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 […]

Improved cab design

A couple of weeks ago, The Boy and I were lucky to be invited to visit Dan Gelbart’s amazing lab. The Boy was so inspired, we’ve been working our way through Dan’s YouTube channel. There, Dan stresses the benefits of keyholes to facilitate removal of parts. As he says, they’re free with a water jet cutter, […]

Sheet metal construction fixtures

When I built #10, one of the innovative and useful ideas was to create both running boards out of a single large piece of brass. This helped me get the boiler level relative to the running boards, and since Pembroke is not an incline railway, a level boiler is desirable. I’ve planned the same approach […]

Engine truck design – the murk beneath

When you model something that has been gone for over a hundred years, you get used to squinting at photographs and trying to imagine a design that might present similar patterns of dark and darker. In the case of the engine truck, which is missing from the erection drawing for 622, I found a drawing […]

OnShape and etched fold lines

Due to flooding, progress on real modelling has halted, and I’ve had to move into the virtual realm. This is okay, as there is loads of drawing work yet to do on 622. I speculated a couple of months ago that some careful manipulation of OnShape’s new Sheet Metal Model feature might yield a good […]

Packing away

Demolition starts tomorrow, and that is somewhat incompatible with fine models. So today, they all went into boxes. Most of my stock fits into some old cookie tins from Christmases past, which are now sadly devoid of cookies, but perfectly shaped for hold HO scale rolling stock. Some ancient rubber foam separates each piece, and […]

Time-travelling Box Queen

A couple of weeks ago, I was lamenting the fact that no trains have run on Pembroke in almost two years. My friend Mark Dance suggested I get a little diesel and convert it; then I could at least bang around a few cars when I want. It reminded me that this was actually part […]

Dave Booth is a demon with a jewellers’ saw

Tonight I cut some spokes in one of my test wheels. I was most interested to see if the wheel gets floppy if you take away most of the material in the centre to replace it with plastic. It doesn’t. But I tell you what: fretting out the spokes is hard work! On this small […]

Quite wheelish

My puttering with the form tool is starting to result in things that could be mistaken for wheels. These ones approximate the 30″ wheels for 622’s pilot truck, but with the gross flange of my homemade form tool. I faced them down to the correct 1.63 mm wide, and cut the spoke recess in the […]