IREC 2023 FDR - 4 March 2023
- Yevgeniy Gorbachev (RIT Student)
- Torin Samples (RIT Student)
Structures
Speakers: William Beckson, Jake Halpern, Nate Aquilio
| Subject | Question | Answer |
|---|---|---|
| Reaction wheel | Why was the reaction wheel scrapped? | Alex Speyer (RIT Student) We don't have much experience with the reaction wheel so we had a few safety concerns with it. Instead of implementing it this year, we'll be testing it some more and hopefully implementing it next year. |
| COTS body tube | Brahm Soltes (RIT Student) The choice to go to COTS seems foolish. You had done a lot of analysis on your materials last year so why are you switching now? Brahm Soltes (RIT Student) Going to COTS feels like going all the way to scratch. This is an engineering competition, why are you going back to square one? | Jake Halpern (RIT Student) We're behind schedule at the moment and have the free tubes to make a COTS airframe; we have no intention of permanently stopping production of SRAD tubes William Beckson (RIT Student) We had an issue with the shrink tape with our tube where one side was larger than the other. We tried to fix this with epoxy but this caused other issues and we didn't have enough time to wind another tube. |
| Analysis | Brahm Soltes: You've done a lot of testing with epoxy, where have you incorporated that in your analysis? | William Beckson (RIT Student) We got some data but we only used two samples, so we don't really have the data to draw strong conclusions. We're still confident the Rocky Pocky will be suitable. |
| RASAero | Brahm Soltes: With regards to your open rocket simulation, I would double check your RASAero. You should check why this deviation is so large. | William Beckson (RIT Student) It wasn't |
| Nose Cone manufacture | Brahm Soltes (RIT Student) Blackout had issues with pushing the coupler in with manufacture, how are you mitigating this? | Jake Halpern (RIT Student) The nose cone has a straight section, and the coupler goes in during curing. |
| Nose Cone manufacture | Zoom Chat: Any concerns with 3D printing the Nose Cone Mold | That's the part we already printed so there aren't many concerns with it at this moment. |
| Fiber Glass Price | Brahm Soltes (RIT Student) Double check the cost of fiber glass. That seems extremely high for 20 yards. | We aren't sure where we are going to purchase fiber glass at this moment so we'll finalize this at a later point. |
COTS Avionics
Speakers: Aaron Chan, Donovan Barros
| Subject | Question | Answer |
|---|---|---|
| S-Meter | Will Merges (RIT Student) : Are you guys giving an S-meter for direction finding? | Aaron Chan (RIT Student) We will be doing it audibly. |
| Mini Tamiyas | Why mini Tamiyas? | James May (RIT Student) Mini Tamiyas are small enough that they will fit the gauge, they are used in many hobbyist RC applications, and therefore are locking connectors and can withstand vibrations. Thought to be a good all around connector. |
| Receiving Flight Data | How are you guys getting flight data? I believe listening to beeps is frowned upon in the competition. | Aaron Chan (RIT Student) This is why we bought the LCD connectors to read out flight data, and the USB connector will be used to get flight data onto our laptops |
| Location of avionics bay | Your avionics bay is fully in the nose cone? | Donovan Barros (RIT Student) It is half in the nose cone and half in the upper body tube. |
| Melting connections | Will Merges (RIT Student) : Any heat concerns since the plastic and bulk charges are in the same bay so you could potentially melt the main connection? | James May (RIT Student) For the ones that control the drogue deployment so they will be behind the bulk head so there is very little risk of them melting, the ones for the TD2 are behind the flame blanket. |
SRAD Avionics
Speakers: Yevgeniy Gorbachev
| Subject | Question | Answer |
|---|---|---|
| RS485 | Is this half duplex or full duplex RS485? | Jim Heaney (RIT Student) : Prompt uses half duplex only from PROMPT to the sensor board, alternatively, due to lack of pins, full duplex is not possible |
| Measuring Temperatures | Are you measuring temp and pressure from the bay or from the charge cups? | Jim Heaney (RIT Student) The preasure transducer itself is directly mounted to prompt. It doesn't need to be located next to the charges but beyond that, we want to measure the preasure of the bay. The thermal couple is located a bit closer to the charge wells. We want to verify what temperature we experience in flights. |
