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jahall4

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Do most of you use the technique of Z-folding your harness (shock-cord) then wrapping with small lengths of masking tape?
 

rharshberger

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Do most of you use the technique of Z-folding your harness (shock-cord) then wrapping with small lengths of masking tape?
I do, but we each have found something that seems to work the best for us, and to me that means I z-fold and tape.
 

jahall4

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Anyone ever have a problem with the harness failing to "break" the tape and unfold?
 

Coop

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Tape? No. But I have used rubber bands with good results on TK...


Later!

--Coop
 

JJSR

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I have with out any failures, down side was it makes the harness sticky in the summer time, at least mine did.
 

RocketFeller

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On a big rocket with a long cord it helps to keep things tidy. On smaller rockets I just stuff the cord in.
 

jahall4

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On a big rocket with a long cord it helps to keep things tidy. On smaller rockets I just stuff the cord in.
Exactly!

Hi Dan, How are you?

That's the challenge I'm trying this nose down configuration on the MWR. Drogue and main along a 50' harness.
 

RocketFeller

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Exactly!

Hi Dan, How are you?

That's the challenge I'm trying this nose down configuration on the MWR. Drogue and main along a 50' harness.
Doing well, thanks!

I think that it would be very helpful in your case. We have a 55' harness on the Dragonfly. We pleated/Z-folded several bundles of six pleats and taped them. We used just a single wrap of blue tape and they came loose very easily. You could do some bundles with one wrap and some with two or three wraps for a shock softening effect.
 

jahall4

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...We pleated/Z-folded several bundles of six pleats and taped them. We used just a single wrap of blue tape and they came loose very easily.
Are you saying you bundled the bundles?
 

RocketFeller

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Are you saying you bundled the bundles?
We didn't, we just left them as five or six individual bundles. To tighten things up you could wrap the individual bundles into one, but we had plenty of space. For our first flight we didn't do anything to the shock cord and it worked fine, but it did seem a lot more tangle-resistant with the pleated cord.
 

rharshberger

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We didn't, we just left them as five or six individual bundles. To tighten things up you could wrap the individual bundles into one, but we had plenty of space. For our first flight we didn't do anything to the shock cord and it worked fine, but it did seem a lot more tangle-resistant with the pleated cord.
Something like this...

L3build49.jpg
 

Onebadhawk

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This really is a great pic Rich,,,
It's very important that you see where the tape is and where the harness comes out from under the tape..
The tape is in a place so that the slightest tension on the 2 legs of the harness is pulling directly on the tape
in a direction so the tape tears,, it's pulling at the edge of the tape, it's weakest point, a bit difficult to describe...

Very important,,,
I ALWAYS Z fold the harnesses.. If you use the rubber bands that are made for a child's braces
everything works the same but there's no sticky residue from the glue on the tape...

https://www.amazon.com/gp/product/B00EXA4AQI/?tag=skimlinks_replacement-20

Teddy
 
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Bat-mite

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I use hairbands (small rubber bands) instead of tape. No residue and nothing is left stuck to the Kevlar after deployment. I have noticed that tubular Kevlar starts to get very "clingy" after it absorbs spent BP. I started using the Z-fold and band method after my tubular Kevlar started coming out in a tangled mess.
 

jimdanforth

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I've always done that and thought it helped take a little shock out of the cord too.
 

les

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Anyone ever have a problem with the harness failing to "break" the tape and unfold?
Sort of. As others have stated, I make multiple bundles (5 or 6). I've had one or two of the bundles not break the tape.
To me the tape is a means of energy management. Some of the energy from the ejection charge gets dissipated in breaking the tape.
So the number of bundles that break will depend on the amount of charge. I do tend to put a little extra powder in, leaning towards the blow it up or blow it out crowd.
 

watermelonman

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Do most of you use the technique of Z-folding your harness (shock-cord) then wrapping with small lengths of masking tape?
I like the idea, plus giving some ability to absorb power to kevlar seems like a great plan.

