Ye Olde Rocket Forum

Ye Olde Rocket Forum (http://www.oldrocketforum.com/index.php)
-   Designer's Studio (http://www.oldrocketforum.com/forumdisplay.php?f=27)
-   -   BARCLONE Designer's Studio 2008 (http://www.oldrocketforum.com/showthread.php?t=2163)

snaquin 11-01-2007 03:05 PM

Quote:
Originally Posted by CPMcGraw
Jay Goemmer emailed me with the heads-up. Change the setting on the first tab "Rocket Design Attributes" where it says "Static Margin Reference" from the default setting of "Nose Cone Base Diameter" to "Maximum Frontal Diameter". Everything else being equal, this should bring a loaded margin (with a D12-5) to about 5. The base diameter of the nose cone is actually larger in this case than the body tube, which is what RockSim normally defaults to. Empty margin comes to 8.

Jay put this info in another thread not too long ago, and I just forgot to make this change. I used his NC drawing method to produce the AV shape.


Thanks Jay / Craig

Jay shot me an email too. I'm going to have to make a mental note to check that feature in some of my designs. That's the same feature that Carl just tweaked on the two Semroc Laser-X design files he had too that showed the wrong margins.

I threw out a contest entry for EMRR one time because I couldn't figure out what was causing this to happen and I don't ever remember the maximum frontal diameter feature ever being covered in one of the Apogee newsletters.

Good to know & thanks guys!

.

snaquin 11-04-2007 01:04 AM

Quote:
Originally Posted by CPMcGraw
Got one of these in working order today, after picking up a dud yesterday. I wanted to see if I could come up with a better booster that would give some real performance, or at least gain some substantial altitude, compared to the booster you get with the camera. This first version is a throw-together, what-if type of design, and I'm just guessing about the actual weight of the camera. I have not yet weighed the payload to get an accurate value, but I'm guessing no more than 2.5 oz. It really doesn't feel that heavy, maybe just a little more than a hollow plastic NC of the same size.

The camera shoulder loose-fits into a standard ST-13 tube, so that's where I'm starting from. Other variations of this theme are coming, so this is just a beginning baseline.

Length: 19.30"
Diameter: 1.34 (ST-13)
Fin Span: 4.84"
Weight: 3.31 oz (Camera estimated at 2.5 oz)

D12-5......1015'......Dv 26 FPS......48" x 3/16" Rod

Takes about 7.2 seconds to reach apogee, so the 12-18 seconds of record time should be enough to get a flight video.

Enjoy!


Craig,

Picked up my AstroVision today at Hobby Lobby with the 40% off coupon. Funny story ..... I took my wife with me to the Hobby Lobby in Hammond today. While I was in the check out line she glanced over at the price tag and said "Hey, how much is that rocket"? When I whipped out my 40% off coupon and it discounted the price of the rocket by $28.00 she said, "hey that's not such a bad deal". I sent her back with another 40% off coupon to pick up a pack of D12-5's.

I'm interested in this BARCLONE design and I'd like to build a dedicated D engine booster. I do want to fly the AstroVision at our launch Nov. 17th so I'll probably put it up on it's first few flights with my EnerJet 1340 booster with a Semroc EM-9115 adapter, since that's what I have already built with Semroc series 13 tubing. I'm interested to see the other booster designs you come up with.

Also, I weighed my AstroVision camera tonight on my scale and with the batteries loaded and flight ready it is 1.4oz. Much lighter than I thought it would be.

.

CPMcGraw 11-04-2007 08:51 AM

Quote:
Originally Posted by snaquin
Craig,

Picked up my AstroVision today at Hobby Lobby with the 40% off coupon. Funny story ..... I took my wife with me to the Hobby Lobby in Hammond today. While I was in the check out line she glanced over at the price tag and said "Hey, how much is that rocket"? When I whipped out my 40% off coupon and it discounted the price of the rocket by $28.00 she said, "hey that's not such a bad deal". I sent her back with another 40% off coupon to pick up a pack of D12-5's.

I'm interested in this BARCLONE design and I'd like to build a dedicated D engine booster. I do want to fly the AstroVision at our launch Nov. 17th so I'll probably put it up on it's first few flights with my EnerJet 1340 booster with a Semroc EM-9115 adapter, since that's what I have already built with Semroc series 13 tubing. I'm interested to see the other booster designs you come up with.

Also, I weighed my AstroVision camera tonight on my scale and with the batteries loaded and flight ready it is 1.4oz. Much lighter than I thought it would be.

.


Nice going, Steve! Those coupons do come in handy for "special" purchases...

Translation: She can use 'em, too... :D

Now I can run the sim over again and get a more accurate profile...

The altitude came to 1138' with a slightly reduced Dv, down to 24 FPS, when burning the D12-5.

Interesting outcome with the C11-5. I get 565' with a Dv of 8 FPS. That's a really nice, clean flight with low velocity over the top.

Both motors seem to need a 48" x 3/16" rod with this bird, as they take at least 33" of guide length to reach flight V. An extra 12" wouldn't hurt.

