Making a Colt Router Base

My wife's father gave me an old sign making kit that used to be her grandfathers. Until recently, I'd forgotten I had it. I'd put it away unused because at the time I didn't own any router bushings and the ones that came with the kit were for some old Craftsman router.

When I bought my Colt, I remembered that I had it. I thought playing around with the sign making kit would be a good test for the router. Unfortunately the Porter Cable style router bushings I had acquired since coming into possession of the kit don't work with the standard base, so I made my own base.

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Tools: Colt, drill press, Forstner, router, router bushings

Tags: Bosch, Menards

Materials: plexiglas

Cutting the Base to Width

The first step was to remove the base from the router. Then I could use it as a template for my new base. I used the base to set the fence on my table saw and ripped a piece of spare 1/4" Plexiglas I had lying around.

Laying Out the Mounting Holes

I decided to leave the plexiglas long to crate an offset base, you can always cut it down later, but you can't put material back. Usually an offset base has a handle, but since the colt is so small and easy to handle I didn't think I needed it.

I transferred the mounting holes from the old base to the new blank with a transfer punch.

Meet the Drill Bits

There's no good place to put this so I'll stop here to talk about the drill bits I needed for this project. To cut the mounting holes I used a 3/8" Forstner for the counter-bore and a 7/32" for the through hole. 7/32" is much larger than the diameter of the screw, but I found that I needed more wiggle room to get the bushing centered around the bit.

Measuring the bushing I found that I would need a 1-1/8" bit to make the through hole and a 1-3/8" bit to make the counter-bore the bushing sits in. Of course I didn't have any bits this size. So I needed to go shopping.

Since I didn't want to travel to five different stores with my three year old, I just bought what I could find at Menards. Luckily they had the 1-3/8" Freud Forstner bit in stock, I wasn't so lucky with the 1-1/8" size. Rather then spending the money on an expensive spade bit I bought a real cheap Tool Shop spade bit. The bit wobbled so badly that I had to use it in a hand drill to make it work at all. You'll see later that it just chewed the plastic rather then cutting a hole.

The Finished Mounting Holes

I used my drill press to first cut the 1/8" counter-bores, then I chucked in a 7/32" bit to cut the though holes. I actually remembered to cut the counter bore first this time!

Locating the Center of the Base

Once I had the mounting holes finished, I screwed the new base to the router. I used a V-shaped bit to locate the center of the base by cranking the router down as far as it would go and turning it on momentarily to cut a pilot hole.

The Bushing Seat

Using the 1-3/8" Forstner, I cut the seat for the bushing. I don't remember the exact depth, but I used a caliper to measure the width of the lip on the bushing and added about 0.01".

Chewing a Through Hole for the Bushing

As I alluded to before, the 1-1/8" spade bit made a mess of the base. Not only did it lead a off-center, chewed up hole, but it melted the plastic too. I was able to salvage the hole with a utility knife and a file.

The Bushing Fits!

After cleaning up the hole I was able to mount the bushing in the base.