Hi
thanks Jim and Arnold
Progress was being made until I realised that on the drawing Sandy had specified using phospher bronze for the slide valve, an oversight on my part
:Doh
Decisions decisions
should I carry on with the brass slide valve, which would be ok for light occasional use or scrap it and start again. In the end I decided to scrap it and start again.
Some time ago we met a guy at a steam fair who is a marine salvage dealer, non ferrous metals. Amongst the many items that will come in handy one day that I bought were a couple of bolts, around 1" diameter and 4" long of phospher bronze, I paid 50p each for them, a bargain.
First job was to square it off.
Then chop the head off, a useful chunk on its own
Which gave me this/
I machined the end down to the size needed.
In the mill and machine the shoulder.
Then machine across and make to size
A test fit of the buckle
Machine down to size
Cut the 1/8" slot
Turn over in the vise and machine to size
Then machine the steam pocket
After parting off from the parent material it was finished to size. Because I machined the square hole in the buckle with a 3/32" cutter it has radiused corners so the slide vakve must have its corners rounded to suit with a smalll file.
A test fit on a bit of 1/8" stainless steel rod.
The valve rod is turned down to 3/32" on one end and threaded 5BA
After cutting to length the other end is threaded 5BA to accept buckle joint.
The valve chest is mounted in the mill vise and the centre found using a laser centre finder, you can just see the red dot. Then cntre drilled.
Set up in the 4 jaw chuck using a spring loaded cntre and dial gauge
I used card and some steel to protect the faces. Its first drill through with a 3/32" drill right into the domed spigot at the far end. The turned down portion on the valve rod will fit in here and guide the rod. Then the outer hole is drilled and reamed 1/8" Finally I have turned a small recess in the end. I have to make a gland for the valve rod onto which I shall turn a spigot which will hopefully when fitted into therecess will align everything.
A trial assembly. The brass nuts are not tightened against the sides of the buckle but will have 1/2 nuts as well as lock nuts. Steam pressure keeps the slide valve pressed against the port face but will lift off in case there is any water present.
Cheers
Rich