I'll be at the launch - I can retrieve heavy stuff.

Impressive rocket. Impressive build rate.

Super! Another rocket buddy! Thanks

Mike, I'm going tomorrow just to assist you, plus I need the exercise. 😉

I have a flight lesson tomorrow morning out of Greeley from 8:00 to 10:00, as soon as I get on the ground I will be out.

Mike, when do you think you will fly Slipstick III?

Art

Well unfortunately I have to at work so wont be able to make it... Good luck with the flights Mike.

ABORT ABORT ABORT

The following photos are at the Northern Colorado Rocketry Atlas site near Ault, CO on Feb 2, 2007. The intended launch was subverted by a previously unflown, brand new, but seemingly defective backup altimeter.

The altimeter seemed to have passed all the intial setup tests and responded correctly to the programming of the set points. However, after the altimeters were powered on and the shunts removed from the charges, we had a premature deployment of the backup charges. This occured about 15-20 seconds after enabling the charges, while we were trying to listen for the optimal 3 beeps from each altimeter. The drogue deployment went off first, while I had my ear to the avbay, with John Nelson supporting the rail. Fortunately the fin can section stayed on while the rest of the rocket left the rail followed immediately by the backup main charge being deployed (since we were obviously below 1000 feet elevation). Both chutes came out clean, an otherwise great deployment, not often seen this close by the spectators.

The picture seconds before everything came apart on us:

...and right after:

We figured that maybe we had triggered the sensors by lowering the launch rails down while the altimeters were armed, so I went ahead and prepared additional charges, and reassembled the rocket for another try. We tested the avbay with the charges armed outside the rocket for over 30 seconds and the backup altimeter and charges seemed to be behaving properly. Once the rocket was back on the pad, I powered the altimeters on, and once we were getting the correct number of beeps (the shunts give the same beeps as the charges in this mode) we connected up the ignitor to the K560W. I enabled the charges and stepped away from the pad. While we were standing fairly close by getting ready to check the continuity of the ignition system, The backup drogue charge went off again, followed by the main. Again the tail section stayed on the pad. I think the nose cone got to 30 foot elevation, the avbay and the rest of the airframe landing hard on the cement pad of the Atlas site. Wind speed was about 10mph in both instance, and the primary charges remained intact the whole time. I'm very thankful we had a slight delay in actually launching it, because if this rocket had separated during the thrust phase, instead of on the pad, it would have been destroyed.

Here we are, leaving it vertical this time, but to no avail:

Back at home, I cleaned the black powder residue off the interior of the airframe, cut 1" off the middle airframe section and 2 inches of the forward airframe (nose cone) section. I will be returning the altimeter back to the manufacturer, and doing another attempt at shakedown flight on March 1st. THEN, maybe I'll paint it.

Here's part of the damage from falling on the concrete:

I'd like to thank Art, Bruce, John N., Tim, Joe, and all the other NCR members who helped get the pad setup and to help me get the rocket prepped (Both times).

On the first attempt, Art and Mike had their heads to the avbay, John rested the rail on his shouder. I was taking the pictures; had I been any good at it, I would've gotten the charges going off. THEN BAM-BAM! What happened to Mike has always been one of my fears. Mike, you're one of the most persistant rocket guys I know! It's definitely an altimeter problem, which you'll work out with the manufacturer privately. I have a vested interest in that, as I had planned to use one on a rocket similar to yours. Great pictures; now we all know what concrete does to PR G10, in close up. You're lucky the nosecone shot off with no damage. Concrete and FG nosecones don't work well with each other either. As we all agreed yesterday, you'll have no trouble pushing your chutes out! Yesterday wasn't what we'd hoped, but a good lesson for all of us.

If I may ask?

Who's altimeter?

All the above scares me also. One of My MHM birds will have
an altimeter and timer. Every thing has been tested and
worked in the past.

I have read in a couple publications.... To. Very on and off
a few times and let the temp. equalize.
No one in person that uses them has ever confirmed the
verying on and off. Just the temp.
The publication said that by turning on, let stand, turn off
a few times will give a more accurate pressure reading. At the
launch site.

If a person was to come up from 1000' to a 5400' launch site,
the altimeter could still be reading 1000' as start. And the other
way around.

Seemed reasonable. I have not been doing electronics long.
input from others would be nice.

Thanks for sharing Your problems.

I'm very sorry for your unexpected malfunction. I'd also like to know who's altimeter and which model caused the problem. Doesn't look too bad, slice off a couple inches and have at it again. Better luck next time Mike. Again, all my sympathies - the same, if not worse, has happened to many of us.

Letting the entire bird temp stablize prior to flight - perhaps even an hour or more, might be a very good idea. Thing with electronics is they tend to be even more temp sensitive. Barometric sensors used in altimeters are essentially strain guages on a piece of foil sealing an absolute pressure chamber (usually a near vacuum of known low pressure and about a cubic millemeter in volume, trending towards smaller volumes.) These are resistive bridge circuits (Wheatstone Bridge) and are typically vapor deposited materials - the very method implies temperature sensitivity. However, the idea that a commercial altimeter would fail in that way boggles. I hate to pick on altimeter manufacturers, but one would think that testing in the temperature range one would encounter in the real world - say 0 degrees F up through 125 degrees F, would be de rigeur.

