Oh, if you don't know what inverted sugar is, it's basically sucrose that has had the glucose and fructose bonds broken with a weak organic acid in the presence of heat. Citric acid for example. Once the inverted sugar cools it doesn't crystallise and remains a syrup. Like Karo.

Interesting... I have not heard of inverted sugar. I'll put that on my list of things to look into. I will say, the honey fuel came out really good and worked well.

I great question. With this type of single fuel cell motor, the center core is really the determining factor for how much "Initial" thrust you get. We have a similar motor design called the Kiwi and it used a 3/8" core. But that motor was only used to launch 2" diameter rockets that were about 2 feet long... Not too heavy. With the DartMonkey, we were trying to develop a small motor that had enough initial thrust to launch a heavier 3" or possibly a 4" rocket. Obviously, it's the initial thrust that gets the rocket moving quickly off the rod in order to maintain good aerodynamics so a powerful initial burst of thrust is critical to a good lift-off. As you have seen, the side effect of that large core is an extremely short burn time for the motor. One last comment... So you could make the core hole smaller and then make the nozzle smaller to provide a powerful thrust BUT... You run the risk of building up too much pressure and exploding the PVC case. Casing strength, core hole, burn rate & nozzle size are a carefully balanced house of cards.

@@rotaryrocketry Definitely a fine balance. ;-)