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REV 2.4 - Fri Apr 6 03:41:27 2012

Deltie Thunder
13326 Preuit Place
Herndon, VA 20170-4341
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ROCKSIM FILE: MISSING - please submit here
SpaceCAD FILE: MISSING - please submit here
REC'D MOTORS: D12-3, E9-4

(Contributed - by Neil Thompson - 09/10/03)

Rocket PicBrief:
This is a HUGE glider made by Edmonds Aerospace. It has a wingspan of 27 inches and the glider is 34 inches long. It has a 24mm pop pod, which is about 2 feet long, give or take an inch or two.

It has one long 24mm tube for the pop pod, and 3 sheets of laser-cut balsa, which I am guessing is about 1/4 inch thick.

Just as easy to build as the original Deltie, but really big. I liked how all the parts fit together. I did not need instructions since I had build the standard Deltie a few weeks earlier and it has the same exact parts, only bigger. Once assembled it is very sturdy. I have gone for a few test glides at a baseball field and it flew very well.

I have not painted it, but may use highlighters like I did on the Deltie.

Construction Rating: 5 out of 5

I used a D12-3. Definitely not enough power. Due to the wind, I had to use the "David Smith hold and RUN" technique. That means holding the glider until the wind dies down, and then let go and RUN while a friend presses the button. The boom broke in half on impact. Pout! Will be easy to repair, however.

I do not know yet. I have only made a few throws in a local baseball field so far.

Flight Rating: 4 ½ out of 5

Easy build, affordable price, and a really big glider. it takes up about half of one of my bedroom walls!

Overall Rating: 4 ½ out of 5

(Contributed - by Hank Helmen [Who's Who Page] - 03/13/06) Edmonds Deltie Thunder

The Deltie Thunder is a single stage boost glider design. The glider is a triangle shape with a profile type fuselage that divides the triangle in the middle. The rocket booster hooks onto the glider at the nose of the glider and pulls it skyward. At ejection the booster separates and returns via parachute while the glider slowly circles back to earth

The kit contains one main body tube, laser cut 1/4" balsa sheeting for the wings, horizontal stabilizer, and two side fins. A balsa nose cone is included as well as fin two reinforcement pieces and two nose reinforcement/booster hooks. There is an elastic shock cord, a black plastic parachute kit, and an eye screw for the nose cone attachment. The kit includes a 3/16" launch lug and some balance clay for the nose section.

The instructions are sparse to say the least. What is there is easy to follow and if you have built the smaller Deltie, detailed instructions are not really needed. No templates are needed as the balsa is all very nicely laser cut. The Deltie Thunder is easy to build. No special tools are needed. I found the balsa in my kit very soft although this makes for a light weight glider, it is too fragile in my opinion. I sanded the balsa wings and vertical stabilizers round at the leading edge and trailing edges.

Edmonds Deltie Thunder Everything lines up nicely, and the kit was finished quickly using CA glue and Elmer's white glue. If you have any rocket building experience you can finish this kit up in just a few hours.

Full paint on a glider this size could add a lot of unwanted weight. I gave the glider and booster some trim colors with a day glo orange paint pen then painted it all over using two coats of Aero Gloss model airplane dope thinned 50%. This adds very little weight yet adds water resistance and needed stiffness. There was no forward motor block, so I cut a 1/4" piece off of a spent Estes D12-3 engine casing and glued it into the booster, allowing the engine to extend 1/2" from the end. The instructions do not say anything about this at all but it is a good idea. You could also use a wire type motor lock.

Construction Rating: 3 ½ out of 5

Edmonds Deltie Thunder

The only recommended motor is a D12-3. You will need wadding to protect the booster's parachute and shock cord. My shock cord burned through or broke on the first launch.

