Author Topic: Parachute Tubes.....  (Read 11988 times)

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Offline Chaz

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Parachute Tubes.....
« on: January 07, 2008, 10:55:32 AM »
I've never seen it done, but has anyone here used PVC for their parachute tubes?  It seems to me to have some advantages. Slippery, lightweight , and inexpensive.
 Would there be any problem rulewise?

Offline Glen

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Re: Parachute Tubes.....
« Reply #1 on: January 07, 2008, 12:26:16 PM »
I have seen plastic tubes but I think they are weak and crack pretty easy. Alum is better and can be welded on for mounting brackets etc. Plastic is not good around heat or fire. I would submit your idea to the tech committee for their input.
Glen
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Offline JackD

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Re: Parachute Tubes.....
« Reply #2 on: January 07, 2008, 08:25:36 PM »
Water main plastic tubing is easily available and in common use.
It can be drilled, bolted in a number of ways, and is very tough.
Usually tougher than the skin of the racer. :wink:
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Offline hitz

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Re: Parachute Tubes.....
« Reply #3 on: January 08, 2008, 01:13:47 AM »
  These look pretty good!

Offline Richard Thomason

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Re: Parachute Tubes.....
« Reply #4 on: January 08, 2008, 02:54:40 PM »
Just don't use as a push point. Other than that, pvc works great

Offline Loose Goose-Terry#1

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Re: Parachute Tubes.....
« Reply #5 on: January 27, 2008, 02:32:55 PM »
 :-D What diameter and what length would be recommended for about a 1500lb ride and something around 200mph + ?  :?
Sorry if this might be a little redundent, I've been away on business and wasn't able to get to the computer.  :-) Thanks for putting up with me.
Terry
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Offline Sumner

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Re: Parachute Tubes.....
« Reply #6 on: January 27, 2008, 09:17:09 PM »
:-D What diameter and what length would be recommended for about a 1500lb ride and something around 200mph + ?  :?
Sorry if this might be a little redundant, I've been away on business and wasn't able to get to the computer.  :-) Thanks for putting up with me.
Terry

Bob Stroud ( http://www.stroudsafety.com/  ) told me that if I put in 6 inch by 36 inch tubes I would be covered for about anything I would ever want.  Tom Burkland said while I was at it put in two tubes and also be covered for about any situation.  Since I respect both of these guys that's what I did.............



( http://purplesagetradingpost.com/sumner/bvillecar-2/construction%20page-80.html   )   

........................... so there is something to chew on,

Sum

Offline Stan Back

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Re: Parachute Tubes.....
« Reply #7 on: January 30, 2008, 11:59:25 AM »
We make our tube 30x6.  Seemed fine at the time -- even put a roll of duct tape down in the back to take up the slack.  When the chute gets dirty or salty, take the tape out.  (Yes, I know you're supposed to wash it every run.)

After Stroud made us a longer lead from the pilot to the chute, and a much larger pilot because of the dead air behind the roadster, it's a bear to get it all in clean.  36'' would probably be a good idea -- you can always fill in the void as we did.
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Offline Loose Goose-Terry#1

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Re: Parachute Tubes.....
« Reply #8 on: February 02, 2008, 07:34:53 PM »
Hi Sum,

Thanks for the picture. Your chute tubes look kind of high. Does that have any effect on deployment? Where are you going to attach the chute line to your LSR?

Thanks,

Terry
If I had it all to do over again...I would!

Offline SPARKY

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Re: Parachute Tubes.....
« Reply #9 on: February 02, 2008, 09:15:51 PM »
chutes don't much care where they ride---but Bob, TECH & you sure need to care where and how you tether and deploy them--- :-D
Miss LIBERTY,  changing T.K.I.  to noise, dust, rust, BLUE HATS & hopefully not scrap!!

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Offline Sumner

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Re: Parachute Tubes.....
« Reply #10 on: February 02, 2008, 09:25:09 PM »
Hi Sum,

Thanks for the picture. Your chute tubes look kind of high. Does that have any effect on deployment? Where are you going to attach the chute line to your LSR?

Thanks,

Terry



The attach point is somewhat adjustable vertically.  More about how the attach points were made here:

http://purplesagetradingpost.com/sumner/bvillecar-2/construction%20page-92.html

c ya,

Sum   

Offline interested bystander

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Re: Parachute Tubes.....
« Reply #11 on: February 02, 2008, 10:57:32 PM »
Nice work on the "spools" for the 'chute anchors, Sum.

There's a sore point with me on the wording regards parachute mounting in the rulebook that IMHOP is REALLY ambiguous and I've been told, even though a change was suggested, that it WONT be changed in the '08 version.

3.M PARACHUTE

". . .Parachutes must be securely mounted to a suitable crossmember."

And that means the shroud lines, the anchorages, the 'chute packs or WHAT?

I brag all the time about the excellent definitions put forth by the SCTA rules, especially compared to the NHRA rulebook, but I think we have a failure to explain here.

DW?
5 mph in pit area (clothed)

Offline Stainless1

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Re: Parachute Tubes.....
« Reply #12 on: February 03, 2008, 11:41:42 AM »
There's a sore point with me on the wording regards parachute mounting in the rulebook that IMHOP is REALLY ambiguous and I've been told, even though a change was suggested, that it WONT be changed in the '08 version.

3.M PARACHUTE

". . .Parachutes must be securely mounted to a suitable crossmember."

And that means the shroud lines, the anchorages, the 'chute packs or WHAT?

IB, what was the rule change you submitted?  Which part did you think needed more explanation or control?
Stainless
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Offline Howard

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Re: Parachute Tubes.....
« Reply #13 on: February 03, 2008, 12:11:59 PM »
 8-)For whatever it's worth, let me share what Jim Deist told me. My only experience on the salt is with liners so take that into account. His advise worked very well for me.
Try to find the cg of your car. ( I balanced mine fore and aft with a large wooden beam across the frame rails). The vertical point is usually about the camshaft on a V engine. Attach a string to that point on the side of the car and walk back the length of the tow line plus the chute and hold the string at arms reach over your head. Where that string intersects the rear of the car is where the chute attachment point should be.
 It not only makes sense when you think about it but it works. When the chute hits it does not upset the car at all, It just puts your eyeballs against the helmet visor.
Howard

Offline tomsmith

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Re: Parachute deployment
« Reply #14 on: February 03, 2008, 12:46:39 PM »
I am just curious and don't have any answers, but does anyone care about disreefing speeds?  Back in the last century when I did data processing for USAF parachute testing in El Centro, I saw chutes that opened in a controlled fashion (initially looking sort of like a tube) in order to minimize the Gs on the chute and tether lines.  If you deploy a chute when going fast (supersonic for example) you don't want it to open all at once or it won't be attached to the vehicle for long.  I once saw a drag chute deployed by a F106 that was in a flat spin - it just wrapped around the vertical stab and the pilot ejected, but that is off subject.  Maybe it is not practical or costs too much or is too complicated for cars or something.  Anyone got any theories?
139mph with no bike, but with speedo and helmet.