Friday, February 5, 2010

Viper building part III

I've got some more building done over the last few days, mostly using my wonderful epoxy clay.

First I installed the shock cord mount. It's an 18" length of 1/8" nylon cord. The instructions say to tape the ends to the inside of the body tube about 4" down from the forward end and slather with epoxy. I used epoxy clay instead, but it's still very strong.

Second is the cluster mount assembly. I epoxyied two nuts between the four 24mm tubes, and used a threaded rod to get them an exact distance apart. I also epoxied a washer to a 2" length of threaded rod. Now, all I have to do to retain all four motors is to thread the rod-with-washer into the middle of the cluster and the washer holds all four motors.

2 comments:

R2K said...

How do you like it so far? I have a Viper IV and it is great fun! It has only gone up a few times, and the last time I tried to do a 4x D12 cluster only 2 D motors burnt (though recovery was ok.)

I plan to fly it on some 2x 24mm RMS motors in the near future, perhaps 2 F39s would be cool. I wonder if 1 F39 would be enough to launch it and recover in the event of a single ignition?

1 D12 certainly is not enough.

The EGE said...

Well... 4 D12s = 1 67F41. Which is 67Ns versus the 48Ns of an F39, but the same thrust. It would fly, certainly.

Personally, I would take 2 F24Ws, use quickburst igniters, and coat the grains with pyrogen. That was it's instant ignition, but the better tracking smoke of the White Lightning.

Or, you could use a single or double F35W, which is 55Ns. Just remember to plug the empty motor tubes.