Crankpins installed

I decided to use the quartering jig to hold onto the crankpins while the epoxy holding them in place cured. The theory was that regardless of where the actual holes in the wheels wound up, the vital metric was the distance between wheel centre and the crankpin itself. So, I gave the quartering jig bosses […]

Another way to wreck a driver

You may recall that one of the previous methods to wreck a driver was to drill the hole for the crankpin off-centre. Actually, that didn’t completely wreck the driver: once the spokes had been taken out, it looked salvageable. A short length of steel soldered in the hole and filed flush made it look as […]

Crankpin nuts: a war of attrition

The crankpins leverage M0.6 bolts, with nuts buried in housings inside the back of the wheel. Those nuts are really tiny – 1 mm across the flats, and so, I had always thought I would glue them into the back of the crankpins, rather than risk having them work loose and disappear amongst the ballast. […]

Just two holes!

All I wanted was two holes. Two holes for crankpins 1mm in diameter and the right distance from the centre holes in the quartering jig. It seemed simple enough when I conceived of them. But then, how to get the holes the right distance from the centre? So I made a tiny bushing to fit […]

Ash pan test fit

I couldn’t think of any reason to keep the frame pan underneath the frame now that the bearing guides are in place. So, I took the jewellers saw and hacked it away. Now the frame begins to look like a locomotive frame. Inspired, I ferreted out the 3D printed ash pan and tested it for […]

Bearing guides installed

Between the extra-long jig axles and some clamping tabs that I etched into the frame pan, installation of the bearing guides was a walk in the park. I had been a little concerned that the jig axles would be a loose fit on the bearings. As it turned out they were a little snug, and […]

Extra-long jig axles

At least I think they should be called jig axles. These pieces of Aluminum rod are used with the coupling rods to ensure the bearings are exactly the right distance apart. Essentially, I will pass these rods through the bearings, fix the coupling rods to the outsides, and then solder the bearing guides to the […]

Crankpins for 622

This weekend I formed the crankpins. They are turned from brass as I found, when turning the prototype, I couldn’t drill a long 0.6 mm hole in steel. I made them slightly over-length so I can trim them after I see how thick the rods really are. The real trick was the washers. These are […]

Surprising failure in wheel experiment

Something has been bothering me. I spent a lot of effort to get the hole in the drivers concentric with the tyre, but then who knows what happens when the axle passes through that hole? Indeed, I’m fairly certain the axles are neither concentric nor perpendicular to the tyre. So, as I have to make […]

Quartering jig

I mostly completed the quartering jig before our vacation. It consists of two steel bars separated by aluminum spacers and with axle holders also made of aluminum. I’ve not yet drilled the crankpin holes, but a test fit of some axle material showed it was remarkably and satisfyingly accurate for a bodger like me.