Re: drop spindle shafts and such
Rum
I've been using the "apprentice" https://www.woodturnerscatalog.com/p/179/4400/Apprentice-Collet-Chuck-7-Piece-Set which isn't to bad for knuckle knocking and I like that it puts the work a bit further from the headstock. The big square headstock is one gripe I have with my 3520, if I had room I'd get a smaller lathe for doing small spindle work like this. So I think I actually get more "clearance" (for some definition of clearance) with the chuck. A $10 MT2 extender would also serve a similar purpose of getting me away from the headstock some.. hrmmm.. Changing the angle on my skew might also help some.
I think the amount of waste should be close to the same, I'm only putting maybe 1" or so into the chuck and only loose 3/4" or so past that so maybe a smidge more but in the ballpark.
I like the gauge, I made a go/no go mt2 gauge that basically mirrors the taper for making mini jam chucks but your method allows making a shorter taper, is more accurate, and much faster as well (funny how you stick with doing things even when you should be able to see a better way - I've used similar things for sizing spindles for a while now). Using the drill bit as mandrel isn't something I'd probably have thought of either, thanks for that! With the detailing you put on them I can certainly see why you'd do most of the finish off of the lathe.
I've made a couple of types of supported spindles - but not the specific type you're describing (yet). Those were already on the list although I think I'll be using brass brazing rod for the spindle part and something else for the whorl as I'm supposed to be making them for cotton and I'm not sure I can go long/thin enough for that (cotton needs about a 1/8" shaft). The bowl inside a board certainly seems like a nice step up from the egg cup between the knees most of the folks are using, also added to the notes 
Hopefully this link works.. Here are two of the supported spindle types I've done.
The maple/walnut is close to what you're describing but a bit heavier and more suited for medium sized yarn (maple was a poor choice for this as its definitely not dense/stable enough at least not soft maple, the walnut wasn't heavy enough either - live and learn). The shaft on this one developed a bit of a sway to it so I never bothered to take it as thin as it should be, it works but not very well (it was one of my earlier attempts and stayed on as a mantle piece).
The other is a Russian lace spindle made out of lytus; these are used for really fine lace (say 3-4 strands thick of some fine staple fiber like cashmere goat) which could be used to make a "ring shawl" (where the entire shawl will pass through a ring). Its used in a similar fashion but doesn't have as much "spin duration" and is mostly used with a longer draw putting the point in a bowl on the floor. This one is imho pretty close to correct for the style although the points on both ends could be a smidge finer. They're also harder to use in my limited experience.
There are also the Navajo spindles that are 2-3' long and technically fall into the "supported spindle" class - but are a bit of a different beast (and I don't have any of those on hand).
Loml is the spinner and has a small collection of wheels (and a larger collection of fiber from various critters). I learned how to drop spindle enough to be somewhat competent so I could figure out what makes a good spindle but never got much past that. I can spin on a wheel but certainly not well (two glasses of wine to start with helps keep the off hand relaxed). I'm also supposed to make an e-spinner (or more correctly "they cost what for what?! I'll make you one".. the motor I want has been surprising hard to source for a reasonable price though and the concerned party has been getting a bit restless).
There are a handful of really good drop spindle turners around here who make a lot nicer ones that I'll likely ever do as an ongoing process (given that that's all they do.. its hard to get the same knack as an occasional hobbiest) so I mostly do things we can't find commercially or to play with design details to see what works differently or just stuff that looks interesting for whatever reason (a lot of the fiber arts tools are pretty interesting around how they work).
Had I known then I'd have made an effort to look you up when we drove through Clinton a few years back (we did stop at the lovely little yarn store downtown). Amusingly I grew up in a town named Clinton, but its in B.C. not TN, loml joked that it would be just like moving back home only not so cold.
The Lendrum is a nicer plying wheel because we have the large plying flyer for it and you can put enormous amounts of yarn on that. We also have an old Canadian Production wheel from the 1860s-1890s (accurately dating it past that proved fairly impossible), its a nice wheel (after some significant fixing) but you have to be a really good spinner to use it - I can't use it at all, loml can use it on a good day but it only does fine yarn and that really fast. I know we have at least one more wheel but I can't remember what it is 
I've been working on a manual portable mini wheel design I hope to make someday (its proven more than a bit complicated so there's still a lot of design and prototyping work to do).
