Kiwi, yes by center height I meant the 'swing' which if you're a Pom means the maximum radius workpiece you can accommodate between the headstock spindle axis/tailstock center and the lathe bed whereas if you hail from the other side of the Atlantic tends to refer to the maximum diameter workpiece.
I'm not sure where the Antipodes sit in this terminology mash up but I assume your 9" machine can turn a max 9" workpiece judging from the pics? If so then 4 1/2" center height whereas mine is 16" swing or 8" center height but I don't mean to show off!
Anyhow I think you've answered my question, thanks, must have another look through all the dimensions.
I’m a brit living in nz so lets just say I’m “confused” by all the terminology, there is a big american influence on language over here tho.
It might be “aloris” who started the “axa” type terminology, see link, but most diy lathe owners will get a chinese knock off for a fraction of the price (from Banggood, aliexpress, ebay etc), for your lathe I suspect you will be looking at bxa or bigger, or maybe just buy one to suit the tool holder size you use? the axa tool holders I bought take 12mm (just) but I guess you would want 20mm or even bigger?
I have noticed that the pre-settable adjuster system (a knurled nut) on the axa does not lift the tool holder up high enough for the boring tool holders (which “rotate” the carbide bits downwards a bit), so I have to set into position manually (higher up) on the “wedge” each use, so I guess I could use a bxa, possibly, but that would look a bit big on my lathe, and it”s more important to be sure the tool height can be set low enough....cos if you can’t that do that you have start using non std tool holders.
Anyway, rather than try to work out all the dimensions I ended up just buying what others bought, the package of one axa post, 3 tool holders and 7 tools with carbide bits was was cheap enough, 200nzd delivered from memory.
https://www.aloris.com/Aloris-super-precision-tool-postEdit: yes the 9A has a 9” nominal swing, 4 1/2 height above the bed, not that I have measured it.