Moxon vise — width between the screws?

I'm a beginner apartment woodworker in San Francisco who volunteers at City College of SF's woodshop as an assistant (last 2 years) for shop access. At home, my kitchen counter peninsula is my bench, so building a Moxon vise is making more and more sense.

Note: the CCSF woodshop is machine-oriented with 6-inch iron vises only. I've never used a twin-screw vise outside a Lie-Nielsen demo day (and I liked it).

I tried to reverse-engineer the practicalities from all the commercial kits and plans for twin-screw / Moxon setups from:

• Lie-Nielsen
• Veritas
• Benchcrafted
• Acer-Ferrous
• Tools for Working Wood
• Lake Erie
• Texas Heritage
• YouTube makers
• Christopher Schwarz

There's one persistent dimension: 24" between the screws, but more than a few guides mention 16" is more practical for all but large casework. Looking at all the casework around me (dressers, kitchen cabinets, drawer boxes, bathroom vanities, console tables) nothing is actually deeper than 20", and most are 3-8" drawers or 12-18" carcasses.

I have the space to store one mega Moxon at home, but probably not a 24" and 16" version. I'm thinking 20" between screws would fit all furniture in my world that conceivably has dovetails. I don't see much commercial furniture deeper than 20" either.

So why is 24" the norm? I'm guessing it's either:

• Option A — deep armoirs and waterfall desks are the outer limit.
• Option B — there's another practical workholding use for long Moxon vises that escapes me (beyond edge planing).
• Option C — you don't want the workpiece side too close to the screws, so 24" gives 2" gap on a 20" case.
• Option D — "go big or go home" prevails only so you won't need two kits.

Heading off the "it depends" answer — I mainly want this vise for hand joinery work on chair/bench parts and small boxes, but I would like to try building a hand-cut dovetail nightstand this year, and a full size dresser next year. So eventually, an 18-20" width will be used.

Appreciate the ideas. Looking to be told if you think 20" between screws is enough just do 24" because XYZ. I'm guessing Option C is that argument, but I've never used a vise like this before.

Note: I already bought the 8/4 maple and ordering Benchcrafted kit. Just deciding where to cross-cut it for the nice face grain.

Brendan,
I just built a Moxon for my last dovetailing project, my need was my guide. I figured 16" would be my largest panel, give 2" either side so I used 20" center to center. Also being frugal person; my ACME threaded screws/hand-wheels look exactly like a dumbbell bar hack-sawed in half and epoxied into drilled holes of the stationary face ...

Brendan,

Its an individual decision depending on the type of work you do. Mine is 16" between screws and because in my work I rarely need anything over 12". If I'm dealing with a wide carcase piece like a dresser, I just clamp it across the bench. For me, it wouldn't be worth hefting a behemoth around for a rarely used task.

That said, if you are doing a lot of large case work, maybe 2 vises would be good: one wide vise and one normal size.