Dovetails headcabs

[dude]

When setting up a dovetail jig, one of the first set-up steps is to set the face pieces with the combs. So both edges are even with the start of the dovetails. You set the face piece, top and bottom pieces of say a head cab to have the same spacing on either side. You do this with the comb, making sure the edges are closest to the center of a comb on both side edges of the face board and bottom. But what if the edges can’t be set close to the center and fall in an area that splits a pin?
When making drawer boxes and this happens, l usually just add or subtract a small amount of wood on the face and sides so that the edges are even and don’t cut a tail on one or both sides. Doesn’t make much difference if the boxes are 1/2” taller or not.
A head cab has to have fixed inside dimension to fix the chassis. I had a 7/16” comb that was impossible to get the comb on both edges falling near the middle of a comb ( under comb on both edges). My 1/2” comb was better but only about 1/16” under the outer edges of a comb on both sides. I’m afraid if l cut the face board that small piece with chip out.
Hopefully someone can follow me or know what l’m talking about.


EDIT: Reading more about centering the dovetails, watching a few video's, I've come to the conclusion that as long one sets up the pieces in the jig to split the pins "or" tails even, both top and bottom will be even whether it splits a pin or tail. But if anyone has any info to share, please do so. 

[Latole]

I have built a lot of cabs of all kinds.
I have never used the dove tail assembly not having the tools for. But especially not seeing the usefulness for me.

I am sure that my cabinets are also strong with my construction method used.

In my opinion, the dove tail can be profitable for manufacturers, because all you need is glue.
My cabs use wood srews, glue and few other hardware

[acheld]

Dovetails take a lot of time and planning when used for amp cabs when the joint will be exposed.   If you're going to cover the cab (Tolex, tweed, etc) -- just have at it and build your box, trim as needed, cover and you are good to go.  I don't worry much where my dovetails land within reason, it doesn't matter. A covered dovetail box is well suited for gigging amps given the strength of the joint.

When the wood will be exposed, it takes more finesse.

First, be aware that when you look at the box from the front, the dovetail sequence is reversed from one side to the other. If this matters to you, then you need to set up your dovetail jig differently (ie, reversed) for the left and the right sided joints.   This "feature" is most certainly noticeable to a woodworker, and you can see it looking at the bottom right and left side joints.  Apologies for the photo, it is not so clear.  This was my first box left uncovered. 

If your cab has a slanted front, as many do, one also needs to plan where your slant cut will land within the dovetails at the top of the box, and adjust your angle accordingly.   It does not need to be perfect in terms of splitting the dovetail in half, but you do want to make sure there is enough wood to avoid splitting.   I generally build my box first, and then trim it down once the glue has set.  You can see where I did not plan well in the second photo. 

As Latole has pointed out, there are many ways to build cabs, and we've seen some beautiful examples on this forum.  A recent build featured dowel joints that I quite liked and plan to use in the future.

But nothing beats dovetails for strength!

[dude]

I am a kitchen cabinetmaker, but haven’t made dovetails in years, no $ in furniture anymore. I did kitchen cabinetry for  30 years, retired. I have an old jig l used many moons ago, for half blind tails but threw tails like your picture are what l want. I needed to revise my jig as it only makes blind tails, works ok but a cheap jig. Threw tails are much harder. I got my draw boxes precut and assembled by a door manufacturer l used, Conestoga Wood, they where way cheaper then what l could make them for.  I give you a lot of credit for making that head cab from plywood. Plywood chips easily but I see you used marine ply, five ply, less chance to chip, good job.
I did figure out the spacing, made the head cab out of pine, looks good. I wanted to make the pine head cab first to get familiar with the jig again, been 25 years since l used it.

[acheld]

Sounds like you could teach me a bunch.   I was actually thinking of half blind tails on my next build, but haven't tried them yet.

The wood pictured is "Baltic Birch."   I used it because of its strength and its thinness (I do not have a planer). I like the laminations. Great stuff, but not cheap. I wanted to keep this particular head cab as small as possible. 

And oh yeah, you identified the main problem with plywood -- chipping.  I did have a couple of chips, but was able to recover them during final assembly with glue.   

Good pine is so much easier to work with!
 

[Latole]

I mostly use pine wood.