mmm... Cake!

Pantherjon said:

I think 25-30fps is reasonable

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REALLY??? I see 15fps recommended just about everywhere. Like I said, if I can get away safely with a faster descent that's great news. I'm an extremely lazy person, so a closer recovery sounds great to me!

for example: LINK

Rocksim averages about 800 feet on a G64, and it agrees with the 15fps thing. I'm attaching the rocksim file for your perusal.

View attachment mmm...CAKE_short.rkt

I don't have a source that comes right out and says it, but it seems like that is a really conservative number (15fps). In particular with the nice soft sod that we land on and the design of your fins not overhanging the end of the rocket (and being ttw).

I've dropped my Lil' Nuke pretty fast with no trouble.

Anybody want to contribute the voice of actual experience?

Nice RKT file..Playing with it some..On an H123(which I have seen is a favorite for Cert L1 flights) the 50" chute in light variable winds drifted quite a distance..I sized the chute down to 32" and the calculated descent rate is 25.8647fps..Ok, running sims as I type this...lol..The 'drift' factor difference between the 50" and 32" is about 125' in light winds(405' w/50", 280' w/32"), so it's really not as big a difference as I thought...

I know the manufactures put smaller then optimal chutes in kits to keep costs down. I checked EMRR calculator and put the weights of my Calisto and Thug in there and they both said about a 48" chute. Both the kits come with 24" chutes and I've never had a problem or any damage with either bird on the 24" chutes. They both seem to drift quite far enough with the 24", I suspect I would be in for a really LONG walk with the 48" chutes.

Alrighty!

Got the parachute made this last night and today. I decided to go for 36". The sims on EMRR say this'll drop my (3#) rocket at 21fps. It should be pretty sturdy considering the fin shape and TTW design. Well, here's hoping anyway....

View attachment mmm...chute.jpg

Wow, that's beautiful. Nice work!

noise said:

Wow, that's beautiful. Nice work!

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Why thank you! I was gonna tie the boy to it and throw him off the deck to test it out. He said no.

falingtrea said:

The candle goes in the back.:rotflol:

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The really big candle is when it catos!:lol:

Bigander said:

The really big candle is when it catos!:lol:

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D00D! Bite your tongue!

Okay I've made some more progress. I was procrastinating because gluing in the fin can seemed so final. I was worried I was forgetting something. So I just went for it last weekend.

Now the fin can is glued in, the motor retention and shock cord are in place. Last night I drilled holes for the brass threaded inserts that the rail buttons will screw into. The brass inserts are held in with JB.

This bad boy is ready to fly naked this weekend!

paparoof said:

Alrighty!

Got the parachute made this last night and today. I decided to go for 36". The sims on EMRR say this'll drop my (3#) rocket at 21fps. It should be pretty sturdy considering the fin shape and TTW design. Well, here's hoping anyway....

Click to expand...

36" chute will do fine in a 3 pound rocket. My L2 was 4 1/2 pounds and I used a 48" chute with no problems.

I've been having a very hard time waiting for good launch weather, so today's forecast of a balmy 22 degrees and 4mph winds sounded good enough to me.

The only remaining problem was that I had a G64-10 and RockSim said I needed a 5.5 second delay. I spent the day reading about drilling delays (mostly here on TRF). I did the math and figured I needed to drill out 7.6mm from the delay element to get 5.5 seconds out of it. So I did that (by hand) and assembled everything.

We dragged everything out to the middle of our lake and set it up. I still haven't worked out a good mount for the rail to my launch pad, but the hole in the center fit one of my launch rods, so I just slipped the rail over that rod and went for it. Wasn't pretty, I'll definitely need to improve on that before the next rail launch, but it worked fine for today.

So we hooked it all up, I handed off the countdown to my 6 year old daughter and pointed the camera thusly:

Nice.

Thanks Pat!

I'm proud to say the delay drilling worked flawlessly. The ejection popped exactly at apogee and my homemade chute deployed gently.

The rocket landed softly with no damage probably 300 feet downwind. No problem for my crack recovery crew.

and I didn't lose the motor casing either!

Nice!