Ross Ohmen's Rocketry Obsession
38 mm Projects
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Here's some of my mid-power projects.  Note that 38mm is the BIGGEST motor these rockets can handle.

Super Crayon - Two Toys-R-Us Crayon banks, coupled.  Used one of the nose cones for an aft reducer.
 
07/19/09 - TCC Fresno - Flew the Super Crayon on an H148.  Tore off the pad, and went much higher than I expected.  Yellow rocket really disappeared in the hazy blue sky.  Saw it eject, and almost lost sight of it.  The parachute would not inflate, and it hit at an angle.  Thankfully, no damage - probably due to the fiberglassed fins.  Whew!
 
07/31/09 - Aeronaut - I flew the Super Crayon on an H148 for another great high, soaring flight.  And this one had a perfect recovery!
 
09/20/09 - XPRS - Flew the Super Crayon on an I218, which didn't eject the 'chute.  Busted the tube.  Nuts!!

 

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090920 - Super Crayon on I218R. Pat W pic.

 
 

10/17/09 - October Skies - I flew the Super Crayon on an I357, for an odd, flight.  Lifted off the pad, but tumbled at about 400 feet, and didn't eject the 'chute.  Busted a fin on landing, again.  Nuts!!

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090831 - Super Crayon

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090718 - Super Crayon on the pad at TCC

 

Replacement "Wahoo" - 38mm Thurnderbolt minimum diameter series.
 
2/11/06 - Flew at Snow Ranch on an H73 - slow liftoff and easy to track to about a thousand feet.  Looked like the main deployed at apogee, and the forward body tube separated at the wrong place.  I'm just happy to get it back in one piece.
 
5/6/06 - Flew at Snow Ranch again, this time on an I357 - Great flight!  (Except I forgot to untie the main, and it came in hard.)  Located with Walston - little damage!  Fly it again on something bigger!  Make the small-finned cousin!  Fly the paper-tube version!  (Adding a small 'chute to be a drogue).  Note that the rocket spun as it tumbled, and made a mess of the shock cord.
 
08/06/06 - Flew Wahoo again, this time at Aeronaut, on an I300 4-grain.  Great, fast flight.  Disappeared at launch, and found on the ground, 1/2 mile away.  Dual Deploy worked as expected, and the rocket went 5159 feet up!
 
05/18/07 - Flew the fiberglass version ("Wahoo") at Dairy Aire on an H999.  Dang that was violent!  That rocket up and disappeared.  Caught sight of the smoke trail, really high and arching over.   Lost sight of it.  Others pointed it out, on the chute, and it landed beautifully.  Went 3800'!
 
09/15/07 - XPRS - Flew the f/g version ("Wahoo") on a J350.  Awesome, fast, straight-outta-sight flight.  Heard it loud and clear on the Walston, but didn't get a visual.  Dave R and I went out for a look, but I had to turn back to LCO.  Dave found it minutes later - 8500' says the Perfectflite!!
 
04/05/08 - Snow Ranch - Flew the Wahoo on an I211, for (my) coolest flight of the day.  Had to recycle and old, home-made igniter, before the I lit, and it ripped the rocket off the pad.  It threw a slight turn, and headed north, and out of sight.  The Walston had a strong tone, which got stronger suddenly, signalling apogee ejection.  (That's a relief.)  No one saw it.  Had a good, strong, signal for a minute, which suddenly cut off.  Gotta be over that hill.  Started hiking.  Went around the hill, and got a "weak" signal across the meadow.  Hiked there.  Now I'm getting a slightly stronger signal 90 degrees away, up the valley (that would be called a "reflection").  Continued hiking and following.  Getting stronger, but the attenuator still kills it.  Kept pursuing.  Spotted it further up the valley.  Great!  Recovered without damage  The altitude?  5271 ft.  That's a new Mile-High Wall record.  Extremly cool!!!!  And I got my exercise hiking back.
 
09/19/08 - XPRS with Aeropac - Friday, I flew Wahoo on an H999.  Hammered off the pad, and went to 3947 ft.  This flight usually pulls 80 g's!

9/21/08 - XPRS Sunday.  I launched the Wahoo on a J570.  Rocket screamed to about 800 ft, and folded in half.  Rear body continued on a ballistic path, while the front body tore out both the 'chutes and fell.  The culprit - a busted coupler.  Snapped neatly off at the rear body joint.  Crud.  The bent up antenna of the Walston caught in shock cord, and tore off the Walston, which disappeared!  Double nuts!!!  Searched a long time with my Yagi - couldn't hear a peep.

