OK,
While we are waiting for clarification, here is my first stab.
It works on a couple of principles: First we build in some controlled elasticity, and second we minimise whipping by creating a 'scientific stick'.
The knots are very simple, the only one you might have to learn is the four strand Matthew Walker Knot (MWK). The best video I have seen for this was made by Phil the Rope here
http://www.gr8-knots.com/Matthew_Walker.htmWhy the MWK? Not because it is a very hansom knot (which it is), but because of its functionality: It is extremely stable and strong and it is one of the best load distributing knots going.
You will also need to make up some harness loops and two loading loops. You will need one harness loop between every box, and a load loop for the top and one for the bottom.
Harness loops can be made out of 3mm polyprop braid as they are not going to do much work - they are only going to keep the load cords centred on the face of the boxes. To make up some harness loops, tape a 1/4" cane to the centre of each face of a box as a template so you have a box with four short canes sticking out of the top of it. Take a length of 3mm, fold back 6" to make a bight and tie an overhand in the bight to make a loop about 1" long - put this over one of the canes and take the cord across the top of the box to the next cane. Make a small loop about an inch from the cane and protruding past the cane sufficiently so that when you tie an overhand to make the second loop, it slips snugly over the cane. Repeat this for the other two canes, then tie the two remaining ends together with a reef knot, then tape or glue the ends to lock them. You should now have a square with four loops that just stick out past the sides of the box. Make up a number of these loops so you have one to go between every box.
Now you need a top harness and a bottom harness. make these out of 1/4" cord almost identical to the harness hoops except extend the loops 2" beyond the side of the box. These harnesses are going to take some tension, so if you can splice, then join the ends with a splice, or otherwise use a good knot like the Double Fisherman's then whip or tape the ends in place.
OK, now you are ready to make up the Instrument Stack.
Place a harness on the floor and put a box onto it so the loops stick out middle of each face. Experience will tell you if it is necessary to strengthen the edges of this bottom box with some card corners.
Put a harness loop on top of the box - loops sticking out each face, another box, another harness etc. etc until you have built the whole stack, then put the top harness loop on the top.
Now take two lengths of 1/4" cord nearly three times the height of the stack. Middle each cord and put the two loops together. Fix them together with an elastic band making two loops about 3" long. Now tie a 4 strand MWK. The double loops will become your tie on for the balloon and the parachute.
Place the MWK in the centre of the top box with a length hanging down each face of the stack. Pass each cord through the loop of the Top harness. Pass one cord down one side, threading it through the harness loops as you go, then through the bottom harness loop and back up the stack, going through the harness loops again and through the top harness loop. Lightly tie it in place with a half hitch around the two strands running down the side of the stack.
Repeat with threading the opposite side cord through the harness loops and back up and tie off.
Now thread the back cord in the same manner, leaving the fronts clear to have the batteries installed.
Install the batteries, close the faces and thread the front cord down and back up.
Once the four cords are threaded, it is time to tighten the assembly up.
Best done with two people, release the half hitches on the side cords and simultaneously pull them down to tighten them, ie. clamping the MWK against the top of the stack. Tie each cord off with two half hitches made around both strands of cord just below the top harness loops.
Now tighten the front and back cords, and tie them off. Make all four ends permanent by taping them to their pair of cords.
As the front and back cords were tightened, if the harness sizes were correct, the cords should have been nipped in at every box/box junction by the tightened harness loops. This is virtually all the work these between box harnesses will do, holding the long cord central to the faces.
The bottom harness is taking all the tension load and will take all the mass load, as well as any whip / shock load that reaches it.
The top harness is taking the 'holding tension of the tightened cords, but will take little more than this.
The four cords are tied off at the top of the stack, but travel down the stack, around and back up the stack to the MWK. This long length of cord acts as the elastic shock absorber, expanding under load and feeding through the loops of the top harness and passing any shock waves in an attenuated form down to the bottom of the stack. For this reason the 1/4" cord should be a dynamic cord rather than a static type, in order to allow the elasticity to be present.
Clip the top loops to the balloon and the chute and Bon Voyarge.
Any good for a first guess?
Derek