Or come on out and fly with us at Battlepark
) so long as the weather cooperates we’re flying twice in February, twice in March, and have a three day launch in April 
Or come on out and fly with us at Battlepark
Feel free to hit me up if you have any questions
Throw a single 1/4 or 5/16 hole in there are call it done.
I would go 800-900 on the main. I've had HED DD chutes get "hung-up" a bit in the cone and wiggled loose just in time. 600 is a bit low IMO.
JFI would go 800-900 on the main. I've had HED DD chutes get "hung-up" a bit in the cone and wiggled loose just in time. 600 is a bit low IMO.
Enjoying the build!
Directly on the bulkhead. Been doing it that way for years with great success. I also know others that run the charges to the nose cone tip and they are also successful. Many ways to skin a cat. But I hate cats, for they are bipolar assholes, buy I digress.... LOL
Since you're here and answering questions
, would you mind sharing how you lay out the main harness? I've seen several options, but most of them have the main chute connected to the harness very close to the nose cone. This makes me worried about the chute not coming out, but somehow staying stuck/partially stuck in the nose cone. Obviously I'm going to ground test, but I would love to start with expert opinion.
Certainly. I'll take some pics and circle back in relative short order.Since you're here and answering questions
Thank you!
Pics below are mocked up from a non HED bird mocked up for the pics, but you can get the idea. First way is pretty basic, chute above the nomex and the recovery cord between the chute and the nomex is folded into the burrito. Based on how its packed, the whole burrito gets pulled out by the cord. I make the burrito longer than wide, and not a tight fit in the cone.
Other method (which I prefer to use on HED birds), use (2) pieces of nomex placed apart and this seems help stretch things out at main deployment. Ground test, rinse, repeat.
Not sure why you tap the shear pin holes. Why is that? What part do you tap? The nose cone under the screw head, or the inside? If you do the inside, how do you get the sheared part out? How much larger do you do the other hole than the tapped hole?
I tap the outside section, nose cone and airframe. Inside is drilled bigger to allow the screw to slide in (or out). I do it so it stays put, but it sounds like that's just another overkill thing I've done.
I'm not sure I'd call it overkill. I just tear off a small piece of blue painters tape to hold the nylon screws in. Guess it's a trade off on the time it takes to screw it in and unscrew it after vs. the tape to hold it in, or what it looks like with just the screws vs. the tape all over. Kind of a person preference to my way of thinking. I just didn't know if there was some big advantage to tapping the holes that I wasn't aware of.
The first "shear pins" I read about (in Make: High Power Rockets) were just styrene rod, but with nylon screws it just seemed intuitive to me to screw them into a tapped hole. I'm probably not going to switch away from it, but your experience will make me think about it next time.
I think the only issue is removal - is it harder to get the pieces out after flight if they holes are tapped and the nylon screws threaded in? If not, no worries.
Not really. The sheared parts fall out or get poked out and the heads screw out really easily with the same screwdriver I use to turn the altimeters on/off.
