Adding a Micro Fence to a Bosch Colt plunge router base

After the last month of cleaning and selling a bunch of antique tools on eBay I bought last fall, I was finally able to get back in the shop. For months I’ve always had a Festool Domino on my wish list but for the nearly $1000.00 for one, I never pulled the trigger. So after cleaning out my router cabinet one day, I came across the Micro Fence I bought about ten years ago collecting dust. I bought it for my Porter Cable laminate trimmer and had intended to use it for inlay work. Needless to say I never used the damn thing as I don’t do inlay work. So I got the idea of using it with a Colt plunge router base for routing mortises for loose tenon joinery.

The first thing I had to do was retro fit the jig to work with the plunge router base. I had to custom make the bar that attached the base to the jig so I used a piece of scrap maple I had lying around. I went to Lowe’s and bought 7/16″ round bar stock and fitted them into the sliding section of base.

Next I threaded the rod and reamed the holes with a 7/16″ 14 TPI tap and die set. Took me a while to get that done because everywhere I looked, didn’t carry both the tap and die. I ended up buying the die at Menards and the tap at O’Reilly’s Auto Parts. A big pain in the ass.

After the base had the bar installed, I lined up the Micro Fence to the base, marked where the holes went and threaded those holes with a 5/16″ tap.

The finished piece was tight and clean with the Micro Fence able to come into full contact with the plunge router base.

I got lucky as the handle from the base was able to extend all the way down without touching any part of the Micro Fence. The distance between the handle and the brass screw is about 1/32″.

Once I got the fence to work, I quickly realized that the center hole on the base was too big to work with plunging mortises into end grain as the work piece would literally fall through the hole. So I had to buy a piece of 1/4″ acrylic plastic and make a zero clearance insert for the base.

The base worked well but the only caveat is that when routing, there is no place for the chips to escape the hole. I have to plunge a little bit, then vacuum or pry out the shavings from the hole, then deepen the cut. Not a big deal to me as I always turn off the router in between depth settings anyway.

The Micro Fence works well but thought it would be nice to add a little light so I could see what I was doing better. I stumbled upon this little book light at Half Price Books for $5.00 and hoped I could get it to work on the router.

I snapped off the piece that slides in a book, grabbed some double stick turners tape and stuck the light on the back of the router. The thing works perfectly. Like it was made for the tool. It has an easy touch on, touch off switch which makes it slick to use.

Now I just needed to put the tool to work to see how it performs.

After cutting a couple of loose tenons, I laid out where I wanted them on the piece to be mortised.

A couple of reference marks and some quick passes with the router, I got a perfect fit. I think this will quickly become one of my favorite tools. Not as slick as a Festool Domino but for the price of the plunge router base at $100 and an unused Micro Fence, I think it’s a really good bargain.

3 thoughts on “Adding a Micro Fence to a Bosch Colt plunge router base

  1. Pingback: Making a Shaker Table from a 2×8 | MVFlaim Furnituremaker

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