Wednesday, June 04, 2008

Weighing in on nose weight

The nose weight issues for both the Pogo and the Tarkus II have been put to bed!

On the Pogo, I needed a bit more weight. As I was cringing at the thought of adding lead shot to the plastic nose tip (I wanted the eye bolt to bear all the weight), I thought about a fishing weight. I have used the type shown in the left of the photo several times. These slip over the line and then are locked in place by a rubber grommet. I spread the lead 'clamshell' and remove the grommet. Until now, I've used them to clamp to a Kevlar shock tether where adding weight to a nose is difficult or impossible. Just insert the cord in the gap and crimp down. Works well. This time I needed half the weight so I cut it in half. Here, I pressed a knife blade into the soft lead and then squeezed it in a vise. Cut like butter (well, almost). I then just screwed the lead weight onto the shaft of the eyebolt. So, my goal of keeping the weight on the eyebolt was attained! The Pogo weighs 5.3 oz without motors. A C6-5 and two A10-P's should take it to the neighborhood of 500'.

The Tarkus II's CG, fully loaded with a dummy motor, was just in front of the leading edge of the aft body. My gut said that this was good enough. I can't model everything in RockSim, but I did make an approximation. This model agrees with my gut so I'll load it on the HPR pads and give it a try. A G64-5 should do the trick. (Note to self: remember to add the rain buttons!)