Construction progress

I continue to make progress on Der Red Mix's electronics bay and motor tubes. Right now I only have e-bay pix, however, so here they are:

The Flip MinoHD camera fits nicely through the side and I have room for both Parrot 2 and Raven altimeters + 2 9V batteries on that removable G10 board. I'm also working on the hinged door for the front and a simple plywood cowling to reduce drag on the dangle-cam.

I also finished building my Madcow Squat for the drag race at LDRS 29. Now I just need to finish and paint that puppy and it's all set:

Der Red Mix tube session and test fit

Tonight I was inspired to drill the extra holes in all four centering rings, cut the motor tubes to length, and mark them precisely according to the plan a few entries below. Everything went together nicely but before I apply any epoxy I realize I need to finalize the electronics bay mounting board first.

You'll notice that I've elected to dual-attach the shock cord on the upper plate. I think this should reduce the tendency to zipper as the load will be divided in half. I'm quite sure the Gates Brothers used to employ that trick. Also that single aluminum tube bridges the electronics bay to the motor area and will facilitate e-match wire transport. Hopefully this week I'll get this whole assembly done and the rest of the build should prove fairly trivial. I think the first flight will probably be a central CTI 1596K500 Red Lightning motor on the ground then air-starting 2 x 408I345 White Thunders. Niiiice!

Viciously Mean Machine 0.75

I'm still working on the full 48" payload for the 100% Viciously Mean Machine but, in the mean time, I bought a Performance Rocketry aluminum-tipped, carbon fiber, conical nosecone and it just looks bad ass with the shorter payload. That booster will fit a CTI 6GXL casing so I hope to fly an L935 in there soon.

[I corrected the lens distortion present in the other version of the image.]

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I'm honored the Mandarin-fluent geniuses like [ElvisS_S blah blah blah] assume that enough people read not only my blog, but comments on individual entries, that it's worth spamming me. I will always immediately delete your drivel so find someone else to pester, shitheads!! Seek some less annoying way to earn a living.

Der Red Mix's precise design

Last night and this morning I worked up several templates based on my size/position guide (click image for larger version):

As this will be my most complicated scratch-built design ever I found it necessary to plan all the part positions precisely up front. I highly recommend either Illustrator or CAD for this purpose and I used the former in this exercise. I just need a few more parts and I can start cutting and adhering.

Repair day

After finishing my taxes today I decided to repair several ailing rockets despite needing to build/finish several others.

First off I fixed the 4" bullet after an early I366 Redline flight with yet another incredibly short delay. That was the last of the Redline motors I bought 'round about 2002 and, even storing the delays separately, these old motors accelerate the delay burn by roughly 6x. As such the ejection charge blows even before the motor has burned out (and yes I'm certain I assembled the motor correctly). This is the third old Redline that's behaved the same way so I sense a trend. The bullet suffered a zipper about 1.5" long right through the carbon fiber reinforcement so it was going damned fast at the time. Luckily I had enough room above the coupler that I could just slice the zipped section off and the nosecone still fits unmodified:

If this rocket suffers another event requiring repair I'm cutting my losses and tossing it!

Secondly I'm trying to correct a warp in my Viciously Mean Machine's 48" payload section. I'm quite certain this happened during carbon fiber reinforcement due to inadequate support while curing in the oven. Today I taped a 10lb. weight to the high point in the tube, suspended it in the curing oven on a contiguous 1" dowel, and post-cured for roughly 35 minutes. I'll check it in a bit but if that didn't work I might be scrapping a second payload section. Dammit:

Finally I had experienced a wall deformation in my 7.5" Nike Smoke on its last M1939 flight. I'm quite certain this was because I flew it single-deploy and, when the 16 foot Rocketman 'chute inflated from the payload section, the payload coupler came out an an angle and cracked/deformed the top of the tube. I mixed up a batch of West Systems epoxy, dropped in a liberal amount of Kevlar pulp and white pigment, and slathered that mess on the inside of the tube. I then used packing tape on the bottom of the tube to prevent leakage, topped it with a sheet of vacuum bag film, laid in a section of 7.5" tubing, and clamped the whole thing together. I think this will work pretty well after I grind off the excess epoxy:

