So, dial gauge arrived on time. It's a bit bigger than expected and will take some getting used to articulating the arm. First job was to strip and clean the 3 jaw chuck. I put 1, 2 & 3 spots on each jaw and on the body nearby for ease of re-assembly. Once stripped down I gave all a good clean in petrol, dried, greased and put it back together again. There was a small ding on the centre rear face in way of the mounting screw. I removed it with a file. Then cleaned and lubed the thread.
Next job was to true up the gripping faces of the soft jaws in the chuck. To do this I put a 1P coin in the chuck and gripped it with the hard part of the jaws. This ensured the chuck is loaded up. I then marked the gripping faces of the soft jaws with magic marker before running the boring tool through and removing the smallest amount from the jaws as shown by the marker. Put a 3/8" tap in the chuck and dial gauged the ground shank and got half a thou run out. I don't have a parallel test bar so I shipped the Jacobs chuck on the tail stock sliding centre, loaded the tap in it then put the dial gauge articulated arm in the 3jaw so that I could run the tip of the gauge around the taps shank. This showed that the tailstock was 5 thou out horizontally. I reset it but was unable to measure vertically as the gauge won't fit underneath the tap. To try and check it I turned a one off centre, left it in the 3 jaw without disturbing it then brought the tailstock centre up to it and visually it's a tiny bit high which means I need to shim the headstock but I'll see how I get on with the next valve.
Today I made a 180 deg inline valve. The spindle, sleeve, nut and wheel are exactly the same as for the 90 deg valve so I'll just write about the main body work.
1) drill a 1/4" hole through some 3/8" hex bar across the flats, centred 5/8" from the end. Measure, mark and centre punch the hole centre then drill through. (I used a large ish pillar drill and started with a small pilot hole and worked my way up to 1/4". It still ended up off centre a bit and I think I need a Taig milling vice to fit the milling attachment as the drill is too big)
2) turn down the hex to 3/8" dia. for 3/4"
3)centre drill the face then drill a 5/64" hole through to the 1/4" hole.
4)drill a 7/32" hole, 3/8" deep and finish hole with a D bit to 1/2" (I don't have a D bit so I used an end mill to get the bottom flat)
5)tap the hole 1/4" x 40 tpi 1/4" deep.
Put the body to one side now and turn to the inlet/outlet tube.
6)put some 1/4" round in the chuck, centre drill, cut a 1/4" x 40tpi thread in the end.
7)drill a hole 3/32" to a depth of 1/2". (this is the inlet side).
8)part off at 1"
9)reverse the part in the chuck and repeat the threading.
10)drill hole 3/32" to a depth of 13/32" (this is the discharge side).
11) degrease, wire wool and flux both pipe and body.
12)drive the 1/4" pipe through hole across the body, even each side.
13)solder together. (I used soft solder not silver, your choice.)
14)re-drill the 5/64" hole in the body, through into the centre of the inlet pipe.
15)freehand drill an angled 5/64" hole adjacent to but clear of the centre hole into the discharge side of the pipe. (Be careful doing this. The original dimensions specified a 3/32" hole in the body centre and into the discharge pipe. When I free handed the last little hole, It wandered into the centre hole and I ruined the piece!!).
The rest is as stated, the same as the previous valve.
I don't use graphite string in the top gland but instead found that the smallest imperial O ring in the last set that Lidl sold is perfik.
Jerry.
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Topic: Jerry C does some turning & milling and builds a new steam plant. (Read 92794 times)