Igniter

Our igniter is based on a simple mixture of potassium nitrate and sugar. The mixture is heated and all ingredients are mixed together on a hot plate at 300F until the mixture only slightly begins to brown.

The ingredients are listed below with the respected mass percentage.

The mixture is then poured into a 3D printed PLA mold where a nichrome wire is then imbedded into it. A thermocouple is also imbedded into the warm mixture before the rocket candy hardens. The mold walls are covered with wax paper and tape to minimize the chance of a mold getting stuck to the igniter.

The resulting igniters are shown below.

Open

Early igniter test pour without thermocouple

Note about Thermocouple

The embedded thermocouple is used in our auto sequencer as a quantifiable metric for ignition. Once a spike in the thermocouple is seen on the DAQ, an internal timer is started for 3 seconds allowing the igniter to burn completely before opening the main oxidizer valve.