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Posted by burkefj | Nov 24, 2014 @ 01:03 PM | 6,567 Views
I wanted to build another large scale rocket using foamy build techniques....Idea is to take a rocket that typically needs lot of nose weight and build it light enough to fly on smaller motors. Using sims using normal 1/4" ply, fiberglass for the nose and LOC 7.5" body tube the balasted weight ready to fly is 20 pounds for this model with a proper CG location using J-570 motor.. My goal was to try to get it close to 3.3 pounds, final result ws 4 pounds 2 oz with balast less motor, motor required will be an H-128 minimum... I'll run altimiter deployment with motor ejection as backup. The hellfire requires about 1.8x the weight in the nose for every ounce of tail weight(motor) so you need to keep the rear end light. This is full scale, the Hellfire is 7" diameter and 64" long. The advantage of building this way is you can create your centering rings and sheeted tube to whatever size you want.

Using rocksim CP calculation which is less pessimistic than barrowman estimations shows the CP to be 31" from the nose and with one caliber of stability margin, CG should be at 24" from the nose, or just in front of hte middle yellow band.

I got good deal on 18" body tubsfrom sunward for $6 (pack of 5), couplers for $3, some leftover 6" 3.9" couplers for $4 each, and a 29mm motor mount kit(provided a tube that fit into the bt-55 and three 3.9 to 29mm centering rings)and used three sheets of 6mm depron and 2 sheets of 2mm sheeting....Continue Reading
Posted by burkefj | Nov 18, 2014 @ 12:17 PM | 7,149 Views
I've been wanting to try this for a while, the work I did on my Dyna-soar/Titan II got me motiviated. I do a lot of depron RC airplane construction, my thought was to do a model that typically needs lots of nose weight or is very heavy, and see if using stringers/centering rings and 1mm depron skin I could make a large light model to fly on E-15's......

The only wood in this model are two centering rings in the upper portion that are lite ply, and the balsa coupler I used for my BT-70 upper tube since it was handy at the hobby shop, the rest is depron sheet, cardboard motor tubes and some .04 styrene sheet.

For drawing centering rings I've been simply using a strip of cardboard, put a thumbtack in one end, and measure to the needed radius, poke a hole and insert my fine sharpe and draw it directly on whatever I need to cut, no need for a compass. This can be used for drawing cones or transition shrouds as well where you need a very long radius.

I cut a 7" by 2" triangle out of 6mm depron, grooved and glued in a 1/8" carbon rod which will take the brunt of the nose cone landing force....I then added perpendicular triangles, and took turns gluing in triangle filler pieces and carving those to match the original triangle pieces a quarter at a time...eventually I had nose cone shape. I left one quadrant unfinished so I could add weight if needed, then finish it. I added a few gradually increasing centering rings to get the needed outer diameter.

I cut off a...Continue Reading
Posted by burkefj | Nov 05, 2014 @ 12:40 PM | 7,169 Views
I've been wanting to try to adapt my X-20 to a titan booster. Since the X-20 is large and lightly constructed, the booster would have to be light enough and large enough that I could use lower powered rocket motors to keep the speed down so that it wouldn't rip the X-20 apart on boost. I wanted to try a center 29mm motor tube and use depron centering rings, longerons and a 2mm skin. I wanted the all up weight without motor to be 60 oz or so less the glider. For reference 60" of standard 7.5" loc cardboard tube with a coupler weighs 60 ounces.
Lots of photos so read the whole thread to see final construction photos of the booster....
Length will be 108.5" and 8.25" for the booster to be standoff scale with the drawing I have. Ideal motor will be a 29mm H-97 or H115 that have a pretty flat mild thrust curve..

Here we go.

Here is the rocket simulation, and here is my original X-20 that boosts off a rail on E-6 24mm reloads, here is a quick video of it flying.

X-20 Dyna-Soar rocket boosted RC glider Launch Video (0 min 33 sec)

If this all works, the glider will be ejected via a piston that will also pull out the booster chute, and then I'll glide the dynasoar back. If that works ok, I may try doing an air start of the dyna-soar once released.
Posted by burkefj | Oct 09, 2014 @ 07:45 PM | 6,453 Views
Had a great launch down in Amity Oregon, Gary Goncher got some great shots of 6' bomarc and 6' boeing ALCM in flight.
These were both flown with 29mm hardware and the new G-25 moonburner Aerotech reload. It's a great motor for these depron planes as it doesn't push them too hard, but has a good spike to get them off the pad, they both weigh 32-35 oz rtf. It's also nice because it uses the normal 29mm highpower motor hardware and not the more expensive and custom sized 32mm RC hardware. It's not as hard a thrust profile as a G-38 or G-40, but it's almost a full 120ns motor.

Posted by burkefj | Aug 10, 2014 @ 09:50 PM | 6,571 Views
I had built a 30" long natter rocket glider back a few years ago, designed for estes E-9's or E-6 aerotech motors. The AUW though due to the forward CG was 13 oz and the wing area was a bit small for a good glide.

