Syringe guide for injections

This is a tool to assist with injections, to make sure the syringe goes in perfectly straight. I have shaky hands, and I have to give myself an intramuscular injection in the leg every week.

See a demonstration here: https://youtu.be/S1fg13HEkVQ

The dimensions are designed for BD Luer-Lock 1mL syringes which I got [here](https://www.allegromedical.com/products/bd-luer-lok-disposable-syringe-1-ml/), but can be adapted for other syringes by changing the dimensions in the `.scad` files.

It is designed so that with a 1-inch needle, the syringe can be loaded without the needle ever touching the plastic. Just tip the syringe toward the back and place it in the 1 cm groove in the top, then turn it so it is straight up and the needle goes through the slot.

The safety stopper top piece can be attached with an M2 screw and nut and attached with elastic. I stuck a rubber foot to the back where the stopper hits it, but it's not necessary.

I also included a device to pull off the cap