The Dreaded Sustainer

The Fernandes Sustainer, along with the Sustainiac, have been around forever and are still the industry standard if you want a little something extra in terms of infinite and controllable sustain/feedback built in to your guitar. However, they're notoriously unreliable and a complete pain to fit. The circuit board and battery need a purpose built home, they're way too big to fit under a pickguard in any way that's reasonable.

It's best to make a template for this sort of thing, it just makes life so much easier:

This was going in to a custom strat built from parts, the body was brand new and completely untouched. Not for long! This is what the point of no return looks like:

It's best to remove a good amount of material using a large forstner bit so you don't have to spend ages with the router.

Once it's finished and blacked out it's ends up looking quite neat:

Since the switches are direct mounted to the board you have to take care to get the holes drilled exactly right, there's no wiggle room at all, over-sizing them by 1mm is a good idea.

I left myself a little extra room, mainly for the wires... there's so many of them and of course none of them were long enough to reach my new cavity. Once everything was fitted to the guard I had this lot to contend with:

After some cable management and making a channel via the jack cavity:

A stereo jack from Pure Tone was necessary here, they're the best jacks anyway but the smaller profile really helped fitting everything in.

After making a new cover for the extra hole it ends up looking not too bad, I managed to find material that was near identical to the trem cover and pickguard: