Percy throws a rod

Earlier, Percy sheared off a crank pin. So, conjecturing that this meant the fast starts and stops were causing the wheels to get out of quarter sufficiently to put some force on the crank pin, I continued to replicate #10 and #622. Both of those have brass crank pins, but I turned some for Percy […]

Percy shears a crank pin

With Percy’s continued resilience to poor alignment, my approach will be to continue to replicate the construction of #10 and #622 until I can make it fail in the same way. This week, I turned some 3 mm axles, having no such stock material in my collection. It turns out to be harder than expected […]

Percy gets compensated

There is a widely held belief among proto:scale modellers that equipment works better if it is compensated or, better yet, sprung, or even better yet, compensated and sprung. It stands to reason that wheels that are able to stay on the rail are less likely to find the ballast. However, in an email, Rob Kirkham […]

Pursuing the Perfect Pasture

We just returned from a week of visiting family in Ontario – the first visit in two years. Because the family is too large to fit in any one of our houses, we usually rent a large cottage and stay there. This year, it was on Big Rideau Lake, near Westport. Aside from a trip […]

Percy’s new connecting rods

One of my theories has been that Percy’s loose connecting rods were more forgiving of minor perturbations in quartering or crankpin eccentricity. So, I printed the middle experiments (8 degrees out of quarter and .022″ off eccentricity) with the thicker crankpins that allow only minimal clearance. These are about 20% bigger than the original crankpins. […]

Converting to hex

For many years, I’ve maintained a small stock of screws. They come in an array of shapes – countersunk, cheese-head, round-head, the oh-so-Canadian fillister-head, and hex. I never stocked the hex-headed ones because I didn’t have the appropriate tools to turn them. The trouble with most of these screws is that they have a simple […]

Percy and the bad drivers

The question of tolerance continues to interest me. With those loose connecting rods, how tolerant is Percy of misalignment of the wheels, or uneven crankpin eccentricity? It turns out, Percy is not only tolerant, he’s indifferent! I didn’t have a front axle with the original crankpins, P87 wheels and the gear printed on, and so […]

Percy and the crankpins

On disassembling Percy, the first surprise was how loose the connecting rods were on the crankpins. I’d read, and have probably reiterated, that the finest line is the one that separates running clearance from slop. I’d always imagined that where crankpins are concerned, it really mattered. I’ve now tried four different crankpin sizes in Percy’s […]

Percy P87

As amazing as it may seem, my 3D printer can actually print Porto:87 wheels that sort of work. Not only that, but a Mod 0.5 20-tooth gear downloaded from Thingiverse printed successfully and runs as well! I wouldn’t expect the wheels to hold the track at speed through a turnout. And the spur gear is […]

Replicating Percy

By using 3D printing, I should be able to save time in my experiments with Percy. That in turn means I will be able to learn more in the same length of time. Indeed, I should be able to run so many experiments, that I can afford to change one variable at a time. The […]