Landracing Forum
Tech Information => Technical Discussion => Topic started by: tauruck on May 22, 2013, 10:00:37 AM
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I haven't done a search in the build diaries but I'm looking for info on building chute tubes with all the fancy internals like the ones on the liners. Thanks guys.
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A search is well worth it, there are quite a few threads with pertinant info. :cheers:
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Re: Chute Tubes - - -
We're nowhere as sophisticated as you guys, but learned a few things along the way.
First year we found we had to install a longer lead from the chute to the pilot to get it out of the dirty air behind the car. And needed a much bigger pilot to pull it all out. (First time the pilot rested on the bumper, second time it alone came out and trailed behind the car.) Bob Stroud happily upgraded it for us. There was no drama, as stopping a Street Roadster (the old, non-slick kind) is not a problem on the long course at SW.
But the added hardware made packing it a real chore. We later added 3" to the tube and it helped. Shoulda added 2" more.
The point being that it's best to make it too long and allow for spacers in the back that might allow you to add to the package or just adjust 'cause you're putting it in dirty, if you know what I mean.
Stan
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Thanks Stan.
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I need more help on the chute issue. I want to use compressed air as propulsion. I have a crude idea on how I think it should be done but I don't have time to waste on figuring the whole system. Before you know it it's August 2014 and I'n still sitting here.. yada yada!!. Can someone please tell me how to build the system?. I'll be eternally grateful guys. I really appreciate all the advice and heed the warnings. I have no experience on these long cars. Thanks.
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More and more are going to two tubes--one for the chute which just stores the chute and a launching tube for the pilot chute, who's job is to make it into CLEAN air an pull the main out this way it is easier to get something into clean air.
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Thanks Sparky. Do I run a hose from the compressed air tank with an actuator in the cockpit to the pilot chute tube. I was thinking of a piston type deal to eject the pilot.
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Nice Build, good to see you back
+1 on what Sparky said, I'm building mine with 2 tubes per chute.
I did look at a making the small chute tube about 2" and blowing the pilot chute out with compressed air.
Ended up using a spring with a cable release, less to go wrong.
Being a streamliner bike the rules say I need to (and I want to) have auto chute deployment if the bike tilts too much so will have a solenoid pull on the cables as well as manual.
The springs I have will launch the pilot with its tether line about 8m if it's not tied to anything, pilot to main chute bag tether line is about 4m (13') long.
Main chute tether line and bridle has the canopy about 12m (40') behind the anchor point.
Edit : you posted while I was typing
A lot of drag guys use a long/small diameter air ram with a push plate to throw out the main chute.
My main chutes (& everyone running pilot chutes I think) are in a deployment bag so the canopy doesn't start to open until the main tether is at full stretch.
Cheers
jon
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On the Vesco streamliners we use a air ejection pilot system on the 444 car with a long teather to pull the main canopys. The Turbinatio uses a spring / piston ejector for the pilot chutes. both work very well. They also have mechanical releases for over ride required by SCTA rules.
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Thanks Jon and Glen. There are no rules here on chute systems. In fact there is no sanctioned salt racing. I'm hoping my liner will get the ball rolling. The place where I'll be running is so long you could coast to a stop way before you hit anything but we don't want to take that chance. The info you've given will help big time. I really appreciate it.
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Mike, stopping in a hurry is desirable when you are on fire or have other emergencies.
You would be wise to build in line with SCTA rules as DLRA has, not only will it allow you guys to run Bville or Gairdner but it has taken years of experience to get the rules to the point thay are now.
A manual back up on chutes could save your life.
A lot of the failed tube chute issues can be related to not packing it tight enough when there is an integral spring loaded pilot. During a run the pack resets itself in the tube & when you deploy at the end there is not enough pilot spring pressure left to get it into clear air.
6ft is a good length for a bridal line.
Sid.
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Point taken Sid. Thanks. Check your email. :-D
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Worth contacting your supplier
5 min conversation with Stroud had me convinced to run a pilot chute in a separate tube to the main
things like the spring staying in the pilot tube and not banging around on the cable , and also not compacting the main chute with the spring seemed like common sense
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I hear you Maj. Thanks.
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If you have room the main "tube" does not have to be round, it can be larger on the inside and round where it exits the car. We use a spring pilot and one tube on the lakester and the 2 tube setup with a 12 inch stroke air cylinder to push the pilot on the liner. Both work well but the liner is easy to pack.
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Thanks Speed Limit. Do you maybe have pics on the sysem for the liner?. It would help me big time. :-)
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Here are a couple. The tubes follow the frame, getting wider as it gets deeper. I could take some other pics if you need them, there is a big dent currently in the top tube....
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Thanks stainless. That really helps.
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My chute tubes taper slightly the other way smaller at the front than the back.
Partly to help get tyre clearance, partly thinking the deployment bag will come out easier.
Thanks for the pics Stainless, would I be able to get a pic of your chute retain/release mechanism on you pilots please?
Thanks
jon
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Jon, the first picture shows that part. The top tube was the manual release chute, spring pilot, the bungee was clipped in by the release cable. The other chutes were retained by the bungees you see, clipped over the posts. a single bungee held the chute and pilot. The pilots were pneumatically ejected, so when it fired, the bungee was popped off the retaining post and the chute deploys.
Let me know if you need a close up. The remains are in the trailer. :|
:cheers:
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Thanks Stainless
Very glad your ok.
Thanks
jon
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My lakester (bought complete less engine) doesn't have a chute tube, and last ran legally (ECTA) in 2009. Have rules changed to now require a chute tube? (I only have a 2010 rulebook).
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Jack, requirements based on speed of standing record.
chute required above 175 IIRC
:cheers:
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My lakester (bought complete less engine) doesn't have a chute tube, and last ran legally (ECTA) in 2009. Have rules changed to now require a chute tube? (I only have a 2010 rulebook).
If you are required to run a chute, you can use a tube, a traditional pack or hatch like Goggles and others have.
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... a traditional pack...
Thanks.