Wheel Progress

Parts for the first wheel rolled off the lathe this week. The engine truck wheels are only 8 mm in diameter, and have eight spokes. The spokes themselves are only a couple of millimetres long, and so, I have elected to make these wheels in two parts – a tyre and a centre. I actually […]

Momentum

I didn’t realize it at the time, but the worst thing about the great flood of 2018 was that it completely destroyed my momentum. At the end of January, I had finally arrived at a place where I thought I might be able to cut Proto:87 wheels for #622. I had even cleaned the lathe […]

Frame pattern for 622

Working fifteen minutes at a go, I’ve finally finished putting together the pattern for the thicker Nickel Silver sheet. I think if I’d been more cunning, I almost could have fit two whole models on there. As it is, there will be plenty of leftover etch and there are doubles of all the riskiest parts. […]

Mutually Assured Alignment

I’m telling you this because, in a few months, you might be me, and we will want to take advantage of some of the cunning plans that we laid in the summer. We’re going to attempt to fold the crossheads up from etched material. I’ve put four of them on the etch because there’s loads […]

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 […]

Virtual dry fit for 622

In typical Panglossian fashion today, I uploaded the STL file for 622’s plastic parts to Shapeways. I might have hit the big “Print” button, if the bounding box hadn’t precluded the use of their highest resolution machine. It’s a good thing I didn’t because the pause gave me an opportunity to assemble all the parts […]

All the parts that are fit to print

I’m just about ready to upload all the printed parts to Shapeways. To support some of the more delicate parts for printing, and more importantly for shipping, I added some sprues. I actually started out making a sprue for all the parts, but then I re-read the pricing guidelines for Shapeways and concluded that this […]

Just about finished drawing #622

Tonight as I was drawing the step that the fireman would use to light the headlight (imagine that at night at -30 Celsius!), I thought I must be just about finished with the drawing. So, I dropped all the parts into an OnShape assembly to see what is yet to be drawn. I discovered the […]

Mud drum plug

The erection drawing for this engine clearly shows a mud drum hanging like a uvula from the bottom of the boiler. Extending from this appendage, the drawing also shows a two-foot lever. This puzzled me for quite a while: surely you would have to unbolt the cover to gain access, and a lever wouldn’t be […]

Boiler keyhole?

Okay, it may be time to admit I have a keyhole problem. Ever since watching Dan Gelbart’s videos on prototyping, I’ve been thinking about them. This latest design element might be a keyhole too far. What if, instead of screwing down through the smoke stack to hold the front of the boiler in place, I […]