Cracker/Cricket Locomotive Build

[skippy]

I love following these sort of projects. Thanks for sharing.

[pminmo]

I do too! Nice job.

[vlmarshall]

Thank you both!
I cut the bushing holes in the boilers yesterday. Straightforward, quick and easy.

[vlmarshall]

Well, my first-ever silver soldering attempt didn't go too badly.
I managed to finish both boilers.
I see a few pinholes around the top bushings, but I went over that arrea twice. I wonder if they'll leak.

[vlmarshall]

I made boiler mounting saddles from some mica block I had... very heat-resistant stuff.

Filler and safety valves are next.

Here's a few more pictures.

[Kipper]

Looking good matey :toot: :toot:

[vlmarshall]

Looking good matey :toot: :toot:

Thank you!
Yesterday I pressure-tested the boilers, ad ran one of the locos on steam.



"http://www.youtube.com/watch?v=Seg6EcyFyiw"]YouTube - Cracker Live Steam Locomotive Construction: First Steam Tests"http://www.youtube.com/watch?v=uakRJp4p7-M"]YouTube - Cracker Live Steam Locomotive Construction: The second Loco runs.

[vlmarshall]

Another Cracker builder, on another forum, asked about the Steam fittings I had made so far. I made them mainly for testing, as a temporary line, but the Cracker's plan doesn't call for anything more complex than what I have here.

Hey,
How about some pics of the banjo fittings and screws. How did you make those ?

Sure thing!

The steam dome fittings, ( the larger in the pic.) are 5/16-24 thread, turned from brass stock, with a lot of extra material left at the head, because I may drill and tap them for either a relief valve, or a filler. (Or, I'll toss these, and make something more suitable.)
The ring portion of the banjo is Phosphur Bronze, turned and drilled. I used one of them for the temporary test line, and since I've read that you can't silver-solder over ANY soft solder, I won't even try cleaning that one, I'll just make another. I'll probably add a groove around the inside at the same time.

The inlet and exhaust port fittings are a bit too simple, just a drilled and turned piece of 8-32 bolt, some turned brass rings, and a couple of nuts that absolutely refuse to seal, always leaking around the threads. The next attempt will use either a cap nut, a bolt, or a straight compression fitting, if only I could find a supplier for something that small.
I don't want any of the lines to be permanently attached at either end; like I said in an earlier post, I'm planning for future maintenance.
Here's a shot of the fittings. Left to right, two leaky bolts, next time, stainless. Two brass fittings, one soldered to a test line, a phosphur bronze steam dome fitting, and two steam dome banjo bolts.

Here's a shot of the inlet port. Nothing special here, other than the clearance notches I had to cut in the cylinder to clear the banjo fittings.
Also visible are the setscrew holding my pivot bolt in place, and the mica-block boiler saddles. The rear saddle bolts to the footplate, the front is captured between the smokebox and the footplate by a through-bolt.

[vlmarshall]

The other day, I made a punch and die, to bash small pipe caps into domes. One of these will be the steam dome cover for Loco #1, which will be a smaller, O-scale, Cracker-like loco for my dad.


On loco #2, (mine) this will be a smaller dome cover over the Goodall valve in the front boiler port, and won't have a cutout for a steam line.

I forgot rivet bumps. I got ahead of myself and silver-soldered the copper ring to the inside of the dome without punching the rivets. That dome REALLY needs some kind of detail, at least a flare at the bottom... I might remake it.

Also, I made a Goodall filler valve for one of the boilers. I wanted to test one before I went through the trouble of making two.
Nothing special, stainless steel, threaded to match the boiler fiitting, drilled .062" into a cross-drilled hole under a short length of silicone tubing. The tubing works as a check valve, to allow filling with a syringe and short piece of 1/8" copper tubing.




These valves really work! Pushing the loco backwards pressurizes the boiler, which I've already played with long enough to flip the engine over a rev or two.

[vlmarshall]

Not much progress Friday.

Made another little dome, this one for "my" Loco, no polished finish, and no steam line cutout, this will cover the fill valve in the forward port. I probably I made the boiler ports too close to each other to use the large dome. Oops. Maybe I can make it look good anyway.

Also, I tried oven-blackening of the extra 12L14 wheelset at 900 degrees, they didn't come out much darker than with the chemical tool black, but the finish does seem more durable, so I added a white stripe, and I'll "test fit" them later to see if I like the look.



Lastly, I started on the burners. Sort of a combination of the slotted-tube burner that's so popular, and a drilled stainless burner I found online somewhere. I used stainless tube and a staggered hole pattern, and I'll make the jet, jet holder, and tube fittings later.
I hope it works. Right now they have no air hole and are too long to burn properly... but they look neat, does that count for anything?


I'll cut them to length later.

The plug in the end is a Stainless 5/16 socket head capscrew, threaded in about .250", with the head ground down to the bottom of the hex hole.

[vlmarshall]

Instead of working on anything yesterday, I spent the morning (goofing off) testing both Crackers by running them on a hand-held torch. The second Cracker hasn't been run with the new piston and cylinder, until now, and still needs to be run-in. They sure don't go far without a burner and the smokebox hanging wide open.

I edited together several runs of Loco #1, to get an idea of what these things will look like when finished.
"http://www.youtube.com/watch?v=Ycz8F3p2fiM"]YouTube - Cracker Live Steam Locomotive Construction: Burnerless Test Runs.

[Kipper]

What a joy to see! Some very neat work indeed Thanks for sharing.