Author Topic: HTP/PLA/KMnO4 Hybrid Rocket Engine (Read 54173 times)

colbourne · « **Reply #80 on:** 09/21/2024 03:49 am »

This video if allowed might help

Jerry Fisher · « **Reply #81 on:** 10/09/2024 04:11 pm »

This month I had two launches of the MkI Viper. Initializing the flaps down on the first launch (https://rumble.com/v5hxp1u-mki-viper-launch-092024.html) did not compensate much for the pitching up. I made my nose cone longer in the second launch but had an equipment failure, so no data. I printed a fuselage mold out of PLA, glued the pieces together, and sanded and waxed the surface. I used the mold to make a fiberglass fuselage. After curing, the fiberglass fuselage popped right out of the mold. The results were better than expected.

Also, thanks for the suggestions. I plan to implement most if not all of these during the coming months. Also, I've viewed the video on hyper-sonic launch and the simple technique of controlling roll. I do plan on going hyper-sonic eventually. Nice to know there is a possible fix to roll.

colbourne · « **Reply #82 on:** 10/11/2024 09:58 am »

I recently bought a toy grade RC ducted fan model of the Chinese J20 from Aliexpress. Model called FX9630
It has a 6 axis gyro built into a very light receiver which allows the auto pilot to maintain stability , which you can turn on and off from the transmitter. The model also has two servos and sockets for another two. The included transmitter is compatible with quality model grade transmitters if longer range is required.

The reason I mention this, is because the light RX and servos would be ideal for your rocket and would auto stabilise it as well. Price is about US$40. There is also a more advanced version with a brushless motor called FX9631

Jerry Fisher · « **Reply #83 on:** 10/14/2024 02:34 pm »

Wow! A 6-axis gyro built into a lightweight receiver. I'll check into it. I was planning on building my own but this would be a great asset. Thanks

Jerry Fisher · « **Reply #84 on:** 11/06/2024 04:30 pm »

This month I had two launch attempts of the MkI Viper. There was a leak at the propellant tank connection on the first attempt and the engine did not ignite on the second attempt. Also this month, I made a port and starboard fiberglass fuselage with a raised rib down the center. This increased the strength with no mass added while improving the streamline of the Viper.

Jerry Fisher · « **Reply #85 on:** 12/03/2024 04:15 pm »

This month I moved the thrust vector up by 1.0 mm to bring it more in line with the center of mass. Also this month, I increased the size of the vertical and horizontal stabilizers tripling the available surface area. Finally, I trimmed the starboard and port panels thus streamlining the MkI Viper.

Jerry Fisher · « **Reply #86 on:** 01/16/2025 02:47 pm »

Not much done in December. Launch activities delayed due to weather and holidays. In my end of year report, I cover some of the major accomplishments of this past year. Big plans for 2025. Launch to maximum altitude, deploy glider, control glide, and glide to a walk away landing.

Jerry Fisher · « **Reply #87 on:** 02/10/2025 02:24 pm »

No launch activity this month due to weather delays (to cold and snowy). Instead, I worked on cleaning and organizing my lab. I moved my workbench next to the wall so I could organize my tools. I plan to continue cleaning and organizing next month. I may get some static engine testing done if the weather cooperates.

Jerry Fisher · « **Reply #88 on:** 04/08/2025 02:24 pm »

This month, I did a static test of the PLA fuel cores infused with a lower concentration of KMnO4. Ignition occurred in less than one second. Lower solubility means lower cost and lesser mess. Also, I did a MkI Viper launch using the larger styrofoam fins. The Viper still pitched up but not as much. The addition of ventral nacelles will introduce drag at the port and starboard fins counteracting the pitch up.

Jerry Fisher · « **Reply #89 on:** 05/05/2025 03:25 pm »

This month, I did two static tests of the PLA fuel cores infused with a lower concentration of KMnO4. This was the 4th infusion of KMnO4 using the original solubility of 50 gm/L. In the first test, ignition occurred in less than one second due primarily to a small leak in the solenoid valve. In the second test, a larger leak in the solenoid resulted in an explosion.

The ignition test of the 4th infusion was inconclusive. However, I surmised that by using a motorized ball valve on the class II engine, I can scale the engine to higher thrust by leaking HTP into the fuel core thus preheating the fuel core prior to ignition.

Jerry Fisher · « **Reply #90 on:** 06/05/2025 03:26 pm »

This month, I had two launch attempts of the MkI Viper rocket glider. On the first launch attempt, the Viper just barely cleared the rail guide and fell to the concrete floor. I had a massive leak at the propellant tank connection. In the second launch attempt (https://rumble.com/v6uch33-05-29-2025-mki-viper-launch.html), the Viper cleared the rail guide and made it to ~ 30 feet while yawing to port, a new record for Fisher Space Systems, LLC.

Jerry Fisher · « **Reply #91 on:** 07/02/2025 07:39 pm »

This month, I had one launch of the MkI Viper rocket glider. The Viper cleared the rail guide at ~ 3.6 m/sec and reached an altitude of ~ 100 feet while arcing over and heading east (https://rumble.com/v6vmqaz-06-13-25-mki-viper-launch.html). The Viper exhausted all of the unstabilized HTP oxidizer in this launch before crashing into the ground, a first for Fisher Space Systems, LLC. Analysis of the spent fuel core showed an almost complete burn of available PLA/KMnO4. I plan a series of test to determine what effect HTP stabilizers play in the combustion efficiency of PLA.