Deconstructing Percy

I was a bit worried, as I offered the Phillips-head screwdriver up to the three screws on Percy’s coverplate, that I would find the two axles were driven by a gear train, the connecting rods coming along just for show. That would defeat the exercise, or at least require further testing to ensure Percy could […]

Re-drafting the taper course ends in a draw

I first noticed the crack in 622’s taper course when I was putting together the slides for my recent clinic on modern tools. Just before going to prime all the parts, I decided there was no point in seeing if it was serious enough to fix. I made the original taper course from .010″ styrene, […]

Better tapered boiler courses

So far, 622’s boiler remains a pair of nicely formed cylindrical sections, joined by a skanky tapered section that is more putty than substance. All that sanding gave me loads of time to think, and to lament the fact that OnShape’s Sheet Metal Model feature doesn’t extend to cones. As I was shaping, and wondering […]

3D CAD Clinic

Four modellers from the North Van NMRA group came by to enjoy a dry run of my clinic for the Railway Modellers’ Meet. It was a bit of an eye-opener! I had thought that I would offer the clinic in both OnShape and SketchUp, but fortunately, everyone chose OnShape; two hours is not enough time […]

Etching pattern begins

As I start work on the pattern for etching, there is good news and bad news. First the good news: it appears that OnShape have improved the compatibility with Inkscape, and so, now I can take flat patterns from OnShape and import them directly into Inkscape without traversing through QCadCam. Someone is still resizing the […]

Accumate coupler boxes

Maybe they should be called “draft gear,” but they don’t look much like them, and they don’t behave much like them, and so, like “throwbars” they should get their own name. “Coupler box” is what I’ve always called them. I standardized on Accumate couplers for a couple of reasons: firstly because they are near-scale size, […]

Drawbar dreams

“I do all my best work in bed,” famously and salaciously declared Mae West. And so it was, I awoke the other night with the solution to a problem I’d given up on long ago – the drawbar. Confusingly, the drawbar of a locomotive is not the thing that pulls the train; I think that’s […]

3D CAD saves the day

…or at least an hour anyway. As I was working my way through design of the running gear for 622, the reach rod for the reverser proved to be an interesting conundrum. According to the drawing from Baldwin, the lever for lifting the valve gear is supposed to be 21 inches long. This, along with […]

Valve gear – a complex OnShape part

The valve gear for #622 will be printed as a single part. As with most of the parts, the original drawing needed to be redone. The first time around, I thought I was very clever by using a minimum of sketches. I chose parts of the sketches to extrude to different depths, but hard-coded the […]

Redesigned crossheads refine OnShape technique

To be honest, I don’t know if I would have this much patience if the real workshop were not still out of commission. The sheet metal design for the crosshead guides and crossheads took several days (well hours, as I don’t spend whole days on this stuff!) due to a disagreement between OnShape and me […]