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Who has used the Jolly Logic Chute Release in a “Dual Event” type configuration...

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jahall4

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...where the “drogue” and main comes out of the tube at apogee, but the main is released at altitude using the JLCR? Note that the drogue and main would be on the same harness.

IOW typical JLCR configuration, BUT add the drogue deployment at apogee. There was a mention of this in a previous thread, but no details on what might work best regarding the configuration of the 2 chutes along the single harness.
 

jahall4

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I have had similar thought process. I am definitely not anywhere near an expert but I think that you would find issues with perfect a apogee drogue event. I haven't flown as much HpR over MpR but from what my MpR knowledge tells me, you would have a difficult time zeroing in apogee on a motor eject delay. If nothing else you would have to modify the motor with a longer delay depending on altitude you are intending on reaching.
Who said anything about motor ejection?
 

Cl(VII)

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I have flown it like you describe with altimeter eject at apogee, and chute release for main. I've gone drogueless at apogee, large streamer at apogee and small chute at apogee in this configuration. I recently flew my 54 Mongoose to 14k', separated at apogee under RRC3 control (drogue less in this case) and let the chute release handle the main deploy at 800'.

The drogue (when there was one) was on the same harness as the chute release. The only problem I had one one such flight was when the shock cord twisted up and bound the chute bundle because I forgot the swivel on the shock cord. I have found the cord is less twisted when I put a swivel at both ends when I go drogueless.

I should add that I always make sure the chutes are farther apart on the cord than the sum of their shroud line lengths.
 
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Exactimator

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I've never tried it, but it seems that setup would have a high chance of tangling the chutes.
 

jahall4

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The drogue (when there was one) was on the same harness as the chute release. The only problem I had one one such flight was when the shock cord twisted up and bound the chute bundle because I forgot the swivel on the shock cord. I have found the cord is less twisted when I put a swivel at both ends when I go drogueless. I should add that I always make sure the chutes are farther apart on the cord than the sum of their shroud line lengths.
Where did you position the "drogue" chute/steamer, between the nose and the main OR between the main and the tail?
 

Cl(VII)

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Where did you position the "drogue" chute/steamer, between the nose and the main OR between the main and the tail?
The rockets I use this in break at the electronics bay, so the payload tube goes with the NC. I put the drogue near the NC/payload end, and the main as close to that as I can keeping the chute line lengths in mind. The total cord length gets decided by making sure that the position of the main keeps the payload section from being able to hit the aft section when the main deploys. This necessitates long shock cords...I use about a 15' cord on a 3' chute to allow for all this.
 

jahall4

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The rockets I use this in break at the electronics bay, so the payload tube goes with the NC. I put the drogue near the NC/payload end, and the main as close to that as I can keeping the chute line lengths in mind. The total cord length gets decided by making sure that the position of the main keeps the payload section from being able to hit the aft section when the main deploys. This necessitates long shock cords...I use about a 15' cord on a 3' chute to allow for all this.
...so 2 sections (front and rear) the drogue exits the tube first because of its position on the harness, correct?

and how is the position of the main going ensure the nose/payload does not hit the aft section during main deploy? Are you explaining that the nose and the drogue "fall" past main as it deploys but the harness length between the nose/payload and the main is shorter than the length from the main to the tail/aftlike this:

N-------D------M-----------------T
 

Cl(VII)

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...so 2 sections (front and rear) the drogue exits the tube first because of its position on the harness, correct?

and how is the position of the main going ensure the nose/payload does not hit the aft section during main deploy? Are you explaining that the nose and the drogue "fall" past main as it deploys but the harness length between the nose/payload and the main is shorter than the length from the main to the tail/aftlike this:

N-------D------M-----------------T
That is how I set it up. I generally use smaller drogue chutes, so the two halves are roughly level, the drogue is rarely more than a foot or two above the body parts. This keeps the main from being drastically below either section, so I think the chances of parts falling through the main chute is low, but admittedly there.
 

