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  1. UhClem

    Adept ST210 Timer

    Page 2 of the instructions has what you require:
  2. UhClem

    Thoughts and Comments on Current Russian,Ukrainian Conflict/War

    Everyone seems to focus on that number. The warhead is the same used in the Harpoon and has a net explosive weight less than half that. There are of course videos from WSMR of flight tests including impact on the target to be found on YouTube.
  3. UhClem

    Tilt inhibit staging configurations for EasyTimer and *Mega boards

    There is a comparator in the FET driver that inhibits the FET if the battery voltage drops out. The voltage dividers set a trip point of 3.5V so the LDO should still be operating. See: https://altusmetrum.org/TeleMega/v5.0/telemega-sch.pdf
  4. UhClem

    What Have You Heard About Windows 11?

    Earlier this year I purchased a new computer. My workhorse dual core AMD machine had started shutting down for no apparent reason. I tolerated that till it did it four times in one day. Later inspection of the motherboard revealed swelled capacitors in the low voltage/ high current CPU supply...
  5. UhClem

    High power cluster restrictions

    It used to be spelled out on the NAR web site. But all I can find now is on the certification form: "We believe this member is qualified to build and operate High Power Rockets with a total installed impulse up to 640 N-sec." The NAR page used to say: "Certification at this level permits single...
  6. UhClem

    Just Put 24mm Motor Mount into BT-55 and Bigger Rockets?

    I put a 24mm mount in this BT55 ATACMS but have never come close to putting a D in it.
  7. UhClem

    Calculating fin flutter using NACA TN 4197: Open Questions

    Keep in mind that this paper was written long before computer modeling became possible so simplifying assumptions and approximations are required. These days you can simulate any fin geometry and composite layup you care to enter into a finite element model.
  8. UhClem

    Calculating fin flutter using NACA TN 4197: Open Questions

    The equations assume constant thickness ratio. (Used to justify equation 15.) aka. tapered in a particular way.
  9. UhClem

    How (and Why) the FBI Mysteriously Shut Down a Federal Solar Observatory - Sunspot Solar Observatory, NM

    Nearby is one of the JIG (Joint Instrumentation Group) antenna sites used by White Sands Missile Range. Information on that and other WSMR facilities can be found here: https://wsmrmuseum.com/historic-background-studies/
  10. UhClem

    fin to body ratio

    Figure 10-13 of the Handbook, seventh edition has this. Root chord = 2D, tip chord = 1D, span = 2D. But it is just a starting point.
  11. UhClem

    Caliber and stability

    It also has another meaning. The main battery on the Iowa class battleships for example are 16" 50 caliber. The 50 caliber means that the gun barrel length is 50 times the shell diameter. You have to be careful as seemingly simple words can have multiple different meanings depending on context.
  12. UhClem

    Open Rocket Math

    Trivial for an engineering student. For some value of trivial. :-) You could always dig up an early version of RASP. The BASIC listing for RASP-93 is in my copy of the Handbook of Model Rocketry. Simple non-graphical interface.
  13. UhClem

    Open Rocket Math

    The documentation includes some of those but there is no closed form equation for apogee, burn out time, etc. Those require numerical simulation which is why you have OpenRocket.
  14. UhClem

    Anyone not pass their Level 2 on first try?

    The NAR revised their certification system in 1996 and introduced the shiny new level 2 written test at that years NSL at Argonia, KS. It wasn't a good weekend for flying rockets. Since Saturday was a blowout, I spent some time going over the study guide they had handed out and took the test...
  15. UhClem

    Thoughts and Comments on Current Russian,Ukrainian Conflict/War

    Which is worse: Admitting defeat and exiting Ukraine (all of it) or getting defeated on the battlefield? Sure you can throw more men and material into the grinder, but to what effect? Nobody fears the Russian military (except perhaps the nuclear arm) anymore. Sticking it out will just make that...
  16. UhClem

    astro-can gets stupid

    Quality micro-SD cards are readily available so try one before retiring the camera. Estes is using something pretty cheap and mine was bad out of the box.
  17. UhClem

    Estes igniter plug colors

    Each set of plugs comes with a little flag on the end which has the motors they go with. I always pull plugs from the non-flag end just in case I ever forget which is which. And don't have another set of plugs to look at.
  18. UhClem

    Zaporizhzhia nuclear reactor — how to keep it from going Kablooey!

    While it has been a decade or three since my EE electrical machinery course, the lack of excitation current isn't a problem. There is always residual magnetization and this will result in power output from the generator. The generator output then feeds back into the excitation. Quickly reaching...
  19. UhClem

    Zaporizhzhia nuclear reactor — how to keep it from going Kablooey!

    Reactors all make heat, a lot of it, after they are turned off because the fission products have short half lives and go on doing their thing. This has always been known. So the reactor keeps producing heat. (Up to 6.5% of full power depending on operating history but dropping rapidly.) The...
  20. UhClem

    Zaporizhzhia nuclear reactor — how to keep it from going Kablooey!

    I still do no understand how a facility designed to turn heat into electricity could melt down due to inadequate cooling resulting from a lack of electricity.
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