No need to oil the tap on cast iron. There's slot of grafite in it so it's self lubricating and the iron oil slurry is hell on the machines (sorry putting the soap box away now)
I don't know if you are in the UK but over here a book by K N Harris "Model boilers and boiler making" has a lot of technical info that may be of interest
Just a concern, you said the bore through the valve wasn't perfectly straight. Will that affect you when you make the crank and cam that it wont be able to line up like it probably should and maybe would get in a bind when the engine tries to spin?
I don't think so. The hole is only off by about 0.030" or so in one direction if I remember correctly (let's just say 0.060" to be conservative), the angle of deviation over the 6 inches of the valvebody is (180/pi)*arctan(0.060"/6")= 0.573 degrees. This angle is the angle that the valve rod will deviate from being perfectly straight. The valve rod itself only moves up and down about 3/4". Meaning the lateral displacement of the rod as it moves back and forth is 0.75*tand(0.573) = 0.007". Luckily, the "off-centered-ness" is in one direction, and in a fortunate direction, because the fork at the bottom will have a joint that will be free to move sideways a bit to take care of this movement of the valve rod (see 13:19). We will see though.
Fair Weather Foundry hopefully it won’t, being less than a degree but if it does you could probably use a universal joint or some type of ball and socket.
I think FWF will be good anyway, but if he wanted to correct for it, he could machine the gasket interface between the valve body and cylinder to bring the valve cylinder into parallel with the piston cylinder. This would run the risk of mucking up the appearance more than just having an out of center valve cylinder head. That is, externally the casting would look wonky WRT the main cylinder but the two cylinders would be in parallel.
Great-looking cylinder and valve body. Massive!
people like you are inspiring, thanks for this great series man
can't wait to see it! its looking really awesome. i'm looking forward to the stuffing box, i've never seen one of those being made.
Coming together nicely!
No need to oil the tap on cast iron. There's slot of grafite in it so it's self lubricating and the iron oil slurry is hell on the machines (sorry putting the soap box away now)
It's coming along nicely :-) Any thoughts on what size of boiler you will need to power the complete engine ?
Not yet, I will need to experiment when the time comes.
I don't know if you are in the UK but over here a book by K N Harris "Model boilers and boiler making" has a lot of technical info that may be of interest
Awesome thanks! I just found the pdf online! Going to give this a read through!
Just a concern, you said the bore through the valve wasn't perfectly straight. Will that affect you when you make the crank and cam that it wont be able to line up like it probably should and maybe would get in a bind when the engine tries to spin?
I don't think so. The hole is only off by about 0.030" or so in one direction if I remember correctly (let's just say 0.060" to be conservative), the angle of deviation over the 6 inches of the valvebody is (180/pi)*arctan(0.060"/6")= 0.573 degrees. This angle is the angle that the valve rod will deviate from being perfectly straight. The valve rod itself only moves up and down about 3/4". Meaning the lateral displacement of the rod as it moves back and forth is 0.75*tand(0.573) = 0.007". Luckily, the "off-centered-ness" is in one direction, and in a fortunate direction, because the fork at the bottom will have a joint that will be free to move sideways a bit to take care of this movement of the valve rod (see 13:19).
We will see though.
Fair Weather Foundry hopefully it won’t, being less than a degree but if it does you could probably use a universal joint or some type of ball and socket.
I think FWF will be good anyway, but if he wanted to correct for it, he could machine the gasket interface between the valve body and cylinder to bring the valve cylinder into parallel with the piston cylinder. This would run the risk of mucking up the appearance more than just having an out of center valve cylinder head. That is, externally the casting would look wonky WRT the main cylinder but the two cylinders would be in parallel.
"Top Valvebody Cylinder Head" AKA the front steamchest cover.
Ticklish HoneyBee Uh oh nerd alert