I do alot of handcut dovetails but there was a time I did alot of box finger joints. So much so that I designed and built my own custom adjustable sled for doing them. 

Here you see the sled with the 1/2" finger insert. 

The knobs on the back allow for micro adjusting looseness and tightness of the fingers. Test cuts are made and insert shifted accordingly.

This is a "stop block" that prevents the sled from disengaging from the table.

It is fitted over the front rail of the tablesaw and locked into place with two knobs. This also can be adjusted along the rail.

There are inserts for 1/8", 1/4", 3/8", and 1/2" (shown installed)

As mentioned each insert can be micro adjusted by loosening the knobs on the back fence, shifting, and re-tightening.

I also have waste pieces placed in front of finger insert so when cutting any tearout is minimized or eliminated.

Feel free to comment, ask questions and "thumbs up" if you like it!

Cheers!
MrRick

Please Note: The dado blade stacks for each insert are not shown in this post. 

It would have been really cool to make one of the knobs for locking the position and the other for a rack and pinion adjustment

I like the idea of micro adjustment would have been helpful a few times with my homemade one.

55 minutes ago, lew said:

It would have been really cool to make one of the knobs for locking the position and the other for a rack and pinion adjustment

Why? It's not really needed and works great the way I designed it.

Edited February 1Feb 1 by MrRick

15 minutes ago, Gunny said:

I like the idea of micro adjustment would have been helpful a few times with my homemade one.

Glad you like it Gunny! Thanks.

7 minutes ago, MrRick said:

Why? It's not really needed and works great the way I designed it.

Guess it is just my German heritage for accuracy and precision

Accuracy and precision is not limited to a nationality or heritage but rather the person.

On 1/31/2026 at 5:28 PM, MrRick said:

Accuracy and precision is not limited to a nationality or heritage but rather the person.

Aw come on Rick, a joke. 😄 I'm Scott Irish, when I drank, I drank for the whole bar! Another joke. Just pulling yer leg Rick. 😉

Nice sled! I made one much simpler for finger joints, same principle as yours, but mine was more of a bolt onto the miter gauge setup. I like yours much mo better!

Good lookin' sled.

On my to-do list

@Fred Wilson Glad you like it !

Very nice work!