The original full flying tail was a bit big on this upscale, so I trimmed the inboard ends and mounted them permanently to the tail which helps stiffen it, and then just did full flying outer portions. I mounted the servos on the underside of the fuse and just angled the pushrods up to the tail surfaces and they lined up nicely. I added two parallel carbon struts from the tail to the fuse to prevent slight twisting under hard roll inputs.

I decided to do 136% upsize to make the length 41" and just fit onto a depron sheet at an angle. This gave me almost 2x the wing area and the Due to the longer length and same tail weight, the nose weight was reduced somewhat and AUW came in at 15 oz rtf.

I used some olive model master spray for the body with some flat gray camo using a cardboard stencil/template I made. I used some silver sharpie to do panel lines and a bit of trim monokote for the windows.

I used some thin styrene sheet laminated on the outside of the depron to support the pivot rod for the tail and to help prevent twisting. Had two test flights today, boost was nice and straight and glide was very slow and docile, a lot nicer than the original smaller version. I now have 11 flights , just put in a bit of downtrim for boost setting and reduced uptrim for glide to make it more hands off.

Here's the video..:

Scratch built Bachem Natter RC Rocketed boosted glider (1 min 22 sec)

Posted by burkefj | Feb 03, 2014 @ 02:55 PM | 6,181 Views
Links to current build threads in my blog:

ME-163 Rocket glider:

X-20 dyna-soar with titan booster:

Bachem Natter:

F-8 Crusader:

F-4 Phantom:

Mig 21:

F-105 Thunderchief:

F-102 Delta Dagger:

F-106 Delta Dart:

B-58 Hustler:

Spaceship one:

X-15 Delta Configuration:


Upscale AGM-86 ALCM:

Upscale Tomahawk:

Space Battleship Yamato:

Upscale Bomarc Missile:

Large InteR/Ceptor:

X-3 Stilleto:

Large X-15: http://www....Continue Reading
Posted by burkefj | Jan 27, 2014 @ 01:53 PM | 7,637 Views
I've been going through my old designs/plans and slowly re-doing them for public consumption, originally I did an F-8U-III super crusader which was basically a similar design except for the nose and intake. I decided to make it a straight crusader this time. You could take these patterns and make a pointy nose and curved intake snout and re-do it as a super crusader. There are slight wing differences but probably not enough to notice. On the super crusader you'd have to figure out a way to model the ventral fins which are either horizontal or vertical and quite large, on mine I just created some ventral strakes that sort of modeled them from the side view in takeoff position.

I used a center piece with tail and then two doublers on each side to give me enough thickness to give a nice rounded nose and intake.
It would be easy to add some formers or pink foam and add thickness to make it fully 3-d.

Originally I mounted the wing on the top of the fuse with some tabs and glued a fairing cover over the top. On this version, since the real plane has some airfoil thickness, I decided to pick the most forward point of the wing leading edge and use that for the slot location. I think it looks ok like this and allows some foam above the wing to hold it in place and model the fairing that is on top of the wing. In order to lock the wing in place, I'll drive some 2" pieces of 1/8" carbon rod down through the top of the fuse through the wing and into the body and...Continue Reading
Posted by burkefj | Jan 17, 2014 @ 02:13 PM | 8,169 Views
I decided to do another Phantom build, make a few changes to the original and plans. I originally did these because there weren't great simple plans for a phantom at the time. I'm not a big fan of mid mounted engines or box fuses, I'd rather have a slim profile, gives less drag in the air and is quieter. It does require you to mount equipment on the bottom of the wing has the battery mounted on the front side of the nose, but I'm ok with that. Due to the thin profile the wing hits the fuse further forward than on a normal fuse. If desired, you could alter the top view of the wing to include the intake profile and nozzle profile on the rear of the wing so that the top view was more representative, I considered this and decided to leave it clean. If you do this you may need to do some glide tests to confirm CG did not shift as the intake profile will add forward wing area. The wing is not mounted on the bottom, but is in a slot, I did this to give a bit of area under the wing to mount the electronics and not get destroyed on landing.

Flight video at:
F-4 Phantom parkjet flight 1 (4 min 18 sec)

Here is the Rocket boosted flights...

F-4 phantom scratch built parkjet/rocket boosted glider (2 min 0 sec)
...Continue Reading
Posted by burkefj | Jan 13, 2014 @ 01:41 AM | 7,422 Views
While recovering from my foot surgery, I was watching all sorts of youtube videos on F-105's etc.....Then I realized I don't have any enemies for my thud. I decided to go back to my original Mig 21 profile and change it to a cruciform style instead of a true profile fuse...This saved a bit of weight, but meant the CG would have to move forward a bit. It did give more surface area though so the wing loading would decrease. I went back to my mig thread and saw some pictures a guy had done with panel lines so I went that route. Looks like rtf it will be about 11.5 oz. Did my normal rocket motor mount so I can do rocket glider or with my pusher pod installed.

I went with Czech markings as I have some bohemian in my blood....

