L1 Build - Upgraded Loc IV

Discussions on mid/high powered model rockets using F powered motors and above.

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Aquaman33
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Re: L1 Build - Upgraded Loc IV

Postby Aquaman33 » Thu Apr 11, 2019 9:38 am

Onboard video:


Lamp
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Re: L1 Build - Upgraded Loc IV

Postby Lamp » Thu Apr 11, 2019 9:55 am

Aquaman33 wrote:One thing I forgot to mention:

Aerotech DMS motors no longer come with a protruding nozzle at the back of the motor or a red cap to hold the igniter in place.

This image from the instructions is incorrect.

Image

I used some masking tape instead, so not a big issue.

I am sure Aerotech will update their instructions soon.


Firstly, Congratulations on obtaining your L1 cert, it was an impressive build and they both sounded like they were excellent flights. :D

The delay column burn times can vary, so the designated 14 second delay might only be 12 or 13 seconds...or 15 or 16 seconds, a small difference in length can be a big difference in time. Also remember that if it takes some time for your motor to light and come up to pressure your motor delay may be burning during this time...I had this happen to me with a J90 that chuffed on the pad for a while before lifting off and the chute came out under boost. It destroyed the chute and because I was using 1/8" Kevlar it also zippered about 500mm of 4" fiberglass tube. Using an altimeter for deployment will stop this problem because it will depend on barometric pressure to detect apogee rather than time.

There is no problem using masking tape to hold your igniter in, I have done this numerous times. :wink:

Blue thunder motors do look unimpressive in the smaller motor range but larger motors like the K1100T are great, I have launched a couple and they can look awesome!

Anyway, congrats again on getting your L1! I think of my 3 cert flights I was most nervous with my L1 flight. :lol:
‘It takes sixty-five thousand errors before you are qualified to make a rocket.’ — Werhner von Braun
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Aquaman33
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Re: L1 Build - Upgraded Loc IV

Postby Aquaman33 » Thu Apr 11, 2019 7:07 pm

Thanks Lamp.

The other thing I noticed with the Universal Delay Drilling tool is that it removes more or less delay charge depending on how much pressure you apply.

Although I had the tool set to 8 seconds for both flights I consciously used slightly more pressure for the H219 because I needed a delay slightly less than 8 seconds. Maybe I applied too much pressure and that brought the delay down to 6.75 seconds.

The washer is equivalent to 2 seconds and its quite thin, so I guess a bit of extra pressure will have an impact.

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SpaceManMat
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Re: L1 Build - Upgraded Loc IV

Postby SpaceManMat » Fri Apr 12, 2019 12:02 pm

There are many things that can potentially affect both the timing of the motor deployment and when apogee occurs. As Lamp says an altimiter takes out the guess work and can save the day if an anomaly occurs. The bigger motors do away with motor ejection as there is just too much variation for it to work reliably.
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Re: L1 Build - Upgraded Loc IV

Postby CATO » Fri Apr 12, 2019 12:19 pm

Congratulations on obtaining your L1 cert.... Great flight(s)... :D :D :D
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OverTheTop
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Re: L1 Build - Upgraded Loc IV

Postby OverTheTop » Fri Apr 12, 2019 2:19 pm

Congrats on the L1 :) .

Motor deployment is easy but a bit scatty. Once you go to electronic deployment you will never look back.
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Aquaman33
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Re: L1 Build - Upgraded Loc IV

Postby Aquaman33 » Fri Apr 12, 2019 7:13 pm

Thanks all for your kind words.

I have a couple of mid power projects I would like to build next, so that I have something new to fly at our local launch days (1,000 foot ceiling). But after that I am keen to try electronic deployment.

I have these tucked away in a drawer and I am excited to try them out.

Image

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Re: L1 Build - Upgraded Loc IV

Postby Lamp » Sat Apr 13, 2019 9:29 am

The on-board flight video is excellent!

Regarding the altimeters, I'm pretty sure the RRC2+ altimeters are Mach immune so you will have no problems flying through the Mach transition with these. I'm not sure about the Co-Pilot though...I would use this only for sub-sonic flights up to the Mach transition (around 0.8 Mach) just to be safe. :wink:
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