The Deltie Thunder will require a long 3/16" launch rod. I bought a nice 50" steel rod from the local machine shop. Since the glider hangs below the booster you will need to prop the booster up. I used a 24" piece of 2" x 2" pine (cut from a regular 2x4). The glider is pretty big and if there is any wind you will need a good sturdy launch pad.

My glider required all of the clay supplied for the nose weight and a little bit more after that! I made numerous test glides, first to get it to glide nicely straight ahead and land smoothly, then to get it to circle slightly by adding clay to one wing. The first test glide broke the nose off.

The first launch was very nice, some curves during boost but overall nominal.

Ejection occurred at a slight nose down attitude. This is a hold your breath moment because the glider can hang up on the booster or the shock cord can wrap around the glider's nose or wing.

On this flight however, the glider separated nicely and began a nice fast glide with a left hand circle. After two or three big circles, the bank angle increased close to the ground and the nose dropped causing it to impact the landing area with a higher than nominal velocity. The forward fuselage completely separated from wing section at the joint despite a carbon fiber reinforcement.

The shock cord broke at the mount, however, there was no damage to the booster and all components were recovered. The glider's fuselage broke apart from forward wing. It needs heavier balsa in this area or side doublers. Also, there was a strange round burn through hole in the right forward portion of the wing. It was extinguished with ground crew's water bottle on scene. The accident investigation team has not concluded what caused this but speculation is that it was caused by main engine burn residue during glider separation.

Flight Rating: 4 out of 5

The Deltie Thunder is a good flying kit and is easy to build. Builders will need to carefully test fly the glider in some nice tall grass in order to get it just right. Fly it does and if you do not put a little clay on one wing to make it turn, you will probably never get a chance to launch it a second time. It would be a good idea to put a mailing label somewhere on the wing or at least write your phone number on the glider.

The main problem with this kit is the fuselage nose area ahead of the wing really needs strengthening. The only other con, and it is a small one, is the motor mount. No engine block ring is supplied in the kit.

The coolest part of the Deltie Thunder is the spectacular flights you can put on! People love to watch it fly. Use a big field because it's a big glider. Do not fly in high winds. Wait for a calm early morning or late afternoon when the wind dies down.

Overall Rating: 4 out of 5

(by Ted H. Apke) 

Well I was really hoping that my package from Edmonds would arrive in time for this weekends METRA launch. I was grumping about it on Saturday when my youngest son asked me what this box was sitting in the garage. I have no idea when it arrived or how it got there but it isn't the first time I've found mail sitting in some peculiar place! 

Spouses <and> children make life so interesting! 

So here I was on Saturday at about 1:00pm with the launch scheduled for Sunday. What the heck. I cleared off the workbench, got out the CA and accelerator and got to work. As others have said, the instructions were straight forward and the work progressed very fast. I took a few extra minutes to round off the edges of the vertical stabs, but not the wings. The only problem I had was that the launch lug packed in with the chute was crushed. I decided that a 1/4" lug wouldn't be a bad thing to have for when I decided to crank up the power and didn't miss a beat with assembly. By 2:30 I was out in the yard doing some test glides. I didn't get too satisfactory of a glide in the yard but I was pushing the limits of my property and I narrowly missed hitting 
a fence. I decided to just give it a test fly. [Picture]

Sunday turned out beautiful. 65 degrees. Winds of maybe 5mph with the occasional thermal. While I had done the power mod that the instructions call for I still decided to start with a D12-3. I used one of the high power pads (longer rod) and placed some tape on it to hold the booster up high enough to fit the glider on. I took a spare rod and pushed it in the ground to keep the glider from flapping in the slight breeze. Pretty straight forward if you've flown a boost glider before. I had plenty of time left to help the other high-power folks get their rockets ready. 

My turn finally came and off she went. The boost was a little off vertical but nothing too scary. Separation came right at, or a little before, apogee. It separated very clean and immediately entered into a nice glide. Lots of cheering from the crowd! The glider then did what none of mine has ever done before. It flew straight! Don't worry, I got it back. It did worry me for a minute, however it flew right over the crowd. Really looked pretty. Proceeded down the hill, lengthening the flight, and landed easily in the weeds. 

