New to Jolly Logic

[Sterk03]

I was thinking to try using my Jolly Logic chute release in a Estes Mean Machine. I was wondering if anyone has had any success with this. I think the book calls for a 24 inch chute and I'm not sure that will work. I know there are chutes of different materials but maybe a 18 inch might work. It might not be big enough to slow the rocket down thou. So I get 40mm or 1.5 inches across the body tube and I think this is the minimum for use. I don't want the chute getting stuck. I know there is a certain way of loading the chute with Jolly but I did see a picture that looked a little different and it stayed narrow, but do not know if it worked. I am asking anyone who has had experience with the Mean Machine and/or Jolly Logic that can chime in with past experiences with either or both.

Thanks for your listening.

Sterk03

 

[SpaceX76]

why are you trying to put a jolly logic chute release in a mean machine it only goes up to around 1000 ft??? i would not recommend putting a 18 in parachute in your mean machine you would be getting a ~18 fps decent rate which is quit fast

 

[Sterk03]

Thanks for your response,
One, I like to try it out, two I want to see if it will work in a 40mm tube no matter what the rocket name is and yes I did mention that the 18 would be too small and our launch fields are not like your great wide open fields in the west so an open chute at 1000 ft and wind your at risk of not getting your rocket back or on top of a big Oak tree. I was asking for info and now I have some from your response.

Thanks,

Sterk03

 

[PayLoad]

40mm tube is more than enough. I use mine in 38s all the time, just make sure you pack the chute & wrap the JLCR so it "snaps" apart. Test multiple times before flight

 

[dhbarr]

I don't like a JLCR in anything smaller than 2in tube, but other folks have good success in 38mm.

 

[Sterk03]

I am not saying I am using it but wanted whether it is tried and successful or not. Yes I understand larger tubes would be better and easier but I figured someone out there has done it and maybe has some advice. I thought somewhere I saw someone used wax paper around it so it would slide out easier. There are many ways to skin a cat. Thanks for the replies!
Sterk03

 

[neil_w]

Did you use the Estes tri-fold mount, or kevlar to somewhere lower? If a tri-fold, I'd be a little nervous about the JLCR getting hung up on it during ejection (maybe not an issue if you position it carefully and it doesn't rotate at all during flight or ejection, but I'd probably not chance it).

Also, if you're using the JLCR, then that is not the time to go smaller on the chute.

 

[Sterk03]

All good points well taken.

 

[dr wogz]

I'm not a fan of a JLCR on a typical Estes plastic chute.

• The binding likely to crush the chute, making it less likely to open (especially in colder weather)
• The rubber band sticking to the plastic chute
• The rubber band & clip getting hung-up on the [thin] shroud lines (which can also likely pull / detach a shroud line or two..)

 

[DrewW]

I am not saying I am using it but wanted whether it is tried and successful or not. Yes I understand larger tubes would be better and easier but I figured someone out there has done it and maybe has some advice. I thought somewhere I saw someone used wax paper around it so it would slide out easier. There are many ways to skin a cat. Thanks for the replies!
Sterk03

Out of 4 attempts I’ve had 3 successful deployments. Be diligent in packing the chute and making sure in slides easily out of the tube. My lone failure the JLCR hung up in the tube (totally my fault) and well, is 6 inches shorter now.

 

[PayLoad]

I simply cannot imagine a JLCR working with an Estes Plastic Chute & lines.

 

[shockie]

I would switch to a thin mil nylon...they are more puffy and fluffy than Estes plastic.

I just wish the thin mil nylon had thinner thread shroud lines.

 

[John Beans]

For what they are worth, I'll offer some thoughts.

Nylon's in general nicer because it isn't as prone to wanting to stay crinkled up. Good parachutes are really worth the money, IMHO.

One test for fuselage packing once you come up with folding method is the Puff Test. With no motor in the rocket, blow into the motor mount with a quick "cough" type of of exhalation and see how easily it ejects. It's surprising how little it takes, and you'll learn that the nosecone inertia and attachment near it can be really helpful in "pulling" the bundle out when there's lots of space in the fuselage and the puff just goes mostly around the chute bundle.

As for folding, here's an idea: for rockets approaching 38mm in diameter consider laying the chute out on a table longwise, folding it so that it is very long and thin, put a small cylindrical roll of paper towel or tissue inside the base of the shroud, then band around just the base of the chute. The pad makes sure you have a large enough diameter to grip and alleviates some of the chute crinkling, while staying less than your fuselage diameter. Upon ejection you'll have a long fluttering chute held closed at the base, and it will act somewhat like a drogue. Be sure to use a swivel so that your lines will stay reasonably untwisted, and carefully make sure you tether it in such a way that Chute Release is never yanked by the tether, but yet is also securely tethered. On a high quality sewn chute that can be a shroud line, but on a simple plastic chute that would be a really bad idea as the shrouds are quite delicate. Feel free to make a long tether if it is needed to prevent yanking.

(Tether yanking is a common failure mode. It can even pull Chute Release apart in violent ejections of larger rockets.)

People have also found that fabric bands have less friction against the fuselage than rubber bands. Fabric stores sell them, as does Amazon. And they are used by some small rockets as shock cords.

As always, ground test your bundles. (And then puff test your loading.)

 

[DrewW]

Out of 4 attempts I’ve had 3 successful deployments. Be diligent in packing the chute and making sure in slides easily out of the tube. My lone failure the JLCR hung up in the tube (totally my fault) and well, is 6 inches shorter now.

I simply cannot imagine a JLCR working with an Estes Plastic Chute & lines.

I would switch to a thin mil nylon...they are more puffy and fluffy than Estes plastic.

I just wish the thin mil nylon had thinner thread shroud lines.

I should probably have mentioned I used a top flight thin mil chute for these 4 JLCR flights.

 

[Culprit]

why are you trying to put a jolly logic chute release in a mean machine it only goes up to around 1000 ft??? ...

When I first bought my Chute Release, I flew it a number of times on an Estes Firebolt to the 800' mark to validate my methods. Low altitude flights like that are perfect for practice. It won't land in the next county if something goes wrong, and you can set the release altitude low enough on those small rockets to see what's happening.