I'm milling about 135ft of a custom (stair) handrail today & tomorrow, and within the job, are several transitions (upeasings, level quarter turns, Bullnose ends, etc)

For this profile, I have matched (very large) Custom Router Bits
-side profile milled from bottom
-side profile milled from top
-top profile milled from top
Shaper Knives (insert)
& Woodmaster Moulder knives

does anyone have any preferred methods for milling the fittings (without a CNC)

I have some interesting jigs & fixtures I've been using the past couple years, but of course I can't leave well enough alone, as there's always someone who knows a better trick for getting the job done!

milling flat rails, turns & bullnose rail ends are straienough, upeasings (especially when they're on the end of a 13ft rail blank!). are a resl challenge!

Any new ideas greatly appreciated!

I like to use the lathe for up and over easings. I have also used an over arm router with a swing jig, as well as a shaper with a swing jig.

your initial comment had one of my brows raised in a "now, does he understand what I'm talking about" ponder. -that it until it "hit me". Lathe? oh! I get it ! but wait a sec. thats a mighty big chunk 'o glue-up you're spinning (if I am understanding correctly).
Now the "swing jig" you mention: how does that work?
Milling the side cuts gives my a couple obstacles (up-easings & over-easings) as the parts get run in a series of reverse profiled "shoes" -in the case of an up-easing, rail blank bottom is down on router table and run with side agsinst a very tall fence.. this is the basic idea of how I usually make easings (and having custom router bits goes a long way when making fittings like these).

but here are my issues with this particular job:
-the up-easings are made on the ends of several 12-13ft rails (two of which also have over-easings on the opposite ends)
ONE PIECE GLUE-UPS. -Im not making fittings, these are 1-pc, horizontally laminated custom rails.

& while a 2-4ft straight rail projecting off an easement could help with the milling procedure, 13foot straight rail is nearly impossible to handle.

has anybody ever heard of a "French Spindle"?
last time I built a curved stair, my helper recalled a conversation she'd had, where an Oldtimer had suggested a "French Spindle" for milling the free-form, horizontally laminated handrails, -I've yet to find out exactly what a "French Spindle" is??? anyone?

while we're on this subject, has anyone ever milled an ascending volute or turnout; by conventional means (without CNC) and without literally hand-carving the part?

From a Google search:
French Spindle
From the magazine "The Woodworker" May 1922.
"Tracery panels are glue-joined with a square edge rubbed joint, so that the sinkings will not show up unsightly. These panels are then worked out by tracing and are jig-sawed or pieced, afterward being molded on the French Spindle as shown in Fig. 5. This spindle is usually 1/2 or 5/8-in. diameter and after the piercings have been made by a jig saw, the panel is dropped carefully over the head of the spindle, onto the machine table, and moved around until the cut is completed. The panels are then passed along to the carver to be cut in at the corners, pockets, etc."
So this a an adaptation of a shaper with a small spindle and a rub collar. It looks like it would be made by using the spindle as the rub collar.
Fig. 4. Is a special tool used on a drill press to make the radius molding shapes. You can see how the knife is retained with set screws. Similar in concept to the French Spindle, I didn't draw it. My drawing is an interpretation of the poor magazine illustration.

View higher quality, full size image (912 X 839)

I constructed a handrail milling machine years ago and it's still on the job although I will plan to lretire soon After more than 20 years now, I've managed to learn a few things although it's still a bit of a proprietary concern. I haven't turned any stair handrail parts on the lathe for 40 years now. I mill descending volutes and all kinds easings and any kind of curved handrail up to about 4"without CNC (see my profile). It hasn't been free though since cutters cost hundreds. I ruined a French spindle recently so I no longer f with that. I've also made myself a sort of expert on tangent handrail too since that was part of the package.

However you approach all this, please be careful as milling handrail fittings without CNC can be hazarded to your health.

The old French spindle shaper was particularly wicked .

Scmi R9 tilted head Can make damn near anything with massive cutters. Takes a big pair to run and will put some hair on em