What I really want is a "D" bird that Dv's below 10 FPS, and still gets off easily on a 36" rod. This one comes close, but I want the next one to be a little quicker on the launch.

CPMcGraw 11-04-2007 08:55 AM

Quote:
Originally Posted by snaquin
...That's the same feature that Carl just tweaked on the two Semroc Laser-X design files he had too that showed the wrong margins...


It also just occurred to my feeble mind that I may want to check this setting on the Andromeda, as the "Maximum Frontal Diameter" is not the nose cone, but the Reactor Shrouds.

Jay, if you're reading this, did you ever run the Tau Zero with this changed setting?

barone 11-04-2007 09:03 AM

Quote:
Originally Posted by snaquin
Craig,

Picked up my AstroVision today at Hobby Lobby with the 40% off coupon. Funny story ..... I took my wife with me to the Hobby Lobby in Hammond today. While I was in the check out line she glanced over at the price tag and said "Hey, how much is that rocket"? When I whipped out my 40% off coupon and it discounted the price of the rocket by $28.00 she said, "hey that's not such a bad deal". I sent her back with another 40% off coupon to pick up a pack of D12-5's.

I'm interested in this BARCLONE design and I'd like to build a dedicated D engine booster. I do want to fly the AstroVision at our launch Nov. 17th so I'll probably put it up on it's first few flights with my EnerJet 1340 booster with a Semroc EM-9115 adapter, since that's what I have already built with Semroc series 13 tubing. I'm interested to see the other booster designs you come up with.

Also, I weighed my AstroVision camera tonight on my scale and with the batteries loaded and flight ready it is 1.4oz. Much lighter than I thought it would be.

.

Something to keep in mind....you only get about 15-16 seconds of video with the AstroVision....

CPMcGraw 11-04-2007 09:21 AM

Quote:
Originally Posted by barone
Something to keep in mind....you only get about 15-16 seconds of video with the AstroVision....


I managed 17-18 seconds with mine, but the point is taken. The box says "launch to landing coverage", which is clearly misleading. On this "D" bird, it takes nearly 8 seconds to reach the moment of deployment (about 2+ seconds of burn, and 5 seconds of delay), but once the parachute pops out, it may take over 60 seconds to reach the ground.

Even with the "snapshot mode", with only three snaps per flight at 1.5 second intervals, you will take all three snaps well before reaching apogee.

The technology of the AV is about three or four years behind the curve; even cell phones from two years ago have better video capability. What the AV has to offer is price - it's relatively cheap if you get one with the HL coupon. I don't think I would have ever shelled out $80 for it, more likely opting for one of those Aipteks instead. Two, if the refurbished prices are still holding.

What this camera needs badly is a better frame rate and an SD card slot, so that we could swap out the memory for each flight.

Tau Zero 11-04-2007 04:44 PM

An Exception to Every Rule...
 
Quote:
Originally Posted by CPMcGraw
Jay, if you're reading this, did you ever run the Tau Zero with this changed setting?
What's interesting about the Tau Zero is that the main body tube is actually *smaller* in diameter than the "base" of the nose cone, since the nose cone and "transition" are turned as a single piece.

I had RockSim guru Bruce S. "teflonrocketry1" Levison take a look at a relatively functional RS file that I'd cobbled together of the TZ. He said I'd done pretty good in working up a fairly complex design (or something to that effect), :cool: and he only tweaked about 4 elements of it to make it "better."

One of the things he did was to change the "Nose Cone Base" setting to the "Reference Base Diameter," and specified the outer diameter of the ST-7 body tube, which is 0.759".

So I guess my Tau Zero is the exception to *this* rule! :o


Cheers,

James Pierson 11-04-2007 05:28 PM

What New Rule!
 
Here I am, all confused again. ;)
So, concider the following Mr. Wizard:

= Do I use the Full Frontal Diameter option if the nose cone is larger than the main body and only then?? :confused: If not then when??

James Pierson
NAR# 77907

CPMcGraw 11-04-2007 05:41 PM

Quote:
Originally Posted by James Pierson
Here I am, all confused again. ;)
So, concider the following Mr. Wizard:

= Do I use the Full Frontal Diameter option if the nose cone is larger than the main body and only then?? :confused: If not then when??

James Pierson
NAR# 77907


Obviously, there are some important exceptions to such a rule. Can anyone remember if the Apogee Newsletter ever covered this topic?

snaquin 11-05-2007 10:50 PM

Quote:
Originally Posted by barone
Something to keep in mind....you only get about 15-16 seconds of video with the AstroVision....


I'm thinking of using the AstroVision on it's first few flights in still mode and saving the video work for my two Aiptek cameras since those record in video mode for 120 secs.

I bring my laptop computer to the launch site to download data from my PerfectFlite altimeter anyway so I'll have it with me to download the AstroVision data.

I do wish the AstroVision had an SD card slot or more onboard memory for longer record times but considering the 40% off price I still think it's a worthwhile purchase. I'm excited to try it out.

.


All times are GMT -5. The time now is 10:44 PM.

Powered by: vBulletin Version 3.0.7
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.