Engine disassembly, inspection, repairs and possible improvements

[shohei]

This part involves disassembly, resdesign of the spacer, replace the spacer, fix the leaks, replace the O-ring for leakage prevention and gain overall understanding of the engine functionality of components

[PMunyao]

We took apart the liquid rocket engine, and found the following information from the practical activity:

1. The rubber gaskets were worn out. possible repair procedure is to replace them with new ones. We are going for fabricating them in-house
2. the bolts and nuts holding the combustion chamber assembly were worn out and corroded. They require replacement with stainless steel bolts and nuts.
3. the O-ring was snapped. A new one is required with respect to the diameter of the combustion chamber(Nozzle-side) and additional sealing for the combustion chamber to prevent leakages.
4. The pipes feeding propellant and oxidizer require improvements/replacements to ensure they can withstand high pressures of fluids being pumped into the engine.

[PMunyao]

One part of particular importance was the spacer halves.

1. They do not fit around the combustion chamber as requirements stated in design. The machining procedure performed on it left it with uneven diameters on perpendicular axes from the longitudinal center, possibly from the blade used to cut it half reducing material.
2. The two halves do not have proportional lengths in the inclined parts meant to rest on the nozzle resulting in an inclined position in the combustion chamber that does not allow it to be fit inside the chamber housing. This requiers redesign of the spacer dimensions.

The above problems are as a result of lack of accuracy in machining caused by a tolerance left during combustion chamber fabrication that results in the machine parts being relatively larger by a few mm than the actual cad design. We collected the actual combustion chamber values and will use them to design a new spacer. A possible solution to this would be:

1. Design the parts with slightly lower dimensions before machining to compensate for the tolerance to be left.
2. Produce an identical 3D printed spacer to be sent alongside the design for fabrication to ensure they are identical after machining.
3. Manufucturing the two split halves of the spacer seperately before assembly to ensure they properly mesh with each other.