I will post some pics of the two racks that BRB uses. The horizontal beam is 1 square aluminum tubing, with a 7/8 wide U channel running underneath that. The wiring runs inside the U channel. Legs are 3/4 PVC. Special adapters hold the legs and plug inside of the 1 Square aluminum tubing.
In the early 1970s, Estes (maybe Centuri?) sold (but did not publicize) a rack system that used all-aluminum racks, including legs that seemed to clamp on to the square aluminum tubing sort of like sawhorses do, except they locked into place and were designed to fit the square tubing they clamped onto. When I was designing these racks, I tried to find something like that, but never did.
A key design criteria of the racks was to be convenient to transport. Nothing is over 48 long. The racks are compact enough that both of them fit inside of a 7 x 8 x 49 box with room to spare. That box easily fits into any car.
Here is one suggestion, regardless of what kind of racks you make. If you ever plan to use the racks set up far apart, so you will launch one rack while another rack is being loaded, add some positive indicators to alert both the LCO and anyone near the rack that a rack is ARMED. Many years ago, NARAMs used racks, and inevitably there was an accidental launch of the wrong rack, and a common issue was there were no arming indicators on any of them.
For BRBs, each rack has a light and a buzzer. The buzzer lets anyone near he rack know it is armed. This is done by running an additional wire from the panel to the rack, branched off between the arming key and launch button, so the wire is energized when the panel is armed (actually, I ran it thru a flip-flopping timer circuit to make the light and buzzer at each armed rack flash and beep). For a normal 5-pad rack, you would use 6 wires (5 pad positive, plus ground). For this, a 7th wire (positive when armed) is added.
The launch panel has a selector switch, for up to three racks (selects the ground wire of which rack to arm). The panel has three lights on top to show switch is armed, and the panel has a piezo beeper to indicate the panel is armed.
But instead of a third rack we have a 5-pad HPR Junction box. The Junction box splits out the five launch leads that can go to up to 5 HPR pads. The Junction box has a plug-in post with a bright tail-light assembly on it, plus a very loud Piezo beeper that alerts everyone when an HPR flight is armed. This is also a re-assurance to those loading the HPR pads that the HPR Junction box is not hot, otherwise they would be hearing that beeper. BTW - in the pics, the junction box is shown with the original strobe light, which proved to be too wimpy, so it was replaced with the tail light seen in the video).
A video on Youtube showing the launch system in operation, plus an HPR cert flight by Brandon Kirkland, last December:
https://www.youtube.com/watch?v=FizWJ518XHI&feature=channel_page
- George Gassaway