What did you do rocket wise today?

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kuririn

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Can you give me the part number and dimensions for the nose cone please? Would like to modify a Hi-Flyer.
Sure.
The nose cone is Estes #033315.
It is approx. 4 7/8 inches long.
The BT-20 tube is 12 inches long.
Streamer recovery.
 

dr wogz

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While not directly "personal" rocket related...

Reviewed 5 student submissions / papers for the COTS 10K' event for Launch Canada. These are basic 'Spaceport America' competition rockets, but for the Canadian version.. Some have, and some will be in New Mexico come June, (if the borders open up!!)

Some very smart kids out there!! Looking forward to these guys!! (nice paper too!!)



after reading these, I think I'm ready for my L3!
 

teepot

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I finished two rockets today. One is an attempt to make a whistling rocket. At first I tried taping 20 whistling Nerf darts parallel to the body. No whistle. This time I cut the heads off and glued then perpendicular to the body. If it whistles then it will be called Whistler. If it doesn't then it will be Warts and All. The other one is a ring fin. I've never done one before. I call that one Ring A Ding Ding. There scratch builds 110 and 111. I also worked on two more. One gets its second color tomorrow and the other gets primed.
 

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OverTheTop

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The hardware integration is completed for the Vertical Trajectory System with the new version two hardware.

VTS1.jpg


That is for a 98mm rocket airframe. Ignore the white thing on the bottom, that is just a stand for working with it on the bench. In the final incarnation the brass spacers and allthreads will be replaced by titanium bike spokes and carbon-fiber spacers, as was done on the first version. This saves about 200g of mass!

Took about a week for me to get the stupid Bluetooth link with the groundstation (Mission Planner) working. Firstly one of the cheap HC-06 BT boards stopped working, then the second one lost its programming and by the time I finally got all the ports, baud rates, adapters, telemetry port mappings and everything else right there was a week of my spare time gone :(. A problem with the BT stack that they used in MP didn't help either. Very pedantic. I hate it when things go that way with many confounding factors.

Next on the list is to get some smaller fins printed on the SLA resin printer. Those ones shown worked ok but gave me far more control authority than I wanted. I will cut the surface area down to about 70%. The new hardware has provision for a pitot-static tube to measure airspeed, and this is used in the PID control loops to modulate control surface excursions based on actual velocity. I guess making a pitot-static tube is in my future as well.

As it stands all my scripts are working, and they control the modes of the system during flight. A main flight script cycles the servos as a visual check of operation , then senses boost and engages the stabilisation at burnout. Stabilisation ceases when tilt exceeds a preset angle, time exceeds 30s, or the NC separates from the module.

I am also working towards getting all the parameters set in the software. There are around 500 parameters that need to be checked and either disregarded or set to the correct anticipated values to get this to cooperate with my application. Slogging away...
 
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jqavins

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Fins sanded.
Centering rings glued.
Blackberry Sour Poured. 🍺
I'm glad you have your priorities straight.

I finished two rockets today. One is an attempt to make a whistling rocket... The other one is a ring fin.
With the diametric rods running across the rings, I wouldn't be too surprised if that's the one that whistles.

The hardware integration is completed for the Vertical Trajectory System with the new version two hardware.
Congratulations. It must be a relief to have that done.
Next on the list is to get some smaller fins printed on the SLA resin printer. Those ones shown worked ok but gave me far more control authority than I wanted.
You could just reduce your gains, couldn't you? More authority than you wanted is sometimes a good thing; it lets you make smaller movements of the fins, which happen quicker, making the system more responsive. (Unless you're having to deal with lash, in which case the movement needs to be a good few times bigger than the lash.) It also means you can make larger corrections than you anticipated needing.
Stabilisation ceases when tilt exceeds a preset angle...
Is that apogee detection? A pretty sizable angle? Otherwise I figure you wouldn't want to shut down just when things are getting bad. Especially if you've got control authority to spare.
There are around 500 parameters...
:eek:o_O!
The new hardware has provision for a pitot-static tube to measure airspeed, and this is used in the PID control loops to modulate control surface excursions based on actual velocity. I guess making a pitot-static tube is in my future as well.
Nice. And I guess once you have that you could also use low airspeed as an additional method of apogee detection.
 

boatgeek

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I got out to fly a little bit with the TARC team on Saturday. Flew my L1 cert (Cheeto Dust) on an AT G78 (Thanks @BEC and Jim for the loan of your launch pad and controller!), plus Spruce Goose on a CTI G83 and Harry Bourland on both CTI F36's (BS and SS). Overall, a great day flying in nearly perfect weather. I do need to troubleshoot the flight controller I built over the winter. Weird gremlins all around in there.
 

