Stephenson's Rocket

[awake]

The outside of the rectangular areas of the cylinder have been machined this morning, all except for the radiused area. This was simple stuff, with the cylinders held in my milling machine vise. The rest of the things I have to do are mostly all rotary table work, so I need shafts mounted in each of the cylinders for my 3 jaw chuck on the rotary table to hold onto.  I could have made an expanding arbor to mount the cylinders on, but this works just as well. I cut a couple of 5/8" cold rolled steel shafts, long enough to stick out each end about 1", and Loctited the shafts into place. After all my machining is finished, a bit of heat applied to the cylinders and the shafts slide right out. If any loctite residue remains in the cylinder it will easily come out by running a 5/8"reamer thru.

Loctite on an auxiliary shaft has quickly become my go-to method for a number of machining tasks - especially when I need to ensure concentricity between the bore and the outside features, and/or have to do a number of different operations on each end of a part.

[crueby]

Brian, you using the loctite 638 for the temp shafts? That version releases with heat like the Red does?  Hmmmm..... Another one for the box o tricks...!

[Jasonb]

Even 648 the high temp version gives under moderate heating.

[Brian Rupnow]

This morning I finished up the two steam chests. I had the outside machined yesterday, which involved 4 jaw set-up in my lathe to turn the round spigot. This morning I put the 4 holes in each corner and the cavity in the center. Once again the machining Gods smiled on me and everything bolts together!!

[Brian Rupnow]

Today we have some steamchest covers and some pistons and piston rods. One noteworthy thing here---these small steam/air engines are not very forgiving of a non-concentric alignment between the pistons and piston rods. To get around that, I turn the pistons to 0.050" oversize, then screw the piston rod into the piston (they are both threaded #10-24) and coat the threads liberally with J.B. Weld.  After it sets up for 24 hours, I will grip the 3/16" diameter piston rod in my lathes 3 jaw chuck, and finish turning the pistons to the correct sliding fit into the cylinders.

[crueby]

Excellent progress, watching along!

[Craig DeShong]

... and finish turning the pistons to the correct sliding fit into the cylinders.

I’ve been known to do that too   great minds must think alike 

[Brian Rupnow]

Nothing real exciting today. I turned down the pistons to finished size and made up the two rod glands that prevent air escaping around the piston rod. While I had the cylinders disassembled I finished off the internal porting in each cylinder. I made up the two brass rod ends and screwed them onto the piston rods. I took a couple of 8-32 hex nuts and rethreaded them to 10-24 because they are a bit smaller and look better. That doesn't sound like much, but I used up most of my day doing it. I just got back from my "fat mans walk" and it is very warm outside.

[Brian Rupnow]

I had the very best intentions today, of building the four brackets which support the cylinders.  However, "The best layed plans of mice and men Gang aft agley"---I did get the four pieces cut to size, and I actually did drill and tap four holes and add two counterbores and a bit of end profiling on one piece and got it mounted. That's not much to show for the day, but I promise---I'll get the other three finished tomorrow. Good wife and I were setting out on the back deck about 4:20 this afternoon having a vodka cooler, when suddenly it began to rain so hard we couldn't see the end of our yard and the wind was blowing so hard that my big oak trees were leaning almost horizontal. We quickly scurried inside and the wife wanted to know if we should head for the basement--She's been through a tornado before---I haven't. I said to wait for a minute and see what happens. Five minutes later the sun was shining again. Crazy, crazy day!!!

[Brian Rupnow]

So, as promised yesterday, today the aluminum feet were finished and bolted in place. The main baseplates for the right and left hand cylinder assemblies were cut to size and drilled to allow mounting of the cylinder assemblies. Tomorrow I will probably make the A shaped pieces that support the cross-head guides. I haven't cut the windows into the baseplates yet. Initially everything will be assembled "for fit" before I cut the windows.

[crueby]

Rolling right along!   

[Brian Rupnow]

Today was the day for cross-head guides and brackets. I don't really know why, but I had a horrible time with these brackets. I kept taking off a little bit here, and a little bit there, and by the time they all matched and looked right, I had almost used up my entire day. The 1/8" cold rolled steel guides themselves were easy enough, but the brackets almost kicked my butt!!

[Art K]

Brian,
I think you nailed those brackets, so they didn't quite kick your butt.
Art

[stevehuckss396]

I'm really enjoying this one. Maybe because it's a loco. I'm a big train fan.

[Brian Rupnow]

Good to have you watching Steve. I have seen some of your builds and admired your craftsmanship.---Brian