FUEL GRAIN PART II

After gaining experience with the 54mm ABS grain shell, I decided to do the 98mm. Using a printed shell allows you to select the right amount of infill based on your fuel viscosity. You will need to account for the high shrinkage of paraffin, approximately 17%, so once it cools a little bit, top off […]

FUEL GRAIN

After a lengthy search, an easily obtainable and inexpensive fuel grain material that requires minimal processing has been found. Since using sorbitol in the previous series of experiments, I wanted to find a material that was cheap and easy to use; paper mache and high-melting-point paraffin fit the bill; large quantities can be had for […]

FLIGHT TANKS

The 98mm hybrid flight tank is readily available in the original configuration if you know what to look for. They do not need to be new, as there are plenty of sources available. I searched around by size based on the original drawing. As you can see, it is 3.2″ in diameter, as it is […]

98mm TANK ADAPTER

The 98mm forward closure uses the same style pin valve as the 54mm. Unfortunately, it is no longer produced and uses a non-standard 13/16-14 thread. Thankfully, we found a solution with the standard paintball remote tank adapter, which uses G1/2-14 and only required a reprofiling of the threads with a die. If you wish to […]

BALLS 34

Lust 4 Thrust II Building on what we learned from the 54mm Aerotech hybrid revival project, my son and I will be working on the 98mm version with some changes to the original design. There is a 7-hole injector vs the original 4, and we may have a shower head style as well. In addition, […]

FLIGHT TANK

The flight tank is no longer supplied by Aerotech and Catalina Cylinders typically does not sell direct to consumer. Thankfully I stumbled across a direct replacement. They are available from racing CO2 shift systems. The best prices I have been able to find are from Jegs and Autometer. https://www.jegs.com/i/JEGS/555/60205/10002/-1 The above bottle requires that you […]

IT WORKED!!!

After test flying the Lust For Thrust on an Aerotech J570 on Saturday it was time to get the rocket up first thing Sunday morning. I was able to squeeze in 385 grams of N2O into the flight tank after chilling it overnight in the cooler and prefiling it with 50 grams of nitrous and […]

Balls Bound!

I had a few tasks to take care just before Balls. Unfortunately I did not get a chance to do a proper test firing due to the 50+ days of 100° and higher temps and the burn ban in my area. This post will update the final configuration for the tank connector and which grains […]

Casting the grain

The propellant grain is cast from a sorbitol mixture consisting of 80% sorbitol, 10% synthetic paraffin wax, 8% AL powder, and 2% red iron oxide as a burn rate catalyst. I was able to make a simple spreadsheet to help with the calculations. I have also included red copper oxide but that will be utilized […]

Fill Adapter

The fill adapter for the tanks can be made from off the shelf components. The fill hose can be obtained from Holley which is one of the listed suppliers in the data pack. There are two types, and the only difference is the color on the fitting, blue or red. The red is supposed to […]