Nose cone tracker - switch or no switch

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kjkcolorado

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I built my Level 2 rocket nose cone with a removable bulkhead in preparation for a GPS tracker. I've seen the new MissleWorks RTX system and am patiently waiting for it to hit the open market. I've got the basic constructs of how I want to mount it and make it removable/interchangeable with future projects. One question I keep going back and forth on is turning the tracker power supply on/off. Option one is a power switch to access once the whole thing is 'buttoned up' ready for flight. I'm assuming this would required some sort of access hole drilled into the nose cone. Option two would be to just plug in the battery before screwing on the bulkhead. I'm planning on using a LiPo battery with JST connector. If I remember correctly, when Jim Amos shared some info on the RTX at the NCR Annual Meeting in January, he said he was easily getting 24 hrs out of a modestly sized LiPo. So, I don't feel like there will be much urgency to shorten the time from turning the unit on to getting it to the pad and launching.

Suggestions, other options, pictures....? What have you all done? Thanks.
 
FWIW, I have never used a switch for nose-cone mounted trackers. If you have the run time, it's one less thing to forget or go wrong.
 
I plug my Beeline RDF units in and go. Good for several hours, but I do only plug it in just before the trip to the safety check table. Why run the battery, plus as a frequency user there's an obligation not to be a pig and broadcast unnecessarily. If I was doing something crazy that might take a long time to recover I'd arrange a battery that was an order of magnitude larger than the usual.

N
 
It takes about a minute for the GPS to acquire lock, so I like to power the transmitter up in the prep area to be sure it is working properly rather than waiting around at the pad holding up the launch. I use EggFinders BTW. There should be plenty of extra run time if you use a 3+ hour battery and it might save you having to pull a rocket off the pad. Also, GPS units are most helpful as the rocket is descending; not so much on the ground until you get close. It is unlikely that the extra time is going to make a difference in whether you are able to recover the rocket.
 
Yep, last thing before heading to RSO is tracker plugin and NC shear pins. Have even endured a 4+ hour rain delay at Airfest with no problem as standby current for Big Red Bee products are very low.
 
The other thing with the BLGPS is one can set the auto cutoff voltage for the battery so it doesn't over discharge. I've replaced a cell simply because it got too old
and didn't hold the charge like new anymore. Kurt
 
I see no need for an on/off switch for the GPS tracker. The battery draw is very low.

I also plug the battery in at the prep area and the transmitter is ready to go when I get to the pad. I fly the BRB900, on two different av- bay sleds. One is mounter to the nose cone bulk plate and one mounts on an PML Inteli NC sled that fits into either my 4" NC or a 3" NC. Having the av-sleds interchangeable saves a lot of prep time. It takes less than five minutes to move the transmitter from one av-sled to the other.
 
I have also thought about putting a switch in my nosecone tracker bays, but in the end I have come to the same conclusion that most others here have posted; one more thing to go wrong and not really necessary.

Pad delays have been one of the motivating factors for me to consider doing this, but to get around this I just oversize the size my battery to make sure I have more than enough run-time to wait on the pad, launch, then worst case scenario take many hours to recover.

I see no sense in not over-doing the run-time, the weight difference is negligible and even if you're really over-stable a few grams difference will not make any difference in flight stability. Of course physical space limitations you can't do much if anything about.
 
Thanks. I was hoping the 'no switch' responses would dominate and there wouldn't be a compelling reason I had not thought of to use a switch. I prefer to keep things as simple as possible as well.

Wingarcher, good point about trying not to be a 'pig' with broadcast time. I've read some preliminary info on the MissleWorks RTX (possibly from Jim Amos also...?) that there will be separate pairing frequencies for each base and transmitter combo sold to try to avoid confusion/competition over signals at a given launch. Not sure my terminology/description of that is techically accurate.
 
This thread inspires me to put a switch in my tracker av-bay! I have a nose cone mount similar to this:

https://www.rocketryforum.com/showthread.php?132392-Minnie-Magg-Build&p=1556489#post1556489

That is 6 screws to fall in the grass and get lost at the launch site and further delay my launch enjoyment. With an external switch, I can button this up in the comfort of home. A nice Shurter rotary switch would be perfect here and is just as reliable as the rest of the system.
 
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