dford

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Who said anything about motor ejection?
The way it is described would call for motor eject or else the idea of using altimeter eject may as well be the sole reason for both events. I assumed you were using motor eject because why else would you put an altimeter event in for apogee, then hope cords stay mess free and continue with a drogue and main anyway? I guess I got lost in my own thinking.
The only reason you would single altimeter deploy at apogee then use chute release would be to get rid of the main altimeter deploy event which means you've only eliminated one event.
But without an event at apogee doesn't that mean you are headed for failure all together at that point? At least dual deploy gives you two chances to get it right.
Best hope the apogee event occurs as planned and the cords don't tangle. Otherwise it has basically become a more expensive loss in my mind.

This is coming from someone without DD knowledge. I'm theoretically speaking thinking out loud about the odds events and what would and could go wrong.
 

jahall4

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... the drogue is rarely more than a foot or two above the body parts. This keeps the main from being drastically below either section, so I think the chances of parts falling through the main chute is low, but admittedly there.
Not quite sure what/when you are describing, but its good to have some corroboration about the configuration. Thank You.
 

jahall4

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The way it is described would call for motor eject or else the idea of using altimeter eject may as well be the sole reason for both events. I assumed you were using motor eject because why else would you put an altimeter event in for apogee, then hope cords stay mess free and continue with a drogue and main anyway? I guess I got lost in my own thinking.
The only reason you would single altimeter deploy at apogee then use chute release would be to get rid of the main altimeter deploy event which means you've only eliminated one event.
But without an event at apogee doesn't that mean you are headed for failure all together at that point? At least dual deploy gives you two chances to get it right.
Best hope the apogee event occurs as planned and the cords don't tangle. Otherwise it has basically become a more expensive loss in my mind.

This is coming from someone without DD knowledge. I'm theoretically speaking thinking out loud about the odds events and what would and could go wrong.
I think you are overthinking this :)

I'll explain some... How we are getting the apogee event (event #1) is not relevant to the question about the chute release (event #2) and location of the chutes, but in my specific case apogee event occurs because electronics fire an ejection charge at apogee. The 2nd event which occurs "at altitude" is a electronics too namely the JLCR, which can simply release the chute since it is already in the air stream. My question was about where best to put the chutes along the single recovery harness and in which order.

Now why make things more complex? Drogues (streamer or chute) typically accomplish at least a couple of things that are desirable: 1) visibility and 2) control... and really a 3rd speed reduction, which also adds an element of safety (although not much) in case the main fails. At least you have something slowing the decent and now visibility becomes paramount as you can't avoid what you can not see.

I'll post some pictures later of how we are testing this today in a MPR.
 

Cl(VII)

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Not quite sure what/when you are describing, but its good to have some corroboration about the configuration. Thank You.
The size drogue I use doesn't slow the parts down enough for them to be hanging straight below it. More it just keeps any part from trying to get stable and dragging the rest along at increased speed. Therefore, the two halves of the rocket tend to be almost parallel to one another during fall. The cord is usually only bowed up toward the drogue chute, not always full taught. I aim for about 35-50 fps under drogue depending on materials used.
 

jahall4

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The size drogue I use doesn't slow the parts down enough for them to be hanging straight below it. More it just keeps any part from trying to get stable and dragging the rest along at increased speed. Therefore, the two halves of the rocket tend to be almost parallel to one another during fall. The cord is usually only bowed up toward the drogue chute, not always full taught. I aim for about 35-50 fps under drogue depending on materials used.
That's what I thought, just while under drogue it "is rarely more than a foot or two above the body parts", but just wanted to be sure. Thx!
 

jahall4

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I would probably use a 12-15" drogue for a 36" main, but same idea.
Those chute measurement are height, not width.

Here is a "nose down" configuration. The harness length comes out to be about the same maybe has to be a little longer.

