SXC Propulsion

Attempting to create the most reliable 3d printed G-class KNSU motor possible. A part of ASA SXC and Exela.

[SXC Propulsion @s___engine]

@Overpressure_ Details?

[SXC Propulsion @s___engine]

By the end of today, we expect to complete software for the test stand and finish printing some final bits to hold in the PCB while also protecting it. The static fire of the next Ashengine may slip into early April as a new method of propellant packing is being tried. More soon.

[SXC Propulsion @s___engine]

Finally, our initial engine tests will be experimental motors that use our original powdered and packed propellant. These tests will be followed by a V2 Ashengine design being tested. Our original replacement engine has been cancelled.

[SXC Propulsion @s___engine]

After months of slowly working up the inspiration to continue work on the project, SXC Propulsion is set to begin testing again by the end of this month! Many changes have been made and are listed below. 1/5

[SXC Propulsion @s___engine]

The most major upgrade by far is the change from using breakout boards to a fully integrated solution for logging load cell data. We now are able to fully shield the electronics of the test stand and will do so prior to firing. 4/5

[SXC Propulsion @s___engine]

Turns out this was in fact what happened, thanks for the idea @TyB_NC

[SXC Propulsion @s___engine]

@TyB_NC It could possibly be sections of propellant breaking free and either speeding up combustion and raising chamber pressure or choking the nozzle for just long enough to cause an explosion. A common thread in all of these anomalies has been a white puff before the explosion.

[SXC Propulsion @s___engine]

Overall, this is an entirely preventable and frankly embarrassing failure mode. We are reevaluating whether to proceed with our new motor design or not following this discovery. Work on our test stand computer continues as well as we get ready for more tests come February. 4/4

[SXC Propulsion @s___engine]

After the intense activity of staring at frames from this test for about 2 minutes, I discovered that I was wrong. In fact, the failure of this Ashengine test was due to a piece of what is likely propellant clogging the nozzle. 1/3

[SXC Propulsion @s___engine]

Ashengine-5 successfully fired for most of the burn's duration, however it exploded near the end. It exploded where the layer height decreases to smooth out the threads. This is a very strange failure and hasn't happened yet and is definitely an issue related to 3d printing.

[SXC Propulsion @s___engine]

This piece of propellant presumably broke off, reached the nozzle, and plugged/restricted the throat. This led to an overpressure of Ashengine-5 and seperation of the critical joint at the bottom between the walls of the engine and the base. Here is the failure sequence. 3/4

[SXC Propulsion @s___engine]

@jackywacky_3 absolute nightmare to print

[SXC Propulsion @s___engine]

The first engine using the new design is printed! This inital engine will still use powdered, uncooked propellant. This will hopefully be changed later.

Name reveal sometime before it static fires...

[SXC Propulsion @s___engine]

All of our work has been paused for now as we look to possibly design a replacement for Ashengine that uses grains instead of propellant directly contacting the motor case. The overall design of Ashengine is restricting what we can do with it. 1/3

[SXC Propulsion @s___engine]

A judgement on whether this is the right move will come as soon as tomorrow. Engine work will be slower than previous months due to work on Exela's Invictus-Redshift rocket, so expect a slower timeline compared to previous testing campaigns. 3/3

[SXC Propulsion @s___engine]

All of our work has been paused for now as we look to possibly design a replacement for Ashengine that uses grains instead of propellant directly contacting the motor case. The overall design of Ashengine is restricting what we can do with it. 1/3

[SXC Propulsion @s___engine]

The nozzle that threads on the interior of the casing makes it difficult to cast propellant without disturbing the threads and makes it impossible for grains to be used, so a different design would be an improvement that would help us develop more reliable engines. 2/3

[SXC Propulsion @s___engine]

@GravlinTheGreat negative thrust

[SXC Propulsion @s___engine]

@DebraAerospace @hunterhartsoe waht is this

[SXC Propulsion @s___engine]

@Overpressure13 Real