When i drilled the holes for fixing the smokebox to the boiler I drilled the holes in the smokebox using the rotary table. I then picked up on each hole with a magdrill and drilled through. Of course I have steel boilers. They weigh close on 100kg so are way to big and heavy for me to manhandle onto the vertical mill.

When I get around to the cylinder mounting i will drill the holes in the cylinder flange on the vertical mill using an angle plate to set the angle for each hole. The holes will be oversize to allow for the cylinder being pulled down onto the gasket. Once I am happy with the cylinder position I'll make a silver steel punch and spot punch through each hole. Then I'll pick up on each location with a pointer in the magdrill chuck. Exact positioning isn't critical. Clearances need to be quite large to ensure the cylinder sits down properly rather than binding on the studs.

Andrew

It's not clear what the material is, but once the material has kinked it will be very difficult to get the kinks out by hammering alone. It might just be possible by heating to red hot and using a wooden mallet.

I haven't flanged my tender sides yet. The former is made and the blanks machined. I will be forming red hot and the job is made easier as my tender sides have a large radius on the flange.

When I made the spectacle plates for my engines I formed them red hot over a steel former. The plates were made from 3mm cold rolled steel sheet and have fairly sharp internal corners:

This is the former:

And the partial former, a test piece and home made wooden mallet:

To summarise; the tender sides really need to be formed hot, and avoid kinks at all costs. For convex curves, as shown, the metal has to compress, or increase in depth, as it is folded over. Trying to bend cold makes that very difficult indeed. On the test piece note that the depth of metal on the curve is larger than the straight flanges although the blank started uniformly oversize.

Andrew

Just to be clear I formed my plates while the metal was red hot. Presumably by heating the brass this evening and hammering tomorrow the heating was only intended to anneal the brass?

Personally I'd use steel for the tender sides. Much cheaper and better behaved when forming. This is an oiler tray made from 1mm cold rolled sheet formed hot on the same former as the spectacle plate for convenience:

Andrew

Some people do cut out Vs before bending to remove excess material. But probably more common when using steel as the sections can be easily welded together afterwards.

Andrew

Derek,

Its about 45 years since I annealed brass for forming so memory is a bit sketchy but I am pretty sure you don’t want to heat it to red heat to anneal (due to the zinc). I have a vague memory of swiping the surface with soap and heating till the soap goes brown / black and letting it cool naturally to anneal. Brass if I remember right tends to work harden quickly (much quicker than plain copper) so regular annealing as soon as it starts to resist is the name of the game. The “extra” material needs to flow somewhere and if the metal has hardened that won’t happen easily or well.

Paul.

I have a 3" Burrell and the pipework is 1/4 copper

H