2016-09-13_10-18-03.jpg
 

AlfaBrewer

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I flew a stubby 7.5" diameter rocket (think Warlock) at AirFEST with a drogue chute (24") and JLCR on the main (7ft Rocketman) using an altimeter at apogee. The drogue was closer to the airframe and the main was near the nose. I didn't have any issues with deployments.
 

AlfaBrewer

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Those chute measurement are height, not width.

Here is a "nose down" configuration. The harness length comes out to be about the same maybe has to be a little longer.

View attachment 301438
I wouldn't recommend having the nose below the fin can. There's no reason to have a decent sized chunk of plastic flopping around to bang up the fins.

I typically have the recovery train as (top to bottom) main-nose-av bay-drogue-fincan.
 

SCrocketfan

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Is this what you are describing...

View attachment 301437
This definitely works well with motor deploy or electronics-as CLVII said be a bit careful with NC placement though. I have flown (motor deploy in this case but would work the same with electronics) with the NC below the booster after main deploy, worked just fine, but nose above fincan may be better, as it can help prevent tangling as mentioned.
P1100925.jpg
 
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jahall4

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This definitely works well with motor deploy or electronics-as CLVII said be a bit careful with NC placement though. I have flown (motor deploy in this case but would work the same with electronics) with the NC below the booster after main deploy, worked just fine, but nose above fincan may be better, as it can help prevent tangling as mentioned.
View attachment 301442
As long as one does not drop past the other when the Main deploys the possibility of tangling (or not) is the same. Your nose down picture is not the same as my nose down drawing, note the position of the drogue. In the nose down configuration I have illustrated the nose gets farther away from the tail during deployment of the main.
 

SCrocketfan

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As long as one does not drop past the other when the Main deploys the possibility of tangling (or not) is the same. Your nose down picture is not the same as my nose down drawing, note the position of the drogue. In the nose down configuration I have illustrated the nose gets farther away from the tail during deployment of the main.
Thanks-that makes sense and definitely a bit less prone to tangling than the way I set it up with the nose above the fincan on drogue and letting it drop below on main. I would worry a bit about the booster floating sideways a bit (could tangle) with a small drogue in your configuration, but otherwise it seems like a safe system. One thing I've done is experiment with different drogue sizes-an 18" or 12" on a 40oz rocket specifically. The 18" is visibly more stable but the 12" is faster and generally works well too.
 

woferry

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I've flown that way, I don't think it's terribly uncommon. Madcow 4" FG Nike Smoke, ~6.5 lbs pad weight, had my drogue attached to the nose cone U-bolt, and a Chute Release-tethered main about 1/4 down the line (two separate chute protectors). I have a video of the first flight here, I was having some trouble with screen glare and the clouds and just missed apogee event but the Chute Release event was in-frame.

The particular flight in the video (and my second one that I basically lost at apogee so I don't have a good video for that one's descent) was motor-eject, but my ultimate plan is to use electronic eject (ET TRS in the nose) for the separation, because (1) I've just had too many problems with very early/late motor ejections that I don't trust them, and (2) I plan to fly motors that have known issues with or don't support motor eject, like CTI VMax motors or plugged motors. My reason for using the Chute Release is because this rocket isn't designed for DD, it has a single separation point so I'd have to go with some sort of tether to do a mid-descent main deployment, and Chute Release looked a lot easier/better than the other options that involve slicing or melting zip ties or the like (I had previously tried making my own hot-wire zip-tie cutter based on a thread here and had nothing but trouble getting a clean break of the zip tie, I had given up on this before the Chute Release came along). This rocket should fly again this weekend at XPRS, not certain if I'll be fully set up for electronic deployment by then or if I'll do one more motor eject. My biggest issue still to sort out was with the safing of the charge, I had originally planned to use a pair of magnetic switches but getting them close to the NC edge was proving to be tricky (base is much wider than my opening, and the part of the NC that is as wide as the opening is a long distance away from the base), I'll probably end up just leaving the TRS electronics powered and using a WiFi Switch for its deployment battery, that way it can be deep within the nose and I can still safely arm it on the pad.
 
