GT2 Splicer for Timing belts

I was searching for a good way to splice belts, and there are a number of methods I found, but of them all, this seemed to be the best, and it's incredibly strong, I tried to pull it apart and I couldn't.

I found an old forum post, I don't recall where, it was for other types of belts, but it included a FreeCAD model that I tried to use but was broken, so I modeled this from scratch based on that idea and instructions.
 

Prep:

After making the part, cut a 60mm piece of extra belt and glue it down, teeth up into the groove, it will hold everything perfectly in place.  You might want alcohol swabs to clean the parts before gluing.  You'll also want superglue, it works incredibly well on rubber, I specifically used Loctite Ultragel Control, it's rubber-toughened so is more flexible and stronger.  Any should work, or contact cement.  The hole for the hinges is made to fit a M3x30 in through each end, it should screw in with no need for anything else, worked very well for my hinges.  The faceplates are held down by three captured M3 nut and M3x10 bolts.  180grit sandpaper or somewhere around that to roughen up the sides to be glued.  Plastic wrap to prevent super glue from getting on jig.

I found that even if the slicing with the razor is uneven, this is easily fixed with the sandpaper.

The size of the jig accommodates an overlap of 10 teeth, I've found this to be sufficient.

Steps:

1) On one end of the belt, mark 10 teeth from the end.  Using a razor slice off the teeth, but don't go deeper than the fine fibers on the inside that provide the support.  I didn't go all the way down, there's still some rubber left.  I found a safety razor to be really superb at easily slicing off the material.  Sand to even and roughen surface.

2) On the other end, mark 10 teeth from the end but this time slice off from the flat back side. It's important that the 2 sides have the same distance cut off.  Sand.

2.5) Put a piece of plastic wrap over the jig so it covers the glued in piece of belt, it should be wide enough to fold over the top after gluing.

3)  Place the end that has the back side sliced off into the left side of the jig.  Line it up so the part that's sliced is just at the edge of the middle section.  Screw down the left side of the jig.

4) Place the end with the teeth cut off on the right side of the jig.  It must be aligned so the first non missing tooth goes into the groove exactly next to the last tooth on the other side, this will ensure it's perfectly continuous.  Then screw down the right side of the jig.

5) MAKE SURE THERE'S NO TWIST!

6) The pieces to be spliced should now be perfectly aligned in the middle.  Wipe them with an alcohol swab.  Apply super glue down center of the back of the belt that's on the bottom.  Place top belt down on it.

7) Fold over the plastic wrap over middle section.  Close middle lid and screw down tight.  Let it sit for like 20min.

8) Done!

I actually screwed up step 5, and I noticed within 30 seconds.  I quickly opened the jig as fast as I could and tried to pull it apart.  It was already bonded really well, when it pulled apart, it didn't pull apart at the faces I'd cut, it actually took a little bit more rubber away from one side and ripped the end in half.  I didn't want to start over so I fixed it and reglued the tattered split end, it still came out looking great and being super strong.