Our Children's Future: An LDRS34 Teen Group Project

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One thing I have not seen posted was the avbay layout. Was there anyway to pressurize the avbay when you were turning on the camera? How big were the static ports, how many did you have? Where you standing in front of them when you were messing with the camera? Was there a breeze? Somehow the altimeter read an apogee. It would have been nice to know what the altimeter was beeping out if anything after it fired. That might have helped you figure out what happened. Now you guys are left with little option than to fix everything and every process without really knowing what caused booboo.
 
patelldp said:
There's your problem. That needs to be done in front of the crowd with the RSO and LCO's attention to avoid any commotion.

Really take a step back and understand what went wrong. Kinda wish that you hadn't thrown the altimeters out...it'd be nice to know if it's an altimeter issue or something with the configuration of your altimeter bay. If you don't learn from mistakes, you're destined to repeat them. Bummer of a failure scenario, but I recommend a complete re-boot prior to attempting an M3500 flight in August.
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Yes, we were told it was ok to do there but now we all know that if it ever needs to be done again we will have to alert RSO and LCO and do it out front to avoid any commotion. I still have one of the altimeters thats still working, the other altimeter actually broke after the rocket hit the ground and can't be powered up or anything anymore. We are thinking that the LDA on the altimeters were set to low so the gusts of wind may have caused a small decrease in pressure making the altimeters begin flight. I'm going to completely redo the avbay and as stated before we are using different altimeters that have a relatively high LDA.
 
grouch said:
One thing I have not seen posted was the avbay layout. Was there anyway to pressurize the avbay when you were turning on the camera? How big were the static ports, how many did you have? Where you standing in front of them when you were messing with the camera? Was there a breeze? Somehow the altimeter read an apogee. It would have been nice to know what the altimeter was beeping out if anything after it fired. That might have helped you figure out what happened. Now you guys are left with little option than to fix everything and every process without really knowing what caused booboo.
Click to expand...


We had 4 1/4" static port holes. i was not standing in front of them. there was a breeze, I just looked at the data from the one still working altimeter an it reads out 300 something feet for that "flight" so it appears the wind may have been the culprit along with the size/placement of the holes. I'm open for suggestions about what we can do differently for the static port sizing. Like I said before we are going with altimeters that have a 500' LDA as well as trying to fix the static ports.
 
The "wind" was very light thursday and friday. More likely a baro sensor or connection that was faulty IMO.
 
It is probably best to use an odd number of vent holes, so the wind cannot blow directly in one and out the opposing one.
 
terryg said:
It is probably best to use an odd number of vent holes, so the wind cannot blow directly in one and out the opposing one.
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Thank you, I will have to change that so that we have an odd number.
 
Let the record show that my Hawk Proteus (same day as yours) flew successfully with four 3/16" vent holes. Altimeters were an ARTS1 and RRC3 Beta.
 
patelldp said:
Let the record show that my Hawk Proteus (same day as yours) flew successfully with four 3/16" vent holes. Altimeters were an ARTS1 and RRC3 Beta.
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So its most likely not our vent hole sizing/placement. That pretty much makes it the LDA on the altimeters that were used. As we are using different altimeters with high LDA's that should no longer be a problem. I'm still going to do a lot of testing and redoing the AV-Bay to make sure the system is flawless.
 
I find it hard to believe that any modern altimeter could be triggered by a wind gust. What altimeters were you using?
 
mikec said:
I find it hard to believe that any modern altimeter could be triggered by a wind gust. What altimeters were you using?
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I agree, I never heard of an alt. that has LDA's above 300. The newer ones I believe you can program to go lower than 300 but have not heard of any that go higher??
 
rcktnut said:
I agree, I never heard of an alt. that has LDA's above 300. The newer ones I believe you can program to go lower than 300 but have not heard of any that go higher??
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I thought most had an LDA of 500'.
 
conman13 said:
I thought most had an LDA of 500'.
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I just looked up the user manual for the Eggtimer, you can program it from 50 to 500. Did you know what it was programed at? First time I seen 500. I believe the RRC's and Stratologers are at 300 max. and can be lowered. The set ones I have are at 300.
 
I just want to say I know you all put a lot of sweat and hard work into that project. It is a beautiful rocket you can all be proud of. We were just down the row from you in spot B7 and passed by often admiring the rocket. We were really eager to see it fly and were sorry you ran into some problems. I'm sure you'll get to the bottom of what went wrong and fly her with confidence in August! :)

Jim Z
 
JimZNJ said:
I just want to say I know you all put a lot of sweat and hard work into that project. It is a beautiful rocket you can all be proud of. We were just down the row from you in spot B7 and passed by often admiring the rocket. We were really eager to see it fly and were sorry you ran into some problems. I'm sure you'll get to the bottom of what went wrong and fly her with confidence in August! :)

Jim Z
Click to expand...

Thank you very much :)
 
Anyone have any ideas on fixing this? This is the only real structural damage that occurred when the rocket fell off the pad and slammed into the blast deflector.

11655723_814767445286435_404187203_o.jpg

IMG_1397.jpg

IMG_1396.jpg


It's only about 2'' in from the back of the fin and it broke right above the fillets so theres no damage to the root. With that said it isn't a huge stress point but I would still like to fix it to the best of my ability.
 
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grind and sand the damaged area to good clean bare wood. then just use filled epoxy to fill the bad area and sand smooth. it looks like a cosmetics problem really.
 
I'll try to get some better pictures later but the back the fin is actually cracked in several different places.
 
It looks like a bit of delimitation. I'd sand it down to bare wood about 2" past the problem area. Cut a couple strips of glass and wrap it around the trailing edge. Then fill and sand it smooth with the rest and repaint. Easy peasy. Or forgo the paint and put a "Chuck Norris was here" sticker on it. You are gonna want to glass that bit for sure or water/mud/crap will eventually get in it and much up the works.
 
grouch said:
It looks like a bit of delimitation. I'd sand it down to bare wood about 2" past the problem area. Cut a couple strips of glass and wrap it around the trailing edge. Then fill and sand it smooth with the rest and repaint. Easy peasy. Or forgo the paint and put a "Chuck Norris was here" sticker on it. You are gonna want to glass that bit for sure or water/mud/crap will eventually get in it and much up the works.
Click to expand...

I think I'm going to go with this. I've already got the Chuck Norris was here sticker picked out ;) thanks!
 
Second what grouch said but I would also try to inject some adhesive into the layers of the plywood and clamp it then glass over it.
 
flynfrog said:
Second what grouch said but I would also try to inject some adhesive into the layers of the plywood and clamp it then glass over it.
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That's actually what I plan on doing, I'm going to inject some epoxy and clamp that and when its cured apply a couple strips of 10oz glass for extra support.
 
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conman13 said:
In other news we ordered the unistrut buttons that we will be using instead of the 1515 as well as 4-40 shear pins that we will now be using to keep the main in, instead of tape and luck ;) I plan on using 3 but if anyone thinks we should use more please speak up :)
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With your charges you should be OK with 47 4-40 pins.

1515 may be easier at a club launch, unless you've arraigned for the uni already.
 
DizWolf said:
With your charges you should be OK with 47 4-40 pins.

1515 may be easier at a club launch, unless you've arraigned for the uni already.
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I was in A21 right across from you guys and the ejection test sounded like a cannon at a civil war reinactment lol
Greg
 

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