dents

[carson]

How do you keep the nose cone from denting the tube when the chute is deployed?? Also is there anything that can be found in say a Home Depot that can be used like the kevlar line on some model kits.????

 

[cls]

you can get kevlar line from many online rocketry suppliers, for example Fliskits, Apogee, ThrustAero ... I haven't seen it or anything suitable at Home Repo. turns out fly fishing stores used to carry kevlar but do not any more. so just order your kevlar online.

while you wait for your package get a big bunch of elastic from the fabric store. for most kits you can just put an extra long length of elastic, and that will prevent the dents.

 

[flying_silverad]

The reason you get some backlash during ejection is the shock cord may not be long enough. When ejection occurs, the nose cone or payload section bangs back against the body tube lip. Ouch! The shock cord should be about twice as long as the rocket is and can be attached to kevlar cord which is anchored around the motor mount.
Some people like to have the connection (between the kevlar and shock cord) to be inside the body tube to reduce "zippering" or rather the ripping of the body tube. If you can't make the connection inside the tube, don't worry, just keep the actual shock cord length as stated before...twice the length of the rocket.

Here's a pic...
Kevlar attached for recovery

 

[user 1400]

there are some good rolls of kevlar thread on ebay. They're listed with rocket in the title. The seller is very helpful, he provided some samples so I could pick out the right kind for my application.

Peace

Mike

 

[astrowolf67]

The best results I've had preventing the dents, is to use a long shock cord, about 3 times the length of the rocket. Attach the chute 2/3's of the way up the shock cord, not to the nose cone. The only thing Home Depot has that can be used in recovery systems, is nylon string. I use this to make LOC Precision style shock cord mounts on all of my rockets.

 

[astrowolf67]

Here is a pic of a LOC style shock cord mount. All you do, is take a length of nylon string, tie a loop in the middle, and a knot at each end. Apply a 1/4" wide strip of masking tape just above the knots, keeping the ends about an inch apart, then tape far enough down the tube so the loop just barely sticks out the end, leaving clearance for the nose cone. Then apply a blob of epoxy making sure the knots, and string ends are laying down against the tube to prevent them from snagging the chute or shock cord. I've yet to have one of these fail on me.

 

[bsexton]

Originally posted by astrowolf67
Here is a pic of a LOC style shock cord mount...

I agree with "astrowolf67" with one improvement - I use kevlar thread instead of nylon string. You can also use epoxy clay from Apogee Components to attach the shock cord mount.