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 […]

Stroke to Path could save me hours!

Over a year ago, when I was working on the patterns for 622, I found that drawings imported from OnShape into InkScape consisted of many individual line segments. There had to be a better way, and Craig Townsend has found it. Here for future reference, is a YouTube video that makes it dead easy. Thanks […]

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.

Crank pin idea

Beautiful summer weather rarely inspires much railway modelling. It’s a better time to sit on the deck and enjoy the outside of the house than the inside of the basement. Today the idea book came with me so I could capture that elegant crankpin solution I suggested a month or so ago. I believe that […]

Bad crank pin holes

When you simultaneously wreck a part and break your last drill bit of that size, it’s a good time to take a little rest. Actually, I’ve now pretty much committed to mulligans on two out of four drivers, which will teach me not to celebrate finishing some parts until I’ve finished working with them. Despite […]