10/15/08 - Reviewed damage.  Rear body needs to be replaced.  Forward body is passable.  Check it again.  Removed fins and motor retainer.  Notice picture with parts missing...

01/29/09 - I've replaced the damaged body sections, and reinforced the rear coupler.  I'm filling the gap between the Aeropack and fin can, and priming.

04/16/09 - I've filled all the gaps, and primed.  I've sprayed on the (traditional) flourescent orange paint, and I'll check for missed spots before I clear-coat.

05/17/09 - With TCC at Dairy Aire - Flew Wahoo on an ancient I154J.   It hissed off the pad, and coasted out of sight.  Managed to pick it up on the drogue chute.  Right at 700 feet, the main fired.  No main chute.  I'm telling myself "This won't hurt, that's fiberglass, and an Acme Fin can", but I'm still nervous.  And I was right - no damage.  And no parachute!!  I forgot to replace it after the rebuild.  :P  3554'.

06/20/09 - With Aeropac at Mudrock - Flew Wahoo on a new Aerotech I59 boost-sustain motor.  Eight-second burn!  Great, high flight to 5600 feet!  The MAWD data suggested the parachute came out at apogee - no wonder, as I had a strong signal for a long time.

09/18/09 - Friday of XPRS - Flew the Wahoo on a J420 for a booming flight to 7722 feet.  Ejected the main at apogee, and took a while to come down.  Then I couldn't find it, using Walston.   Took me a great deal of hunting around the desert to find this, as well.  No damage!

09/20/09 - Sunday of XPRS - Flew the Wahoo on a J570!  (After all, that's what I came here to do...)  Rocket tore off the pad, and went straight up.  Then it separated and rained down parts.  Nuts!!!  Forward body threw out the main at 500 feet, so no damage there.  Found the shock cord, streamer, and (oh crud) Walston antenna behind the equipment trailer.  Got a bead on the Walston, and quickly found that.  Only missing the rear body and motor.  Started searching southwest of the launch site - after all that's where I last saw it, coasting up.  Looked and looked, with binoculars.  No dice.  Went back to camp dejected.  Informed by Jeff R that he had already found the body, and returned it!  Of course, he found it in the southeast - I was searching in the wrong place.  Glad to get it back. 

The damage - a torn open eye-bolt, a broken shock cord, and broken Walston antenna (and I have a spare.) 

The culprit was drag-separation.  Pin it, next time.

wahoo_reduced.jpg
Wahoo - 2 pounds of fiberglass fun

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Tang (above) and Wahoo (below)

 

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Wahoo during repairs caused by J570

Phenolic version - "Tang" - 38mm Thurnderbolt minimum diameter series.
 
02/18/07 - Flew the Tang on a G67R, with the dual deploy, and the shortened fins (removed 1" with the table saw).  Flew fine - straight up.  Deployed the streamer at apogee (and shredded the mylar), and tried to deploy the main at 300'.  No dice - chute didn't clear the tube, and it came in hard.  Rats.  No damage, though.
 
04/07/07 - Flew the Tang on an H73 at Snow Ranch.  Rocket weathercocked greatly, and didn't separate at apogee!  300' deploy ripped off the 'chute, zippered the forward BT, and separated 1/4" tubular nylon.  Talk about violent!  Thankfully, I found all the parts, and there was no other damage.
 
08/03/07 - Flew the Paper version ("Tang") at Aeronaut on a G339.  Fast liftoff, and easy coast to 1000'.  The MAWD ejected on time, and the streamer flapped to 300', where the main came out.  Perfect flight!
 
10/20/07 - October Skies - Flew the Tang at October Skies on an H242.  Fast, cool flight - good visuals through main deploy.  Separation!!  Can't believe it - just burned right through the shock cord.  Had to walk the alfalfa for a while, but eventually found it, minus the nose cone.  Rats!  Small tear/crack in the upper body, and a neatly parted shock cord.  Gotta protect it better, and/or use less BP.  Someone turned in the nose and main chute, so it can be rebuilt.  Altimeter says 2992 feet - high!!!
 
06/21/08 - At Mudrock, flew the Tang on an H112.  No ejection at apogee!  (Not enough BP.)  Main fired at 300 - much too late.  Tore off the parachute and nosecone.  Crashed hard!  Destroyed the Perfectflite MAWD, and heavily damaged the Walston.  Dang!@!%&@!
 
04/16/09 - I salvaged the nosecone and part of the rear body.  I grafted on a new rear tube, and replaced the rest.  It's primed and ready for more paint.  Getting geeked about flying it on a G339, H112, or I49 (super long-burning Warp 9 end-burner.)  I'll use enough BP, this time.
 