I'm way behind in my blog posts so I'll list what I still owe here so I don't forget:

• March Plaster City launch report
• April Plaster City Launch report (featuring 9,140' I284 flight which I think is a record)
• Inexplicably wacky ARTS2 altimeter behavior
• Mad Cow Squat build (due before LDRS 29 in early June)
• 2000MPH President's Challenge build (Due before May Plaster City launch)
• Der Red Mix build (Due before LDRS)

Darkstar lite build

I recently purchased an all fiberglass Darkstar Lite kit from Wildman Rocketry:

I needed an easy sport flyer for 29mm motors as my Arreaux is aging. This kit goes together so fast! Here's the AeroPack motor retainer end:

And the forward end:

And the overview of the motor tube assembly:

And, using this stupidly simple masking tape rig, I was able to tack all 6 fins to the motor tube at one time. Big fan!:

And these last two pics complete the assembly. I forgot to take them before flying this three times on Saturday so that's why the white tail end epoxy looks soiled:

And no the top fins are not tilted. Chalk that up to wide-angle lens distortion. Now onto finishing...

Slightly late... Plaster Blaster 1/1/10 launch report

Yeah this has taken awhile but I sorta got hung up editing vid. I marvel that Apple's Final Cut Pro 7 supports neither AVCHD nor Flip MinoHD formats natively. Guess what though -- Adobe Premier CS4 does!! WTF, Apple? Git yo shite togetha. Rant mode off.
I didn't think I'd be able to fly this month because I was backup shooter at a wedding for my buddy Jaime on Saturday. However, our club scored an FAA waiver all day Friday, 1/1/10, so I went for it. El Bee accompanied me and fun was had by all even though the crew was sparse. Actually when you have Jack Garabaldi vending AND flying, Russ Sands successfully attaining his L3, and Paul Snow bustin' out a K1999 no options exist except to have a good time. Here are my select photos for the day.
I flew light-ish today as it was short notice but I'm still happy with the results. I started with my Loc Bullet on a J825 for a thermite ignition test. I experienced ignition system issues and had three sequential misfires with an electric match + 0.5 g of thermite. The fourth time was sort of the charm with the match popping, the thermite doing something without emitting smoke, and the J825 igniting about 8 seconds too late for me to catch a photo. The flight was awesomely fast and now I know to use at least 1-2 g of thermite next time since instant ignition is my goal.
Then El Bee and I took it easy and flew a super convenient Cesaroni Pro29 159G118 Blue Streak motor in my trusty Aerotech Arreaux for a very quick and cool ascent. Again we captured no photos but the rocket landed on a moto burm and again managed to avoid destruction.
Next we flew the same Arreaux on a Cesaroni Pro29 176H123 but this time El Bee caught a great video with the Flip MinoHD video camera (watch in HD on YouTube):

Finally I started prepping my new Viciously Mean Machine design which suffered from unusable curvature of the payload section last month. I substituted the Em Sem Fity payload section, dubbed this kludge as VMM v0.75, and planned to fly it on the Cesaroni Pro54 1016J360 Skidmark. As always the dual deploy electronics took awhile to prep but the flight was pure greatness (prep photo ©El Bee):

Unfortunately I did an awful job of catching the liftoff because I was busy pushing the launch button and watching the flight. I like that our club offers control over one's own flight but it greatly complicates photography and videography. (Watch in HD on YouTube):
The flight portion sucked but El Bee caught a nice liftoff sequence and here's the best frame (click for larger version):

I recently had my 1Ds III serviced and it nailed the focus on most shots today. The detail in the flame of that shot is awesome! It looks sorta like flamey fur:

Oh and here's another bonus... this flight attained 9,217' and I believe that's a record that should make it into Rick's altitude record database! There's another Pro38 J360 record from 2005 but this Pro54 J360 Skidmark wasn't released until 2009 so it must be new and different! :P Heh heh.

