B1 - 61161

[Dave Holt]

0.27 mm for Gibson medium (2 mm) knobs, according my trig.
However, there are two holes in the cab spectacle plate that locate the ends of the hand rail and these are much closer (approx 1.325 mm - I can just get a 1.1 mm drill bit between the hand rail wire and the boiler) to the boiler than the medium knob standout so I'm going to use Gibson shoulder-less knobs. The shank of these is 0.6 mm diameter, so the 0.65 mm holes I've already drilled are slightly oversize, but not enough to warrant plugging and re-drilling - just plenty of glue.
The drawback with these knobs is that they have no mounting flange (by design) but I've found some custom etched washers (1.3 mm diameter, 0.125 mm thick) that will represent the flanges on the boiler. There should be 13, including the front of the smokebox, but unfortunately one pinged off and defies being found, so the front will have to manage without.

 

[Dave Holt]

Oft laid plans, etc.....
A washer was placed onto the shank of the first handrail knob and cyno glue applied inside the drilled hole then the washer fell off the knob to be lost in the carpet. Now there were only 11 available so the knob was inserted without. Oh well I'll just have to live with it. The left hand side now has all the knobs fixed in place and has a temporary piece of handrail wire fitted in the photo. Consistent stand out from the boiler was achieved by using a suitable drill shank as a spacer/gauge. Height above the foot plate was checked with another simple sheet metal gauge but was in any case set by the drilled mounting holes.
I'm more and more taken with the split handrail idea when I come to do the actual rails. I've never tried this approach before, but it could be much easier than trying one continuous rail round the front and down both sides. However, the ball on the front stanchion isn't going to provide much land to locate the ends of the separate rails.
Dave.

 

[Dave F.]

Hi Dave, on my B16 and others I made a handrail joint on the third knob down the boiler on both sides so there are two straight lengths down the boiler sides and that leaves a quite manageable piece to make up for the front end. I soldered the straight wires half way through the third knob and made the front portion over long to allow for the bending then slid it through the first two knobs and marked it for cutting, again slightly long and then filed the wire to exact length attached the shortest knob I could find for the smokebox and checked the alignment again and soldered it all together. Just a tiny touch of the soldering iron on plastic models though.
Hope that helps,

Dave F.