The end of the bar, which will be the base of the dome, needs to be filed to suit the top of the saddletank. I started with a half-round needle file, roughing out the shape whilst comparing it to the casting. Once the shape was reasonably close I 'blued' the filed end with a marker pen, wrapped a piece of fine wet+dry paper around the tank and gently rubbed the blued end along it. Any high spots were highlighted by the emery paper removed the blueing, the high spots then being gently filed and scraped away (with a three-sided scraper) until all high spots were removed and the end sat nicely on the tank top;
Its worth taking time over this part, as any gaps between dome and tank would stand out and look awfull.
Now the bar could be held in the lathe and turned. First of all I turned down the flange dia. (7.7mm), then using a round-nosed tool turned the main body down to 5.9mm dia. A 2mm hole was then drilled to 3.5mm deep;
The workpiece was then removed to the workbench, and the flange sides filed to shape using a round needle file, strips of fine wet+dry paper, and plenty of care;
Again, time and patience is needed for a good result.
After returning the workpiece to the lathe and parting the dome off a short length of 2mm dia. rod could then be soldered into the drilled hole;
This not only allows the dome to be held in the lathe for final finishing but also locates the dome on the tank.
First of all it was faced to length, then a .7mm hole drilled in the end, before filing the top to shape. A short piece of .7mm rod was cyano'd into the end, to represent the top fixing bolt, and rounded off with a file. Rubbing sticks were used for finishing;
Model engineers and Unimat enthusiasts would no doubt be horrified by my use of an ER16 collet in an E16 holder!
Now with the 2mm rod cut down, here it is on the loco;
And next to the supplied casting;
Paul.
That is just stunning. As you say nothing looks like brass more than brass and even though I don't think the casting is bad, it pales alongside the turned dome.
ReplyDeleteI really can't wait to see the finished loco, with all the very fine extra details it's going to be superb.
Thanks Mark.
DeleteI really want to get it finished now, just to see how the dome looks against a painted tank! Unfortunetely I lose interest at the painting stage...
Hopefully you won't lose interest this time, as I really wanted to see it finished. I enjoy doing the painting and seeing a finished model, although I find it tends to be the painting stage where it all goes horribly wrong, as it did with my Hunslet.
DeleteThat dome is beautiful, what a wizard you are with the lathe. This is going to be some Hunslet! I agree with Mark, it will look fabulous when the paint job is finished.
ReplyDeleteThanks Iain.
DeleteThis is the first dome that I've attempted, and I'm quite pleased with how its shaped up. Mostly the job is just basic turning, the hard part is filing the flange shape and blending it in.
Hi Paul. Ah now that is a lovely thing! Being a GWR man you've made me go all soft with a shiny dome like that. Real craftmanship.
ReplyDeleteJust read your blog about the new point also, very inspirational as I'm hoping to have a go with C+L points next year. Thanks for sharing it.
Thanks Mikkel. Its really the wrong material for you Great Western fans I'm afraid!
DeleteC+L points would suit Farthing well, a small diorama style layout needs first class trackwork. It will be interesting to know how you get on with them.