valkrider15
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This is a bit long- but there are some real good learnings here so it might be worth the read.
This last weekend I was lucky enough to achieve my Level 2 on one of the donated J350 motors at NSL! I missed alot since my first posts and this last weekend but early build thread on this rocket is here:
https://www.rocketryforum.com/showthread.php?s=&threadid=16457
The rocket was set-up as a deal deploy running a Missileworks RRC2 altimeter. I spent several hours on Friday ground testing the ejection system and I am glad that I did. This would be my first dual deploy and although I am confident in my building techniques and concepts, nothing beats hands on experience. I ran probably 4 rounds of testing and learned something each time.
My first test I learned that I need to put the altimeter bay in the rocket facing right direction. I prepped the rocket and hooked up the main main ejection charge to my launch controller. (I used estes igniters to light the charges since I didn't want to burn through the expensive e-matches). Everything looked good and I did a 1-2-3 count down and hit the button. Low and Behold the Rear of the rocket ejects (apogee end). Hmmmm, that is interesting because I definetally had the controller hooked to the Main wires. (Once back on the table I realized I had put the altimeter bay in backwards - MAJOR MENTAL NOTE HERE). I fired off the other charge and it worked like a champ. A good starting point.
The next 2 tests were very concerning. Since I had inverted the altimeter bay that means that the larger - main - ejection charge actually fired the apogee end and the smaller appogee charge fired the main (nosecone with shear pins). Good news on the main because I knew that 2 Grams would easily deploy the main, but bad news on the appogee charge because I was intending on using less that the 2 1/5 grams that was fired by accident.
When I ran the second test the booster section (apogge), barely moved and was still very much on the rocket. **** - this is bad. I ran 2 grams with a body tube length of 18" - should have come flying out of there. The main section worked like a champ again so I was fine there. But I did manage to burn a hole in the BRAND NEW MAIN CHUTE. So I guess I am back off to Andy's tent to pick up ANOTHER TopFLight 70" main. What's another $35 at this point.
So now on to Ground Test 3. Only testing the Apogee charge as I am confident that the main is figured out. I thought that maybe the problem on the previous test was that I had secured the middle section of the body tube and was ejecting the heavier booster section. Yeah - that must have been the problem. So I load up the charge again, get the test ready, bracing the booster section against the trailer tire and hit the launch controller button. The charge fires and the tubes seperate about 2" with the drogue still in the lower airframe section. Needless to say - I am completely baffled. As I am sitting there in disbelief, trying to figure out why 2 grams of BP won't kick out the drogue in an 18" body tube section the "Baffling" becomes the answer. I am looking right at the top end of the booster, and what do I see??? That's Right - The baffle holes for the motor ejection backup - MAJOR DUH!!!! I didn't plug the motor tube or baffle so the pressure was simply flowing right out the 54MM motor tube. HOW STUPID COULD I BE??
So now with renewed vigor I tape over the baffles holes with several layers. Go build another ejection charge, which I am getting very good at doing by this point. BTW - I used the finger off the vinal glove trick for the charge container and it worked great. I connected up the e-bay (have got it in the right way every time now), laid the rocket back down, brace the booster, hold my breath, count to 5 and hit the button. This time the apogge section FLYS APART. WOW - It will work!!!!! What a relief.
Now on to testing the e-matched on the altimeter. Interesting background here is that I purchsed some homemade e-matches for initial testing and had mixed success. 2 fired perfectly, 3 not at all so I wasn't overly confident when starting this test. I purchased a box of the M-tecs (I took the heart all the comments on not skimping on the ematches - after all - I had already ruined a brand new 70" chute, so what a few dollars in REAL ematches) from Andy so had plenty to test if needed. I pulled the altimeter out the ebay so I could put it into test mode. Hooked up everything just like it will really be, had one e-match on each lead. Turned the power on, toggled switch 2, and waited. After the 10 second wait time the apogee match fires perfectly and then 1 second later the Main match. Just like it should. I am feeling better now.
