Part B
This disk of about 2" diameter will be used to form the firedoor ring. Two slices will then be made in it to create the two semicircles that will form the top and bottom of the firedoor opening. I'm waiting on the copper strip that will form the firedoor ring. September 2, 2023.
Here we see the throat sheet mounted on a fixture that was bolted to a rotary table to true up the cradle that the boiler shell will rest in. The sides and bottom have also been trued up on the mill. The three large holes in the copper will be used for the 1/4" staybolts. The two smaller holes at far left will be used to secure the mudring while it is being soldered in place. This step also required the machining of an #2 MT plug with 1/8" locating pin so that the wood fixture could be accurately centered on the rotary table. The throat sheet is now ready for final assembly and soldering. September 4, 2023.
The firedoor ring was formed out of a copper strip approximately 3/4" x 6" long bent into a ring of about 2" diameter. The flats were cut from the bronze ring a couple photos up and then soldered to the ring. September 9, 2023.
Today was spent making a wooden backing plate for the front tube sheet and laying out the tube locations in the two tube sheets. These will be bolted together on a faceplate so that the tube holes can be bored simultaneously in both sheets. The tubes will be 3/4" copper pipe with 10 tubes running through the boiler. September 10, 2023.
My grandfather's old South Bend lathe didn't come with a slotted faceplate so I had to pick one up on epay. This one isn't in to bad of shape and was fairly reasonable. September 10, 2023.
Boring on the lathe with the faceplate didn't work out since the swing of the lathe needed to be about an inch larger. Instead I am using a boring head on the mill. Here we see the first two tube holes opened up to accept the 3/4" tubes in both the front tube sheet and the firebox tube sheet.. The third hole has been drilled about as large as I want to go and will be bored to the final size. Drilling alone isn't an option since the holes are so close together and large drill bits might deform the hole next to the one being drilled. Just seven and a half more to go! September 17, 2023.