Відео

@@ralstondorn7874 that’s just the default Featherweight voice. Kate would blow my budget haha.

Nice! I am planning a proper 75mm minimum diameter build for Airfest this year. Hoping for around 30k. How thick were your fins? Or did you mean fins were 3/16 thick? I gotta order some plate for those soon.

@@pathtouch1 actually the fins were 3d printed plastic! I gave them three layers of tip to tip carbon fiber layup, but after the flight I noticed that the carbon had delaminated in the hot sun. They were about 4mm thick, and the cardboard tube itself was 3/16" (it was a McMaster Carr shipping tube)

@@daytonpyro There’s a few different ways I’ve seen the main attached, each with its own pros and cons. The majority of folks have the harness go from the rocket to nose cone and connect the chute about 1/3 the way down the shock cord between them. So the nose cone hangs below the chute but doesn’t hit the rocket on descent. I’ve had the nose cone swing up through my shroud lines and foul the chute this way though. So now I swapped the chute and nose cone. This way it can’t swing around because the harness is pulled tight. Some people attach the chute right to the base of the nose cone. This is pretty common on smaller rockets. I think there’s still a risk of the nose cone flipping through shrouds, but most smaller rockets are fine if the main chute is a little tangled anyways. It’s harder to wrap that configuration with nomex too. Again in a smaller rocket I may just be using dog barf to protect the chute so no big deal.

WHAT DOES HE use?

First good step is finding local folks in your area that do the same. Where abouts are you located?

@pathtouch1 I'm in Austin Indiana I've been in contact with nar and am going for my level one asap and try to be level 2 this summer so I can at least get access to the APCP and other necessary chemical

@@ArjunK-yz4vx hey!!! Glad the algorithm is working. Did you guys have any new insights on why it popped? I forgot to ask if you had looked at port to throat area or mass flux to see if it was possibly erosive.

@@WilliamSun-h5u Do you have a Tripoli membership? There’s a whole presentation about it on the 2024 TRA Tech page under media. It’s basically Tiger Tail, 76% 200 AP, 4% Aluminum, and the liquids were just R45 and MDI. Nothing special at all.

​@@pathtouch1 Thank you， i am the high school students form China, most apcp formula in our forum are very liquid, but i want pressure casting so haha, You provided a simple formula.

@@pathtouch1 sorry. i can't find TRA Tech page.

I've found without any peel ply I would get an very uneven finish and some parts of the fiberglass cloth wouldn't be fully wet out and end up with dry spots. Using a porous peel ply, for me, allows it to sweat out excess epoxy in thick areas, and fill in drier areas when I overcoat it. Essentially leveling epoxy. This teflon coated stuff also removes very easily, but you have to be super aware it's probably leaving teflon on the surface and thorough surface prep is needed for additional bonding at areas like fins. It does leave a very finely textured surface but it much easier to finish sand versus un covered epoxy. Again all just my opinion, feel free to experiment on small parts. Some folks use solid Mylar as a finish, see LOC Precision's videos on that. Others like to do a very light 1-2oz cloth us a finish layer.

@@daytonpyro here’s the stuff I use from Aircraft Spruce www.aircraftspruce.com/catalog/cmpages/vb7025.php

@@pathtouch1 thanks. seem odd you soak that as well to get the extra to come off. t

Sometimes the plastic chutes don’t like to open in cold weather. I typically load up a nylon chute when I can fit them these days.

@pathtouch1 fill it with baby powder. 😉

@pathtouch1 Baby powder on the chute works.

Yup it's just Pathtouch on TRF.

Hand mixed too! 1.5 kg batches give the forearms a workout.

Yep..I'm doing a SwampGas P later this year..65 pounds 12 batches..

@@tysonreissfelder6710 closer to down east, there’s a Tripoli prefecture in Cherryfield. Does seem like there’s lots of potential up in potato country though!

@pathtouch1 Great to know that! I'm a few hours away where wide open fields are rare. Great place for high power launches!

It’s about 18lb without propellent. Kinda heavy since i fiberglassed it. Stock 72” LOC chute is fine though, right around 20 feet per second on descent for me.

@@pathtouch1 Mine is 64 inch and 17 lbs but rsk shows right at 1.00 margin stability. I thnk I will add 6inches to move it to about 1.40 and more like the 10:1 body ratio for stability. Do you recall your cg and did you sim it? I would be interested if you did for comparison.

@@Sterk03 look up the base drag hack for open rocket. Without adding that cone, my CP is about 47.8” from the tip, also 64” long. No base drag hack I have 0.6 calibers of stability. Super straight flight. I do have an AV bay so quite a bit of weight forward. I’ve flown 75mm motors with about the same stability just fine.

@@pathtouch1 Sorry for the delay sometimes life gets in the way. SO yes I have rocksim and LOC has it on their web site. I inquired to a few about running the CD and equation do to the stubby fat rocket I got that no one uses it. I do not show the DC either. So at about 15.8 lbs no motor I show 42.5cg and 51.4 cp with a 1.16 Margin. With the J425R I got 43.7 51.4 and 1.00 Margin... At MDRA you need at least 1.0 margin to launch. I have the weight system in the nose cause people said you will need it but I'm right there. I want a buffer so instead of adding more weight to the nose as weight I do not need, I am increasing the body 6 inches and this spreads out the cp to 56.8 which gives me a 1.94/1.71 margin. I might make it less then 6 inches but at least I know I have above 1.00 and little added weight. I believe it would be fine at 1.00. Ok I appreciate your info and I believe I saw your Doorknob at Pen Yan this past June. Cheers Sterk03

@@DougieDollasX these were massive 3/8” plywood fins so I just used a round over bit before glassing the fins and sanded the interface smooth.

This was actually an ARR liner and casting tube but a graphite nozzle. Running this at 600-700psi with Wimpy Red is about the limits for ARR liners. I've fired used AT phenolic 54mm liners though, and they last about 3 firings before I'm uncomfortable trusting them! For static test I re-use o-rings too as long as they don't have any crunching spots.

@@pathtouch1 what micron strontium nitrate do you use

75mm makes everything look better haha. Thank you. Hopefully flying it this weekend.

@@pathtouch1 to fly homemade motors is there a certification you need to do through NAR maybe? Hope the flight goes well

@@duhsq In the USA, it's a Level 2 Certification and has to be at a Tripoli Rocketry Association sanctioned launch.

@@pathtouch1 oh nice - I’m currently working on my L1 but I’m not 18 yet… so I can’t launch my L1 rocket for 4 years. However I got a LOT of G80Ts though so they should keep me company

It's Wimpy Red. The formula is pretty readily available with some searching online. uses Strontium Nitrate as a secondary oxidizer to Ammonium Perchlorate to give a nice red color!

@@pathtouch1 strontium nitrate? Never heard of that in composite propellants, only flares. I would assume it sacrifices performance for the color? I have used blackjack in all my motors so far

@@SeñorTortouise for successful flights I now use: Main 4.5g and drogue 6.0g. The backups are 20% larger for each. i got (2). 4-40 shear pins on drogue and (4) for main. I used a Cert-3 XL. I think fully loaded I was around 45 pounds and it came down at 22 fps. Good luck!

@@captainf1027 yup! Love them and very useful. It’s always lead me right to my rockets.