But we all know that one test is not enough so I grab 3 matches this time and hook it back up. I sed 3 matches because I wanted to use 2 in the main charge (a little backup) and one in the apogee since I was also using motor backup on the apogee charge. With everything hooked up I cycled the test and everything worked great. Now I was Finally confident that everything would work.
Saturday morning I spent probably 1 1/2 hours preping the rocket. Taking my time and double checking everything. Z-folded the shock cord with taped off section about every 7 feet. Used 45 feet of 1/2" tubular on the drogue and 30' on the main. Each end have 4' of kevlar on the ejection charge side.
With everything together except the motor, I headed off to take the test. Having spent the last several weeks taking the on-line test multiple times the test was a breeze. I did take the time to double check all my answers and ended up with 100%. Good way to start the day. Picked up the J350 and loaner case and set off to finish the preping.
When I pulled the motor casing out of the package there was a slight chip in one end. Now this isn't good - so back off to Andy's again to find out what to do. Andy was great with all on my questions and really helped me. He took a split second look at the chip and said "No problem, put the chiped end towards the front". So I nodded and turned around, took 2 steps and stopped. Turned back to Andy and said "Front being the ??????", NOZZLE END said Andy. Right I thought to myself, I knew that.
So I am getting the motor put together following the directions carefully. Everything looks good, but when I get to the Front End (Yes I know, where the Nozzle Goes) The end of the grains are about 1/4" below the casing. Hmmm, Is this right I wonder. So off I go, not back to Andy (only because it's too long of a walk - not because I would feel silly asking him ANOTHER question) but right to my next door neighbor, who based on the rockets I see in his camp is obviously L3. I ask about the space and am assured that it is as it should be. Good. Back to the rest of the motor build and prep.
So now I am ready to go. Off to the RSO for a rocket check, everything looks good. Now to the Pad. Load up the rocket. Put in an igniter that I actually made (figured if the igniter doesn't work there is no real problem, although I did ground test my first batch of igniters with 100% success), take the photo and am ready to go. Turn on the altimeter and wait for the 3-beep continuity confirmation. Everything looks great to off to the launch pad.
Standing there for what seems like 30 mins, although I am sure it was only like 5. Finally get my number called. Everything clear, certification group watching. Countdown starts (Deep breath), down to 1 (another deep breath) then 0 and hit the button. I can see the igniter flash out the nozzle (nice big flame), then in an instant the motor is fully up to pressure and the rocket is off.
The flight was perfectly straight, up and over the apogee event fires and drogue is out. 1/2 there now. Floating down to 800' and right on queue the main is out, fully inflates and starts the remaining gentle float to earth. A short walk to the East of the launch area finds the rocket nicely laid out. Altimeter beeping out 2159'. Not too bad. Get it all back together and back to the certify group for inspection. All is good and another L2 flyer is born.
On my way back to the trailer something strange happens. I take hard right hand turn into one of the vendor's tents and somehow end up with a K550 in my hand. WHY NOT I think!!!
I prepped the rocket Saturday evening, built the motor as well (**** this is BIG) so Sunday would be relaxing. This time the rocket flies perfectly traight again with perfect dual deploy (although the guy next to me was calling out his estimated altitude and was down to 600' when the main fired, but I didn't believe him!!). This time the altimeter is beeping out 6544'!!!
WOW - THIS IS FUN!!!!
So my lessons from this are:
1. Big rockets and Big motors are WAY COOL.
2. Ground Test till you get it right. I felt so confident prepping the rocket for the real launch after going through so many ground test cycles.
3. ASK QUESTIONS - If you are not sure, ask. Everyone was so very nice and helpfull.
4. BRING MORE CACH TO LAUNCHES. But luckly the vendors take Credit Cards too.
Thanks to everyone that helped me. Maybe someday I can do the same for another flyer.