Tech 68

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Rough documentation of my Lvl 3 avionics interconnect wiring.
That way I won't need to figure it out / "ring it out" next time.
 

boatgeek

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It had a couple of "I'm just not going to light this igniter" snits, and the continuity light started coming on even when the safety pin was out. It looks like there was a stray connection made in there somewhere, and possibly resulted in low battery power. But then it started lighting igniters later, so who knows? I think I need to rebuild the pin switch and maybe put some of the components on to a fiberglass board. Or maybe just give up and buy a PS2 controller. I've only got about 3x the cost of a PS2 into this one, with similar functionality. But the sunk cost fallacy is hard to resist. :rolleyes:
 

jqavins

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I assume you've done the very things I would suggest if you haven't. Check all the connections, looking especially for stray strands out of stranded wire. Then reflow any the soldered connections. Then give a little tug on any crimp connections. There's only low to medium probability of finding the problem, but it's a small investment of time, so it's worth it.
 

boatgeek

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I assume you've done the very things I would suggest if you haven't. Check all the connections, looking especially for stray strands out of stranded wire. Then reflow any the soldered connections. Then give a little tug on any crimp connections. There's only low to medium probability of finding the problem, but it's a small investment of time, so it's worth it.
So far, I've only done the basic field check of opening it up, looking for any gross issues, and closing it back up again. I will do the basic check as well once I have time to get it on the bench. Thanks!
 

BEC

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I got out to fly a little bit with the TARC team on Saturday. Flew my L1 cert (Cheeto Dust) on an AT G78 (Thanks @BEC and Jim for the loan of your launch pad and controller!), plus Spruce Goose on a CTI G83 and Harry Bourland on both CTI F36's (BS and SS). Overall, a great day flying in nearly perfect weather. I do need to troubleshoot the flight controller I built over the winter. Weird gremlins all around in there.
It was all Mr. Pommert. I was just kibitzing...

Gremlins and igniters are not a happy combination :eek:

It was about as good a day as we get in February. I got back up there Sunday as well and did a bunch of two-altimeter flights test flying some new firmware for Russ Parrish. Fewer people, but a bit more chilly breeze at times.
 

boatgeek

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It was all Mr. Pommert. I was just kibitzing...

Gremlins and igniters are not a happy combination :eek:

It was about as good a day as we get in February. I got back up there Sunday as well and did a bunch of two-altimeter flights test flying some new firmware for Russ Parrish. Fewer people, but a bit more chilly breeze at times.
I definitely tested a couple of igniters for serious gremlins before putting anything into a motor!

We were originally going to launch on Sunday. I'm glad I convinced the kids to come out on Saturday instead. It seemed a lot nicer for launching, with Sunday a lot nicer for holing up in the basement over the sewing machine.
 

OverTheTop

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You could just reduce your gains, couldn't you?
I am only going for relatively small excursions, limited to about 7deg mechanically. At small numbers the PWM stream starts to become quantised so by using a larger excursion but with smaller fins I get the authority I want with a more contiguous movement (smaller steps). I have flown with those fins and it makes for a surprisingly agile flight path. I want nice, calm corrections :)

Nice. And I guess once you have that you could also use low airspeed as an additional method of apogee detection.
I could, but apogee detection is done by the TeleMega in the NC. That keeps the rest of the rocket a standard HPR flight.
 

jqavins

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I am only going for relatively small excursions, limited to about 7deg mechanically. At small numbers the PWM stream starts to become quantised so by using a larger excursion but with smaller fins I get the authority I want with a more contiguous movement (smaller steps).
Ah, resolution, or course. Foolish of me to be thinking analog.
 

Cape Byron

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Received my 2021 cattledog from Estes.

Continued looking to Russia for inspiration:

10697078p.jpg


 

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