The other two J6 mechanisms are now built up and running smoothly, ready for addition of pick-ups and cosmetic bits.
There's something of a mixture of spares-box wheels on these two. The leading loco is shod with 20mm 16 spoke wheels (not quite right, but close) which came my way as a freebie from the man at Little Bytham. I think they may be Sharman wheels of some vintage. The axles required cutting to length by the user, as did the rather long crankpin bushes. They don't run quite as true as Markits wheels, nor do the Gibsons on the first J6 I built, but they do the job.
The third J6 has Romford / Markits wheels, possibly in fact a mixture of the two, all 21mm 18 spoke. Those hidden on the other side of the loco are the type with blackened spokes, RP25 flanges and no cast-in balance weights. Although I had three more 21mm Markits wheels with RP25 flanges, those were 16 spoke, not blackened either. I could have used them, just to see whether anybody was pedantic enough to count the spokes on both sides of the loco, but for some reason I chose to do things the hard way. The three wheels on this side of the loco had the older deep flanges, cast in weights and the correct number of spokes. For some reason ONE wheel had a plain un-tapped hole for a crankpin and the other two weren't even drilled. Fairly ancient ones I imagine. Using an electric drill in a vice to spin the wheels on their axles I reduced the flanges with files, getting as near to the size and shape of an RP25 flange as I could. Using the one drilled wheel as a pattern I put the other two in succession back-to-back with it and drilled their crankpin holes, then tapped them all 10BA. I suspect that somewhere in this process I got one crankpin hole slightly out of position, because when I fitted up the rods onto the leading and middle set of wheels they spun perfectly freely with holes in the rods only 0.1mm larger than the 1mm crankpin size. When I then tried out the rods separately on the middle and rear sets of wheels I got persistent binding with the cranks in the 45 degree positions and had to enlarge the holes in those rods to 1.3mm before the problem cleared. Having thought about this problem again, after the event and too late to change my tactics, I think I ought to have swapped the leading a trailing wheel from the prehistoric set. I might then have been able to keep the rear sections of the rods snug on their pins, rather than sloppy, even if the front sections had in turn to become a loose fit. I don't much like the idea of already having so much slop in the rods that transmit the forces from the driven rear axle, but it works for the time being.
Just as well there's a squadron on the way 
