Category Archives: Uncategorized

Altitude control w/ Kalman filter

I incorporated a Kalman filter into the altitude control loop; it estimates altitude and velocity from a model of the helicopter and the altitude measurement from the LIDAR Lite. It doesn’t compensate for tilt errors, so it only works for small … Continue reading

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3 gallon tank burst test

I tested the LRD-3 Aluminum air tank and it burst at 828 psi (57.1 bar). Dry Mass: 2.34 kg (5.16 lbm) OD: 7.271″ (18.47 cm) Wall thickness: 0.097″ (2.46 mm) Ultimate strength: 30,204 psi (208.2 MPa) This ultimate strength is about 10% higher than … Continue reading

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Pressurant tanks, crude vehicle model

For the vehicle, I’m considering downsizing from 5 gallon propellant tanks to 3 gallon tanks and from 250 lbf thrust to 180 lbf. Low Rider Depot makes a 3 gallon version of the 5 gallon tanks I’ve had success with … Continue reading

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Tanks, Heatsink Engine

I purchased two more 5 gallon aluminum tanks from KMW Performance and proof tested them to 400 psi (27.6 bar). I’m presently looking for somebody to clean one for LOX service; the local welding supply stores could not recommend a vendor … Continue reading

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Another aluminum tank burst test

This week, I burst this 5 gallon aluminum air tank. I like this tank because it comes with five NPT ports and two brackets welded to it. It failed at 46.5 bar (674 psi) in the heat affected zone of … Continue reading

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Aluminum air tank burst test

I bought this hydrostatic pressure tester from Amazon and used it to burst a 7 gallon (26.5 L) aluminum air tank I bought on sale from Harbor Freight. I thought the aluminum air tank might make a good LOX and … Continue reading

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100 lbf LOX/alcohol heat sink engine

I designed a 100 lbf (445 N) LOX/ethanol engine, similar to Robert Watzlavick’s heat sink kerolox engine. The analysis is nothing more than the 1D isentropic compressible flow equations and thermodynamic data from RPA: 100 lbf engine Propellants: 70%ethanol and liquid … Continue reading

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