This video demonstrates the detailed manufacturing process for boiler bolt-ons in model steam engines, including the construction of doors, draincocks, whistles, safety valves, chimneys, and sightglasses. The builder explains key design principles such as efficient material utilization by machining both sides of stock before parting, the importance of proper tapering for valve functionality, and the need for threaded connections to prevent component seizure from residue buildup. The content emphasizes learning from experience through iterative design improvements, such as redesigning draincock slots from 90° angles to diagonal cuts for better functionality, and avoiding soldering domes on whistles which can dampen sound production.
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Boiler Bolt-Ons: Doll 366 Replica #7Added:
[music] >> It doesn't look too shabby, actually.
Right here, something happened that I don't know what because suddenly there is an overlap and I didn't chuck it up in a way that there was one. Anyways, I think we can grind that flush. And uh for the rest, I mean, yes, there is a small seam visible, but uh that's all right. I mean, the originals were just folded over uh tin strips, which would have a parting line as well. So, if we tidy that up a little bit and then, you know, glue it, it's going to work just fine. We've got the boiler house. We've got the chimney.
Now, I want something to have the chimney rest on.
That's this little piece here, and I think it makes sense to make it in conjunction with the crown that sits on top of the chimney cuz then I can take it from one big piece of raw stock, machine both sides of it, and then part it in the middle without having to worry about space to chuck it on and wasted material due to cutting off. It's just split right in the middle, and uh both sides are going to be happy. So, yeah, it's going to look a little bit odd, but when you've got the big plan added, then it's all going to make sense.
>> [music] [music] [music] >> I wanted you mine. I gave you my line, you rose to my bait.
Take heed to your fate, you can't escape from me.
Just take my advice and keep acting nice, don't give me a fight.
That's romance in sight, you can't escape from me.
You know that I care, I'm walking on air.
>> [singing] >> With stars above, I'm glowing with love, baby. I think you'll agree to my new decree, my arms are your jail.
A kiss is your bail, you can't escape from me.
>> [music] [music] [music] [music] [music] >> Next, I think it's time to shut this hole on the firebox.
The recipe is going to be the same as always. Have a base plate with the hinge on here and then have a frame around it for decorative purposes, handle and lock. Pretty much the same. Little different design this time with holes around the perimeter for rivets, just to make things look a little bit more interesting.
Already prepared two blanks here, one for the base, one for the frame.
I'm going to drill the holes into them and then hacksaw the contours out.
>> [music] [music] [music] [music] [music] [music] [music] >> Nicht die Propelläs, nicht die Propelläs, nicht die Krakehläs, nein.
Wir sind die Jodläs, DIE YANKEE DOODLE-LäS und die Parout-läs the fein.
WIR SEIN ZWARS IN ALLEN BARS.
Wir sind die Tanzos, kommen aus Kansas mit der Schimpanzäs-läs.
>> Next we'll start filling up all of the threaded holes here. I'm going to start with the drain and the whistle and the regulator because the bodies for them are pretty much [snorts] all the same. They've got a thread to screw into the boiler. They've got this rounded cross-section here for the valve and then they've got a hole in the other end which a tube is going to connect into.
>> [music] [music] [music] [music] [music] [laughter] >> Takes longer to make the valves than the drain bodies themselves.
You know, getting the taper just right is crucial.
And the last ones I just peened over at the end.
After two, three, four years, I've now realized that's not the real permanently good way to go because these will start freezing up with the residues from the boiling water and they'll start getting hard to turn. So, now I've put a thread on the end and with two nuts and a washer, I'll hopefully be able to compensate for sticktivity and be able to take them apart, clean them out if I need to.
Now, I'll have to drill the cross holes into here to make them open and shuttable. And I'm also going to improve on that design a little bit rather than putting a 90° angle hole into the one draincock for the water pump so that I can switch between pumping in a circle and pumping feed water into the boiler.
I'm now going to go with the diagonal cut slot which is just going to be tangentially on the body of the thing because trying to hit two 90° holes at a dead center hasn't really worked out. It sort of worked on the 362. It didn't work out on the 512.
So, on the 512, that draincock is just decorative.
And I want to be able to feed water with this one just as a gimmick maybe or maybe the huge engine is going to need so much water that it's actually going to come in handy. We'll see.
But, um yeah, little differences, learning from experience as I keep building these things. And on the whistle, I'm also going to hopefully learn from my mistakes.
The whistle on the 362 worked until I then made the mistake to first machine the tube and then the little domes to go on top of it. And rather than have a press fit with them, I made them a loose fit and then later decided to solder it on. And the solder seems to have had such a dampening effect that the whistle is now silent.
And for the whistle on the 512 overtype, I think I cut the slot too wide so there is no resonance at all.
I am always too lazy you make these things twice so I just left them the way they are. And with this whistle, I'm going to try and get it to whistle and then try and keep it whistling even after soldering. And I think the best way to do that is to eliminate the domes and just make a nice decorative whistle tube in itself.
>> [music] [music] [music] [music] >> There we go.
>> [music] [music] [music] [music] [music] [music] [music] [music] >> I like the make the sight glass next.
For that, we need these uh square angle pieces.
And for that, we need some square material.
Uh I don't have square right now, but I've got some hexagonal, which I'm never going to use. So, we're going to take that and turn it into square.
>> [music] [music] [music] >> So, now I've preassembled this with a gasket, and then this is just hand tight in here. So, I know that I can give it like that 45° turn. Same goes with this one here. So, I know I can drill the hole in here and the hole in here, and then we should be golden.
I've also taken a look at what I thought I would here years ago when I made these plans.
And I've come up with that this is not going to work the way I intended it. So, I've redesigned things a little bit here.
Here we have the angle piece with a cross hole drilled from the boiler into the threaded cross hole.
We're going to insert a rubber or gasket in here.
And now the thumb screw is cross drilled as well. Right here and right here.
And the cross hole will intersect with the small hole in here, uh transporting the water from the boiler into the tube. So, when I tighten this fully down and the two holes align.
Also, when I tighten this fully down, the O-ring gets squeezed together.
And when I now insert this tube, well, I almost can't because the O-ring is gripping on it, therefore hopefully creating a seal.
And that's how it looks like all mounted up.
>> [music] [music] [music] [music] [music] [music] [music] [music] [music] [music] [music] [music] [music] [music] >> Well, there you saw me make the safety valve. I once again deviated from the plans a little bit to create yet again a bit more subtle differences to the last one.
Uh, for example, usually I would have made the lever for the safety valve out of two pieces, one flat and one round, and then I would make the flange like this.
Now, the flange is flat on the sides and round in the middle, and the lever is made out of a continuous piece of round stock with flat punched onto the end.
The valve weight is a little different to the ones I've done before, and I think, you know, it suits the whole appearance quite nicely. That concludes this video because in essence the boiler housing is now complete. All it needs is some tubing and a base plate and of course a burner.
So, be sure to tune in next time when I make all that.
See you. Bye-bye.
>> [music] [music]
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