Hello from Seattle

[robwell]

I live in Seattle and have a shop in my basement. I’ve been looking at building the Pennsylvania A3 Switcher as modeled by Kozo Hiraoka. Toward better understanding of that design, I’ve been 3D modeling the design. So far, I’ve completed the tender except for some rivit work and the flexible hose (which I’ll model when the engine is further along). I’m making good progress on the engine, though I am struggling with some alignment issues. I suspect I will be done in a month or so. Here are some pictures of the work so far. I’m happy to post progress if people are interested. - Cheers, Bob

[RReid]

Hello Bob, and Welcome! This forum is becoming quite a hotbed of A3 builders!

[Kim]

Hi Bob, and welcome to the forum!

Your CAD models look great, and they are about up to the same point I am with my A3 build!  That's a lot of work there!
You must be going linearly through the book in the same order Kozo presents it?

Great looking model there.  And a FUN build. I'll look forward to seeing your build log!   

Kim

[robwell]

Kim,

I’ve been looking at your build log - WOW, beautiful work. Yes, I’m going linearly. I’ve found a few small dimension errors in the book. Debugging alignment problems it kind of frustrating. I’m having way to much fun and look forward to making real parts.

[Kim]

Yeah, there are a few errors in Kozo's book, but very few!  Would you be willing to share the issues you've found?  It could be very helpful to others!  (And to me!  )

For me, most of the time I thought a dimension was wrong I found I was misreading the drawing in some way.  Or that I found a dimension that I thought was missing in a different view of the part.  But I have found a few errors in the book.

Kim

[robwell]

Here are two:

page 61 fig 9-12: #32 (.166) Drill should be .116

page 88 fig 14-19: hole width 1 1/32 should be 1 5/16 (to match the steam chest dimensions)

[internal_fire]

That is why that Kozo said after the A3 he would never again publish a design using Imperial units. And he did not.

Gene

[robwell]

I started my adventure modeling his Shay design, which is metric, and yea, inches are a total pain.

[vtsteam]

Welcome, Bob! 

[Kim]

Here are two:

page 61 fig 9-12: #32 (.166) Drill should be .116

page 88 fig 14-19: hole width 1 1/32 should be 1 5/16 (to match the steam chest dimensions)

You're so right, Bob!

I didn't notice that first one you list, on page 61.  But the second one (page 88) I remember that one!  It doesn't match the steam chest dimensions in the drawing.

An error I found recently is in the Boiler section (chapter 23).
In figure 23-1 (upper side view of the boiler) it shows the mounting boss on the smokebox studs to be 1/4" dia.
But in figure 23-11 he shows to ream the hole for the smoke box stud to 7/32".
I'm sure either dimension would work, but you they better be the same.  I went with 7/32" because I'd already drilled and reamed the holes in the front tube sheet.

Sorry for derailing your Welcome thread with this minutia!

Maybe we should have a different thread where we recorded all these?  Just a thought.

Kim

[robwell]

I looked around for an errata sheet for the A3 book but could not find one. I think it would be great to have a place for that. Similarly, I found some of the drawings hard to interpret and I think it might be worth having a - “what the heck does he mean” discussion. I found, as an example, the crosshead drawing very confusing. I’ve been able to model most parts from the drawing only but not that one - and my model is still not right.