Video rocket project--pics and pre-launch questions

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SCE to AUX

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Here are a few pics of a recent project that I hope to launch in the next few weeks. An Estes "SuperNova Payloader" with a video downlink system.

The rocket itself is essentially a stock build, with the only modifications being a stronger shockcord and the mounting of an SMA bulkhead connector in the tip of the nosecone to take the antenna.

The payload bay has been slotted to accept the camera lens, and drilled with a hole to allow access to the power switch. Because of the slot, the nose cone had to be attached using small screws. I may paint the payload section black/blue to match the rest of the body, or leave it clear to show off the guts. The camera is a 1.25" square color CCD with a wide angle lens, and the transmitter is a 500 mW 900 MHz unit from SuperCircuits. Power for both comes from a single 9V battery. There is a red LED installed to provide power indication. All the electronics are mounted on a fiberglass carrier which slides in and out easily for battery replacement. I plan to capture the video using a USB video digitizer and a laptop connected to the receiver on the ground. At the moment, there is no audio link, but the transmitter can handle it, so I may eventually use the audio channel for audio or telemetry.

I want to incorporate a mirror and fairing to angle the camera view down at the ground during ascent. It will mount just above the camera lens, over the slot in the payload tube. I have some very thin mirror material, and plan on making the fairing from balsa or foam. Do you think that the fairing is going to cause instability problems due to asymmetrical drag? Would a dummy fairing on the opposite side be a good idea to counteract this?

I plan to do initial flights on a D12-3 motor, but the total weight is 13.5 ounces, only 1/2 ounce under the maximum lift weight for a D12-3. Is this pushing things too much, or should I be OK? I am planning to use a 5' long launch rod to help stabilize the rocket off the pad, as I assume the liftoff will be slow. Eventually, I want to go with a 24mm RMS system and higher power loads, but initial tests seem to call for caution. First tests will be with the payload bay empty, just to check basic stability/recovery, then a few flights with a simulated payload weight. I REALLY don't want to prang this thing on the first launch with all the electronics onboard. :)

First flight tests are planned for the October GSSS launch on the 27th.

PA140469.jpg

PA140470.jpg

PA140471.jpg

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PA140473.jpg
 
Awesome!

Would you mind sharing where you got the CCD from and how you connected it to the transmitter? And also all of the receiver to laptop stuff?

Thanks!
 
The camera module was yanked out of a video "baby monitor" that I found at a garage sale for $5 because the receiving unit was busted. Similar units are available from various companies that deal with covert video stuff. Here is one possible source:

https://www.scdlink.com/Details.cfm?ProdID=1444&category=13

The transmitter hookup is very simple, 4 wires (2 for power (+9V and ground), one for audio in, and one for video in). The antenna output is an "SMA" connector, which is fed through a short length of miniature coax cable (RG-174) to a bulkhead connector in the nose cone.

The receiving end is just a box with an antenna, which outputs audio and video. I take the video and feed it into the USB port on a laptop using one of these:

https://www.usbvideoadapter.com/

You can record the video using the included software.
 
Cool! Do you have a link to the transmitter/receiver package?
 
OMG that is exspensive!
No wonder you wanted to do some non-camera flights first :)
 
Juts an YI. www.x10.com has some wired camera units that would work in a rocket. The website is a little "busy" but has some nice stuff.
 
Interesting project... video is also a special interest of mine.

... and the mounting of an SMA bulkhead connector in the tip of the nosecone to take the antenna.

Hmmmm... that antenna, known in ham radio circles as a "rubber ducky" is going to flop around something awful when the rocket starts accelerating. Have you thought about finding a way to mount the antenna internally within the nosecone instead of out there in the wind?

As an alternative, you might try a metallic tape antenna on the surface of the nosecone.

At the moment, there is no audio link, but the transmitter can handle it, so I may eventually use the audio channel for audio or telemetry.

My only complaint about my Oracle is the lack of audio... by all means, add that if you can.

I want to incorporate a mirror and fairing to angle the camera view down at the ground during ascent. It will mount just above the camera lens, over the slot in the payload tube. I have some very thin mirror material, and plan on making the fairing from balsa or foam. Do you think that the fairing is going to cause instability problems due to asymmetrical drag? Would a dummy fairing on the opposite side be a good idea to counteract this?

