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SB 9 Back Gear will not stay engaged
- Thread starter RVbeemer
- Start date
- Joined
- Oct 16, 2019
- Messages
- 6,595
According to the Steve Wells South Bend Serial number database the bed is from 1935.
But the red gear ratio plaque on the gearbox indicates the gearbox is definitely from a later model.
This parts diagram from 1935 shows the back gear adjusting screws as part #246 on pg. 3 of the pdf
It looks like your machine was painted, is it possible that the holes were filled and painted?
I will go look at it again but i looks as though the casting is unmolested. Strange! It' as if they forgot to drill and tap the hole at the factory but surely it was run through a test to make sure the back gears engaged. If not then there is no way the back gear could ever have been used. I'll go look it over again. Thanks
- Joined
- Sep 24, 2020
- Messages
- 1,921
Those early lathes did not have the same set-up as the newer version.
Looking at that parts list does not show the screw and shoe you are looking for.
Someone added a later QCGB to an older workshop model, or upgraded the old single tumbler to a double tumbler.
You DO NOT have an A model or a "converted C model.You have a "workshop" Q model with a newer gearbox.
Looking at that parts list does not show the screw and shoe you are looking for.
Someone added a later QCGB to an older workshop model, or upgraded the old single tumbler to a double tumbler.
You DO NOT have an A model or a "converted C model.You have a "workshop" Q model with a newer gearbox.
Okay, I went out and looked the back gear over and I found something very interesting. There is a hole approximately 1/4" just below the back gear lever. It looked as though it was threaded but I blew it out with air and there is a spring in there. I tried to push it in with a small screw driver to see if it was threaded. Couldn't tell. But the lever covers just enough of the hole that the spring won't come out. I will have to remove the lever to remove the spring. The hole is 5/8" deep. I'm pretty sure it's not threaded as the lever covers too much of the hole for something to be threaded in it. See pictures. Perhaps something fits in the gap between the lever and the headstock?
Attachments
David,
This screw adjusts the gear mesh but does not lock it in. The lock in screw puts tension on the eccentrics to hold it in place.
- Joined
- Mar 3, 2020
- Messages
- 506
Will this help? It’s parts list for horizontal & underdrive 9” models fron June 15 1957.
The toolmaker or workshop models. Not the Junior (or heavy 9) which was discontinued in late 30’s or in the 40’s.
rvbeemer your lathe is not a junior or heavy 9.
it is an early workshop or toolmaker From the ’30’s. It has top spindle oilers.
also, to convert an early C like yours (there was not an A, B, or C model in the early ones) you would need a frame as well as the gearbox, as the frame did not have the relieved frame that the later A B or C had.
The toolmaker or workshop models. Not the Junior (or heavy 9) which was discontinued in late 30’s or in the 40’s.
rvbeemer your lathe is not a junior or heavy 9.
it is an early workshop or toolmaker From the ’30’s. It has top spindle oilers.
also, to convert an early C like yours (there was not an A, B, or C model in the early ones) you would need a frame as well as the gearbox, as the frame did not have the relieved frame that the later A B or C had.
Attachments
Mmmm. I'll go play with mine and see what happens. Do you remember if you went tighter or looser?