MAC Performance Rayzor Ballistic Return To Earth

[Jozef]

Flew my MAC Performance Rayzor on an Aerotech J350 Sunday at URRF4. The "Up" part of the flight was perfect and in the exact direction I wanted for wind drift. Unfortunately, the drogue section did not fire. The rocket came in ballistic. The main deployed at 80O feet and we saw the chute tear away from the harness. Though the airframe core sampled 18 inches of hard Upstate NY soil, the booster section was without a scratch. The electronics surrvived as well. A testament to the toughness of MAC Performance airframes. Post launch analysis provide the drogue E-match was faulty and failed the OHM meter check. Going forward I will test each E-match before it is installed

 

[crossfire]

That's why I like to use the motor ejection for back up. At least the rocket separates.

 

[mpitfield]

Hi Joe,

That is too bad, but from what I saw, remarkably, it won't take much for you to rebuild her. BTW your rockets are very well put together and the paint is fantastic...nice job!

I didn't mention to you but I had a similar looking e-match fail, on the bench, a few years ago. Beyond motor eject backup, my answer at that time was to use 2 e-matches per channel, however I moved away from that out of fear of overloading and blowing a channel on my StratoLogger. I like the StratoLoggers but my one complaint would be they don't have the same level of circuit protection as more recently revised altimeters. So you have to be careful on your LiPo choices and in cases like this I chose to stay away from dual e-matches.

 

[Jozef]

Hi Joe,

That is too bad, but from what I saw, remarkably, it won't take much for you to rebuild her. BTW your rockets are very well put together and the paint is fantastic...nice job!

I didn't mention to you but I had a similar looking e-match fail, on the bench, a few years ago. Beyond motor eject backup, my answer at that time was to use 2 e-matches per channel, however I moved away from that out of fear of overloading and blowing a channel on my StratoLogger. I like the StratoLoggers but my one complaint would be they don't have the same level of circuit protection as more recently revised altimeters. So you have to be careful on your LiPo choices and in cases like this I chose to stay away from dual e-matches.

thanks for the comments and suggestions regarding my flight. MAC Performance is already preparing replacement nosecone and payload section for the rebuild. I have the paint from the build and will get vinyl from Mark. It will fly at Air Fest for sure. I use the Missileworks RRC3 in this rocket and have confidence in its function. However, I don't understand why the system will beep continuity with a break in one of the two circuits. Ill have to look into my simulations to see if motor eject would works as backup from a timing standpoint. Appreciate the comments on my build. Was hoping to see your Black Fly ion the pad this weekend.

 

[DavidMcCann]

I've had a few match failures recently. luckily a couple were in testing on the ground, but I still had one fail in the air, a main "luckily".

I'm now running everything possible on 4 channel altimeters.

 

[calambert]

The booster looks like it has yet to fly. Should be a simple fix. I put my new MAC Performance Villain up for the first time over the weekend. Great flight to a bit 4700 ft on an AT J450 Dark Matter.

 

[Oberon]

Sad to see such a good looking bird dinged up, but glad to hear she'll fly again.

I know the Eggtimer Quantum has a failsafe feature that can blow the main immediately if it detects you're coming in ballistic - do any other altimeters out there have a similar feature? I've been flying without this till I get a better feel for speed under drogue, but having seen a few of these drogue deployment failures, I think I'll start enabling it by default.

Anyone out there have a "successful" failed recovery using this feature?

 

[cwbullet]

That's why I like to use the motor ejection for back up. At least the rocket separates.

Ditto

 

[Jozef]

I've had a few match failures recently. luckily a couple were in testing on the ground, but I still had one fail in the air, a main "luckily".

I'm now running everything possible on 4 channel altimeters.

Dave...what is a 4 channel altimeter?

 

[Jozef]

Sad to see such a good looking bird dinged up, but glad to hear she'll fly again.

I know the Eggtimer Quantum has a failsafe feature that can blow the main immediately if it detects you're coming in ballistic - do any other altimeters out there have a similar feature? I've been flying without this till I get a better feel for speed under drogue, but having seen a few of these drogue deployment failures, I think I'll start enabling it by default.

