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Discussion in 'High Power Rocketry (HPR)' started by DAllen, Dec 1, 2018.
Doesn't that describe most of Indiana???
Seriously, glad to hear Indiana Rocketry has a field again.
Hahaha yeah well this place is exceptionally in the middle of nowhere even by Indiana standards.
First time I’ve ever used a big thin mil chute like this and am completely impressed with how small it packs. This is without even trying real hard to get it small.
Beer mug for attention (and scale) lol.
It's like the Skyangle Classic - they get itty-bitty when you fold them. Karen won't make me one out of that stuff. she says it's like sewing snot. So Preston gets my money. I just wish they came in more colors.
So important testing last night. In the first picture is my set up to test the stresses on the lower basket stopper plate. Loaded up 2 buckets with a little over 5 gallons total between the 2 of them and put them in the basket. In the second picture you see the stopper plate glued to the green center tube and I just want to make sure it's going to hold up to to the flight stresses of the lower basket assembly resting on it. So the average thrust is going to be around 10:1 or roughly 10g's of force for 1.4 seconds. This part of the basket weighs in at 52 or so ounces so ten times that is 520 ounces or 32.5 lbs and since water is 8.33 lbs/gallon thats about 3.9 gallons. The two buckets were placed like this for a little over 4 seconds and nothing happened - thank goodness. So now I know this needs no extra reinforcement and anything I do from this point to that plate is just bonus strength.
The last picture is what a Lokie I377 looks like and FINALLY some prints I ordered from LDRS came in the mail. Yay!
So more progress tonight:
First is a pic of the 45 degree bend that I am going to suspend the chains from. Might as well use them - I had a lot of extras.
Next is the rail guides I need to launch off of a rail. The plywood is there to help stiffen the connection.
Lastly is another layer of glue placed on the stopper plate
Hopefully, tomorrow I can get off work at a decent time and start working on the ebay and the upper spoke connection to the main tube.
So it's time to start on the chute cannon which I decided to be 12" long. I have about 15' of this 4.25" diameter round paper tubing so this was the obvious choice. I cut out three 1' sections from my supply. One, I designated as the cannon itself, the second was for the coupler and the third is for the splice that will hold the coupler together. The first photo shows coupler has been cut lengthwise so the diameter can be reduced. The second shows the arrangement of the three parts to be glued together. Except that I do not want the coupler to be glued to the inside of the cannon. So I put a piece of wax paper between the coupler and cannon which is what the third photo shows. This may not make a lot of sense now but as things progress it'll become more clear.
This is very entertaining to watch you discover and overcome the difficulties of such an odd launch.
"How many rockets did you build this year?
"Well it depends how you define 'rocket'"
(Coincidentally, my girlfriend brought me up here to watch the game this weekend)
Hey! I usher at ND games. Sadly I couldn’t make it today due to my real job. Hope you have a good time. That truly is a beautiful stadium.
So it's basically done. There's been a lot of little things I've completed between now and the last post and I don't have pictures of everything so if you want some more detail don't hesitate to ask and I will try to oblige. Did some ground testing last night of the ejection charge and it looks like 2.5g will do the trick so I'll load up 3g just to be safe. Final weight with motor is going to be 10.23 lbs and with the Loki I377 that puts it at around 8:1 thrust to weight ratio which is better than the 5:1 thrust to weight ratio I had on the original Aerotech I140. And yes, ad space is for sale.
3g? Wow! Is the cannon pinned?
No it isn't pinned...I think part of the issue is that the lid is not real tight which is something I will address in the field with the addition of masking tape on the shoulder. However, it is 4.2" diameter and 12" long so it is a fair amount of volume to fill and that chute really doesn't take up that much space. Plus the hole I had the wire coming out of for the test (which will be plugged for the flight) probably wasn't sealed real well either. The home made coupler is pretty good but imperfect. The tubing I used is not very good for rocketry applications. Doesn't cut real cleanly and every cut edge needs to be hardened with CA glue in order to keep it clean. I believe had I used better fitting standard rocketry tubing I would not need so much BP.
Gotcha, those considerations make sense.
My only similar size comparison are my 4" rockets that have always got along fine with the standard Pro38 ejection charge.
No videos - yet. But there are some pictures. We had the Notre Dame Rocket team out in the field with me today because they have to do some test flights on a small scale model of their project. A few of the kiddos shot some video and said they'd send it to me. They're aerospace/engineering students so I don't push for things like that haha.
