Tuesday, July 11, 2017

Estes Apollo Little Joe II Build, Part 37, Capsule Sling TIP

EDIT: I didn't take into account the Estes reissue kit has LOTS of nose weight. The sling as shown below won't work with all the weight in the escape motor tube. I tied the sling before gluing on the escape motor assembly. In the end I had to go back and re-balance and tie everything a second time.
The pictures and copy below show the sling being tied on before I realized my mistake.

The kit includes a rubber shock cord, 1/4" wide by 48" long. The instructions have the body and capsule assembly coming down under a single 24" parachute.
If tied like shown in the instructions, the heavy capsule tower top could hit the ground first.

I referred back to the original Centuri kit instructions. Their kit had the capsule and tower descending on its own 16" parachute. The main body used a 24" parachute.

Study the drawing at the left. If tied this way the capsule will fall shoulder base first. I'd recommend upgrading the model this better, no tower break recovery.
There is a snap swivel clipped onto the low end of the tower. There is no chance of snap-back. The capsule and tower are ejected forward away from the body with much less shock.

The 1/8" elastic (on the left) ends up at about 7" long. Cotton embroidery thread (4" or so) is tied to the snap swivel and clipped to the tower.

The shock cord tie down was slid into place and the liquid glue brushed on the joint afterward.

The tower has already been glued into the command module. Here I haven't glued the escape nozzles and tube on yet.
Some strong cotton embroidery string was tied to a snap swivel and clipped to the low end of the tower. TIP: #10 Cotton embroidery string is also great for parachute shroud lines - VERY strong.

At the 7" mark from the base of the C.M., tie an overhand knot around the tower string. This allows you to slip the string through the knot and get the correct ascent angle.

The cotton string is then tied around the shock cord knot and secured with a very small drop of white glue. NEVER use CA glue (super glue) to secure a knot.

On the left is the angle I ended up with. It's not exactly the 7" and 4" lengths, but pretty close.

After all was tied up, the clay loaded tower jettison motor assembly was glued to the top of the tower.

The string (under my thumb in the picture) slides in between the capsule shoulder and body tube when packed for flight. Un-clip the snap swivel from the tower when the model is on display.

1 comment:

  1. Per your advise, Chris, this is what I did with mine, and it worked great, except the loss of the nozzles on landing, but that was from me not securing them properly. The sling did its job perfectly.