While building the fuselage for my Chuperosa, I needed a way to square up the bulkheads. My regular T-squares were too big for this job, so I quickly built a simple mini T-square. It's easy to make, and if constructed correctly will be very accurate. Below are a few sequence photos with descriptions that will show you how to build one.
These are the tools you'll need. A larger drafting T-square and a builder's triangle. The ridge on the builder's triangle needs to be flush up against the blade of the T-square.
I used 1" by 1/8" bass wood strips from the hobby/art supply shop, and squared it up on the combination tri/drafting t-square and then used slow CA glue, and pinched it with my fingers for a few seconds until the glue dried.
After the glue dried, I cut the long side to match the other side of the beam. As you can see it is perfectly square.
Here's the mini T-square in action, as you can see, a normal drafting type square wouldn't work for this hand launch glider. If you build one, please let me know about it and post a comment.