BXA tool post on a 9" lathe?

[paul_c]

Will I be able to get tools centered with something this big? My problem is that I'd like to use a knurling tool with a 3/4" shaft (and those don't fit in AXA tool holders)
thanks

 

[Bob Korves]

An AXA tool post makes more sense for a South Bend 9" lathe. You can often machine down the shanks so they will fit in the AXA holders. It is also possible to cut dovetails into larger tool holders so they fit directly on the tool post, no QCTP tool holder used...

 

[paul_c]

An AXA tool post makes more sense for a South Bend 9" lathe. You can often machine down the shanks so they will fit in the AXA holders. It is also possible to cut dovetails into larger tool holders so they fit directly on the tool post, no QCTP tool holder used...

Yeah I was going not to grind on this new knurling tool to make it fit my AXA

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[Ulma Doctor]

as a point of information, there are oversize AXA holders for 5/8" tooling
as Bob suggested, thinning the shank would be relatively easy.
tool shanks are generally not hard

BXA is too big, IMO

 

[RJSakowski]

Will I be able to get tools centered with something this big? My problem is that I'd like to use a knurling tool with a 3/4" shaft (and those don't fit in AXA tool holders)
thanks

As to your question whether a BXA QCTP will work with a 9" lathe, the issue is whether a tool placed in the tool holder will be at or below the spindle center line when the tool holder is at its lowest position which is usually the top of the compound. If you go to one of the vendors for BXA tool posts, you will find dimensions for the tool holders and you can compare the height of the bottom shelf of the tool holder plus the tools you expect to use with your spindle to compound distance.
For example Shars shows a 1/2" height for the shelf and with a 1/2" tool bit, the minimum height above the compound that the tool can be set is 1". If the centerline to compound distance is less than 1", you will not be able to set the tool to the centerline. You could, of course, use 3/8" tool bits which would then put the minimum height at 7/8".

 

[paul_c]

As to your question whether a BXA QCTP will work with a 9" lathe, the issue is whether a tool placed in the tool holder will be at or below the spindle center line when the tool holder is at its lowest position which is usually the top of the compound. If you go to one of the vendors for BXA tool posts, you will find dimensions for the tool holders and you can compare the height of the bottom shelf of the tool holder plus the tools you expect to use with your spindle to compound distance.
For example Shars shows a 1/2" height for the shelf and with a 1/2" tool bit, the minimum height above the compound that the tool can be set is 1". If the centerline to compound distance is less than 1", you will not be able to set the tool to the centerline. You could, of course, use 3/8" tool bits which would then put the minimum height at 7/8".

Yes I know, if you see my original post, I realize tool height can be an issue. I have oversize AXA holders for 5/8" shanks, but not 3/4". I guess I'll grind down, thanks all

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[darkzero]

You already got your answer regarding a BXA being too big for a 9" lathe but just to give you an idea....

I have a 12x lathe with a BXA. Oversize holder is 3/4" I have barely enough room to get a 3/4" shank tool on centerline.

Dorian's current holders are "extreme" oversize, they go up 2 shank sizes. So Dorian's current holder accepts up to 3/4" shank for AXA. This would fit your tool post & tool you are asking about but you still may not have enough room to get that 3/4" tool on center.

I have a Dorian "extreme" oversie tool holder that again goes up 2 shank sizes. But I don't have enough room to get a 1" shank tool on center line.

Info in post #8 http://www.hobby-machinist.com/threads/upgrading-to-a-qctp-advice-please.26610/#post-234322