Kozo A3 in 1.5" scale

[B36Peacemaker]

That's a shame. How much would you sell it for?

You might have luck putting it on the Discover Live Steam website.

 

[kvom]

I have about $4K in it out of pocket. Would sell it for that. The tender is not an A3 tender and would be additional $900. For the time being I'm not going to the track because of the pandemic.

 

[johnnyo]

I too had started this engine in 2008 and let it sit in my shop for maybe seven years or so while I built many other models. I finally picked it up again last summer after visiting the Finger Lakes Live Steamers and Steam Town in scranton, Pa. I took advantage of the stay at home orders and got it running on air. I am now designing the boiler and using many resources from these sites and steam clubs like The Cinder Sniffers. I have read many build logs, yours included KVOM, and learned much. I just got the Australian model steel boiler code and started reading up. I have seen these boilers built many ways right down to one with 1/4” thick tube sheets and only 3/16” plates. Can I ask you KVOM for some insight to your build? I have a few questions and would love to share my knowledge and experience so far. Heres apic or two.
Thanks
Johnny O

 

[kvom]

Sure, ask away. I had my boiler built by Godshall. The error in the plans for the steam dome location was a bummer though.

Your build looks quite far along already and high quality. I see you have the axle pump installed. I was advised against it by experienced people at our track.

 

[B36Peacemaker]

What's wrong with the axle pump? Would injectors be preferable?

 

[kvom]

Axle pump takes energy circulating water when boiler is not being filled, but is easier to manage. I used injectors, which take getting used to. Ideal is electric pump IMO.

 

[B36Peacemaker]

This thread is now officially hijacked for my own purposes! I will be documenting progress on my A3 build, which is exactly like kvom's, except that I don't have CNC capabilities. Now anyone looking to build this locomotive in the future will have TWO projects for reference! If we hit an image limit, I'll start a new thread.

A buddy of mine let me drive his 2-8-2 Mikado around the club track, which has inspired more progress on my own locomotive. Been working on the brake system for the engine this past week. Today I made the bracket which holds the foot brake pedal in place. Used some scrap 1.5x1.5 CRS, since I didn't have any 1.25x1.25 as the plans implied. Since I hadn't drilled/tapped the holes in the footplate yet, I changed the spacing of the bolts to better fit my wider-than-spec bracket (1.5" instead of 1.25").

This is one of those parts that is an odd shape, seemingly designed to give the first-time builder a hard time! A simpler shape would get the job done, but I decided to oblige Mr. Hiraoka and machine the profile as drawn. Here's the profile marked out:

I drilled the required holes first, so the drill bits wouldn't have to break out of the metal at a weird angle:

The surface finish on the main hole is absolutely atrocious, due to my clapped-out 9/16 drill bit. Plans say to ream, but I don't have a reamer at the moment, and it's not really necessary since the bronze bushings that get loctited into this hole will be turned to fit anyways. This is an example of a non-critical component that can be "close enough" and still work just fine. As long as it works I'm happy.

Next I got creative with the bandsaw, hacking away as much material as possible to spare my endmill the work:

I used calipers and a rule to markup the straight edges, but totally eyeballed the radius. Again, not critical.

I ended up making a few more cuts, but this is basically what I was left with:

Next it's off to the mill to cut away more metal. I lined up the scribed lines with the top of the vise jaws, then milled down until I hit the line:

I repeated this process for all straight surfaces, then roughed out the radius with several cuts:

I finished rounding off the profile with a disc sander, then cleaned up the part with files and sandpaper. The last operation was to counterbore for the rear bolts with my 5/16 endmill:

Finally, I clamped the bracket to the footplate, spot drilled the holes, then drilled and tapped them 8-32. Here's the bracket mounted in its final position:

All-in-all, this one part took about three hours to make. If you're gonna build one of these locomotives, you have to be able to enjoy the building process! More brake progress coming soon...

 

[B36Peacemaker]

Short session at the makerspace to turn the two bushings for the bracket I made yesterday. Don't have any bronze laying around at the moment, so I used some scraps from a chess set I made last year. The "black" pieces had bases made of melted bullet casings that I poured into a steel mold, then turned to shape. The "white" side had stainless bases (white bishop made from .444 Marlin case shown in picture). Anyways, cartridge brass is probably not the best bearing material; but it machines nice and is better than steel-on-steel:

Once I loctited the bushings in place, I re-reamed them by hand to make sure they were concentric. This was necessary since they were not a perfect fit in the bracket (due to loose tolerances and that crappy surface finish):

Finished bracket mounted back on the locomotive. Tested it with a 1/2" rod to confirm the re-reaming had worked. Kinda neat that I've got parts made from casings now; thinking about casting the bell and number plate from bullets as well, just for the neat-o factor.

 

[428Bird]

Man I just ran across this build and read the entire thing in one sitting. I ordered the book and am anxiously waiting it's arrival. I do have a couple of questions though;

1. Does the book have dimensions for 1.5 scale, or did you just double everything?
2. You mentioned that you needed to build/install brakes. Does the 3/4 scale model not have brakes? If not, how did you design them?
3. Has anyone ever tried to stretch the frame to make an 0-6-0, or add a pilot truck?

Nice work!

Britt Bettell

 

[B36Peacemaker]

Britt,

Kozo's book includes a section in the back on how to scale the locomotive up to 1.5". It guides you through the differences in the two scales. Some components are different than the 3/4" scale version, such as the frame, boiler, pistons, etc., while others are completely new, such as the braking system.

As far as modifying the design, you're on your own! I doubt anyone has tried it; the work required to redesign the loco is probably not worth it.

I see you're from Houston; are you a member of the Houston Area Live Steamers? You'll need a place to run your locomotive eventually! And I know a few guys there that can help you with live steam questions.

 

[kvom]

I'm away from home at the moment, but what I did was as follows.

Any dimensions inside the frame are scaled to the track ratio, 7.25/3.5.

Anything that is outside the frame is 2:1.