Search found 614 matches

by Passaretti
Wed May 30, 2018 4:32 am
Forum: Mid/High Powered Rocketry
Topic: Don't Debate This, Too
Replies: 32
Views: 876

Re: Don't Debate This, Too

SpaceManMat wrote:Hold the nut still (weld it to an end plate) turn the rod instead (either a lock nut on the end of the rod weld a nut on). By turning the rod you can also use a drill or air gun to speed things up.


Good idea!
by Passaretti
Wed May 30, 2018 4:23 am
Forum: Mid/High Powered Rocketry
Topic: Don't Debate This, Too
Replies: 32
Views: 876

Re: Don't Debate This, Too

Thanks for sharing all the great details of your build Mike! Looks a like a fascinating project. Would it help to cool the mandrel with ice when extracting it from the tube? I am looking very closely with what you do with carbon fiber casing, as we too are in the process of making some high-pressur...
by Passaretti
Sun May 27, 2018 5:08 am
Forum: Mid/High Powered Rocketry
Topic: Don't Debate This, Too
Replies: 32
Views: 876

Re: Don't Debate This, Too

I recently made a 2" roll-wrapped FG tube (for this project) over a polished aluminum mandrel which is something I haven't done before. I used a new mold release on the mandrel, which worked but the tube was very difficult to get off. I figured this was a good a time as any to build a simple ma...
by Passaretti
Fri May 25, 2018 6:15 am
Forum: Mid/High Powered Rocketry
Topic: Don't Debate This, Too
Replies: 32
Views: 876

Re: Don't Debate This, Too

Can you post a little info about your mandrel Sure thing. The mandrel I am using to make the motor case is Cast Acrylic Tube from ePlastics.com. Its spec is 3.625" OD x 0.125" WT x 72" L. The actual OD is about 3.610-3.615". Which worked out to my advantage by allowing space to ...
by Passaretti
Tue May 22, 2018 7:35 am
Forum: Mid/High Powered Rocketry
Topic: Don't Debate This, Too
Replies: 32
Views: 876

Re: Don't Debate This, Too

My original question (a few weeks ago) was ... Q: Does the rocket motor casing need to be gas-tight AND withstand the forces exerted by the motor, OR does it only need to withstand the latter? Well, the consensus seems to be both. Over the past few weeks, I've had a few conversations with folks offl...
by Passaretti
Fri May 18, 2018 7:48 am
Forum: Mid/High Powered Rocketry
Topic: Don't Debate This, Too
Replies: 32
Views: 876

Re: Don't Debate This, Too

What do you mean by "control volume analysis"? If I am not too tired this weekend I will attempt a control volume analysis of the rocket engine Mike to try and get a handle on the forward and aft closure stuff. I'm a bit rusty and busy though so I can't make any promises. Also, there is a ...
by Passaretti
Fri May 18, 2018 7:44 am
Forum: Mid/High Powered Rocketry
Topic: Don't Debate This, Too
Replies: 32
Views: 876

Re: Don't Debate This, Too

Subscribed! I'm keen to see how integrating the fins into the motor mount pays off. Losing the tail weight and cross-sectional area attributed to the fin-can has multiple benefits, some of which pay dividends. Less tail mass, which is inherently closer to the CG, means even less nose weight (which ...
by Passaretti
Wed May 02, 2018 8:07 am
Forum: Mid/High Powered Rocketry
Topic: Don't Debate This, Too
Replies: 32
Views: 876

Re: Don't Debate This

Q: Does the rocket motor casing need to be gas-tight AND withstand the forces exerted by the motor, OR does it only need to withstand the latter? Ok here’s my thoughts on this. The gas inside the the motor is being expelled at a rapid rate. So at least in part the thrust being applied to the motor ...
by Passaretti
Wed May 02, 2018 7:55 am
Forum: Mid/High Powered Rocketry
Topic: Don't Debate This, Too
Replies: 32
Views: 876

Re: Don't Debate This, Too

If you are working with composites, especially at the performance edge, process consistency is king. Most reliable testing methods for composites rely on destructive testing and statistics for a reliable outcome. 100% in agreement here. I spent part of last year getting set-up to hydrostatically te...
by Passaretti
Tue May 01, 2018 8:54 am
Forum: Mid/High Powered Rocketry
Topic: Don't Debate This, Too
Replies: 32
Views: 876

Re: Don't Debate This, Too

I have seen this video, Matt. In fact, I received quotes from several composite driveshaft manufacturers who are set up well to engineer CF Filament Wound tubes. I'm just about convinced that FWCF is the way to go to properly make rocket motors, however, the upfront costs are too high for me. So it'...
by Passaretti
Tue May 01, 2018 8:20 am
Forum: Mid/High Powered Rocketry
Topic: Don't Debate This, Too
Replies: 32
Views: 876

Re: Don't Debate This, Too

Thank you OTT. I have so much to share, so I'll be playing catchup for a while ... Hopefully, I'll get caught up on the forum by September! I have considered tapered fins, mainly for the benefits of reducing mass and increasing the stiffness of the whole fin. At this stage, it's certainly on the tab...
by Passaretti
Tue May 01, 2018 8:00 am
Forum: Mid/High Powered Rocketry
Topic: Don't Debate This, Too
Replies: 32
Views: 876

Re: Don't Debate This, Too

What can I say - Some people are just ahead of the curve ... It might take me a while, but I eventually come around :) Thanks for sharing Mike looks awesome, I'm sure it will be a great flight (as always). please keep us updated..... To answer both of these questions, I started looking hard at the a...
by Passaretti
Sat Apr 28, 2018 10:08 pm
Forum: Mid/High Powered Rocketry
Topic: Don't Debate This, Too
Replies: 32
Views: 876

Re: Don't Debate This, Too

Hi Matt, In this case, these are test fins and won't be going very fast (if at all). Their main purpose is to test infusion technique, measure how much the materials consolidate, be used for mock-ups of the rocket and possibly for low-altitude test flights to test the recovery system. I haven't deci...
by Passaretti
Sat Apr 28, 2018 10:10 am
Forum: Mid/High Powered Rocketry
Topic: Don't Debate This, Too
Replies: 32
Views: 876

Don't Debate This, Too

The goal is to fly and safely recover a minimum diameter CTI N5800 rocket in a single-use composite motor case. The target launch is BALLS 27, 21-23 September (147 days left). This project has been in the works since returning from BALLS in 2014. I've been working on it on and off since then. Unfort...
by Passaretti
Sat Apr 28, 2018 6:40 am
Forum: Self Introductions
Topic: Hello Again
Replies: 6
Views: 381

Re: Hello Again

Thank you guys!

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