Loco frame jig

The basement shows no sign of being finished, and so, I am continuing to refine the plans for 622. One of the challenges will be maintaining the relationship between the two frame halves while the insulating epoxy layer sets. I had been thinking I would add sacrificial tabs at the ends of the frame, and […]

Brakes in the darkness

It appears that the brakes are another part that has now been redesigned. I’ve simplified them somewhat from the first version. To tell the truth, I’m hoping that someone can point me to a resource that shows how this pattern of brakes worked. It seems they were favoured by Baldwin for a short period in […]

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 […]

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 […]

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 […]