rear or side, no matter how I twisted and turned things! By this time I was as "not amused" as Queen Victoria.
Short of dismantling a lot more than I wanted to disturb, the only thing for it was to de-solder, put the wheels back in, and then re-solder with great difficulty - I couldn't turn the keeper plate on edge by anything like as much as 90 degrees, couldn't hold the wire, and had to steer the iron in from an angle, carefully avoiding any plastic items. Somehow, it worked....
In the image at the top, I'd already straightened up the contact strips, but this close-up of the left strip after a first round of straightening shows the many kinks and ripples in the central portion that had been coming into contact with the crankpin on the back of the wheel. That pin (or its nut) rather surprisingly appeared to be fully-home, flush in the wheel. Regardless of that, while I had good access I made sure that my thin layer of insulating, retaining epoxy was smooth and complete over all of the backs of the pins/nuts.
After several trial re-builds and test runs, and much tweaking of pick-up strip shape, I finally had full power collection and no shorting on starights or curves, in both forward and reverse running, but an annoying tight-spot had re-appeared
. I eventually detected the fact that the outer keeper plate with its re-drilled holes and bodged joints had shuffled along slightly allowing one of the brake blocks to scuff intermittently. Only when I attended to this, so as to get the brakes well clear of the wheels as pictured here, was all finally well.
The brakes problem won't recur on any future examples of this loco, as I'll make more of a point of NOT breaking up the outer keeper plate and I'll have a finished example to work from when setting out positions for new holes.
Here you can see evidence of my belated further adjustment to the screw holes, filing them out at one side and filling them with epoxy at the other. This moved the front hole out of the edge of the outer plate altogether, so I made a brass plate to screw down over the end of that plate to maintain the secure fit.
As you may see, at least those resin cylinders have tidied up and painted nicely.......
. I've not had much time to investigate until today, when I ran on my own "real electricity", on which it was much less troublesome but clearly "not quite right" - a bit stuttery or lurchy at times.
Somebody must be even more amused now than they were in first place. But we shouldn't laugh at others experiencing vowel trouble......