9" reverse mechanism

I have a 9" SB Model 405 which requires a few minutes to insert a reverse gear into the train when reverse is wanted. This is not a game-changer but it IS a bit of a nuisance. Years ago, before I retired and have all the spare time that I now have, I bought a reverse-gear mechanism from a later Model B or A. Has anyone ever done a retro-fit like this? I know that it wouldn't be simple, and it appears to me that the banjo would have to be replaced with a later Y-shaped one.As I said, I have lots of time now to fritter away on unnecessary projects! One concern that I have is that such a change might invalidate my change gear chart!

Adding one or more idlers won't have any affect on the ratio between the spindle and lead screw. Only compound gearing will do that.

You cannot attach the reverse tumbler to the 405 headstock- there is not enough meat to bore the mounting hole. I suggest you replace the entire headstock.

allan

kitno455 said:

You cannot attach the reverse tumbler to the 405 headstock- there is not enough meat to bore the mounting hole. I suggest you replace the entire headstock.

allan

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Ah, I didn't thing about that! I'm not familiar with the 405's, I had to google a picture to see what one even looks like. What head stock would fit on that bed? Would a 9a,b,c head stock fit or is the bed wider?

ron vella said:

I have a 9" SB Model 405 which requires a few minutes to insert a reverse gear into the train when reverse is wanted. This is not a game-changer but it IS a bit of a nuisance. Years ago, before I retired and have all the spare time that I now have, I bought a reverse-gear mechanism from a later Model B or A. Has anyone ever done a retro-fit like this? I know that it wouldn't be simple, and it appears to me that the banjo would have to be replaced with a later Y-shaped one.As I said, I have lots of time now to fritter away on unnecessary projects! One concern that I have is that such a change might invalidate my change gear chart!

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A friend of mine designed a "direction" gear setup on his old Ozzie lathe to enable reversing like you require. On his lathe, he used the shaft of the back gear (well,he actually made a new one although he could have extended the original)- the back gear handle goes back on the new shaft. The longer shaft enabled a gear carrier to be slid on that could be "swung in" when needed and parked away when not in use. The yellow gear is on the aforementioned carrier. Whether that can be done on yours would have to be determined by yourself. It works very well on my mates lathe though. The plastic parts that I made for him were just meant to be proof of concept but he still uses them! Anyway, have a look at the pic.