05/06/09 - Repairs complete.  Prepped, and ready for a motor (and a Walston?)
 
05/16/09 - Dairy Aire at Maddox Dairy - I launched Tang on an H123, which ejected the parachute at Apogee.  Rats!  Drifted a long way, but at least there was no damage.  2698'.
 
07/19/09 - TCC Fresno - Flew the Tang ("Like the fruit drink - Hey, it's orange!") on a G69 Warp 9 end-burner.  Great soaring flight to 1400 feet (where it disappeared), but the main popped at 700 feet, where we could see it.  Long, hot walk to recover, but no damage.
 
09/18/09 - XPRS on Friday - Flew the Tang on an I49, after getting a new nozzle from Karl B.  Went about 4725 feet, with a slight wobble off the pad.  No damage, but another long hunt using the Walston.

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Tang - Acme fin can and phenolic - no f/g

 

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070218 - Tang on G67R at TCC Fresno

PML Io
 
   One of my work-horses.  I've flown this rocket on F, G, H, and even I engines, and it keeps together.
 
06/20/03 - Mudrock, with Aeropac.  I flew the PML Io on an F50-6, a G40-7, and a G80-7.  Worked fine!
 
09/20/03 - XPRS with AeroPac - Flew the Io on H210R - fine flight.
 
12/27/03 - Mojave Desert Area Rocketry at Aeriel Acres - Flew the Io on an H242 -  38mm.  Very fast and high - great flight!
 
07/17/04 - Flew the Io on Econojet G35-7 at TCC Fresno.  "Bang!"  Cato'ing motor blew out aft retainer.  What a mess.
 
09/12/04 - Fresno - Flew repaired PML Io on a G80-7.  Great flight, though it looked like the chute came out early.  No damage, though.  Tough rocket!
 
07/17/05 - Flew the Io on an 29/180 H128 to a high, screaming flight.  Took forever to come down on the parachute.  There was light damage from the high-speed flight: The PML sticker had peeled back, the return-address was hanging on by a thread, and there were many cracks near the base of one of the fins.  All this adds up to a rocket saying "This much and NO MORE".
 
05/06/08 - With Lunar at Snow Ranch - Flew the Io on a G40-7 - Great flight.
 
08/04/06 - With Aeropac at Aeronaut - Flew the Io on F22-7J - Too low!  Almost too long a delay...
 
09/22/06 - XPRS - Flew the Io on an H73 - Great, high, flight.
 
03/03/07 - Flew the Io on a G64-7 at Snow Ranch - great flight that landed close.
 
04/21/07 - Flew the Io on a G77R at TCC - another great flight.
 
08/03/07 - Aeronaut with Aeropac - Flew on an H123 - Great, high flight.
 
09/15/07 - Flew the Io on a Cesaroni I212 - the biggest motor this rocket has ever seen.  The rocket tore into the sky, and turned into a speck - but recovered successfully!
 
10/20/07 - October Skies - Flew on a G61W - good motor for a windy day.
 
11/18/07 - Thanksgiving launch at Fresno - Flew on a G67R for a good flight.
 
02/09/08 - Flew at Snow Ranch on a G61W-M, built by Jason.  Great flight, and nearby recovery.
 
05/16/08 - Dairy Aire, 2008.  Karl B offered me a G76G-10, and I said "sure!".  Ripped off the pad, and deployed right in front of the sun.  I never had eyeballs on it, but I had a Walston in it.  Recovered at the end of the flight line in good shape.
 
06/28/08 - Newark - Flew the Io on an F50-4 - Loud.  Flew great!
 
01/18/09 - TCC - Flew on a H123.  Ripped off the pad, and flew great and high.  Didn't need the Walston, as Mark Canepa retrieved it.  Thanks!
 
02/21/09 - TCC - Flew Io on an old G80-7.   Flew fine, but managed to jack loose a fin.  Rats!
 
06/20/09 - Mudrock - Flew the new Io strobe payload with a G76-7G.  Took two igniters, but it roared off the pad, for a nice flight.  Discovered that the parachute was a little small for the additional weight, and the rocket came down a little fast.  No damage.
 
09/18/09 - Friday night at XPRS - Flew Io on a G61, for a cool, high flight.  Thanks to the young couple who retrieved it, so I could continue LCO'ing.

09/20/09 - Sunday Night at XPRS - Flew the Io on a G76G, for a great flight.  Threw out a red cyalume stick on a streamer, which I didn't see at all.  While walking to the flashing rocket to the south, I came upon the streamer - very cool!!