Oh yes - The pic!!
This last weekend I was lucky enough to achieve my Level 2 on one of the donated J350 motors at NSL! I missed alot since my first posts and this last weekend but early build thread on this rocket is here:
https://www.rocketryforum.com/showthread.php?s=&threadid=16457
The rocket was set-up as a deal deploy running a Missileworks RRC2 altimeter. I spent several hours on Friday ground testing the ejection system and I am glad that I did. This would be my first dual deploy and although I am confident in my building techniques and concepts, nothing beats hands on experience. I ran probably 4 rounds of testing and learned something each time.
My first test I learned that I need to put the altimeter bay in the rocket facing right direction. I prepped the rocket and hooked up the main main ejection charge to my launch controller. (I used estes igniters to light the charges since I didn't want to burn through the expensive e-matches). Everything looked good and I did a 1-2-3 count down and hit the button. Low and Behold the Rear of the rocket ejects (apogee end). Hmmmm, that is interesting because I definetally had the controller hooked to the Main wires. (Once back on the table I realized I had put the altimeter bay in backwards - MAJOR MENTAL NOTE HERE). I fired off the other charge and it worked like a champ. A good starting point.
The next 2 tests were very concerning. Since I had inverted the altimeter bay that means that the larger - main - ejection charge actually fired the apogee end and the smaller appogee charge fired the main (nosecone with shear pins). Good news on the main because I knew that 2 Grams would easily deploy the main, but bad news on the appogee charge because I was intending on using less that the 2 1/5 grams that was fired by accident.
When I ran the second test the booster section (apogge), barely moved and was still very much on the rocket. **** - this is bad. I ran 2 grams with a body tube length of 18" - should have come flying out of there. The main section worked like a champ again so I was fine there. But I did manage to burn a hole in the BRAND NEW MAIN CHUTE. So I guess I am back off to Andy's tent to pick up ANOTHER TopFLight 70" main. What's another $35 at this point.
So now on to Ground Test 3. Only testing the Apogee charge as I am confident that the main is figured out. I thought that maybe the problem on the previous test was that I had secured the middle section of the body tube and was ejecting the heavier booster section. Yeah - that must have been the problem. So I load up the charge again, get the test ready, bracing the booster section against the trailer tire and hit the launch controller button. The charge fires and the tubes seperate about 2" with the drogue still in the lower airframe section. Needless to say - I am completely baffled. As I am sitting there in disbelief, trying to figure out why 2 grams of BP won't kick out the drogue in an 18" body tube section the "Baffling" becomes the answer. I am looking right at the top end of the booster, and what do I see??? That's Right - The baffle holes for the motor ejection backup - MAJOR DUH!!!! I didn't plug the motor tube or baffle so the pressure was simply flowing right out the 54MM motor tube. HOW STUPID COULD I BE??
So now with renewed vigor I tape over the baffles holes with several layers. Go build another ejection charge, which I am getting very good at doing by this point. BTW - I used the finger off the vinal glove trick for the charge container and it worked great. I connected up the e-bay (have got it in the right way every time now), laid the rocket back down, brace the booster, hold my breath, count to 5 and hit the button. This time the apogge section FLYS APART. WOW - It will work!!!!! What a relief.
Now on to testing the e-matched on the altimeter. Interesting background here is that I purchsed some homemade e-matches for initial testing and had mixed success. 2 fired perfectly, 3 not at all so I wasn't overly confident when starting this test. I purchased a box of the M-tecs (I took the heart all the comments on not skimping on the ematches - after all - I had already ruined a brand new 70" chute, so what a few dollars in REAL ematches) from Andy so had plenty to test if needed. I pulled the altimeter out the ebay so I could put it into test mode. Hooked up everything just like it will really be, had one e-match on each lead. Turned the power on, toggled switch 2, and waited. After the 10 second wait time the apogee match fires perfectly and then 1 second later the Main match. Just like it should. I am feeling better now.
