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I've been following this thread as I'm in the process of developing a hybrid controller on an Arduino platform. It will operate a servo, take pressure readings from the supply tank and do some...

I also prefer the single piece machined buttons. Don't know why but I do. I also like how you can make them into integral standoffs for rockets like the HoJo and Nike.

Edward

$1.50 per railbutton isn't that expensive when you think about it. Say you make $20/hr. That is 9 minutes worth of your time (not counting materials) to fabricate those rail buttons. Especially...

Give me a weight and length requirement and I'll be on it :) I'm guessing I could do 3 ounces CO2 for deployment, hardware all up for about 1.5 pounds, 9" long, 2" diameter. You would still use an...

CO2 canister with servo valve? There was an Aussie who had a *very* elegant solution, but for the life of me I can't think of his name. It was a work of art.

Edward

People use masking tape, electrical tape or rubber bands for this exact purpose. Easier than sewing thread.

Edward

When Nick did this years ago - the one thing he always worried about was stripping a chute/some malfunction because then you'd be tossing out the main in a configuration that was purely ballistic. ...

Many moons ago Nick @ Aerosleeves had a rocket like this. It was high performance and it came down ballistic to 5,000'. Then he had the fincan and the airframe separate at that point with a lot of...

Do you need to be a NAR member to fly?

Edward

Hey,

The parachutes are sewn, but I'm waiting on getting more suspension line material to finish them up.

Edward

Some nomex I've seen used is quite porous. You want something that has a tight weaver or is non-porous. A few people have used the material in vinyl signs.

Edward

Yes, Hancock or JoAnn should have them.

Edward

I use ironing board fabric. I make them double thick and I've never had an issue with burning through. Inexpensive also, about $6/yard on sale.

Edward

I was at the launch, this wasn't the only rocket that came in ballistic. A couple landed on the other side of the road away from us that were angled away.

In general, the up part most people...

I find that neon pink/black works best for the prairie where we fly.

Edward

Toothpick across the top grain of the motor, and the wire wrapped around that.


Edward

John,

Thank you for the reply. I didn't know if SCORE had and hybrid GSE. They are a rarity these days.

Edward

Will there be any hybrid support at NSL?

Edward

Try irrigation pipe - it generally has a thinner wall. Class 200 (200 psi rated) has a .060" wall in 3/4" size. It goes to Class 125, which would be a thinner wall.

Edward

If I'm not connecting the e-match directly to the altimeter, I use 20 gauge hook-up or lead wire. This wire is meant for repeated bending and moving around over and over. I found some at a local...

Chuck,

Your first test was a bit anemic, but I believe that you have fixed it with the test posted above, DD Test #3. I would keep your main parachute charge at that amount, then if you have do a...

Use the sticky at the top of this Forum - Technical References for Parachute and Recovery Systems.

That will tell you all you need to know. As for the frontal area, it is generally an number...

In any recovery situation, I try to choose a parachute that minimizes horizontal velocity. I have had rockets come down at 5 fps vertically, but 20 fps horizontally and they cartwheel. I stick with...

*SOAPBOX ON*

I wish a long, long time ago when standards were being created that 75mm motors would have been left at 3" OD, and 98mm motors would have been left at 4" OD. I can only imagine the...

A club member has the Contrail setup. He has flown it a couple of times. His one issue is that the hardware is very heavy for the impulse. They fly well though.

Edward

As previously mentioned, I use drill bits in 1/64" increments for nozzles up to 1". Anything bigger and I use a set of bore gauges.

Would it be cheaper to include with each reload a piece of...

My Mg/PTFE grains give volumes of white smoke - almost like white lightning. It is why I do them - something different.

Edward

Very nice, but bummer on recovery. I think the dense black smoke is a direct result of using more dense N2O. I've used PVC grains also with 700-900 PSI N2O (at the corresponding densities and...

There are few photos of the incident. The fewer, the better. But, it did make a 16' 1010 rail about 4' shorter.

:)

Edward

I have seen more commercial motor failures than research ones. And, like Kevin, rocket recovery issues cause me much more concern.

Edward