Never built an ebay.

[Capt. Eric]

Suggestions above are all good. I try to learn from others' experience as much as possible, and generally seek to keep it as straight forward as possible. Here's 2 suggestions for you to consider.

I liked the idea of a switch between the battery and controller (vs between controller and charge well). I used a pin switch from Lab Rat Rocketry. Easy to add. Effective. Easy to see if the switch is open or closed (pin in, or out), and the pin can be secured well with a Velcro strap if you feel the need. (As was said, it's kinda fun to use a "remove before flight" flag on the pin.) Most of all, it's easy to pull or insert with no tools, or struggle to hit a small button with a stick somewhere inside unseen.

I've also seen some folks struggle to hear the tones at startup from their controller that is encased inside the rocket. Seeing that my stratologger CF has an output to an indicator light, I added a LED light that is mounted in a hole in the switch band. You don't need to hear the low beeps - you can see the flashing lights. Very helpful, especially if a little wind is whistling through your ears! I don't know if many other controllers have that feature, but I like having it.

 

[vixenrider]

That makes complete sense, and I think you're approaching it from a solid way - look at what people have done, ask questions, find tutorials.

Don't be afraid to build one and toss it out if you don't like it. I know how I approach them is very different from the first one I built years ago.

Some things to keep in mind - how many altimeters? Will you have a transmitter - if so, allow for room for the antenna. What type(s) of batteries, and how to properly restraint them. How about switches - magnetic, screw, or twist & tape?

What type of material do you plan to build the sled from? G10, plywood and 3D printing are all viable options.

Here's an example of a couple sleds that @roytyson 3D printed for me. They're two piece sleds, designed for a TeleMega and an EasyMega. The batteries go in the rectangular box, and a MissileWorks screw switch is mounted to each side, one for each altimeter. 1/4-20 allthread runs up two channels between the two pieces.

View attachment 658539

Good info, I might try 3D printed sleds next time on mine. It's all a matter of cost since I'm retired LOL!
Love your tag line BTW, mine used to "Holder of the Mallet O' Understanding" which was a 16 inch diameter tree trunk with an axe handle attached to it.

 

[troj]

Good info, I might try 3D printed sleds next time on mine. It's all a matter of cost since I'm retired LOL!
Love your tag line BTW, mine used to "Holder of the Mallet O' Understanding" which was a 16 inch diameter tree trunk with an axe handle attached to it.

3D printing is amazing. I just don't have the patience for the design side of it.

That tag line was bestowed upon me by John Lee, back when I was running this site.

 

[mtnmanak]

I have a tutorial on my website - see Dual Deploy on the HPR primer page:

https://www.mountainmanrockets.com/index.php/hpr-primer/

It needs some updates, but should walk you through most of the things you need

Also, look through some of the builds on this page:

https://www.mountainmanrockets.com/index.php/builds/

I walk through some detailed ebay builds on everything from a small 2.6" rocket up to large ebays on 8" rockets.

 

[b0g_nerd]

Another update: I decided to try to build my own flight computer. I've got readings for velocity, acceleration, altitude, angular velocity, orientation, etc. I still need to add a MOSFET module for dual deploy. I also want to connect an SD card reader for post-flight analysis. Please excuse the mess of wires, I'm still prototyping.

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