There is another size of insulin syringe that has a capacity
of 1 ml, this has a needle that is cemented in place, but there are
modifications that we can do to make this type useful as well. The
drawing above is about twice full size and the one on the right is
about eight times life size to show the detail. The tubular metal
needle can be pulled free using pliers and a bit of a twisting action.
Alternatively the metal needle can be heated with a soldering iron, in
which case it pulls out effortlessly.
The three plastic fins can be pared
down using a scalpel or a modeling knife. Which leaves a cylindrical
nipple at the tip that can have plastic tubing pushed over it's end
for saline delivery. As illustrated at left.