Insulin Syringe 6.25

by Jim Myers & Eric Myers

(Click for PDF)

After my son was diagnosed as a type I diabetic (on April 1st, no less), We decided to upscale an insulin syringe, as comic relief from the new daily routine of carb counting, finger poking, blood glucose monitoring and injections.  

The syringe is a 625% upscale of a BD Ultrafine 3/10 CC.  It is made from a 1 1/4" polycarbonate T-20 fluorescent tube slip cover for the main body tube. The 1/8" acrylic fins are the shape of the finger pads of the original syringe.  The plunger is made from BT-20 with foamcore centering rings and 18mm engine mount. The cap is balsa, turned and strips glued on to make the ribs.  

Recovery is an 18" mylar chute, with a semi-pop pod/plunger design.  The ejection pops the plunger back to deploy the chute, and ejection venting pops the (kevlar tethered) cap off the needle.  The plunger is stopped 1/2 way back by two cotterpins, catching a centering ring.

It has flown, on a C6-3. It is heavy, so altitude was limited to about 100 ft. The pop plunger recovery worked so-so. The chute deployed, but the plunger popped past the stop, It eventually came free and separated about 2/3 the way down. Broke a fin and cracked the cap on landing. We will be making more solid centering rings of masonite and go again. It worked well enough to prove it works, just needs beefier CRs.