I'll reference my Oracle, again, since it appears to be similar in size to your system... I haven't heard of, nor have I seen, any tendency to be unstable with the camera fairing sticking out (less than an inch) from the nose cone. There are a few different ways to accomplish such a covering.. a search through the archives will point out several build threads from other folks who've ventured that way before.

Good luck with your project and hope to see your video, soon!
 
If yer under the max weight, then yer under the max weight. Go for it.

Seriously, it sounds like you're taking appropriate precautions and thinking everything through carefully.

It looks great so far. Launch it and post some video already.
 
Interesting project... video is also a special interest of mine.



Hmmmm... that antenna, known in ham radio circles as a "rubber ducky" is going to flop around something awful when the rocket starts accelerating. Have you thought about finding a way to mount the antenna internally within the nosecone instead of out there in the wind?

My original thought was to mount inside the nosecone, but was surprised to find that doing so dropped the signal strength by over 10 dB! My only guess is that the black pigment in the plastic is carbon black or something else conductive, and is causing a "Faraday cage" effect. I have a few spare antennas, so I will try to stiffen one up by covering it with a layer or 2 of adhesive-lined heatshrink.


As an alternative, you might try a metallic tape antenna on the surface of the nosecone.

Interesting idea. Do you have a commercial source for these, or is this something you make yourself from foil tape?
 
If the total weight includes the motor, you should be fine. I think the estes recommended max lift weight includes the motor.
 
This is an awesome project, and I'm looking forward to seeing the video. I had a similiar system in one of my R/C planes a few years back, and the results were good.

SS
 
It seems no one has truely addressed your main questions...so, I'll attempt to shed a little light on you inquires.

I plan to do initial flights on a D12-3 motor, but the total weight is 13.5 ounces, only 1/2 ounce under the maximum lift weight for a D12-3. Is this pushing things too much, or should I be OK?

Your under the 14 Estes states you're GOOD there! I've pushed them to dead on the 14 mark multiple times with no problems, the 5' rod is good, personally I use a 6' but 9 out of 10 times that is over kill, but that's just me... I did a launch at Orangeburge this last weekend using a cluster of ''E's" that the rocksim program insisted on a 6' rod...using a D cluster I would of had no concerns as the thrust of the D's are well over the E's, but I was looking for the ceiling for my rocket...I was very concerned as they only had a 5' available with about 6" of it gone (due to mounting)...to shorten this up, it was a "heads up" flight and it when off like a champ with no problems! Sorry for the rambling...anywho, your fine with the weight / rod.
Now to address the drag factor, that one "can" be touchy... Not saying it is, but the addition of this could be pushing the CP forward too much in relationship to the CG, (although, your CG will be moving forward also with the weight) if you're awhere of both and know there is a 1.2 or higher then you're good there.
Now the drag in relationship to a non-curving flight assuming the above is in order and it's stable. If the protrusion is no more than 1/2" max and it is nicely aero dynamic I wouldn't be too concerned there, if you feel it will be causing a lot of drag then yes, do the same on the opposite side, after all, overkill is better than a loss or injury! Hoped I helped!
 
Hi SCE to AUX,

I just dealt with this very same issue! Or kinda...

Anyway, I've been working on a Mid-power design that incorporates a zipperless mid-body ejection separation with ejection baffle, and uses the Estes Oracle camera nose cone and an Alt15K altimeter in the payload section. But not wanting to jump straight into theses unfamiliar areas, I decided to "build" a test bed airframe.

My test bed for this combination was the original Oracle rocket with an added 4" payload section and splitting the tube at the coupler and using an ejection baffle. The all-up weight was 12 oz (with motor) - RockSim suggested a D12-3 motor. I used a 3-ft 3/16 launch rod, which the sim showed might be slightly inadequate and could cause significant weathercocking in a strong wind (> 15 mph). But, I used it anyway.

I tested this combination last Saturday (10/13), taking video from the ground and later blending it with video from the rocket. This is what I found.

1. The initial test flight - to test the zipperless mid-body ejection (without alt. or camera - since, like you, I didn't want to sacrifice $200 worth of equipment on an untested rocket), was flawless on a D12-5. (9 oz.)

