icarus

[JSvolfan]

I just finished building a quest icarus. The rocket turned out nice and the finish is O.K. The problem is the second time I shot the rocket it burned up both the really cheap chutes. I am thinking about connecting the two body parts together with some kind of shock cord and using one 18 inch chute. Does this sound like a good idea and if it is how long should the shock cord be.

 

[KarlD]

I had the same problem with my Quest Superbird. When I tied the booster and payload sections together, the fiber bulkhead on the payload tube began to disintegrate. Too much load on the paper bulkhead.
I would recommend at least 2 to 3 times the length of the rocket for your shock cord. You should be able to reuse the Kevlar thread for your shock cord mount, or install a tri-fold mount.
Attach the chute to the shock cord about a third of the way down on the shock cord from the payload tube. The Fiber bulkhead will not stand much stress.

 

[Mister Rogers]

Hi,
I would be more concerned about WHY both original chutes were melted. Until you know why, it seems there is good reason to believe your single larger chute will suffer the same fate. What type of wadding did you use to protect your chutes and how much of it did you use? Any hot ejection gas getting past the flameproof wadding will melt the chute of course.
To answer your question about anchoring the larger chute, I would say your shock cord should be 2 to 3 times the length of the body tube. If your original mount is still in good shape, then just splice onto the end of it and run it to the nose section mount (which I take it was originally for the forward chute only). Then you can mount your larger chute either to the same nose cone mount or tie it on half the distance between the body and nose on the new longer shock cord. Good Luck

 

[KarlD]

Slight clarification...

I never had a chute melt on my Superbird, but getting both chutes to deploy properly was difficult. Plus the payload section on one chute would float wayyyy to far.

Just be careful about the fiber bulkhead in the payload section. Too much strain and it will fail.

 

[powderburner]

Whatever you end up with (and the above recommendations are good), add a length of tether to one end of the shock cord. You can use kevlar or whatever is handy, I often use woven cord. Either attach the tether to the bottom portion of the rocket and then add the shock cord beyond that, or attach the shock cord to the lower rocket section and use the tether to attach the NC.
Tie your parachute into this tether/shock cord so that the lower rocket section hangs low and the NC/payload section hangs above it and does not bang into it. That way, when the first section hits the ground (preferably on the protruding motor case?) part of the weight will 'come off' the parachute and your NC will be lowered to the ground more gently.

 

[JRThro]

I've only flown my Super Bird once, and haven't finished the Icarus yet, but they're essentially the same rocket with slightly different fins.

On the one flight the Super Bird has had, the NC and payload section ejected fine and *that* chute deployed perfectly.

I used some extra elastic to tie the NC to the elastic loop that passes through the 2 holes in the cardboard disc at the bottom of the payload section just in case the NC separated from the payload section, but that turned out not to be necessary.

The chute on the main body section ejected fine, but it failed to open, and 2 of the shroud line anchors, complete with the adhesive reinforcing things, ripped off the parachute. The parachute itself was still wrapped nicely in the remaining shroud lines and attached to the shock cord. The only damage was a ding to the front end of the main BT, which hit the ground first.

Anyway... I would certainly consider linking the two parts of this rocket together with shock cord as others have described, but what I'll probably end up doing is flying it without any payload section at all. It's long enough as is, and even with the payload section deleted, it's still stable according to RockSim.

 

[JSvolfan]

The times I shoot my icarus rocket I was using estes wadding and probably not enough. After the advice you guys have give me The photo below is what I came up with. I am going to attatch the chute at the top where shock cord is folded, Right now I do not have a good 18 inch parachute, but I am considering buying some of those mylar ones from somwhere. I think I will buy some of the cellulose insulation from the home depot store today.

 

[powderburner]

Whether you use Estes-type paper wadding or the TRF-advocated 'dog barf,' you need to use enough protective material to create a wad 1.5 to 2 times longer than the diameter of the BT of your recovery section (that was a horrible sentence, did it make sense?)
If you are using a BT-60-size tube (diam = 1.6 inches) then you should have a wad of protection that is 2.5 to 3 inches long.
If you are using a BT-101-size tube (diam = 4 inches) then you should have a wad of protection that is 6 to 8 inches long. (and that's a LOT of sheets!)
The material should be moderately packed, to create a seal, but should still be loose enough inside the BT to be able to eject easily. You can test this yourself by rolling up a sheet of paper into a tube, insert into the rear of the rocket (instead of a motor), and blowing a puff of breath through the tube to see if your wadding, recovery system, and NC work. DO NOT INHALE (duh?)
You can quickly see that for big BT sizes, you are going to use quite a lot of protective wadding. If it gets too expensive for you, then check into using other protective means (pistons, nomex barriers, etc).

