A question for anyone who has built the reversing gear for the #1. When I got the castings for my #1 second hand many years ago, also included were the reverse gear castings. I have started working on them and the drawing I have although showing most dimensions is more of a GA than parts drawing. Many of the parts don't have all the dimensions (like the eccentric sheaves and straps ). When I got them the box was open and I am wondering if there was another sheet of drawings that is missing, dimesioning the individual parts , there is one with the 5A reverse gear castings I have. The drawing I have is numbered 70090 dated 18.10.56 Alt # 32 20-1-67 and issued 18 Sep 1975.

John

Jason

Thanks for the reply. What I have been doing is as you suggest, using the main engine drawings for the sheaves and straps and scaling from the drawing elsewhere as necessary. I was just wondering if there was another drawing sheet I was missing? At the moment all I have left to do are the eccentric straps and rods.

John

Here are a couple of more pictures with different views. The first, Jason, is from the back and shows that with all the reverse linkages lined up the eccentrics are spaced out on the crank shaft and the valve rod and the expansion link don't line up.. The second shows the eccentrics moved in on the crank to line up the valve rod and the expansion link, but now the reverse lever is spaced out from the rest of the reverse linkage. The position of the reverse lever is fixed by its fastening to the slotted link which is bolted to the valve chest cover. The obvious fix is to make a longer 1/4" pivot pin and a spacer between the reverse lever and the rest of the linkage. But my question is have other people had this problem or am I missing something, or are the drawings of the reverse gear in error?

John

Edited By John Purdy on 17/02/2022 18:32:01

Thank you Jason, I'm not crazy after all. I had also added up the dimensions as you have done and came to the same conclusion, but was wondering if I was missing something. I'm sure many examples of this reversing gear have been made to these drawings, how many others have had the same problem and how have they got around it? Are Stuart Turner aware of the errors, are the current drawings the same as ours or have they been amended?

John

Got a reply from Stuart Models this morning. Seems they are still using the same plans and are not aware of the problem. Here's a quote from their msg.

"We are still working from the same drawings as you seem to have,

I haven’t had anyone notify me of this issue before, but this maybe that they have worked around the issue.

Will moving the reverse shaft bracket solve the valve rod alignment, also on our engine, there is a spacer between the reverse shaft bracket and the reversing lever, so this may be the get around."

Looks like their fix is the same as I have come up with!

I've added a post to the "Drawing Errors " section about this error in the drawings.

John

Edited By John Purdy on 18/02/2022 17:12:51

Noel

I sent a msg. back to Stuart Models thanking them for their reply and included the following statement:

"If the drawing was amended to show the boss on the reverse lever to be 1/4" wide (vice 3/32" ) and not the width across the whole reverse lever this would solve the problem. Either that or a note with the drawings specifying a 5/32" wide spacer between the reverse shaft and the support bracket boss."

We'll see how they respond.

John

Edited By John Purdy on 18/02/2022 18:26:23

Agreed. But that would mean a re-draw of the plans. We'll see how they respond!

I've just checked the reverse lever casting in my 5A reverse gear set ( they both use the same one, also the same expansion link casting )  and I don't think the boss is long enough as cast to make it 1/4" and keep the turned handle at the end centred on the shaft.

John

Edited By John Purdy on 18/02/2022 18:51:30