Overfilled Switch Box

I am running 12 ga circuits and have a 2-gang switch box that I am now realizing will have too much wire in it. [Note: don't waste your breath pointing out that using 12 ga was illogical - I'm already aware of this. Hindsight is 20/20, live & learn]
I have a feed and a load for one switch and the other switch is a middle-of-run 3-way that has the feed coming in to it, going to other switch (12/3) and lights (12/2). Total of 11 conductors, 2 devices, grounds, clamp = too much for 32 cu in (in fact, even using 14 ga would've been too much for this box). Plus, I was planning on both of these switches being dimmers (toggle switch w/slide), so some extra cu in would be better.
I was thinking of running feed for 3-way lighting to lights first, but even pulling out those 2 conductors doesn't save me enough volume (this would just barely work for 14 ga). I could possibly split switches into two separate boxes, but that won't look as clean on wall.
I guess I thought having a line and load for each switch in a 2-gang, with one being 3-way, would've been commonplace and boxes would be large enough to do this and give some extra cu in as well (if extra feed needed, like my case). And I didn't think the extra 0.25 cu in for 12 ga vs 14 would've done me in either....

Any suggestions??

 

Why are there two feeds? Are the two switches on separate circuits? If not, why don't they share one feed?

You mention clamps--is the box metal?

If you eliminate one of the feeds, and change the box to one without an internal clamp, you can still use the 12-gauge.

 

On you light with the three ways, do this:

P---L---S2===S1

S1 is switch in this double box
S2 is other 3way switch
L is light
P is power coming in
- is 12-2wg
= is 12-3wg

That eliminates four conductors from this box...

 

Thanks for the tips so far guys....some addt'l info

Yes.
No, plastic
Can you get a 2-gang plastic box w/o internal clamp? I included 1 volume count due to internal clamps
I'll have to see if this puts me in same position in my "S2" box then. It is in a 3-gang, with a 2-way and another 3-way switch.

Also, as a general question on running wire, is there any cause for concern (even a little?) when running power to lights first, then to switch? I tried to avoid this as all of the lights would then have a hot wire at all times, vs. when lights are after switch, hots are dead when switch is off. Just a little extra safety (someone fiddling with lights or possible shorted wires) I was trying to allow for, but if it's overboard, then say so...

Thanks again!

 

[Opinion]
I'd MUCH rather have power at the light first. Then all you need is a switch loop down to the switch, eliminating box fill problems. Then, if you ever want a ceiling fan/light combo, the light can be controlled by the switch and the fan can be independant of the switch. I can't stand it when I can't turn off the lights in a room at the switch without also killing the fan.
[/Opinion]

Anyone working on the light fixture should kill the breaker before starting to work. If they don't, the live wire isn't the main thing making the situation dangerous...it's that person's carelessness that makes it dangerous.

That S2 box may well end up with problems with fill as well. That's where going to the ceiling first, then using a switch loop can really help simplify things.

One thing you also may want to consider with these switches from different breakers: When you work in that common box, you need to know ALL the breakers that need to be turned off to kill ALL power to that box. LABEL well!

 

Seems to me that a double pole breaker would be appropriate for two circuits in the same box.

 

Are you sure your plastic box has an internal clamp? Most don't.

Why are they on two separate circuits? Can you put them on the same circuit?

Can you buy a deeper box?

 

I start seeing clamps (if you want to call them that) when you get into multi gang plastic boxes. I don't count these in box fill calculations, I assume the cu in. listed on the box is the usable cu in. available for use from the factory. Also, feed your light from the other 3 way switch. In other words, power coming in to your before mentioned box, feed the 3way, travelers & neutral to feed the other 3way 12-3, then feed the light from the other 3 way 12-2. This gives you 5 conductors & ground at ea 3way. Also agreeing with John, why not 1 power feed? Also makes it safer to work on in the future.

 

Thanks for all of your info/replies. I think I'll be able to use Chirks suggestion to eliminate 4 conductors without causing any other problems.
Just to follow up from some of the recent replies posted....

All of the 2-, 3- & 4-gangs I've seen (@HD & Lowes) have the internal clamps. And the volume of 2-gangs is either 32 or 35. I was hoping to find something larger/deeper, but haven't seen anything. If anyone knows that one exists, I'd be glad to hear about it....

The switches are for 9 cans & 8 cans respectively, and I'm not sure I'd want to have all 17 on one circuit - plus, I already have most wiring done. It'd be a lot of re-doing.

And, finally regarding volume stamped on the plastic boxes, Carlon (who seems to be the main manufacturer - both HD & Lowes carries them) says "The volume inside an outlet box does not include any deductions for integral clamps.... a single deduction in the NEC is required for the space the
clamps take up inside the box. A B520A (20 cu in) is 18 cubic inches after the clamp deduction for #14 wire."

Thanks again for all comments/suggestions!!