Saddle Slotting Jig for Acoustic Guitar Bridge

If you look carefully at the picture on the left you'll see I laid out some lines and marks and stuff like that there on a hunk of wood.

I'm making a saddle-slot routing jig.  I got the plans from Ultimate Guitar Online.  There are a lot of good-looking plans there.  I was wondering how I was going to accurately rout the slot, and I think I now have the solution.

Basically, the jig holds an adjustable aluminum fence that guides the router.  There are slots for the fence adjustment, for router stops, and for two blocks that hold the bridge in place during routing.

The plan calls for drilling holes at the end of each slot using a forstner bit.  This part is easy.  Even I can do it.

I don't use a router a lot.  So when I do, who knows what the end result will be.

In this case, it goes ok.  One thing I always forget is that routers tend to jerk when you start them up.  They will also easily jump out of line if you let them.

So, let's just say I relearned all of this during this project.  Some of my routs aren't perfect.  But they are functional.

The fence is made of 1/4 inch thick aluminum.  I had some 1/8 aluminum stock from the bridge pad removal iron, so cut two pieces and then used JB Weld to epoxy them together.

Then I filed the edges a bit so I couldn't accidentally get cut.

I did the cuts with a metal blade on my jigsaw.  Not perfect, but functional.

Here's the finished jig.  The plans call for a hardwood - I used poplar.

Underneath there are 1/2 inch wide routed slots to carry the heads of carriage bolts.  The bolts come up through the 1/4 inch wide slots you see on the top.  I got some cool aluminum knobs from McMaster-Carr to use as adjustment knobs.

This is the bridge side.  The two blocks at the front are adjustable to hold a bridge in place.

The two center knobs are adjustable router stops.  In practice, I found I could only use one of them - the knobs might be a bit too big.  But they're not a critical feature to have.

The aluminum fence is adjustable fore-and-aft to the desired slot angle.  The router base runs against the fence to make the slot.

This is a shot with a bridge in place.  You can see how the fence is angled and the router base rides against it.  The router (Dremel tool) is not in place in this picture.

Hopefully this will work well for the slot I need to cut.

I did make the bridge-holding adjustment slots a little longer than called for in the hopes I can adapt this for smaller bridges, i.e., ukuleles.

One word about McMaster-Carr.  The place is amazing.  There is nothing they don't have in terms of fasteners, tools, material, any kind of hardware - you name it.  I bought the bolts and knobs for this project there.  Their web site is also incredibly well organized - it's mind-boggling given the thousands of items they sell.  Very highly recommended!