Blog

Fiberglass reinforced phenolic resin may be used for the production of nozzles and other heat resistant components.
After several attempts, we performed a successful production test in collaboration with the Innovation Studio of Inholland Delft.

First test of slow white propellant. Not so slow at all. Weird regressive thrust profile.

Despite the enhanced safety features, the Chiron 4 booster exploded upon ignition.

The CHIRON4 booster is ready for testing on the 22nd of September. This 6 grain 21000Ns booster is inspired on previous 8 grain CHIRON motors with several enhanced safety features:

1. The core was increased to 45mm to reduce mass flux erosive burning.
2. The multi nozzle design allows for smaller graphite inserts, reducing the risk of nozzle cracking. In addition, multiple nozzles may reduce the risk of nozzle blockage.
3. The diameter of the grain was slightly decreased to allow for a full layer of insulating EPDM, reducing the thermal stress on the casing.
4. Radial bolts were replaced by a circlip ring to improve strength.

To allow for effective bonding of the sugar propellant to the aluminium casting tubes, tubes were sanded with grain 60 and degreased. Subsequently, a 0.5mm layer of plain cotton cloth was glued on the inside of the retainer.

The cotton cloth is an improvement over the previously used kraftpaper, as the kraftpaper could be easily split into two separate layers. Furthermore, airpockets can be easily removed underneath the cotton layer.

Test of the PB51 motor for the InHolland Delft Aquilo rocket.