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AlfaBrewer

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How would it be flopping around the fins if it is hanging below them?
Flopping around the fins may not have been the best description, but the nose has to get past the fin can to hang below it, right?

I actually had a rocket set up similar to this whack the nose into a fin as the parts settled in under the main. The big difference was that I wasn't using DD or a chute release. Adding those steps may provide enough part orientation/separation to prevent the parts from knocking together. Just wanted to make sure you recognized there was a potential failure mode there.
 

jahall4

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... but the nose has to get past the fin can to hang below it, right?
Nope, Not any more so than the fin can falling past the nose. Take a look at the 2nd illustration I posted, you'll note that under drogue AND main the nose is beneath the tail. A nose down configuration is really just a reversal of the traditional tail down config. Keep in mind that the recovery process starts (hopefully :wink:) when the rocket is more or less horizontal. So as the drogue starts to vertical-ize the rocket parts the nose swings down under the tail the same way the tail would swing down under the nose. The chance of them hitting as they swing into position is the same.
 

jahall4

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I've flown that way, I don't think it's terribly uncommon. Madcow 4" FG Nike Smoke, ~6.5 lbs pad weight, had my drogue attached to the nose cone U-bolt, and a Chute Release-tethered main about 1/4 down the line (two separate chute protectors). I have a video of the first flight here, I was having some trouble with screen glare and the clouds and just missed apogee event but the Chute Release event was in-frame.

The particular flight in the video (and my second one that I basically lost at apogee so I don't have a good video for that one's descent) was motor-eject, but my ultimate plan is to use electronic eject (ET TRS in the nose) for the separation, because (1) I've just had too many problems with very early/late motor ejections that I don't trust them, and (2) I plan to fly motors that have known issues with or don't support motor eject, like CTI VMax motors or plugged motors. My reason for using the Chute Release is because this rocket isn't designed for DD, it has a single separation point so I'd have to go with some sort of tether to do a mid-descent main deployment, and Chute Release looked a lot easier/better than the other options that involve slicing or melting zip ties or the like (I had previously tried making my own hot-wire zip-tie cutter based on a thread here and had nothing but trouble getting a clean break of the zip tie, I had given up on this before the Chute Release came along). This rocket should fly again this weekend at XPRS, not certain if I'll be fully set up for electronic deployment by then or if I'll do one more motor eject. My biggest issue still to sort out was with the safing of the charge, I had originally planned to use a pair of magnetic switches but getting them close to the NC edge was proving to be tricky (base is much wider than my opening, and the part of the NC that is as wide as the opening is a long distance away from the base), I'll probably end up just leaving the TRS electronics powered and using a WiFi Switch for its deployment battery, that way it can be deep within the nose and I can still safely arm it on the pad.

Will, Then you are going to appreciate a project I’m working on where we have worked all that out using a design based on the PML Intellicone. Just today we did a small scale test using motor eject. You can check out our testing and the project here: https://www.facebook.com/TheMarvinWrightRocket/posts/1137235703038099

Also here is a pic of my first Intellicone implementation that so far has worked flawlessly, including NSL this year:

IMG_3334.jpg
 
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AlfaBrewer

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Nope, Not any more so than the fin can falling past the nose.
My experience with having the nose below the fin can showed otherwise. I had an Initiator set up this way for 3 flights, and had the nose hit the fin can on one of those flights. In the dozens of flights with the more traditional set up, I've never observed nose/fin can contact, other than that due to shock cord snap-back.

Again, I only had a main and was using motor eject, so it's not exactly an apples-to-apples comparison. Just something to consider.
 

jahall4

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Yes exactly, if you where using motor eject then there is a very good chance the recovery process was NOT starting more or less horizontal. If you ARE starting horizontally then the nose would swing below the the tail, just as the tail would swing below the nose in a more traditional configuration. They never pass each other per se.
 
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