What did you do rocket wise today?

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jqavins

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Unfortunately not. I've been pretty remiss at taking pics or videos. Need to chance that at the next launch.
What you've been remiss in (if anything; this stuff is not truly required) is getting someone else to take pictures or video for you. You concentrate on watching the rocket, and hand off the camera.
 

Adam3836

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I see the supervisor is fully inspecting your work lol lol


QUOTE="Tech 68, post: 2185153, member: 29976"]
Did a full up balance check so I'd have a pretty good idea of CG location (not having much luck with RockSim's "mass override"...
Was closely supervised by the "Weight & Balance" Inspector.
[/QUOTE]
 

Antares JS

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Baby Bertha build. Got all he fins on, got the launch lug on, and got the engine mount assembled and painted. Unfortunately, one fin I glued about 1/8 of an inch lower than the others so its a little lopsided sitting on the ground.
I have to ask... why did you paint the motor mount? It's going to go up inside the rocket anyway. Either way, be sure to sand the paint off the outer edges of the rings so they don't get blocked from accepting glue.
 

mjremijan

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No reason other than I saw it somewhere and thought I'd give it a try. Yes, I will sand it before installing it.
 

jqavins

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Baby Bertha build. Got all he fins on, got the launch lug on, and got the engine mount assembled and painted. Unfortunately, one fin I glued about 1/8 of an inch lower than the others so its a little lopsided sitting on the ground.
And I have to ask, are you going to cut the one fin off and fix it? I probably wouldn't in your shoes, but I'd agonize over it.

No, wait, actually, if I caught the mistake before the fillets went on then I probably would fix it.
 
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I talked with my professor and my college design team about the possibility of making active stability canards as our capstone project. Got a word of hurt ahead of us I think...
 

prfesser

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I talked with my professor and my college design team about the possibility of making active stability canards as our capstone project. Got a word of hurt ahead of us I think...
You may be right. :( Active stabilization, at least at a regional/national launch, is a bit questionable at this time. One of the important points that the national organizations make to the AHJ is that we fly UNguided rockets. The concern is the closeness of active stabilization techniques and hardware to active guidance techniques/hardware.

FWIW I saw an active-stabilization rocket (used a gimballed motor mount, if memory serves) about 25 years ago in High Power Rocketry magazine.

Best -- Terry
 

Doug Holverson

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Update on the RC Apogee Condor: It flies nice when it's not the Red Baronest thing. Much better than the brick that I expected it to be.
 

GrouchoDuke

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I talked with my professor and my college design team about the possibility of making active stability canards as our capstone project. Got a word of hurt ahead of us I think...
I think this would be a fun capstone project. Challenging & a ton of work, but fun. It'd be a good mix of controls, aerodynamics, structures, sensors, electronics & more. Joe Barnard is doing thrust-related control for his rockets. Jim Jarvis is working on aerodynamic surface control. Joe's stuff is mostly on YouTube and his website. Jim has at least one good thread here detailing his progress. There are probably others.

Looking through their work and designs of smaller missiles should be valuable. There are lots of potential gotchas in a project like this.

As with everything, the simulations you do will only be a starting point. You'll need good flight test data & time to iterate to get a workable solution. Finding the right place to fly will be a factor too (multiple FAR trips maybe - or a university waived airspace location?).

Good luck & have fun!
 

OverTheTop

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I talked with my professor and my college design team about the possibility of making active stability canards as our capstone project. Got a word of hurt ahead of us I think...
There is quite a bit of complexity in the mathematics of this sort of control. See what you can learn from other people to help you along your path. There were the people mentioned above, and I have done some work down this path also, particularly the canard flight control.

Here is a link to a project I have in work currently:
There are more details on the servos and canards in the Mk1 version which you can find a link for in the above link.

It would have flown the Mk2 this year but covid still has us grounded. We are in our sixth lockdown. I am taking the opportunity to upgrade telemetry systems and make some general improvement in the relatively rough breadboard of the system, and also working towards an Automatic Antenna Tracker to follow the flight.
allresize.jpg


PadResize.jpg
 
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I think this would be a fun capstone project. Challenging & a ton of work, but fun. It'd be a good mix of controls, aerodynamics, structures, sensors, electronics & more. Joe Barnard is doing thrust-related control for his rockets. Jim Jarvis is working on aerodynamic surface control. Joe's stuff is mostly on YouTube and his website. Jim has at least one good thread here detailing his progress. There are probably others.

Looking through their work and designs of smaller missiles should be valuable. There are lots of potential gotchas in a project like this.

As with everything, the simulations you do will only be a starting point. You'll need good flight test data & time to iterate to get a workable solution. Finding the right place to fly will be a factor too (multiple FAR trips maybe - or a university waived airspace location?).

Good luck & have fun!
We will absolutely be looking into both Jim and Joes stuff. I think I ran into a few of Joes videos on Youtube before. They have a lot of good information in them so definitely worth watching. As you alluded to there can be a lot of "gotchas" so any more information we can get and use to avoid these gotchas would be good to have and reference.

Thank you @OverTheTop for the link to the your project post, we will probably reference your post multiple times throughout our design process to avoid said "gotchas".

Also thanks to @prfesser, totally forgot about launch logistics. We'll have to work on figuring something out now.

It'll definitely be a fun project but i'm sure I will be ripping my hair out at a couple of points. Just part of the fun!
 

JimJarvis50

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We will absolutely be looking into both Jim and Joes stuff.
I think a stabilization system is the perfect project for college teams. There are a lot of diverse issues to consider, and it is a lot of fun. Just expect it to be a multi-year project. My thread on this subject is here:


I have lots of videos of various flights. You can search Youtube for Jiminaus50 to find them, but this was a good one:


Jim
 

teepot

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Boy, that's a tough act to follow. All I did was put the switches I soldered into rockets without switches. And I marveled at the great response my last build got. Thank you all.
 

Lee

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I just started using epoxy rivets - great technique for bonding to plastic
 

Lee

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Yes, the holes are for epoxy rivets. I think it would provide some additional fin support in the event of a hard landing.
Which cure rate epoxy are you using? 5, 15, slow cure 30 minute?
 

RocketTree

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Which cure rate epoxy are you using? 5, 15, slow cure 30 minute?
I typically use JB weld, which is very slow cure (hours). Its sets up nice and smooth for fillets. I had previous experience with this product, so it was my first choice for rocketry.
 

Jim Hinton

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The UPS man brought me a big old box of awesome from MAC Performance. It's a 75mm 4" Bolt, FWFG. I purchased a tailcone retainer as well as some other accoutrements. This is the first kit that I've had from MAC. It looks very nice. I just happen to have a spot available to build such a project.
Jim
 

NateB

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I cursed cheap rattle can paint. I'll wait until I can find what I want before I'll make that mistake again.
 

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