Question on Kozo A3 Switcher

[grobertson10765]

Hi all -

I am about 3 weeks into my first Live Steam project - the Kozo A3 Switcher. In general I find the detailed instructions and plans great, but I would like to see some small changes. In particular I don't like the use of 3-48 and (I think) some 1-72 screws. They are unusual.

Does anyone have any experience or had any problems with substituting 4-40 and 2-56 threads? The reason is that the odd numbers must be special ordered from McMaster or some other vendor, whereas 4-40 and 2-56 can be got at the local hardware store which is very useful if you suddenly lose a screw.

Gordon

 

[Patrick]

Hi all -

I am about 3 weeks into my first Live Steam project - the Kozo A3 Switcher. In general I find the detailed instructions and plans great, but I would like to see some small changes. In particular I don't like the use of 3-48 and (I think) some 1-72 screws. They are unusual.

Does anyone have any experience or had any problems with substituting 4-40 and 2-56 threads? The reason is that the odd numbers must be special ordered from McMaster or some other vendor, whereas 4-40 and 2-56 can be got at the local hardware store which is very useful if you suddenly lose a screw.

Gordon

Gordon, I think that Kozo did that in an attempt to keep the fasteners somewhat in scale with the rest of the loco and tender. I am building a Yankee Friends Atlantic 4-4-2 and Lester Friend also used some hard to get fasteners for scale purposes, I suppose. I am substituting another fastener close to the original spec as shown on the original drawing. I have modified the hex head on some fasteners, meaning making the hex smaller but keeping the integrity of the screw to help with acquiring the needed screws. It takes a lot of time depending on how many you need, I too don't know what else to do other than make all the fastener on the lathe and I'm not up to making 100's of miniature screws.

Patrick

 

[grobertson10765]

Thanks, I appreciate the information.

 

[Inflight]

I stuck with Kozo's size recommendations but ended up ordering some fasteners from Micro Fasteners.


Matt

 

[dickr]

I'm 1/2 to 2/3 thru the A-1 and changed all the screw sizes to 4-40, 2-56, 0-80. Even the 6-40 to 6-32 and so on. I even counter bored instead 82^ where ever it works because it looks cleaner to me, not to mention assemble with allen wrenches instead off screw drivers. Kozo works with metrics so obviously that's what he calls out You won't find any problem in doing so.
I've had to put it on hold for other reasons right now but hope to get back to it in the near future.
dickr

 

[grobertson10765]

I'm 1/2 to 2/3 thru the A-1 and changed all the screw sizes to 4-40, 2-56, 0-80. Even the 6-40 to 6-32 and so on. I even counter bored instead 82^ where ever it works because it looks cleaner to me, not to mention assemble with allen wrenches instead off screw drivers. Kozo works with metrics so obviously that's what he calls out You won't find any problem in doing so.
I've had to put it on hold for other reasons right now but hope to get back to it in the near future.
dickr

Thanks - that is just the information I needed - namely are there any problems/issues down the road? Your answer seems to indicate that there are not. I am not that concerned with scale issues, because I don't think the A3 is strictly a scale reproduction, but the convenience of hex-head screws, allen wrenches etc. and standard hardware sizes seems worth the change.

Gordon