One final thing I would note. If you had a Missileworks RRC2 or RRC2X and you installed the battery with reverse polarity, exactly the same result occurs - the charges go off shortly after enabling the altimeter. The newer RRC2X mini has a zener diode across each output that prevents this issue. Jon Skuba did this accidentally at an MHM with a very substantial charge and was lucky he didn't get worse than a ringing in the ears. I did it once when assembling my 38mm altitude bird in my basement and had nearly 2 grams go off within 2' of my head. Quite invigorating I should say...

Warren

I would like to point out that until the manufacturer can analyze the unit and both the flier and the manufacturer can determine what the problem was, then no assumptions or judgments should be made. The units are so vigorously tested that it is unlikely that a “defective” unit made it to a consumer. Again, please, do not make assumptions until all the facts are known.

I was there and had an ear to the electronics durind both the malfunctions and the test in between. What I heard and witnessed was something that I am not familiar with but since I have never used the until itself and I am not familiar with it, I cannot comment on what really happened. Let the manufacturer and the people who were there deal with this one.

Mike did have to endure what many of us fear and he kept a good attitude throughout the whole thing, for that I commend him. As Bruce said, that is one of the worst fears of a rocketeer that flies electronics. It happens to the best of us though. More complex rockets are subject to more types of issues and failures, sometimes, that is how it goes.

Mike, you still have time, get the unit figured out and we will see you back in March! When you do get your L3, the satisfaction will be that much better.

Art

PS – The motor was a K560W.

Folks,

At this moment it doesn't matter as to what brand it was or what Altimeter. First and foremost we all know that the majority of altimeter issues and failures are user based specifically with the most proven brands that have been in use for some time. That being said, it does not mean that I am saying Mike is at fault at this moment either, nor am I saying that manufactures are perfect either as things do happen. But until Mike gets with the manufacture of the altimeter sends the unit in and has it verified as to what the issue is no one is in any position to condemn anything from anyone. Only the manufacture can do so. Sorry but one thing that irritates me highly is people quick to jump and point as well as many that jump on board with feelings of "Oh that happened and I have one...."You all know what I am saying in regards to the knee jerk reactions that happen.. Just wait till the facts come out. I'm sure if the issue is a defective unit it will be told so by the said manufacture.

Mike. My highest recommendations would be first do NOT change any setting on the altimeter in question and I would also NOT disassemble anything from the Ebay. Leave everything in the ebay in place and ask the manufacture if they prefer you to send the whole ebay to the manufacture for verification and testing. There may be other issues there that might help trouble shoot with it as is. If you change any settings on the altimeter it could mean the difference of finding out what happened. So first things first contact the manufacture find out what they need to do.

Conway

I agree on what Conway said about saying which altimeter it was. I personally have seen this model fly VERY successfully, on all levels. This is between Mike and the manufacturer. They must determine WHY it failed, until then it really isn't our business. Just hang in there, guys. And speaking of rocketry, MAN, THAT WAS ONE OF THE BEST SUPER BOWLS I'VE SEEN... and I'm old enough to have seen them all. Now back to our rocketry channel... 😉

Mike. My highest recommendations would be first do NOT change any setting on the altimeter that has failed and I would also NOT disassemble anything from the Ebay. Leave everything in the ebay in place and ask the manufacture if they prefer you to send the whole ebay to the manufacture for verification and testing. There may be other issues there that might help trouble shoot with it as is. If you change any settings on the altimeter it could mean the difference of finding out what happened. So first things first contact the manufacture find out what they need to do.

Conway

Agreed! Leave everything as is, don't change anything else as of now even if you have played with it already. Pretend you had an aviation accident and the manufacturer is the FAA and NTSB! 😉

Art

On the first attempt, Art and Mike had their heads to the avbay, John rested the rail on his shouder. I was taking the pictures; had I been any good at it, I would've gotten the charges going off. THEN BAM-BAM! What happened to Mike has always been one of my fears. Mike, you're one of the most persistant rocket guys I know! It's definitely an altimeter problem, which you'll work out with the manufacturer privately. I have a vested interest in that, as I had planned to use one on a rocket similar to yours. Great pictures; now we all know what concrete does to PR G10, in close up. You're lucky the nosecone shot off with no damage. Concrete and FG nosecones don't work well with each other either. As we all agreed yesterday, you'll have no trouble pushing your chutes out! Yesterday wasn't what we'd hoped, but a good lesson for all of us.

Mike
Hind site is 20-20 If only you knew the alt. was bad(hard to tell out there), I had the same one (tested too) sitting in the back of the van you could of barrowed! Might of made the differance.
Oh Well, a shame. Thats why I wanted that vacume chamber. Not everything coming off the assembly line is perfect. Good luck next time.

Scotte