Woah man, that's real groovy! Thanks Col.
There is one thing I noticed on that clip though; all those amazing gear designs had one common factor; they were dangling in blanc, white space! Unfortunately, my own simple version has to operate in an awkward environment, with various (some unforeseen) elements effecting the operation. I was to discover that later, and there were almost tears before bedtime!
Before all that, and with the aforementioned confidence that only the wiring needed reversing, I set to finishing off the work on the gearbox.
First up was the task of replacing the temporary nut and bolt on the lever arm with a proper pivot pin...
I also decided to make three equal spacers to fit between the plates in place of the nuts on bolt construction.
Using the same method adopted for the boiler tube ends, and by cutting each slightly over length, then popping over a carefully squared dowel, and filing down flush ensured that they all ended up exactly the same length...
With the box practically finished, and still running sweetly on the bench after a wee bit of fettling, the fun of setting it up in position on the bulkhead commenced.
Oh boy, oh boy! It seemed like a good idea the time?
I know I said that clearances were tight, and on paper that was fairly self evident, but I hadn't fully grasped how impossibly so! I really should have known better and considered any potential pitfalls a long, long time ago - at least much earlier in the boiler barrel construction anyway. As a result of that error, I found myself somewhat stuck in a hole - and one turning out to be rather smaller and darker than I had previously imagined!
There is no opportunity to adjust the large regulator stuffing box attached to the boiler backhead, and the journal in same is quite deep - thus ensuring that there is no slack, and that the regulator handle describes a perfectly parallel arc, In order to clear the firebox, the operating rod needs to be quite long, so the alignment of the arm and pivot in the gearbox on the internal bulkhead has to be very precise indeed. With the notion of keeping everything simple, the top two spacer screws were intended to be long enough to pass through and fit the box to that distant bulkhead. That shouldn't itself have presented much of a problem?
The first problem was that in order to find that critical alignment and to mark the centres for the screw pilot holes, the backhead needed to remain firmly in place on the boiler. With the firebox removed, I could still easily get my hand - and hold a small tool in the vacant space - but I can't see what I'm doing in there at the same time!
After an awful lot of blindly fumbling around, I thought I had got the marks where they were needed to be. There was absolutely no way to get a drill in there, so the backhead - plus all the plumbing - had to be taken down and removed. I then discovered that the holes would be too close to the barrel roof and rib structures for sufficient clearance of any drill chucks available!
After much rigging and jigging about, I finally got the holes drilled, the gearbox screwed firmly in and the backhead back on...
Missed!
Only by a little - but it might just as well have been by a mile! Not even a chance of slightly adjusting one odd hole to make it fit! There was nothing I could do but dismantle everything, plug the holes with glued in dowels, wait awhile for them to set, and go through the rigmarole of marking, drilling and reassembly all over again?!
I had to do that two more times!
It's ruddy well in there now...
Gosh, what a mess though, for lurking behind that neat looking gearbox and circuit board on the other side, the poor old bulkhead looks as if it had been used as a target for gunnery practice?!
I suppose that if I am honest, my decision to do battle with a steely determination, rather than just sitting down and quietly rethinking the backplate design was the second problem? The latter course might have been less wounding, and saved a few tattered nerves at the end of the day?!
Pete.
.