2. The second test flight was with altimeter only on a D12-5. Again, another flawless flight - This time to 384'.

3. The next two flights, with camera and alt. on board, the rocket launched flawlessly - twice! First flight went to 286' - second to 281'.

4. With an 8 mph wind, there was a slight weather cock of about 5 degrees at about 10 feet above the launcher. The rest of the flight was fairly straight with only a slight rotation.

5. The 24" chute was a perfect solution for the weight.

6. The nose camera has a mirror/hood combo. It didn't seem to have any adverse effect, especially not at the velocities the rocket was traveling.

7. The three second delay was as close to perfect as I could get. The ejection occurs right as the rocket goes horizontal. It's kinda fun watching frame-by-frame as the chute tumbles out of the tube...

In short, based on my experience this weekend, I would say that a dummy faring would not help the project and the D12-3 in your design will work fine. Also, a longer rod would be a good idea, but in any event, launch with winds less than 10 mph - preferably less than 5 mph.

Good luck

Ashley
 
Another thing to think about concerning the fairings is the AstroCam: It has only one, and it's arguably the most aerodynamically inefficient orientation possible (flat lens end into the airstream). You would probably be just fine without a "balancing" fairing.

I'm going to watch this thread. Over the winter I'll be building my own video rocket.
 
Thanks for all the input on this!

The 13.5 ounce weight does include the motor weight, so it looks like liftoff weight won't be a problem.

I will make up a single mirror fairing, and install it. If the rocket arcs too much, I can add the "dummy" later. Good point about the Astrocam. That was a pretty aerodynamically "ugly" design.

Will post pics (and maybe video if all goes well) after the 10/27 launch.
 
My original thought was to mount inside the nosecone, but was surprised to find that doing so dropped the signal strength by over 10 dB! My only guess is that the black pigment in the plastic is carbon black or something else conductive, and is causing a "Faraday cage" effect. I have a few spare antennas, so I will try to stiffen one up by covering it with a layer or 2 of adhesive-lined heatshrink.

Your guess about the attenuation is probably spot on... 10db is a lot, probably too much to deal with at such QRP levels. Do ya have a balsa nosecone you might substitute? <<SLAP>> Duh! Nevermind! It's been a loooong day! ;)


Interesting idea. Do you have a commercial source for these, or is this something you make yourself from foil tape?

I've used the aluminiumized foil tape sold by Radio Shack for alarm systems with pretty fair results at 2m and 445 MHz... but I'd hate to have guessed the SWR of either (no, I didn't model them in any of the NEC programs. Probably wouldn't have worked as well if I had HI).
 
Doesn't the payloader use a standard BT-50 nosecone? You could replace the nosecone with a white one that should let you put the antenna in the nosecone.

Dave
 
I've used the aluminiumized foil tape sold by Radio Shack for alarm systems with pretty fair results at 2m and 445 MHz... but I'd hate to have guessed the SWR of either (no, I didn't model them in any of the NEC programs. Probably wouldn't have worked as well if I had HI).

What kind of tape layout did you use for these? Folded dipole or something more complex? How did you connect the coax feedline to the foil? I know that they make stick-on screw terminals for this stuff when you use it in alarm applications, but those would be far too big here. With Aluminum tape, soldering would be difficult at best. I may have some copper foil shielding tape kicking around, that might be worth a try.

The nosecone is a standard BT-50. I don't have another one handy, but could order one if I need to.
 
What kind of tape layout did you use for these? Folded dipole or something more complex? How did you connect the coax feedline to the foil? I know that they make stick-on screw terminals for this stuff when you use it in alarm applications, but those would be far too big here. With Aluminum tape, soldering would be difficult at best. I may have some copper foil shielding tape kicking around, that might be worth a try.

This was for a "fox" that was going to be hunted - we slid the transmitter portion of an old Wilson 2m HT into a fiberglass tube, running the RG-174 up through the tube till it got to the apex of a very rounded cap. The tape was basically two crossed dipoles, brought into the inside of the cap where a good mechanical connection was made with a small terminal strip. Tried to solder it but it was marginal, at best, so went with the mechanical and that worked like a champ. Copper foil would definitely have been easier, especially since we painted everything to help with the camoflauge (sp?).
 
