I know, I know. This is going to be one of those "hold your rocket up to the keyboard so I can see it" type of things. I usually fly in a smaller field, and occasionally I'd like to upsize the motors a bit. I can probably get away with this if I bring the rocket down a little quicker.
Doing sims on the various Estes kits I've built seems that the included chute sizes give descent rates around 15fps. Yes, I know that safe (non-destructive) rates depend greatly on rocket weight (i.e. heavy rocket that might land on a fin needs to go a bit slower) and how robust it is. Assuming 3-5 oz, basic 3 or 4 fins, papered balsa or plywood. I'm thinking of bumping the descent rate up to 18 or maybe 20fps. For a rocket that I'm probably going to launch tomorrow, that would (according to OpenRocket) entail going from an 18" chute to a 15". I'm talking about the basic cheap-o plastic Estes chutes. The rocket flew an actual 576' on a D12-5 with a reasonably comfortable landing distance from the pad using the 18" in low wind. But I'm considering a Qjet D22-7, which sims to 770 feet. It might be a nail biter on the 18" chute with 15 seconds more descent time from that altitude than with the D12. Switching to the 15" gives a similar descent time with the D22.
Tomorrow's weather forecast has minimal wind in the morning.....
Hans.
Doing sims on the various Estes kits I've built seems that the included chute sizes give descent rates around 15fps. Yes, I know that safe (non-destructive) rates depend greatly on rocket weight (i.e. heavy rocket that might land on a fin needs to go a bit slower) and how robust it is. Assuming 3-5 oz, basic 3 or 4 fins, papered balsa or plywood. I'm thinking of bumping the descent rate up to 18 or maybe 20fps. For a rocket that I'm probably going to launch tomorrow, that would (according to OpenRocket) entail going from an 18" chute to a 15". I'm talking about the basic cheap-o plastic Estes chutes. The rocket flew an actual 576' on a D12-5 with a reasonably comfortable landing distance from the pad using the 18" in low wind. But I'm considering a Qjet D22-7, which sims to 770 feet. It might be a nail biter on the 18" chute with 15 seconds more descent time from that altitude than with the D12. Switching to the 15" gives a similar descent time with the D22.
Tomorrow's weather forecast has minimal wind in the morning.....
Hans.