The windless, perfect day ended beautifully with one of the most enduringly stunning sunset's I've seen in my life! (photo ©El Bee):

Kick-off: 7.5" Der Red Mix

This will be my first scratch-built, upscale design. As a kid I built the 1.6" diameter Estes kit "Der Red Max" and found the design appealing and the decals amusing. I'm not a fan of huge fins so on my design I've taken the liberty of scaling them down to just enable a static margin of 1.16 with the heaviest motor array (L935, 2xJ530, 4xI224). While 1.16 might sound low for a cluster I've learned to trust RockSim's stability equations and find the original Barrowman equations to be too conservative. Also I'm not likely to fire the cluster on the ground and will probably always start with a powerful 54mm motor to send the rocket up and away before igniting outboard motor pairs. Here are some screengrabs from RockSim 9:

I'm still working out the details of the electronics bay but I plan to seat a removable trap door just above the fin tops to conveniently seat two multi-function altimeters and a Flip MinoHD video camera. The onboard video should rock! I've slowly been buying components for this design from Jack at What's Up Hobbies as well as Loc Precision. I also ordered my first set of laser-cut fins and centering rings from Balsa Machining Services and an AMAZING set of decals from Mark Hayes at StickerShock23.com. Here's the array of parts pre-assembly:

The fins are only 1/4" thick so I'll reinforce both sides of each with one layer of 6 oz carbon fiber to improve rigidity. Having just cleaned my garage I plan to start on this build ASAP!

Plaster City Launch, 12/5/09

I had three goals for this month's launch:

1. Test my Beeline GPS on a lower altitude flight to visually verify the position data. I also wanted to test a G10 fiberglass support I'd cut to stabilize the otherwise fragile electronics board/antenna.
2. Test thermite ignition on an older Redline motor like the I366 I've had for seven years as these are notoriously slow starting.
3. Fly my Viciously Mean Machine on a CTI J360 Skidmark (Pro 54, 3-grain).

I was mildly breezy and very cloudy when I arrived at about 10:15AM. If we weren't in the desert it probably would have been raining. I headed over to Jack Garabaldi's trailer to buy some components and a CTI 55F29 Imax motor for my GPS flight. I set up the GPS unit in the payload of my AT Arreaux and Frank Hermes helped me set my radio up to receive the APRS packets to monitor the flight's position every 5 seconds. I trimmed the F29 motor's delay from 12 seconds to 9 seconds forgetting how weak an F29 was. I really haven't flown mid-power for about a year now. Basically I should have used a 5 second delay on this cold day because 9 seconds was way too long. I came painfully close to crashing my $300 GPS unit on it's first otherwise underwhelming flight! I stripped two parachute strings but the whole thing came in tethered and fluttering. Everything was intact and I was able to download the flight profile successfully:

At first I was trying to figure out why the rocket only flew to 269 feet then realized that GPS altitude is recorded in meters. As such I actually attained 882 feet. Much better. :) I'm also confused by the region marked "What's this?" That's about where the 'chute finally ejected but it certainly didn't shock upward or sideways. Besides this isn't an accelerometer-based device and should only be storing actual GPS coordinates every second. Weird.

Then I spent another two hours prepping the Viciously Mean Machine for a dual deploy flight using the Parrot2 altimeter and the predictably spectacular J360 Skidmark. I finally got it out to the pad to discover a) I had managed to misalign the rail guides so there's no way I could fly it and b) looking up the 8+ foot skinny rocket that the payload section was warped. I had used Blue Tube 1.0 for the payload section and read that it was subject to warping at higher humidities. I had never noticed the curve while building so perhaps it happened afterward. I threw that part in the trash today as it's a total loss. I need to decide now if I want to try Blue Tube 2.0 for the rebuild. I feel pretty burned right now because I spent a great deal of time and money reinforcing the tube and coupler with two wraps of carbon fiber each. I disassembled everything and packed it away.

Finally I quickly prepped my horribly battered and thrice repaired LOC Bullet with a CTI 660J381 Skidmark. I really can't get enough of these loud and impressive motors. The flight was cool and uneventful except the ~1.5 mile walk east since I'd used a 45" parachute. I was able to track it visually but I'm still glad I put my radio tracking beacon in there as an insurance policy. I left the AVCHD camera on it's tripod during my roughly half-hour walk and captured some other flights before the wind wall kicked up effectively shutting down the launch for the day:

The song is Tenori by Francois Dubois. I never got around to the thermite ignition test but I vow to git 'er dun one of these days!