# South Bend 9 Steady Rest What Missing



## Gman45acp (Jul 24, 2019)

I picked up a SB 9A and this steady rest was in the box.    It is the correct size for the lathe but I have never seen one that has a offset mount.
At least that is what I think it is.    Anyone seen this and if so what is the missing part supposed to look like.   I can probably cut off most of the offset and make a base for it that can mount between the bed rails.    Also got a bunch gears if anyone is looking for some.


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## lordbeezer (Jul 24, 2019)

I have a 9" model c I need gears for if you have extra..


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## Gman45acp (Jul 25, 2019)

lordbeezer said:


> I have a 9" model c I need gears for if you have extra..


What  number teeth gears you need and shaft diameter


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## benmychree (Jul 25, 2019)

That steady rest is for a tool & cutter grinder.


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## Bob Korves (Jul 25, 2019)

Make very sure you have all the change gears that would have come with the lathe when new before selling any.  Then sell duplicates and any that will not fit your lathe.


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## SLK001 (Jul 25, 2019)

Bob Korves said:


> Make very sure you have all the change gears that would have come with the lathe when new before selling any.  Then sell duplicates and any that will not fit your lathe.



A 9A doesn't use any change gears.  It has a QCGB.


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## craptain (Jul 25, 2019)

SLK001 said:


> A 9A doesn't use any change gears. It has a QCGB.


It would need change gears to cut metric threads. It might just be one, I don't recall offhand. 

Sent from my SM-G930T using Tapatalk


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## Gman45acp (Jul 25, 2019)

Yes mine has a QC gearbox but there were a bunch of single gears. 80, 56,52, 48, 40, 36, 32, 20,    Will have to check but I think there numbers are correct.   Can verify tomorrow.


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## Gman45acp (Jul 25, 2019)

benmychree said:


> That steady rest is for a tool & cutter grinder.


Has any one converted it to work off the bed.   Is there any demand for it as it is


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## Bob Korves (Jul 26, 2019)

Gman45acp said:


> Yes mine has a QC gearbox but there were a bunch of single gears. 80, 56,52, 48, 40, 36, 32, 20,    Will have to check but I think there numbers are correct.   Can verify tomorrow.


Any change gears that will fit your lathe (mesh with the other gears, have the same mounting style, or can be machined to fit the same) should be kept.  Many of us think that the only combinations needed for the lathe are the ones shown on the charts that came with the lathe.  NOT TRUE!  There are always lots of additional ratios that can be made with the gears that came with the lathe, and can be useful if you want to cut a specific lead that is not on the chart.  The charts that come with the lathe are just a fraction of the ratios that can be cut, and the builder only shows charts showing gearing in common use.  I wanted a way to make 27 tpi threads, and none were shown on the lathe charts.  jbolt on this group very kindly made me a spreadsheet of ALL the combinations that my 13x40 Chinese lathe can make with just the gears that come with it and the QCGB, and it is a HUGE list.  With more tooth counts available, lots more can be accomplished.  Here is the file with the Excel chart that jbolt put together for gearing my Kent KLS-1340a lathe:


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## ErichKeane (Jul 26, 2019)

Also note that even a QCGB requires at least 1 additional stud gear to even use the whole chart.  See this one I found for a 9A: https://www.practicalmachinist.com/...-part-1-removal-disassembly-index-plate-1.jpg

In order to get the top row, you need a 40 gear tooth on your stud-gear.  Everything else uses a 20.  Once you recognize the relationship between the two rows (stud gear ratio is the same as gearbox ratio!) you can discover a bunch of new options!


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## Gman45acp (Jul 26, 2019)

ErichKeane said:


> Also note that even a QCGB requires at least 1 additional stud gear to even use the whole chart.  See this one I found for a 9A: https://www.practicalmachinist.com/...-part-1-removal-disassembly-index-plate-1.jpg
> 
> In order to get the top row, you need a 40 gear tooth on your stud-gear.  Everything else uses a 20.  Once you recognize the relationship between the two rows (stud gear ratio is the same as gearbox ratio!) you can discover a bunch of new options!


Yep. I saw that and have both the 20 and 40 tooth gear plus extras


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