K-27? lets hope so

Started by bernienufc · 62 replies · 11,787 views

bernienufc
19 Apr 2026, 15:39
The Kozo books have arrived, even in my wildest expectations did i think they would be so good, i can start to understand why people buy the set and also not part with any.

It is my intention to try to build the 3.5 K-27 with little experience but with a lot of enthusiasm and inspiration from several members on here.

I have several sets of UK steam loco drawings but somehow i just got stuck so i a hoping with the book an this forum i can keep the momentum up.
I am putting the design into cad as i go because a: i have a bit of an issue with swapping digits around :-) and cad allows me to hopefully catch the errors and b: i'm not that ofay with the terminology of steam locos and by drawing them i am getting a good understanding of how they work.
Being a full time carer will restrict my time so short cuts will be (for me) inevitable but one thing i really want to try is to make the boiler, but as a recent helpful member noted by starting at the beginning of the book by the time i get to the boiler i should have more confidence and skills to do it.
First up, sell my huge laser cutter to give some space for a mill, wifey does not mind me doing the model but not in the living room for some reason :-D

Study the books to get a understanding of where i am going, then list my materials and hide it from her indoors.
Onwards and upward  a pleasure to be here

malc

crueby
Reply #1 · 19 Apr 2026, 16:12
Fun!  Looking forward to seeing your K27 take shape. Years ago my first real scratch big build was his New Shay, learned SO much from following that book.
krt2
Reply #2 · 19 Apr 2026, 16:13
How exciting!
Yes, Kozo's books are very good!  Lots of good techniques and wonderful drawings to look at. I've got the set of books too!

I'm looking forward to seeing your progress on this project!
Kim

bent
Reply #4 · 29 Apr 2026, 01:46
For a moment, I was thinking you were building an RC submarine along the lines of the Russian K-19...but a locomotive works too.  :embarassed:
bernienufc
Reply #6 · 3 May 2026, 14:28
Can someone help me with this Rear Head, i cannot seem to fathom why my lines do not tangent up to the D4 (R2) Circle, i have checked until blue in the face to Kozo's drawing but cannot find my error, anyone who has made this piece did you do it without issue?


many thanks Malc
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crueby
Reply #7 · 3 May 2026, 15:07
Kozo does all his drawings pen/ink by hand, not with CAD, so perhaps his dimensions did not calculate out as precisely?
bernienufc
Reply #8 · 3 May 2026, 15:12
Quote from: cruebyKozo does all his drawings pen/ink by hand, not with CAD, so perhaps his dimensions did not calculate out as precisely?


I can understand that, but so far i have to say they have been bang on which is why i put it down to me, if i had not used cad i know i would have made a good number of mistakes so looking to solve this before i move on.
Thanks for post
crueby
Reply #9 · 3 May 2026, 16:03
If you want another pair of eyes on his drawing to compare to yours, you could message me a picture of his page, and I'll give it a look.
krt2
Reply #10 · 3 May 2026, 16:10
When I look at the drawing in the book, he doesn't seem to specify the radius of those back rounded corners - the ones you show as R2.  He defines the radius of the front round part of the opening as 2R (which matches your 4D).  But the back corners of the tranigle-ish cutout aren't defined in Kozo's drawing.

So you might be trying to overconstrain it?  Just a thought.

Kim
crueby
Reply #11 · 3 May 2026, 16:54
Quote from: KimWhen I look at the drawing in the book, he doesn't seem to specify the radius of those back rounded corners - the ones you show as R2.  He defines the radius of the front round part of the opening as 2R (which matches your 4D).  But the back corners of the tranigle-ish cutout aren't defined in Kozo's drawing.

So you might be trying to overconstrain it?  Just a thought.

Kim
Not having seen the drawing, but that sounds like it is likely it.
bernienufc
Reply #12 · 3 May 2026, 17:18
If i change the radius of the 2 rear circles surely the straight lines that join them would not be parallel i.e the 4mm offset if that makes sense.
crueby
Reply #13 · 3 May 2026, 17:22
Quote from: bernienufcIf i change the radius of the 2 rear circles surely the straight lines that join them would not be parallel i.e the 4mm offset if that makes sense.

Not correct - the lines could still be parallel but the 4mm distance could change so the lines go tangent to the left circle. Does the book show the 4mm distance? Hard to diagnose without having the picture from the book...

Is that 4mm circle supposed to be tangent to the 22mm distance you have it at, or centered on it?
bernienufc
Reply #14 · 3 May 2026, 18:04
Quote from: crueby
Quote from: bernienufcIf i change the radius of the 2 rear circles surely the straight lines that join them would not be parallel i.e the 4mm offset if that makes sense.

Not correct - the lines could still be parallel but the 4mm distance could change so the lines go tangent to the left circle. Does the book show the 4mm distance? Hard to diagnose without having the picture from the book...

Is that 4mm circle supposed to be tangent to the 22mm distance you have it at, or centered on it?

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