So while out in the field I brought out about 10 discs and handed them out to the students. Told them they could throw at the basket while it was in the air. I tried to throw but just couldn't bring myself to do so. I was just laughing my a$$ off so hard at the shear absurdity of the situation I thought I was going to hyperventilate. I think 2 or 3 of them tried but didn't even come remotely close to the basket. I just cannot believe how perfect that flight was. Absolutely laser straight and the timer was set to 3 seconds which could not have been more perfect as the chute came out right at apogee. The 70" chute didn't even get any char marks from the ejection charge.
After flying this version for the first time I now realize there's a lot I need to do. First, I need a wireless switch to power on and off the timer. This setup is great but that timer is really hard to turn off and on as it is. Eggtimer Rocketry sells a WiFi switch so I'm probably going to order one of those in the next few days. Then, the chute cannon needs some serious work. That tube material is not great so I'm going to need to seal it up with a laminating epoxy or some good layers of paint. Same goes for all the wood donuts.
While I don’t have a good flight photo (yet ) I do at least have this:
Sooooo I have a question for the collective hive-mind that is TRF...I want to seal up the chute cannon and all the exposed wood to help extend the longevity. If I brush on some cheap 30 minute epoxy if I can paint over it and will the paint last ok or will it crack? I also have some Envirotex Lite on hand I used for a non-rocket project that I could use as well but brushing that onto the round chute cannon would be challenging to get an even coating. So if there's anyone out there with some experience with this sort of stuff who can provide some feedback I would appreciate it. Thanks!
Epoxy or fiberglass resin can be thinned. Whatever you may use, myself, I would thin it down for better penetration. let it soak, and then coat again. Also, 2 part paints are very "tough".
I have used ceramic header spray paint on the inside of my bigger projects.
Epoxy would help make the tube stronger but add weight.
Mmmm yes, don't want to add burdensome weight and waste the Flying Disc Golf Basket's high performance profile
I actually thought he was holding it upside down. isn't the big end where the motor goes???
I also would like to buy ad space!
No, that is the parachute cannon. See his profile image, it shows the basket in flight. He is holding it right side up.
Ok! Next flight is in December. So it’s $10/panel/flight. Get all 8 panels for $60/flight and pictures. Each panel is roughly 6.5”x8” and I’ll put whatever graphic you want so long as it’s PG rated or milder lol and let’s stay away from politics too. Drop me a PM here if interested
I am hoping to get the I dark matter motor for the 38/720 case. I believe that’s the I357.
Oh and watch the video:
See, I told you so, when the chute blew the big end was down
So this happened on Twitter last night lol. Brodie Smith is a ultimate frisbee trick shot guy who just recently did a trickshot/disc golf video with Paul McBeth and Simon Lizotte. Paul is the #1 disc golfer in the world and I am pretty sure Simon is in the top 10. I'm pretty shocked anyone responded much less responded so soon. This could be a really fun development.
That's awesome, it'd be fun to see some folks take shots at it, especially some of the best in the world. Sounds like an event that ought to happen.
No response from any disc golf pros other than what I've posted so far. Oh well...I don't care. Anyways I invited a bunch of my disc golf buddies to the next Michiana Rocketry launch on 12/14 via Facebook. And lookie here...I found a video of the flight on 11/10 at Indiana Rocketry's field:
So you think just because I've had a successful flight there is no need for improvements? Haha WRONG.
Anyways, first up is (and I don't have photos of this boring process) is laminating all the exposed wood with a thin layer of epoxy. So there's the new fad of making these wild looking epoxy coated counter tops with these high gloss and clear epoxies. This stuff is great and I bought some from Hobby Lobby for another project a few months ago. So I used this stuff to laminate and seal the chute cannon and the wood centering rings. The chute cannon tube really needed it most because its just a plain paper tube.
After some sanding I bought some really cheap vinyl contact sheets from the local Michaels. This stuff is really difficult to work with but its cheap at $2 per 12"x12" sheet. Unfortunately once you apply it and then decide to peel it off the sheet is trash and you have to start over with a new one. But on the other hand, should I ever want to change out the yellow for something else it's pretty easy compared to painting. Not a product I'd use on a regular high powered rocket since I am not sure it could stay on with the higher speeds.
And today in the mail I got a cool new toy for this project from Eggtimer Rocketry. A WiFi switch so I can turn my timer off and on remotely without having to take everything apart. This means I can place the FBD&D out on the pad and wait until everything is set on the rail before I turn it on with a smartphone. Some assembly required - So now I have to try my hand at soldering...I think I can do it lol. Just needs to be done before the 12/14 launch.
And yes, the center pole looks to be a little off perpendicular but thats only because I was too lazy to bolt it in place like I would for flight.
That is an improvement, looks sharp. I'm wondering what "par" your I motor flight qualifies as. If H is par 3, is I par 4???
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