Right Angle Brace for V-Slot Bear Upgrade - Helper tool

I've just purchased the parts for a full Bear upgrade (https://www.thingiverse.com/thing:2808408) of my Prusa Mk2.5, and as usual, making sure the frame is exactly perpendicular is extremely tricky. So, I created this 90 degree right-angle brace for the V-slot.

The idea here is that you use M5 bolts (I only had 25mm bolts on-hand, so used a washer and a nut as spacers) and Tee-nuts to temporarily clamp the right-angle in place on the V-Slot aluminium extrusions, so you can then easily screw the 90 degree joining plates in place.

The X supports on the diagonal brace do restrict access to the slots closest to the apex of the corner, however, it is possible to use a long necked screw driver to screw the bolts in place. I didn't have a problem with it.

I made do with printing just one, but I can definitely see the advantage of printing and using two.

There's a little bit of juggling with Tee-nuts and making sure you don't leave any behind in inaccessible slots, but for the most part I was able to use the permanent ones in the base horizontal frame. I had to use two slot-in removable tee-nuts for the vertical frame.