Anyone out there have a "successful" failed recovery using this feature?

Seems like a great feature, however would not have helped in this case as the E-match was the failure, not the altimeter.

 

[Jozef]

The booster looks like it has yet to fly. Should be a simple fix. I put my new MAC Performance Villain up for the first time over the weekend. Great flight to a bit 4700 ft on an AT J450 Dark Matter.

I watched your flight up, Craig. Looked great. Where did it land? I ran out if time Sunday to fly my Villain... wanted to take it apart and check the e-matches before the maiden.

 

[tim cubbedge]

what is a 4 channel altimeter?

Any altimeter with at least 4 pyro channels. MARSA54, EasyMega & TeleMega to name a few. I think Raven also qualifies.

EasyMega

MARSA54

 

[boatgeek]

Seems like a great feature, however would not have helped in this case as the E-match was the failure, not the altimeter.

The Quantum's failsafe doesn't try again on the drogue chute, it blows the main. Since your main deployed properly at 800 feet, it should have worked, just a lot higher. Longer walk, but less repair work, hopefully. I haven't had the opportunity to test the feature yet, thank goodness.

 

[Jozef]

The Quantum's failsafe doesn't try again on the drogue chute, it blows the main. Since your main deployed properly at 800 feet, it should have worked, just a lot higher. Longer walk, but less repair work, hopefully. I haven't had the opportunity to test the feature yet, thank goodness.

Thanks for the clarification....

 

[cerving]

The Quantum's failsafe doesn't try again on the drogue chute, it blows the main. Since your main deployed properly at 800 feet, it should have worked, just a lot higher. Longer walk, but less repair work, hopefully. I haven't had the opportunity to test the feature yet, thank goodness.

I've done it intentionally a few times during software testing, of course, but I've also had it save one of my rockets. I didn't know that it had until after I got it back... I thought the shear pins just shook loose or something. It's a nice feature... I wish I had the code space to put it in the Eggtimer Classic and the TRS, too.

 

[DavidMcCann]

Dave...what is a 4 channel altimeter?

4 bang boxes per altimeter set two for apogee, two for main. or, with dual 4 channel altimeters, set 4 for apogee and 4 for main. I put two matches into one pyro charge, but if you want to reduce the chance of a poorly packed charge, you could have a charge set for each match. I wouldn't do that running 4 on each side, as a 4x the powder going off at once (if things didn't stagger) would be epically bad.

 

[Bat-mite]

With my MAC Radial Flyer, I had dual alts and motor backup, and still got no apogee separation. Total destruction.

 

[Buckeye]

Hi Joe,

That is too bad, but from what I saw, remarkably, it won't take much for you to rebuild her. BTW your rockets are very well put together and the paint is fantastic...nice job!

I didn't mention to you but I had a similar looking e-match fail, on the bench, a few years ago. Beyond motor eject backup, my answer at that time was to use 2 e-matches per channel, however I moved away from that out of fear of overloading and blowing a channel on my StratoLogger. I like the StratoLoggers but my one complaint would be they don't have the same level of circuit protection as more recently revised altimeters. So you have to be careful on your LiPo choices and in cases like this I chose to stay away from dual e-matches.

There are a few threads that discuss this using some simple V=IR calculations. If you use a 9V with the SL, then two matches in parallel are just fine. With the 1S and 2S LiPos, you are probably safe with two matches in series. I like the physics on my side, so I now wire all dual charges in series, regardless of battery and altimeter.

 

[MWC]

Joe -

I just talked to you and you hadn't mentioned this "incident"?

I was getting caught up with forum topics this holiday weekend and read through your posts. I'm confused over your mention of "beeping continuity"? The unit should beep accordingly based on simple continuity, but it doesn't know resistance (shorts vs. valid bridgewires). I presume this was your failure mode (a shorted ematch?).

Pre-measuring all ematches with a DVM for nominal resistance is a "must" pre-flight prep step in my regimen of "eliminating unknows" before launch. That way if you're standing next to a lawn darted project your list of unknowns is much smaller.