 

[Micromeister]

Heres a hint for getting your dual chutes to deploy, this thick works with Slik, Rip-Stop Nylon, plastic or mylar.. Flat, X-Form or Hemispherial chute.. or any combination.

Fold, roll and pack both chutes as you normally would, install whatever type wadding your going to use, insert the TOP (nose sections) chute FIRST, then pack the body (lower chute) on top. loosely fold in the remaining lines, and install the nose/forward section. I've never had a dual chute par fail to leave and seperate for the main model body using this method. If your having trouble getting the chutes to blossom After leaving the tube. try baby powdering the heck out of them just before folding and packing.
Would you believe an 18" and 20" rip stip Hemi-chutes from a BT-55 body?
Hope this helps.

 

[JRThro]

Originally posted by JSvolfan
The times I shoot my icarus rocket I was using estes wadding and probably not enough. After the advice you guys have give me The photo below is what I came up with. I am going to attatch the chute at the top where shock cord is folded, Right now I do not have a good 18 inch parachute, but I am considering buying some of those mylar ones from somwhere. I think I will buy some of the cellulose insulation from the home depot store today.

That looks good, but I'd keep in mind KarlD's concern about the paper disc with the elastic loop through it. How wide was the flat elastic you used for the shock cord, 1/4"?

Originally posted by KarlD
... When I tied the booster and payload sections together, the fiber bulkhead on the payload tube began to disintegrate. Too much load on the paper bulkhead. ...

Frankly, if he hadn't said anything, I probably would have wound up doing the same thing you did, but now I think I'll find an alternate way to attach the shock cord to the payload/nosecone section.

 

[JRThro]

Originally posted by Micromeister
Heres a hint for getting your dual chutes to deploy, this thick works with Slik, Rip-Stop Nylon, plastic or mylar.. Flat, X-Form or Hemispherial chute.. or any combination.

Fold, roll and pack both chutes as you normally would, install whatever type wadding your going to use, insert the TOP (nose sections) chute FIRST, then pack the body (lower chute) on top. loosely fold in the remaining lines, and install the nose/forward section. I've never had a dual chute par fail to leave and seperate for the main model body using this method. If your having trouble getting the chutes to blossom After leaving the tube. try baby powdering the heck out of them just before folding and packing.
Would you believe an 18" and 20" rip stip Hemi-chutes from a BT-55 body?
Hope this helps.

I'm kind of surprised that you've never had your chutes hang up on each other, but if you say it works, I believe you.

I think the problem with my main body chute not opening was that it was one of the "crinkly" Quest ones, I packed it the night before, and I may well have wrapped the shroud lines around it too tightly.

 

[JSvolfan]

The elastic was 1/4". I tried soaking the fiber ring on the payload section with thin ca. I am hoping this will strengthen it some.
I am sure I will find out after a couple more launches.

 

[Micromeister]

JR:
The method discribed earlier has been in use by Scale and PMC modelers for a very long time. It was actually one of the FAI international flyers that convinced me to try it more the a decade ago it's worked beautfully every time ever since.
I must say packing chutes the night before a launch has never seemed to make much of a difference in warm weather, in cooler/cold weather is sometimes gives the chute a bent toward not opening.ie Plastic Wad recovery.
I use a number of Quest Stiff plastic chutes in some sport flying models. I per-condition them while watching TV or When I need to work on my forearm muscles crinkle your new quest or any plastic chute into a small ball in your hand, smooth it out, start from another corner mashing it into a ball again. continue this process until the chute almost Falls open from your hand.
Heres a procedure pictorial using a mylar chute so the wrinkling is more visible. After your happy with the "softness" of the plastic Talc baby powder the heck out of both sides. At least before the first use.
Hope this helps.

 

[JRThro]

Originally posted by JSvolfan
The elastic was 1/4". I tried soaking the fiber ring on the payload section with thin ca. I am hoping this will strengthen it some.
I am sure I will find out after a couple more launches.

Yep, one way or another!

Let us know what happens.