I was anxious to fly again but I spent most of the day helping out at the launch site and helping my son fly. I'm really looking forward to more launches in the future. 
I got the chance to fly my Deltie Thunder again this past weekend at RATS IV. I made up a pad similar to what Rob shows in the instructions and this made setup pretty simple. 

Flight 1: Couldn't get a single use E18 with a short delay so went with a E11-4J in my 24mm reload case. The flight weathercocked to horizontal at about 75 to 100' which is when the motor burned out and the glider separated. Had that glider on nice and loose! The glide was great. Got many a compliment. Hopefully a few will contact Rob. I used the full ejection charge and ended up blowing the chute apart. I suppose it could have been due to the higher speed at deployment due to the weathercock, but it wasn't going all that fast. The booster still recovered fine. 

Flight 2: Bought a E18 reload and flew it on Sunday. The boost was much better but things went down hill from there. I had replaced the chute with a nylon one and cut the ejection charge in half. Oh my. The ejection seemed a bit late, with the rocket past apogee. The nose pulled out but didn't deploy the chute. The glider did it's best to pull the booster out but it augured in. This resulted in some serious damage to the forward half of the booster which can easily be replaced. The glider suffered a split boom which can easily be CA'd. People still thought it looked cool! 

Relinquished by Scott Johnson @[Picture]

(by The Silent Observer) 

How's this for a start: I ordered on the last day of the Frenzy -- then go the envelope back, returned for postage, so Rob didn't get my order until around the 5th of October. I got the Deltie Thunder kit in the mail Wednesday (they tried to deliver on Monday, but I'd already left for work). 

So far, I've opened the box -- this thing is>immense<! The booster pod is about 2 feet of 24mm ID tube with an elliptical cone; the glider has enough balsa in it to make a whole>fleet< of Vaughn Brothers Buzzards. It looks like it lives up to Rob's claim of being able to build it in a single morning, but I'm going to spend a little more time on it than that; I can't stand the thought of launching anything with square leading edges, and I prefer to fill and sand, at least cursorily, and paint as well. I'll probably dig through the basement and find some Monokote left over from when I built R/C airplanes, and use that for color trim on the glider. 

I noticed that there's no motor hook; I plan to add one, and may also install a thrust block to keep the hook from tearing forward in the tube; it'll make prep and motor removal easier than the thrust-ring and friction method recommended in the instructions. The shock cord for the pod is actually about long enough; it's as long as the pod tube, if not a little longer, and sturdy material (1/4" wide, I think). 

I already have two packs of D12-3 motors -- and I should be able to have this ready to fly, barring lack of painting weather, before the December launch at Monroe, WA. 

Relinquished by Scott Johnson @[Picture]

[Submit your Opinion]

08/09 - "If you managed to beef it up a bit and reinforce the boom, I think it'd be an awesome flier on an F12 or F32. It'd need a lot of space, though." (D.S.)

03/06 - "The balsa in the kit is light weight (very soft) Where the wing joins the fuselage of the glider at the front is a weak spot. Broke on my first test glide. Reinforced with 1/2" carbon fiber tape from Hobby Lobby Intl. Broke again on another test flight. Added more carbon fiber and CA glue. Had to use all the clay in the kit plus a little more for good test flight. First flight with D12-3 was good boost, but then glided a little nose down. Fuselage broke again at front of wing joiner! Took away some clay! Wing has round burn through on front left hand side about the size of a quarter!" (H.W.H)

[Enter Rocket Specific Tip]

