Yes, I have the original Incra jig so I should be able to advance the fence in precise, small increments. I am not actually making a box but a small case/cabinet to hold Keurig Cups.
That's good, the Incra LS system that is. The reason that I asked is that with the 3/4"set up block used to make the set up for 3/4" stock you can then mathematically adjuse the fence and the height of bit for any thickness of material between 3/8" and the 3/4" setting.
For example, let's say that your stock is some odd thickness, .465" just to make up an example. The difference between .750" and .465" .285". If you divide .285 by two you get .143 rounded up. Oops, I didn't ask you if you have a router lift that lets you also move up in small increments, sorry about that. But to go on. If you were to lower the bit by .143" and move the fence forward the same amount you would be set up for the .465" thick stock.
If you woud lke more clarification on that concept, let me know.
The idea of course is with a setting for 3/4" stock had you had the Infinity set up gauge you would have had the hash mark on the gauge set at a height of 3/8".
Since all the gauge does is allow you set the set the height of the bit to a point that the cutter is where it sould both for height and the position of the fence, once you have a reference that is correct for one thickness of material, it's just a matter of mathamatics to move to any other position, that is of course if you have the tools to do that accurately.
The small bit is, as you know however, limited to work on material between 3/8" and 3/4".
Let me know what you think.
You will need to create a zero clearance fence added to your Incra fence, I have purchased some Jedssem feather boards to use wih my set up and if you would like, I can send photos of my set up if you would like, but this may be starteing to sound to much like a can of worms that you don't want to get into and I sure do understand that..
In my case, for me anyway, the move to the Infinity miter lock bit was a good one.
I had tried what you say you have done with the 45 deegee cuts, but because of the way I have to cut mortises for the hinges for the lid, I could not put the bottom on the box until the hinges would be installed and I had trouble keeping the joints together, but the miter lock joint is, in my opinion a much better way to go.
Now, it's time for true confessions. I have not completed a box to my satisfaction yet. I have spent time learning how to make jigs for cutting the mortises for the hinges which for me was a project in itself, but I finally found a way to do it, the learning about the miter lock bit that I described above and all have been, collectively and great learning experience for me. That's why your thead caught my attention as it did.
I'll be watching for your reply, I will add that one of our favorite members of this forum has watched my slow progress and it almost driven him over the edge, and for that I am truly sorry,