I decided to make up a new nosecone/antenna assembly, and a simple mirror/fairing for the camera lens.

The nosecone was made from rigid Styrofoam insulation board, turned and sanded to a non-specific "nosecone shape" on a lathe, then coated with 2 thin layers of West System epoxy thickened with phenolic microspheres. After curing, a PVC mounting ring was attached with 5 minute epoxy, and the entire surface sanded. Holes were drilled for the coaxial feedline, and a pair of copper tape dipoles were affixed to the surface. After a quick check of the VSWR (was able to get about 1.4:1 at the center of the 916 MHz band) , and pruning of the elements to tune the antenna, the whole thing was given a thick final coat of epoxy for weather protection. Even with the 3 coats of epoxy, the replacement nosecone assembly comes in slightly lighter than the original plastic one with the rubber duckie mounted on it. Should be a lot less damage-prone, as well.

The fairing is a simple chunk of balsa, carved out on a bandsaw and belt sander. The mirror is at about a 50 degree angle, to include a bit of the rocket in the shot, but show mostly the ground in the frame. The mirror itself is a very thin plastic mirror cut and sanded to shape and epoxied to the balsa block. The entire block is attached to the airframe with a #4 sheetmetal screw into the nosecone attach ring, and a nylon cable tie around the body (not shown in the image). The black color is a quickie job done with a sharpie marker, as I was out of black spraypaint. :)

Hoping for a good day of flying this Saturday, and keeping my fingers crossed that the weather cooperates. Not looking too promising at the moment... :(

PA250486.jpg
 
Unfortunately, weather forced a scrub of today's launch. Next "launch window" 11/24/07. :(
 
... Next "launch window" 11/24/07.

Good luck with the launch... hope you're able to bring back some great video! I like what you wound up with for the antenna... may be a great writeup for QST! ;)
 
Well, after a couple not-so successful tests, and several scrubs due to weather, I finally flew the camera package today. :D Results here:

https://www.youtube.com/watch?v=sadZXo6I7Hc

Since this thread was started, there was a dummy test with simulated payload which pointed out some deficiencies in the recovery system. A liberal helping of kevlar and separate chutes for the booster and payload section solved that.

Then a really cold launch day had a bad effect on the output capacity of the battery, dropping the output of the battery to below the minimum needed for the camera to produce video. A small boost regulator in the camera B+ line was added to keep the camera power at a steady 12V, even if the battery drops as low as 4.5V (the transmitter will drop out well before that point).

Unfortunately, all the modifications pushed the launch weight over the limit for the Estes D12-3 I was originally planning to use for initial flights. So an Aerotech E15-4 was loaded up, and away she went...

Electronics package recovered with no problems, but there was some damage to the booster, as the parachute never deployed (reason unknown). Nothing a new length of BT-60 and a little paint won't fix. As suggested by another flyer at the launch today, a piston system for deployment may be the next modification.
 
Very Nice! I like the fact that the camera was looking down. What kind of altitude did you get with the E-15?
 
My best guess on altitude is ~700'. Just a guesstimate, as I didn't have a tracking device handy.

Will probably make a few more flights on the E motors to get all the kinks worked out, while building another booster to work with 29mm motors.

It appears that the breakup in the video on the descent portion of the flight is related to the sun entering the camera frame. Apparently the bright light overloads the camera CCD.

Here is a still shot right after leaving the pad...

vidroc.jpg
 
I was at this launch and saw the flight, which was great until the upper portion with the camera separated from the booster. At least the camera part had the chute coming down, it's a lot easier (and cheaper) to build a new booster...

Glenn
 
The camera pod and booster actually had 2 separate parachutes. They were intended to come down separately. For some reason (still a mystery to me), the booster chute never deployed. It was found lying, still neatly folded, next to the crumpled booster. :(

All the wadding was blown out of the tube, so it would seem that the ejection charge had enough power to push everything out OK. I will probably rig up a piston system before the next flight, just to be sure.

The booster damage looked a lot worse than it really is. 2 12" sections of BT-60 and some paint are all that are going to be needed. The entire fin can, motor mount, and coupler are just fine, and can be reused as-is.

I've got enough parts left over from other projects to build another booster, and will probably build for 29mm motors, as there are a lot more propulsion options there than in the 24mm size.
 
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