| Ground tests | Are you planning on doing ground tests? | Jim Heaney (RIT Student) All of avionics will be doing ground tests to verify functionality and will be part of the rocket during vacuum testing. The most important thing is getting these to 10,000 feet so other tests are to ensure these work at that altitude. |
| Software Testing | Is there any way to begin software testing before all modules are in hand? | Yes, we are beginning as we have the switchbox and wiznet breakouts in hand |
| Current vs Voltage | Is the pressure transducer constant current or constant voltage? | Jim Heaney (RIT Student) The chip we are using to measure the value |
| Documentation | Has the team documented any of these testing plans? | Yevgeniy Gorbachev (RIT Student) No full list of the testing plans yet, will be going off of the engineering requirements. |
| IC and Transducer | Between the IC and transducer is the voltage less than 50 volts? |
Payload
Speakers: Grace Dertinger, Joshua Rosenberg, Louis Fleisher
| Subject | Question | Answer |
|---|---|---|
| Radio | Can the share receiver with backplane radio? | SCRAP and radio use the same RF chip but will operate on different frequencies. We looked into time slotting but ultimately decided on using two different frequencies. |
| Recovery | Are the line cutters COTS successful and are there plans to test it? | Yes we plan on testing them. |
| Analysis | Does the snatch force calculation account for reefing? | Yes |
| Electronics | How is SCRAP detecting when it's left in the sabot? | There is no way for force SCRAP to open it's air brake. The only way to manually trigger the air brakes is to use a USB. Hardware has limit switches that will tell the SCRAP is outside the sabot, all need to be returning true for the SCRAP to know it's outside. An array of photo-transistors will measure natural sunlight which will also tell SCRAP when it's outside. Software also has the accelerometer to tell SCRAP when it's reached apogee and we also can measure acceleration. The airbrake is also under powered so it will not cause serious damage inside the rocket. |
| Radio | 900MHz is the Wild West | |
| Testing | How is the payload going to be tested? | Test the loadcell system by physically loading it. Linecutter testing would be a normal recovery system. |
| Airbrake | What would the airbrake and COTS system look like in previous years? | We've seen other teams use airbrakes before so we wanted to try this design. |
| Airbrake | Can SCRAP detect how much the airbrake should open and close? | SCRAP will take data of how much preasure is being put on the airbrake and will take actions according to that. |
| Airbrake | How do you know this system will scale reliably to a much higher load? | Grace Dertinger (RIT Alumni) It's not a one-to-one replacement, but we did some testing with an L1. Jim Heaney (RIT Student) The system will activate after the rocket slows below Mach in an actual implementation |
| Airbrake | Why is this a violation of IREC rules? | Jim Heaney (RIT Student) If SCRAP were to pop out of the rocket and influence the flight of the rocket, that would violate IREC rules. |
| Airbrake | Why not do ground testing? Even this flight isn't one-to-one. | Grace Dertinger (RIT Alumni) Good point, but there are factors such as the acceleration on boost we won't capture in a ground test Jim Heaney (RIT Student) All we'd verify on the ground is that we can actuate a motor |
| Drop Test | Ground drop test? | Grace Dertinger (RIT Alumni) We thought about this, but not practical |
Recovery
Speaker: James May
| Subject | Question | Answer |
|---|---|---|
| PROMT | Use PROMPT for deployment testing? | |
| Tangling | Avoid tangling streamer with main? | James May (RIT Student) They're far away, separated by most of the 50' shock cord |
| Wiring | GW Lisk: How are you managing wires from av bay to TD? | James May (RIT Student) TD are very close to the bulkhead, slack pulled back through. |
| Wiring | Why Mini Tamiya? | James May (RIT Student) We think they're reliable but will test more. |
| Streamer | How are you calculating streamer cut if you're underweight? | James May (RIT Student) We aren't relying on OR because they can't do large streamers; we are interpolating Rocketman's ratings linearly; error won't matter much since they're Could also use drag force equation |
| Wiring | Why not do non-critical testing of mini Tamiya? | James May (RIT Student) Good point - |