I have never done it myself, though, as I typically cram the cord in at the last second while rushed for time before launch.
 

Coop

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Sorry, I don't have photos right now of one I've done--however, if you take the basic idea that Over The Top posted, delete the center-bundle part, and replace the tape with rubber bands, that's about it. Tape can leave residue, which I don't like touching, and I don't figure having a soot/dirt attractor on the cord is a swell idea, either. It may make zero difference in the long run (I have no data), but regardless, I prefer the rubber bands.

Later!

--Coop
 

manixFan

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As a cautionary tale on using tape to secure things:

http://www.moonrace2001.org/n1_launch.shtml

Read through to the recovery section and you'll find the chutes failed to inflate fully due to too much masking tape holding them together.

I like the rubber band method but have used blue tape without much residue. With either method the separation charge should be strong enough to fully extend everything to make sure the chute is free and clear to inflate.


Tony
 

timbucktoo

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Read through to the recovery section and you'll find the chutes failed to inflate fully due to too much masking tape holding them together.

Tony
Why did they tape the shroud lines? That sounds like disaster waiting to happen!
 

manixFan

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Why did they tape the shroud lines? That sounds like disaster waiting to happen!
Well they didn't have to wait long! It's pretty painful to watch the video but it mostly survived.

I think I read that the taped the shroud lines to keep them organized but intended to remove or cut the tape before launch. Based on this and other examples, I try to never do anything that requires me to undo it later to have a successful launch. Learned to live within my organizational limitations.


Tony
 

Handeman

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Well they didn't have to wait long! It's pretty painful to watch the video but it mostly survived.

I think I read that the taped the shroud lines to keep them organized but intended to remove or cut the tape before launch. Based on this and other examples, I try to never do anything that requires me to undo it later to have a successful launch. Learned to live within my organizational limitations.


Tony
+5 on that. I never seem to remember to "undo" what I've done pre-launch. I'm with you, I never do anything that needs to be undone.
 

G_T

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http://www.rocketryforum.com/showthread.php?37382-Sprite-6-quot-and-a-baby-O/page4

I show how I packed the laundary for my 6" rocket starting at post 92 on that page. I never did take pictures of how it was organized in the airframe. Sorry about that. Perhaps people will find some useful ideas here. The system I used was very consistent and reliable. I opened fairly low, on a fast descent under drogue - up to around 110fps with main deployment set at 700' AGL. It was stable and slow by about 500', every time. No tangles, no fuss. Pad weight was around 83# when loaded with the small O motor.

Gerald
 

Onebadhawk

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I dun get it...
Why in the world would you tape a chutes shroud lines ?????

Teddy
 

NickAdams

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I took teddy's suggestion on the rubber bands since I got tired of dinging all the bits of tape left on the harness and TK seams to pull the threads away from each other when ripping the tape off.

My kids have the little rubber band bracket loom.... And for some reason Dad stole and entire pack of the little rubber bands huh

View attachment 302891
 

Onebadhawk

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I took teddy's suggestion on the rubber bands since I got tired of dinging all the bits of tape left on the harness and TK seams to pull the threads away from each other when ripping the tape off.

My kids have the little rubber band bracket loom.... And for some reason Dad stole and entire pack of the little rubber bands huh

View attachment 302891
Man is that a nice harness set up,,, lol...

I use 1 rubberband per bundle Nick...
On the back side of the bundle, if that makes sense...
So that it's held together while you pack and in flight but pops off at the first bit of tension...

Teddy
 

NickAdams

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Man is that a nice harness set up,,, lol...

I use 1 rubberband per bundle Nick...
On the back side of the bundle, if that makes sense...
So that it's held together while you pack and in flight but pops off at the first bit of tension...

Teddy
Hi Teddy;
Yes, a fine harness!
If I use one band then the harness doesn't stay perfectly inline - and I'm using lots o BP on this one.
Can u explain or have a pick on what you mean from the backside? I'm getting ready to test ejection charges again today
 

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