Jolly Logic Chute Release tips and technique

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
This is a great thread.

...and so far, no issues (except getting that larger band thru the %^&*% small opening in the JLCR unit!)

The easiest way to get any rubber band through that small hole is to get a piece of string (or a tether, or dental floss), put it through the hole then through the loop of the band, then back through the CR hole. Use the string to pull the band through the mounting hole.
 
I love my Chute Release. I have about 10-12 flights on mine, and have never had a deployment issue. I always test it before each launch, and somehow I've remembered to turn it on every time! I attach mine to the nosecone. I also attach my chute to the nosecone. I make sure it's packed in a way that that when I pull on the packed chute, the chute release cord get tension on it before the parachute shroud lines. That way when it's free falling, the only thing with tension on it is the chute release itself, and not the shroud lines, so the chute isn't trying to pull itself out on the way down.
 
This is a great thread.

The easiest way to get any rubber band through that small hole is to get a piece of string (or a tether, or dental floss), put it through the hole then through the loop of the band, then back through the CR hole. Use the string to pull the band through the mounting hole.

And that's why you sit in the big comfy chair!! thanks John, great bit of advice! (and will now add a small length of string to my field box..)
 
And now we know that the JLCR also promotes good oral hygiene :)
 
Talcum powder on the new rubber band helps substantially on getting it through the tether point.
 
HAHA, I'm starting to think anyone not in the know will start to thing of us Rocketeers as big babies, or at least as baby owners..

Baby Wipes in the our launch box (to clean motor cases & hands)
Baby Powder, to fluff parachutes & ease rubber band insertion
Dental Floss, to help with above
Baby Blankets, to wrap our beloved birds form getting banged up in the car / on long trips
Baby booties to be used as small deployment bags..


:D :D
 
Love my JLCR, although the rubber bands and tether have been weak points for me. The former has created some "main at apogee" events, and the latter caused me to lose my first JLCR. So I'd recommend beefing them up - sewing elastic seems to be much more durable than the supplied rubber bands, which have, for me anyway, tended to fail after 1 or 2 flights (or even when I try to tie them on the first time!). Also has the advantage of being more length customizable, to really dial in the tension. For the tether, I'm swapping out a longer length of heavier Kevlar - with the supplied tether, it seems critical to be triply sure the tether will never be under tension. Pretty sure my JLCR loss came when the tether, which was too far down the shroud lines, took a big shock when deployment occurred at a relatively high velocity.

Only other issue I've had is some slow/non-opening chutes in certain circumstances (the JLCR always functioned), mostly light rockets with big fins that aren't falling very fast. So be careful not to oversize your drogue (if any) and if it falls slow even drogueless, add some altitude on your JLCR setting. Takes time to inflate a big chute at low velocity!
 
I just had my first experience with the Chute Release at NEFAR's Bunnell Blast last Sunday. I launched "Bracha's Mosquito" on an Aerotech J250W DMS motor. I used the Chute Release on a Top Flight 84"parachute.












[video=youtube;7sA8GMlxwQU]https://www.youtube.com/watch?v=7sA8GMlxwQU[/video]​

The Chute Release worked well and I caught a good video of it deploying the parachute. I did make the mistake of setting the deploy altitude too low, but the chute did open in time. And, the rocket landed close to use and not far from the launch pads. Unfortunately, it decided to take a trip across the field after landing!

-- Roger
 
That was not a too-late release, you had 5 full seconds! Looks like you had plenty of distance and time to slow down - but the footage of the wind dragging your chute/rocket across the field is priceless! Nice rocket and nice flight :)
 
That was not a too-late release, you had 5 full seconds!

Well it had me holding my breath for a couple of seconds. :)

Our LCO stopped the launches so that someone could run out and stop the runaway rocket. It was blowing away from me faster than I can run, so I didn't go after it. I was afraid that "Yakity Sax" would play over the PA as I ran like Benny Hill after it. A different, younger, Roger, starting from the other end of the flight line, ran out and caught it.

-- Roger (the older, slower one)
 
That rocket taking off after landing looked like a scared jellyfish swimming for its life! Classic!! [emoji16][emoji1303][emoji12]


Sent from my iPhone using Tapatalk Pro
 
I took a different path then DDSrocdoc on seeing what I could do differently with a chute release. I used two rocket builds for this experiment. A 3 inch MAC rayzor, and a Madcow Adventurer 3. One canvas phenolic and the other fiberglass. Both 3 inch rockets.

With only one parachute, either the booster section or the payload bay would be empty. I decided to put the main chute in the booster section. That gave me the option of using motor eject as a backup if available. So now the payload bay was empty! What if we move all the electronics out of the AVbay coupler and into the payload bay? So I built a payload bay cage. I had (plenty of) room to include a tracker in the cage with an altimeter. The cage is made out of wood so it won't effect the tracker. And the cage fits in the payload bay of both rockets!

The AV bay coupler is now empty except for the wires running through it to connect the altimeter to a charge well.

Installing the cage in the payload bay gave me pause. I didn't want to have to align screw holes in both rockets payload bay tubes with the cage. I took inspiration from an Aerotech reload adapter system. Use spacers. Amazon sells pool noodles and physical therapy foam tubes in 3, 3.5, and 4 inch diameters. I ordered several to try out. After some testing, I ended up with foam spacers to fit the cage into payload bay of both rockets. The foam is dense and the fit is very tight. Also, I used an Eggtimer Quantum so I don't need an external switch to turn anything on. The tracker is a teleGPS by Altus Metrum.

Here is the layout of how the cage fits into the MAC rayzor payload bay.
AV-bay coupler | blue foam spacer | cage | black foam spacer | nosecone.


View attachment 330569

I put a shelf in the nose cone, so the black foam spacer sits against the top of the cage and the shelf in the nose cone.

I can fly the Rayzor, pull the cage out, slide it into the Adventurer, and it's ready to fly. Modular electronics. Thanks to the chute release and a wifi altimeter, I'm able to burn through motors faster then ever. $$$ :facepalm:$$$

What a great idea, patent it, sell it! Something I will incorporate in future builds.
I'm planning a single airframe/NC 3" minimum diameter bird for Balls 2018. Fly on CTI M840. My plan is to eject both streamer and Dbag at apogee (Dbag first, the extra weight will pull out the streamer then use the JLCR for the main). Will probably tether the Dbag to the main harness at the ebay connection. GPS in NC. Beacon tracker attached to main harness. Expected alt 35K.
Thanks for sharing.
Dave Porter
TRA 12341 L3
 
Other than forgetting to turn it back on after you test it, chute rigging is what makes it reliably deploy the chute. There was a discussion a while back about this and I summarized and wrote up the best of it (posts from Cameron Anderson) in the attachment. I had several failures prior, but since I have followed it have had a string of only successes.
 

Attachments

  • Chute Rigging for Chute Release.pdf
    723 KB · Views: 43
Back
Top