24mm MD 10,000 ft and Mach 1.6 on a CTI G150

[Viking]

Apologies, you are correct, I was reading ANSI and not 'P' grades.

 

[Viking]

Pick a standard, any standard....
https://www.knifeforums.com/forums/fbbuploads/1307988541-Gritchart_1.png

 

[TRFfan]

Very impressive design

Thanks

 

[TRFfan]

ive got the fineshed design of the rocket...will post it later tomarrow once i get to my computer.

 

[dford]

Why don't you just build one & see what happens? Remember, it is rocket science.

A little late but I second that from experience. Just lost [learned a TON] my first casing off my first mid power build.

Go for it, the worst that can happen is building another rocket!

 

[MostafaAwad]

follower

 

[TRFfan]

A little late but I second that from experience. Just lost [learned a TON] my first casing off my first mid power build.

Go for it, the worst that can happen is building another rocket!

Agreed

 

[retortec]

Follower

 

[tim cubbedge]

Agreed

Got any pics of your build?

 

[TRFfan]

Nope, not yet. My parts havnt came in yet.

 

[TRFfan]

final design.

View attachment 292539

 

[dhkaiser]

Late to the game, however I will chip in, that micro beacon is a waste. I have one and I left it in my bedroom and walked to the end of the hall and could not hear it.

 

[retortec]

Still following. I looked at your .ork file and had a thought to keep in mined. If you are relying on barometric sampling for your speed and altitude the port positions are critical. At least 3 body widths back from the nose cone shoulder. I say at least because I was just shy of the standard 3 and ended up with some wild data. My barely supersonic flight registered speeds near Mach 3. Different shaped nose cones produce different pressure zones on the airframe. Unfortunately the only way to see what works for your design is to put something in the air.

 

[TRFfan]

Late to the game, however I will chip in, that micro beacon is a waste. I have one and I left it in my bedroom and walked to the end of the hall and could not hear it.

Yeah, to be honest i wasn't really looking forward to using the Microbeacon, but it was the only cheap tracker i could find on the market at that time. Now I'm going to be using a telemini for tracking (as well as deployment and altitude measurement) and a peizo buzzer just as a backup. I think the peizo buzzers are really nice, only 1.50 for one of them and supposedly they are quite loud too.

 

[TRFfan]

Still following. I looked at your .ork file and had a thought to keep in mined. If you are relying on barometric sampling for your speed and altitude the port positions are critical. At least 3 body widths back from the nose cone shoulder. I say at least because I was just shy of the standard 3 and ended up with some wild data. My barely supersonic flight registered speeds near Mach 3. Different shaped nose cones produce different pressure zones on the airframe. Unfortunately the only way to see what works for your design is to put something in the air.

Yeah i know, i was wondering about the placement of the air holes so now im going to do a little research of them, once i get the time.

 

[TRFfan]

And there was something else i was wondering, my telemini is in the nose cone so do i need to place it back near the air holes?

 

[retortec]

And there was something else i was wondering, my telemini is in the nose cone so do i need to place it back near the air holes?

No. But you need to consider the total volume of the section you are venting. Perfect Flight and some others have basic guidelines for given volumes.

 

[tim cubbedge]

Where are you launching this at?

 

[Jimmy F.]

Where are you launching this at?

computer

 

[TRFfan]

Where are you launching this at?

Rage at the Gage, in new brunswick

 

[retortec]

Still following to check out the build and the flight. I just flew design #9 this week end and got schooled in the basics. We had a very gusty wind at the launch site. But I was so excited to see her fly I decided to go for it. Soon as it cleared the tower it drove into the wind in grand fashion. Straight as an arrow at mach 1.69+ 3/4 mile or more up range. It took over 1000 feet off the total altitude. Just proves it may take a couple attempts to get it right. #10 is already in the works with some improvements to get past mach 1.7 and 7000 feet.

 

[TRFfan]

Still following to check out the build and the flight. I just flew design #9 this week end and got schooled in the basics. We had a very gusty wind at the launch site. But I was so excited to see her fly I decided to go for it. Soon as it cleared the tower it drove into the wind in grand fashion. Straight as an arrow at mach 1.69+ 3/4 mile or more up range. It took over 1000 feet off the total altitude. Just proves it may take a couple attempts to get it right. #10 is already in the works with some improvements to get past mach 1.7 and 7000 feet.

Which design did you use and do you have a screenshot of its ORK file?

 

[tim cubbedge]

Which design did you use and do you have a screenshot of its ORK file?

Dude just build one & fly it & see what happens. As many have said, this will be trial & error.

 

[retortec]

Design is my own and has evolved over the last year and a half. timbocktoo is right just build and see what happens. It is all best guess until you put it in the air. Computer results can differ drastically from actual flight performance. Especially with small high speed rockets. They seem to have a cornucopia unique fun. I like to build and fly so my design is based on reinforced craft paper tubes. Reinforced by design or surface treatments like paints or epoxy. The drawback is I only get one or two flights before the rocket is retired. The big advantage is I build and improve for $10.00-15.00 per rocket. In the end I will build a full carbon version but I doubt it will preform much better. #9 weighed 3oz with altimeter and low power tracker and 4"x4' streamer.

 

[tim cubbedge]

Retorec - are you using a tower or rail buttons? A buddy of mine had to resort to buttons. His was CF & just couldn't get it to fly straight on a tower. Good luck with your next attempt

 

[retortec]

I think a fly away or tower are the best bet. The drag from the buttons or lugs is pretty phenomenal. I settled on a tower a while back. My first tower was the regular three round rods with halos. It was hard to fine tune and seemed not quite rigid enough. So I decided to build a self supporting tower with integrated blast plate and cone. The plate and cone help redirect the start blast away from the rocket. I just think flying turf and dirt can't help a straight flight on a 3oz rocket. This tower is real pain to adjust but you can move the rails in micro amounts if needed. Solid as a rock and stays square no mater what. Flights are much straighter but I still get a wild one once in a while. I think the root of the problem is the G80 thrust ring. It is larger in diameter than most light weight airframes. This in my opinion can start a wobble or mis alignment in the tower. Last few months I have been working on a peel away sabot or rail guide. Several low power flights have been promising. Thanks for the luck. I need all I can get.

 

[retortec]

op:

 

[tim cubbedge]

Cool tower!

I'm convinced the OP will never build his rocket but I hope he proves me wrong.

 

[retortec]

Thanks. I hope he does build it. The .ork file has some good ideas but it still has room to evolve. I finished the air frame for #10. I was able to reduce the drag on the fins by a significant margin. The surface finish has improved also. Flight simulations put it well beyond Mach 1.7. Now I am moving on to electronics and recovery.

 

[Estesbasher]

Thanks. I hope he does build it. The .ork file has some good ideas but it still has room to evolve. I finished the air frame for #10. I was able to reduce the drag on the fins by a significant margin. The surface finish has improved also. Flight simulations put it well beyond Mach 1.7. Now I am moving on to electronics and recovery.

View attachment 295024

Beautiful job retortec. Ya there a lot easier to build than get back. I've found that this plate is stiffer, made from tighter carbon fiber https://www.cstsales.com/carbon_plate.html This one was made from that type of plate. Only flew it once never to be seen again.