But we all know that one test is not enough so I grab 3 matches this time and hook it back up. I sed 3 matches because I wanted to use 2 in the main charge (a little backup) and one in the apogee since I was also using motor backup on the apogee charge. With everything hooked up I cycled the test and everything worked great. Now I was Finally confident that everything would work.
Saturday morning I spent probably 1 1/2 hours preping the rocket. Taking my time and double checking everything. Z-folded the shock cord with taped off section about every 7 feet. Used 45 feet of 1/2" tubular on the drogue and 30' on the main. Each end have 4' of kevlar on the ejection charge side.
With everything together except the motor, I headed off to take the test. Having spent the last several weeks taking the on-line test multiple times the test was a breeze. I did take the time to double check all my answers and ended up with 100%. Good way to start the day. Picked up the J350 and loaner case and set off to finish the preping.
When I pulled the motor casing out of the package there was a slight chip in one end. Now this isn't good - so back off to Andy's again to find out what to do. Andy was great with all on my questions and really helped me. He took a split second look at the chip and said "No problem, put the chiped end towards the front". So I nodded and turned around, took 2 steps and stopped. Turned back to Andy and said "Front being the ??????", NOZZLE END said Andy. Right I thought to myself, I knew that.
So I am getting the motor put together following the directions carefully. Everything looks good, but when I get to the Front End (Yes I know, where the Nozzle Goes) The end of the grains are about 1/4" below the casing. Hmmm, Is this right I wonder. So off I go, not back to Andy (only because it's too long of a walk - not because I would feel silly asking him ANOTHER question) but right to my next door neighbor, who based on the rockets I see in his camp is obviously L3. I ask about the space and am assured that it is as it should be. Good. Back to the rest of the motor build and prep.
So now I am ready to go. Off to the RSO for a rocket check, everything looks good. Now to the Pad. Load up the rocket. Put in an igniter that I actually made (figured if the igniter doesn't work there is no real problem, although I did ground test my first batch of igniters with 100% success), take the photo and am ready to go. Turn on the altimeter and wait for the 3-beep continuity confirmation. Everything looks great to off to the launch pad.
Standing there for what seems like 30 mins, although I am sure it was only like 5. Finally get my number called. Everything clear, certification group watching. Countdown starts (Deep breath), down to 1 (another deep breath) then 0 and hit the button. I can see the igniter flash out the nozzle (nice big flame), then in an instant the motor is fully up to pressure and the rocket is off.
The flight was perfectly straight, up and over the apogee event fires and drogue is out. 1/2 there now. Floating down to 800' and right on queue the main is out, fully inflates and starts the remaining gentle float to earth. A short walk to the East of the launch area finds the rocket nicely laid out. Altimeter beeping out 2159'. Not too bad. Get it all back together and back to the certify group for inspection. All is good and another L2 flyer is born.
On my way back to the trailer something strange happens. I take hard right hand turn into one of the vendor's tents and somehow end up with a K550 in my hand. WHY NOT I think!!!
I prepped the rocket Saturday evening, built the motor as well (**** this is BIG) so Sunday would be relaxing. This time the rocket flies perfectly traight again with perfect dual deploy (although the guy next to me was calling out his estimated altitude and was down to 600' when the main fired, but I didn't believe him!!). This time the altimeter is beeping out 6544'!!!
WOW - THIS IS FUN!!!!
So my lessons from this are:
1. Big rockets and Big motors are WAY COOL.
2. Ground Test till you get it right. I felt so confident prepping the rocket for the real launch after going through so many ground test cycles.
3. ASK QUESTIONS - If you are not sure, ask. Everyone was so very nice and helpfull.
4. BRING MORE CACH TO LAUNCHES. But luckly the vendors take Credit Cards too.
Thanks to everyone that helped me. Maybe someday I can do the same for another flyer.
Oh yes - The pic!!
