andypugh

Some elements of the New Imperial look the same (tank shifter and oiler, extra right-side pulley, probably for a brake rather than drive) but the magneto drive setup is all wrong: https://images.app.goo.gl/r9tTr4mtewaKaRBc9

Are the starting handle dogs incorporated into the pulley on the Bovington example? It's hard to be sure. In any case, I feel that having them as a separate part, in steel, is probably a better idea. They are actually a bit of a game to machine, as ideally the included angle < 90 degrees between the drive flank and the ramp. I have a setup that can do it, if you want to decline the challenge 😉

Chainsaw oil is also meant to be delivered from a reservoir, though. It's not all that tenacious. It is used as a cheaper alternative by some motorcyclists who have chain oilers (like the Scottoiler) But for the drive chains on a truck I think it would make sense to use motorcycle chain lube products, as this is actually _exactly_ the same application. Here is a review of 55 of them: https://www.bennetts.co.uk/bikesocial/reviews/products/motorcycle-maintenance-and-servicing/best-motorcycle-chain-lube

Inrerestingly, hot-melt chain wax has just been rediscovered by the cycling crowd, and is now the hot new thing that they rave about. Unfortunately the stuff aimed at such cyclists is very expensive. Linkyfe equivalents exist, such as https://www.ebay.co.uk/itm/361926663197 but enough to soak your chains would be expensive. Do you know Dr Fish, the "God of Grease" ? He might have advice on a hot-melt grease that is used industrially.

It prevents your face from becoming pebble-dashed. 🙂

The cab roof is set very low, maybe they were sleeping in there?

If that was our Dennis Fire Engine then you should take any reading from our speedometer with a pinch of salt. Though it generally under-reads.... 1982 and 1984 are a bit before my time, my first Brighton run on LP8389 was in 1986 but I have done nearly every one since.

If that was our Dennis Fire Engine then you should take any reading from our speedometer with a pinch of salt. Though it generally under-reads.... 1982 and 1984 are a bit before my time, my first Brighton run on LP8389 was in 1986 but I have done nearly every one since.

Cutting old window glass is always much harder than cutting new stuff. I can imagine that the same is true of glass tube. You might have found brand-new tube rather easier. You can buy glass tube on Amazon, amongst other places.

I was talking to someone earlier who has a large maple tree that was felled a couple of years ago. He reckoned that would make some decent planks.

The planks I got from worldofwood had been sticked and air drying for a while. They haven't moved much since being installed as windowsills (very thick walls need very deep windowsills)

From Wikipedia " One can thus presume that rotary lathe plywood manufacturing was an established process in France in the 1860s. Plywood was introduced into the United States in 1865[7] and industrial production there started shortly after. In 1928, the first standard-sized 4 ft by 8 ft (1.22 m by 2.44 m) plywood sheets were introduced in the United States for use as a general building material.[4]" It seems quite likely that some manufacturers might have used plywood as a convenient (or even high-tech) material for the bulkhead when others were still using glued boards. There is probably a lot of Ash being felled at the moment, if you want wide boards. I got some 20" wide oak boards (via an ebay ad) from https://www.worldofwoodsuffolk.com/ a couple of years ago. I don't think that getting wide boards is difficult if you are able to process them yourself. It's getting then in a sawn, planed state that is less easy, and possibly is best approached in as two steps: 1) Find the wood 2) Bribe the owner of a wide planer/thicknesser.

Right, 6 cylinders, but 4 exhausts. That was what was confusing me.

The engine in the "Captured English motor tug for large guns that got stuck in the water" looks interesting, almost like 4 separate engines in a row. (I am familiar with single-cast cylinders, this looks to be wider spaced than that) I guess it's a 15 ton Holt, but the engine looks different to other photos I can see online.

Found on YouTube. I think this might have been a solution to Steve's bearing removal epic. It appears to be a lot more precise than one might guess. I suppose it's like arc welding, in that it only happens where you strike the arc, and you can stop the arc at any time.

https://goo.gl/maps/nF7weBWW8GvsbXSJ6 How did you work that out?

Sorry, I was going a bit off piste and hijacking your thread to reply to mammoth's requirement for a similar shaft machined from solid. I have since concluded that making a suitable cutter isn't as hard as I thought. You could CNC wire-erode replaceable blades from HSS or carbide, and fit them into a holder. Like this: https://a360.co/3ClcKKi

I have been thinking about how to machine this from solid, and can think of at least two ways. 1) Use a form cutter on a horizontal milling machine. This is probably how it would have been done in the day, but making the tool for a one-off would be a lot of effort. 2) CNC with a rotary axis, much like I used here: The key to making it work is a coordinated movement of the tool at right-angles to the shaft axis as the work rotates so that the shoulder of the tool is in the right place when it gets to the key flank. I suspect that my machine is too short to make one, I can only machine parts up to 356mm long. 3) Amongst the ways that I can think of are.... The shaft could be wire-eroded in sections (I doubt that any wire eroders can do the whole shaft in one) and joined by Hirth couplings and a draw-bolt down the middle. As the torsional strength of a shaft is almost all in the outside, the presence of a drawbolt would have little effect. I don't know off-hand how strong a Hirth joint is relative to a solid shaft (I would guess at about half as strong) but they work well enough to be used in racing crankshafts

That's quite a gear ratio on that fan. The White and Poppe engines seem to have a 1:1 ratio.

Wikipedia: Some applications and patents connected with friction welding date back to the turn of the 20th century,[3] and rotary friction welding is the oldest of these methods.[4] W. Richter patented the method of linear friction welding (LFW) process in 1924[5] in England and 1929[5] in the Weimar Republic, however, the description of the process was vague[4] and H. Klopstock patented the same process in the Soviet Union in 1924.[5]The first description and experiments related to rotary friction welding took place in the Soviet Union in 1956,[3][5]

3D printed patterns typically need a fair bit of filling and painting to be usable. I am surprised it came out at all.

Dennis did that "Two keyways at 90 degrees" thing too. It's deeply misguided 🙂 The issue is that the two keyways define an axis, and the taper defines another axis, and they are not likely to be exactly the same. So the two elements "fight" each other. Or less anthropomorphically, such an arrangement is kinematically redundant. With the N-type we have taken to using only one key. Partly as 100 years of kinematic redundancy and subsequent repairs has resulted in a rather inexact keyway positioning.

Do you mean the tyres, or just the bands? I would have said that tyres were somewhat past their best.

That's definitely a job that I would have farmed-out to the local laser cutter (or an online one)

It doesn't have to be done that way. You could turn the chassis upside down and lower the gearbox onto it.