Category Archives: Uncategorized

Motor gimbal rotation matrices

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Improved rocket data OCR

I gave up on training Tesseract because I couldn’t figure out how to make the open source training tools work, so I downloaded a 45 day trial of the LabVIEW Vision toolkit and had decent success after training the time, … Continue reading

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Speed and altitude from New Shepard webcast

The Blue Origin webcast has speed and altitude data vs. time, so I tried to download it and automatically parse the data with Tesseract. 1. Take screenshot of the webcast once per second. 2. Crop the time, altitude, and speed … Continue reading

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1DOF sounding rocket

Apropos last weekend’s Exos launch, what does it take to build a reusable VTVL sounding rocket? Start w/ a 1DOF ascent-only simulation w/ a few realisms added: Time-varying mass Altitude-varying engine performance (LOX/ethanol at 350 psi and r = 1.1 … Continue reading

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DIY Prox Probes

I wanted to see if cheap inductive proximity switches could be reworked to output a voltage proportional to displacement. This is what it looks like on the inside after I ham-handedly snapped off the fragile copper coil (inductor). Some strands … Continue reading

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Reviving a bricked Arduino ProMini

Something anomalous happened to the ProMini on a flight about a month ago, and the ProMini would not run the sketch that was uploaded to it. I tried to reupload the sketch and got the following errors: avrdude: stk500_recv(): programmer … Continue reading

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Helicopter upgrades and stupid I2C problem

I replaced the stock 11T pinion with a 12T pinion, and replaced the stock E-Flite 800 mAh LiPos (68 g) with Turnigy Nano-Tech 370 mAh (38 g) batteries. The Turnigy batteries are 30 g lighter, and deliver 7.5 to 8 … Continue reading

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