03/06 - "Reinforce the fuselage just in front of the main wing and where it joins the wing. Be careful not to put anything where the rocket booster engages the glider hook. The hook must be free to slide easily off at ejection. This is a weak spot in all of the Deltie kits. Since it is in front of the Center of Gravity the extra weight can be compensated for by removing a little nose clay. The ' Thunder needs quite a bit of nose weight anyway. I suggest doing this even before test gliding your Deltie Thunder. You can use 1/16 inch aircraft plywood, or a good hard grade of balsa. I used 1/2" carbon fiber tape. When it broke again I went back and used 6 oz. Glass cloth shaped to the nose area, and coated with Z-poxy epoxy resin thinned 50% with alcohol." (H.W.H )

06/04 - "This is potentially a beautiful flyer. A couple of things need to be kept in mind. 1. If you use the braces provided for the tails in higher power it is a bit hard to balance. I could not get enough clay in the provided area. Ended up with lead fishing weights. 2. The joint at the leading edge of the wing is a wicked stress riser. Easy to snap. I'm actually thinking about adding a layer of glass to beef it up. 3. I like the pop pod better with a streamer. I don't want to track two drifting objects. " (A.H.G. )

03/02 - "I can't answer as a glider expert, but I have built and flown the Deltie Thunder. I did not airfoil ANY of the surfaces. The glider flies great that way. It's not going to set any records, but gives a graceful boost and recovery on D12-3 and E15-4 motors. I would suspect that airfoiling would negatively alter the boost characteristics of the glider." (B.M. of RMR )

[Enter Flight Log]
Date Name Motor Ejection/
Wind Notes
05-28-2005 Brian Carpenter Est SU D12-3 None - Unknown Calm - Oops, you need long launch rod for this rocket/glider. Rocket had 6inches of rod to stabalize. It didn't stabalize and did big arch into the soft sand. Glider never left rocket. Ejection happened on the ground. No damage.
06-19-2004 Al Gloer Est SU D12-5 Just Past (1-2sec) 10+ mph winds Event: CATO 90
- Beautiful first flight. Was balanced perfectly according to Edomnd's instructions. Still behaved nose down. Pop pod is better with a streamer. Broke fuselage packing it to go home - easy repair
03-11-2006 Hank Helmen Est SU D12-3 Apogee - Perfect
(180 ft)
Calm Event: RAF Meet Virginia
- Good straight boost Good seperation. Booster returned on black parachute. Glider circled nicely landed in nose down angle broke fuselage from wing at front, too much nose down glide. Added too much nose and wing clay during numerous 12+ test glides.
04-22-2007 Hank Helmen Est SU D12-3 Apogee - NC Down
(185 ft)
0-5 mph winds RIPEvent: Field Day 07
- Perfect boost! Beautiful 55 sec., glides too well. 3rd launch of model. Just like a Disney Movie: black parachute deployed blue sky, big Deltie glider circling nearby. Until it hit Huge tree! DRAT! Still there! Status: Tree/Roof
06-07-2002 MikeyR Est SU E9-4 Apogee - Perfect Calm The Clone - Nicely up and good deployment. Glided a bit steep and broke boom on landing. Not a bad flight.
03-28-2009 David Sindel Est SU D12-3 Very Late Didn't Record - Bonus delay. Ejected about 3' up and just barely escaped serious damage.
04-18-2009 David Sindel AT RMS D15-4 Very Late Didn't Record - Ejected just above ground again. Needed lots of repairs but will fly again.
08-22-2009 David Sindel Est SU D12-3 Late (2-3sec) 5-10 mph winds Event: CATO 152
- Nice glide.
06-26-2010 David Sindel AT RMS F12-3 Just Past (1-2sec) 5-10 mph winds Event: NERRF 6
- Beautiful flight; glider circled for 2 mins. Pod damaged but will fly again.
01-16-2010 Fred Williams Est SU D12-3 Very Late 0-5 mph winds Event: Frozen Fingers launch, PETR
- Slight breeze caused glider to arc over, horizontal at apogee. Continued on first loop, landing horizontal. Slight damage to canard. AT E15 better suited!

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