With regard to redundant events, the RRC3 AUX channel is easily set for a redundant apogee event (apogee trigger + time delay), or if one wanted you could create a post apogee comparator that was AGL or descent velocity based. The downside with a descent velocity based redundant charge would be you'd have an unfired cannister should everything operate up to par and you never reached this failsafe velocity. The downside with AGL based comparators is one needs a good guess on real world performance.

Providing additional AUX output control sequencing is something I have considered in the past, however it's not been a pressing request from the user base.

 

[Jozef]

Joe -

I just talked to you and you hadn't mentioned this "incident"?

I was getting caught up with forum topics this holiday weekend and read through your posts. I'm confused over your mention of "beeping continuity"? The unit should beep accordingly based on simple continuity, but it doesn't know resistance (shorts vs. valid bridgewires). I presume this was your failure mode (a shorted ematch?).

Pre-measuring all ematches with a DVM for nominal resistance is a "must" pre-flight prep step in my regimen of "eliminating unknows" before launch. That way if you're standing next to a lawn darted project your list of unknowns is much smaller.

With regard to redundant events, the RRC3 AUX channel is easily set for a redundant apogee event (apogee trigger + time delay), or if one wanted you could create a post apogee comparator that was AGL or descent velocity based. The downside with a descent velocity based redundant charge would be you'd have an unfired cannister should everything operate up to par and you never reached this failsafe velocity. The downside with AGL based comparators is one needs a good guess on real world performance.

Providing additional AUX output control sequencing is something I have considered in the past, however it's not been a pressing request from the user base.

Jim, I didn't mention this during our conversation regarding your GPS system as I had already concluded that the cause was due to my not detecting a faulty e-macth in advance of the launch and not that of the altimeter. My initial post regarding "beeping continuity" was my misunderstanding of what that system was telling me. I will follow up with the owners manual regarding use of the AUX channel for a redundant apogee event. My Radio Shack VOM is now in my rocketry tool box.

 

[tfish]

Joe,

Here is a link how I have my Aux channel set up. https://www.rocketryforum.com/showthread.php?124501-Aux-Output

You'll also be listening for a deferent series of beeps when using the Aux channel.

Normal Dual Deploy: Drogue and Main 3 beeps repeating every 5 seconds

Dual Deploy plus Aux: 7 Short Beeps Continuity on Drogue, Main, and Auxiliary (not to be confused with low battery beeps)


Tony

 

[Jozef]

Joe,

Here is a link how I have my Aux channel set up. https://www.rocketryforum.com/showthread.php?124501-Aux-Output

You'll also be listening for a deferent series of beeps when using the Aux channel.

Normal Dual Deploy: Drogue and Main 3 beeps repeating every 5 seconds

Dual Deploy plus Aux: 7 Short Beeps Continuity on Drogue, Main, and Auxiliary (not to be confused with low battery beeps)


Tony

Tony, Thanks for the post, but that is Greek to me. I have no idea what Mdacs is, or does.

 

[tim cubbedge]

Tony, Thanks for the post, but that is Greek to me. I have no idea what Mdacs is, or does.

Mdacs is the program used to download flight data from RRC3. Also used to program/modify flight parameters of RRC3. You can download it from missile works website. You also need the USB interface.

 

[Jozef]

Mdacs is the program used to download flight data from RRC3. Also used to program/modify flight parameters of RRC3. You can download it from missile works website. You also need the USB interface.

Yep...found that in my user manual after responding to Tony. Mdacs requires a PC/Windows based platform. I switched to MAC several years ago. At the ned of the day, had I followed Jim Amos' instructions in the RRC3 user manual to test igniters for resistance I would not have a rocket to repair. Thanks to all who have responded with suggestions. Good stuff

 

[DavidMcCann]

Yep...found that in my user manual after responding to Tony. Mdacs requires a PC/Windows based platform. I switched to MAC several years ago.

I switched to Mac in the early 90's. would have preferred to stay with Apple II but they made that harder and harder to do.

Myself and a couple other friends have grabbed either cheap $150 laptops, or picked up old laptops for $40 on eBay. Tossing a cheap SSD drive in and stripping the system down (two things I still need to do) can help things. Luckily most rocketry apps don't need too much in the way of computing power.