Tender wheels for GTR 1120

The 3D-printed centres for the tender wheels took two tries, not because the print failed in some way, but because I assumed the drawing, which I worked on months ago, was finished. It wasn’t and the axle holes were about a quarter millimetre oversize. It took minutes over days to get correct centres and a […]

Engine Truck for GTR 1120

As with many commercial models, the engine truck for the Spectrum 4-4-0 is just along for the ride. It plays no role in supporting the cylinders, and doesn’t even guide the driving wheels into corners. Effectively, it is its own vehicle, shackled to the front of the frame. Consequently it needs to be as heavy […]

Wheel-fitting Heresy

The standard approach to putting wheels on axles seems to be – well – to put the wheels on the axles. The assumption is that the wheels are complete: they have their tyres and crank pins. It’s easy to see why that would be the standard. If you buy your wheels, they naturally have tyres […]

Bearings

There is a point after you’ve accumulated some hours with a tool or technique when it becomes enjoyable. I think, after five years with the lathe I am finally there. Sure, there will always be parts that will challenge me, but simple ones, like these bearings enable me to get into a rhythm of turning, […]

Finding the slots

Although, being jig-made, the slots are probably in the same place on the two axles, the question remains: where exactly are they? The right-hand (red is always right in my workshop) end is noticeably off-centre, while the left-hand looks pretty good. Our eyes are fantastic at noticing things that are not straight or centred, but […]

Slotted axles

Once the jig was made, slotting the axles took a remarkably small number of swipes with the hack saw. Percy’s 1/8″ axles, being made of 316 stainless, were much tougher than this 3mm 12L14 steel axle material from Northwest Short Line. I made a little go-no-go gauge out of a couple of pieces of wire […]

Axle Jig

Percy helped me determine that a keyed connection between axle and wheel works best for me. I don’t have a milling machine, and so a jig is the only way to make the slots in the axles reasonably precise. My thoughtful wife bought me a four-jaw chuck for the lathe for my birthday, and it […]

Percy and the Driver Test

I’m nearly ready to go ahead with the “final” set of wheels for Percy. These will feature a combination of keys and Loctite to ensure everything goes together in alignment and, more importantly, stays that way. The 3D printer makes test fits unusually easy, and so, I’ve broken from my damn-the-torpedoes tradition, and made a […]

12L14 Tyres

Up until now, I’ve only made tyres out of 316 Stainless Steel, which is supposed to be machinable. While small wheels were not too bad, my little Sherline lathe struggled with the 17.5 mm drivers of #622. So, I asked the local Metal Supermarket to bring in some 1″ 12L14 free-machining steel. They probably sell […]

Pretend engineering

Before we proceed to make a decision about the best path forward for attaching wheels to axles here in North Vancouver, I have one more round of experiments to share. I still believe that a keyed wheel will be superior in holding onto the axle compared to any sort of a glue bond, but the […]