So the next part top consider is the steam chest chamber.
The photo shows the casting as delivered from Reeves.
I(t has the valve guide positions caste into the casting so caruful consideration will need to be given as to how to clean up the outside on that edge and the only way will be to file away the flashing and make as good as possible with out damaging the slide vale guides.
Top and bottom surfaces will be machined in the 4 jaw vice and the edges machined in the mill as was the top of the steam chest shown earlier.
The steam chest was held in a 4 jaw chuck and after measurement the fist side brought to size.
The unit was then turned over in the 4 jaw chuck and the other side machined to bring the unit to the overall thickness required.
The inside was then cleaned up with hand file and my small battery belt sander.
Now I have to decide how to mark out and hold the pieces to drill and tap as needed so that the part secure together and then decide how to drill the holes in the steam chest for the valve spindles.
All sounds easy but needs thinking about !!
Total time today just short of 2 hours !!!
The steam chest top is now coloured withthe marking out blue.
The holes to be drilled must be carefully marked out so the they miss the steam ways.
When marked they will then be centre popped using my optical centre punch and then drilled taping drill size for 4BA bolts. Eventually the holes will be opened up to clearance size for 4BA in both the steam chest and the steam chest top but not until the holes in the steam chest and cylinders have been drilled with the tapping drill as those in the cylinder need to be tapped 4BA.
Not much done today but the top is now marked out.
I hope I can drill the holes after centre popping tomorrow.
So the marking out was centre punched.
Then onto the drilling but no correct size drill for the 4BA. So they are now ordered and will all being well arrive tomorrow !!!
The new drills arrived as hoped for and they are very nice and drilled all the holes in the top of the steam chest in about 30 minutes.
Nest will be the setting up to drill all the holes through the steam chest and into the cylinder block initially as tapping holes and the widen out in the steam chest and steam chest top to clearance holes.
Then tape the cylinder holes 4BA !!
To ensure that the remaining holes were drilled correctly the two corner holes were tapped into the cylinder and the cover and steam chest drill out clearance size.
Then the remaining hole were drill tapping size.
The front edge of trhe steam chest was stamped with an T to indicate top so that there could be no mistake.
I have decided to cut the he3ads off the bolts and use them as studs as to cut the bolt the exact length required to tighten down would require more skill then I have !!
But that is for another day !!!
Cut the heads off the bolts located the centre of the Steam chest cover and drilled a pilot hole.
The steam chest spacer is a simple turning piece and made in brass and threaded at both ends
The top end is also threaded to take the exhaust steam up the chimney.
Blue marking out fluid applied to cylinder casting.
Must avoid the drill going into the cylinder bore !!
After a few days thought I set up the angle vice and held the cylinder block as shown ( actually this is as it was for the second hole).
The angle was checked as on the drawing above and the DRO used to indicate the depth.
First a centre drill eas used to make a location for the 1/4" drill which was then used to drill down to the vertical hole drilled previously. A piece of plastic hose was then placed into the exhaust hole and blown through top prove the exhaust way was clear.
Then the block was reversed to as shown in the photo and the same procedure to centre drill fist and then the 1/4" drill but the angle and position on the bed remained unchanged.
The cylinder block was then removed and a good blow through (with eyes closed) to ensure that both ways were filly clear.