10/17/09 - October Skies - Flew the Io on a G76G.  Craig made the motor, with copious advice from me, and everyone in Alan T's camp!  Eventually got the  motor built and lit.  Surprise!  That flame is red!  (Sneaky Jake substituted a G71-7R.)  The Io tore into the sky.  At least we were smart enough to angle the rod into the wind.  Still landed out in the field, for the last long, tiring walk of the day.

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PML Io on H128 at Fresno 050717

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080517 - The Io on a G76 green at Dairy Aire

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090622 - Io without strobe

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090622 - Io with strobe

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090622 - Io strobe closeup.

Original "Wahoo" - 38mm Thurnderbolt minimum diameter series.
 
Features:
1) Giant Leap 38mm fiberglass body tubes (or 38mm phenolic)
2) Perfectflight MAWD controlling dual deployment
3) Acme fin can
4) Aeropack engine retainer
 
History:
02/18/04 - Fresno - Flew on a Aerotech H123 for the first flight. It took off spectacularly, went up, arched over (no ejection!), fell past the main deploy, (no ejection!), and slammed into the ground, burying 3 1/2 feet of the rocket, and breaking off the back 1 foot with the fin can and motor. DANG!!
 
Borrowed a shovel, and started digging. An hour later, I had it back, and a hole that went up to my hips. Diagnosis revealed that I had drilled a hole in a capacitor of the MAWD as I was assembling the electronics bay. Let's just say that "that dog won't hunt", and let it go at that. SO...
 
Repaired the MAWD (new capacitor shipped to me, and soldered in). Don't trust it - new MAWD. Replaced most of the body tubes, and repaired the one with the fin can and engine retainer. Filled and sanded and filled and sanded, and finally painted the rocket a sweet red color.
 
07/18/04 - Fresno -  Put rocket on the pad and turned on the electronics. Wrong "main deploy" altitude, and what's that extra beeping? Pulled it off and disassembled. Reset "main deploy" altitude, and verified extra beeping - just arming tones. Not low battery. Turned off, and went back to pad. Loaded. Launched. Spectacular flight on I211. So spectacular, it disappeared. <<SUDDEN THOUGHT>> I DIDN'T TURN ON THE ELECTRONICS. <insert many obscenities here...> So, it's going to lawn-dart again. That is if I can find it. I hiked that plowed field for an hour - no sign of it. Hunted from my car with binoculars - no sign of it. IT'S GONE. All that effort and hardware - gone. At least my contact information is on it, so if someone ever finds the fins sticking out of the ground...
 
Lessons: 1) Checkoff lists. 2) If you have a Walston unit, use it. 3) Get help spotting. 4) Paint your rockets flourescent colors. 5) Turn on the electronics. 6) Be happy.
 
Build two more - they're cool!  I've got the tubes already!
 
10/18/04 - Message from another rocketeer - they found my rocket!!!  Retrieve and salvage what's usable.
 
08/02/05 - Well, not much was salvable (of the body), but the electronics are good, and the motor case was fine as well.  The rear body will become another one of these (shortened to single deploy), and the recovery stuff will go in others of the series.
 
STATUS:  Salvaged

 

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On the pad, ready to fly for the first flight.

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Lift off on the H123

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Airframe buried 3 1/2 feet in the soil!

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Tail broken off after "lawn-darting"

 
"HoJo Montana" - Honest John / Joe Montana
 
The remains of a crashed Thunderbolt 38, and a football "mashed-up".
 
1/26/09 - Flew the new HoJo Montana on a G67R.  Nice, high boost, and ejected at apogee.  Unfortunately, the rear body tore out the shock cord, and it tumbled in.  No other damage.  One comment:  "At least it didn't spiral in!"
 
2/21/09 -   Flew the HoJo Montana on an H123, and had a successful, though wiggly, flight.  It was definitely a "Hail Mary!"

 

hojomontana_tcc_090118_small.jpg
Other than this, we're very serious when we fly.

03/14/09 - Flew the HoJo Montana on a G67R.  Great flight, but it ejected a little early - guess I cut a little deeply into the delay grain.  Still, a fun flight, with me calling signals for the launch - but I called "touchdown!" too early...:)
09/20/09 - Sunday afternoon at XPRS - Late afternoon, I flew the HoJo Montana on an old I161.  It angled off the pad, and augered in!  Brought the remains back to the camp, and suddenly realized I I had not put in BP in the ejection well.  Gahhh!!!
 
Status:  DEAD

 

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HoJo Montana on G67, TCC Fresno, 1/18/09