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Spent the day yesterday the 8th, at ROCtober 2011 on the playa at Lucerne Dry Lake Bed in Lucerne Valley, California. The weather was absolutely perfect for most of the day. There were occasional periods of wind, but never sustained. Temps were in the high 20's C, (80's F if you are still doing that thing). Low humidity. Perfect.
I really had one goal in mind this launch... the background
I had (and still do) many G38s single use EconoJets bought probably 8 or 9 years ago. When I went to use them in February of this year I discover that each and every one of them was swelled such that the slot for the igniter was closed.
:y: I wrote Aerotech and got no response. I was not really expecting one since the warranty is probably 90 days if that. They were stored in a case, but not in the original packaging
What to do? Destroy them? Take them apart and try using the grains in a 29 casing? I talked with a few people, and they gave me two pieces of advice. Try using an ice pick to find the slot and pry it open as best as possible. Or use a drill by hand. I tried the pick.
Modifying a motor is a no-no... However I was not modifying it, I was restoring it to working order.
I never could tell however if I got the slot completely open. Hence would the delay grain ignite? I could not count on that. I took three of them, removed the black powered (because of the delay grain issue) and loaded them in my 3x29 cluster which uses an accelerometer and altitude based altimeter for apogee deploy. Also the rocket is light enough that a single SU can lift it in no-wind conditions, which is what we had at the time. I also aimed the rod outbound - which you can clearly see in the second picture.
Using Quick Burst Ignitors that I dipped, and adding a 6 foot length of zip cord to help climb out with any that ignited late. The countdown ended. All three chuffed in staccato like manner for a second or two... (you can see the blocks aiming the pad outbound.)
Then took off in a hurry on wonderful plume of smoke (you can see that zip cord in the smoke in the first image!).
The altimeter did it's part and I was punching the air in success. Oh and yes I wrote HEADS-UP on the flight cards. All HPR clusters should be H.U.
The chuffing tells me I probably had not gotten to the top of the grain. It's a complicated prep... and it went well. And I did not waste 45 dollars worth of motors. All three had lit.
That went well so I prepped my upscaled Osiris for a H97-S flight. It was great up. Simply gorgeous big The Launch Pad upscale on thick black smoke.
However I knew 2 seconds into the flight I had made a mistake. :bang: :bangpan: It got no where NEAR high enough even for a short delay - it MIGHT deploy in time, but all I needed was the 10-20% delay variation and I was toast. Well I was toast. It deployed a moment after impact. Ouch. :cry::kill:
Damage was limited to the nose cone and upper body tube.
The fin can is fine. So we'll cut the tube square add a short payload bay for an altimeter and a new (well.... used actually nose cone) and it'll fly in a month at ROCStock.
Edit: Now that I have looked at the sim's... there is no reason it should not have attained sufficient altitude to deploy even on a medium delay (tho that would be waaay too fast). I wonder if my rail guides were sticking or such? I have calibrated the sim results with other recording altimeter flights, so I think the sim is correct.
The rest of the day I spent being abused and cussed at by 'parents' of scouts setting a good example for there sons and daughters will they waited to launch. :eyeroll:
I really had one goal in mind this launch... the background
I had (and still do) many G38s single use EconoJets bought probably 8 or 9 years ago. When I went to use them in February of this year I discover that each and every one of them was swelled such that the slot for the igniter was closed.
:y: I wrote Aerotech and got no response. I was not really expecting one since the warranty is probably 90 days if that. They were stored in a case, but not in the original packagingWhat to do? Destroy them? Take them apart and try using the grains in a 29 casing?
I talked with a few people, and they gave me two pieces of advice. Try using an ice pick to find the slot and pry it open as best as possible. Or use a drill by hand. I tried the pick. Modifying a motor is a no-no... However I was not modifying it, I was restoring it to working order.
I never could tell however if I got the slot completely open. Hence would the delay grain ignite? I could not count on that. I took three of them, removed the black powered (because of the delay grain issue) and loaded them in my 3x29 cluster which uses an accelerometer and altitude based altimeter for apogee deploy. Also the rocket is light enough that a single SU can lift it in no-wind conditions, which is what we had at the time. I also aimed the rod outbound - which you can clearly see in the second picture.
Using Quick Burst Ignitors that I dipped, and adding a 6 foot length of zip cord to help climb out with any that ignited late. The countdown ended. All three chuffed in staccato like manner for a second or two... (you can see the blocks aiming the pad outbound.)
Then took off in a hurry on wonderful plume of smoke (you can see that zip cord in the smoke in the first image!).
The altimeter did it's part and I was punching the air in success. Oh and yes I wrote HEADS-UP on the flight cards. All HPR clusters should be H.U.
The chuffing tells me I probably had not gotten to the top of the grain. It's a complicated prep... and it went well. And I did not waste 45 dollars worth of motors. All three had lit.
That went well so I prepped my upscaled Osiris for a H97-S flight. It was great up. Simply gorgeous big The Launch Pad upscale on thick black smoke.
However I knew 2 seconds into the flight I had made a mistake. :bang: :bangpan: It got no where NEAR high enough even for a short delay - it MIGHT deploy in time, but all I needed was the 10-20% delay variation and I was toast. Well I was toast. It deployed a moment after impact. Ouch. :cry::kill:
Damage was limited to the nose cone and upper body tube.
The fin can is fine. So we'll cut the tube square add a short payload bay for an altimeter and a new (well.... used actually nose cone) and it'll fly in a month at ROCStock.
Edit: Now that I have looked at the sim's... there is no reason it should not have attained sufficient altitude to deploy even on a medium delay (tho that would be waaay too fast). I wonder if my rail guides were sticking or such? I have calibrated the sim results with other recording altimeter flights, so I think the sim is correct.
The rest of the day I spent being abused and cussed at by 'parents' of scouts setting a good example for there sons and daughters will they waited to launch.
:eyeroll:
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