13" South Bend. I've got a Multifix 'A' tool post on the way for it. I can get a holder up to MT2 for the 'A' size. 'B' or larger would be required for an MT3. Not an issue since I haven't purchased any tapered shank bits just yet.
How does one center up a drill bit in the tool post precisely? There are three separate degrees of freedom which must be precisely aligned.
Just one, actually. A holder for drilling from the carriage doesn't have anything to do with "compound" nor toolpost, either one.
A stout 4-Way directly mounted to the topslide, no compound even installed, "industrial style" can handle a drill. But hobby lathe users usually have a compound on the lathe even when they don't need it for a short taper.
4-Way, Multifix or Aloris on a compound - even if pinned - just swivels the compound. SB easiest of all. Handy clamping system for the compound, SB's have. But nowhere NEAR as twist-resistant as an
industrial lathe.
Best of both world's?
Dowel and screw a monoblock directly to the cross topslide rearward (away from the operator) and leave the compound on the lathe.
Set a witness mark or arrange a shot-pin for that cross position.
Finish bore, if not also drill (from the HS) the holder right on the lathe.
When ready to drill, move the cross to the witness mark or drop the shot pin into position.
Drill the hole.
Since you line bored it ON the lathe? The height is dead-nuts already.
No interference with the compound or toolpost at all.
PS:
Do NOT buy "any tapered shank drills just yet".
Make the bore of that monobloc a straight cylinder, not a MT.
Now it can hold a short ER or TG collet holder or an Ortleib tap holder on a straight tail.
Cheap, cheerful, easy to afford more than one.
Jacobs, Albrecht take up too much
space. Even so, they can be had on straight tails, too.
You don't want long
body MT tail drills for a lathe anyway! Same reason.
They eat too much long-axis daylight. ELSAE you are going to be into three sets right away, not just one or two.
Also not cheap in all the
varieties lathe work wants. Jobbers. Stub. longish Bell-hanger, centering. Spot. Reamers. Counterbores. Spot-facers, Countersinks. ... yadda, yadda. Cheaper in straight shank, every one of those
You see the value of the shorty collet holder or the Jacobs or Albrecht?
One cannot AFFORD to cover all that speciality stuff with MT tail goods ... even if you could FIND them made that way. And one cannot, actually.
MT tail drills are for
drillpresses. Plain-old ignorant HOLES.
NOW "long" is all you need in MT tail. Only ONE of my three DP handles 5 MT "native". All-else I have reducers for. The two smaller DP have chucks. Drillpress doesn't HAVE to be limited to MT. It can mount all the other stuff, too.
You know what a drillpress is, yah?
A drillpress is the second machine you bought right after a general-purpose bench-grinder.
Knowing in advance a mill makes a shitty drillpress and a lathe an even WORSE one.
Drillpress sucks smelly orifices at being a lathe or mill, too, to be fair.
"Horses for courses"