Maiden went well, was a little too nose heavy, so removed some weight and it flies really nicely, was a bit windy today.

Mig 21 profile pusher RC parkjet (3 min 42 sec)

Posted by burkefj | Jan 06, 2014 @ 07:36 PM | 7,915 Views
I discovered that the evergreen aviation museum has a thunderchief now on display....It was a nice sunny day so I took some photos....didn't take me long to decide to upscale my original 3mm micro version to 6mm and 39" long...Kinkos did the scaling for me from my original plans. I decided to use a doubled central fuse with two side doublers, and 3mm covers over the rocket mount that also doubles for mounting my grayson microjet motor. Plane is already framed up awaiting an esc and maiden to confirm the CG. I stuck with a full flying tail only. This is a single seat D version. Not sure on the colors yet, I'll probably go with the light bottom and camo top like these photos..... Here are some pictures from Evergreen.....The original small version, and my newer version.

Update 1/7 Finished the painting, now just need to do some panel lines, a few letter markings and wait for my ESC.

Update 1/8 Finished the markings and panel lines, esc is in today but rain for the next week Looks like right around 14 oz rtf.

Update 1/13 Maiden went well, CG was right on, was very windy today but handled it well.

Video will be at:
F-105 Thunderchief RC parkjet (2 min 17 sec)

...Continue Reading
Posted by burkefj | Dec 31, 2013 @ 01:22 PM | 6,452 Views
Well, my son got his learners permit so I had him drive down to the Evergreen Aviation museum for some practice, got in some flight time on my dart at the RC field there and took some photos of the Dart they have. Right next to it is a dagger, and while I like the dart a bit better, I figured I could modify the airframe slightly of the dart, keep the same wing/CG and create a dagger as well. I've got the plans and parts done and cut out, it took a bit more work, and some extra pieces. The canopy is moved back and the nose portion is relatively longer. The tail and speed brake shape are different. I created some wing strake pieces and the tail strakes as well.

For the rear engine humps(my name) they lined up perfectly with where I wanted my motor mount so they posed a bit of a problem. I finally wound up laminating two 6mm pieces with just the outer ones having the extensions and they sort of surround the microjet motor.

Plans are on the plans page.

12.5 oz rtf with the same components I used on the six.

...Continue Reading
Posted by burkefj | Dec 29, 2013 @ 08:00 PM | 6,408 Views
I've always wanted to do a dart, but there have been a lot of them and so I never got around to it till now. This takes a single sheet of 6mm 26.5x39" depron. I used one piece of tubular 1/8" carbon rod to do the wing spar, pushrod reinforcements, and nose reinforcement. No other carbon needed.

You simply print out the plans making sure they are not scaled and you are using borderless printing. Then cut out the templates and mark the depron. Once you have marked the right and left fuse sides, you can cut out the intake doublers and make a left and right of those as well. Only half the wing is shown, simple flip over and trace the other side. Cut out the depron. I grooved and inserted a piece of 1/8" carbon rod in the nose running to about 3" aft and below the wing leading edge to reinforce the nose. I used 3M77 spray to joint the right and left sides. I then sanded the rounded portions of the nose and fuse/vertical stab. Once that is done you can slot for the wing. I then rounded the left and right intake doublers and glued them with 3m77 spray just above the wing slot. You can cut out for the motor tube if you are makiing a rocket glider, or cut out to fit your motor. If you are mounting the motor on a plate you should put a small piece of carbon rod in the middle of the motor plate and drill and glue that into the tail to give it some strength. Make sure to leave clearance for the prop to clear the speed brake extension.

I then did all...Continue Reading
Posted by burkefj | Dec 22, 2013 @ 04:18 PM | 6,259 Views
Flight video
Scratch built V-1 Buzzbomb RC pusher parkjet (4 min 7 sec)

I've been slowly going through some of my less flown rocket gliders to convert them for pusher so i can give them some more flight time. Normally this means a slight modification of the motor clip to use my grayson microjet V-3 that is mounted on an adapter. I have to swap a 20a esc for the BEC, and install the motor wires back to the rear and then re-balance. Most of the time I can just use an 800mah 3s pack for this motor on planes up to 16 oz. I normally use a 8002s pack for rocket boost and have the CG set for that, and with the pusher and the 3s pack I normally only have to add a quarter ounce or so to get the CG back to spec.

I decided to modify my Buzzbomb but thought a tractor setup would be better since I wouldn't have to trim the rudder to clear the prop if I did it as a pusher. I considered doing a tractor in the front of the pulsejet pod but there wasn't enough prop clearance in this small of a model(I had done it that way on my larger buzzbomb back in the day).

Well, it was a very interesting day yesterday. Really strange behavior, like it was tail heavy. Had to run it very nose heavy to get any control at all. Had all sorts of adverse yaw in banks. I tried all sorts of down and right thrust and it was slightly better. Finally upon suggestion I tried a bit of aileron reflex and it got better, but still wasn't flying normally. I finally concluded that the rotating...Continue Reading
Posted by burkefj | Oct 21, 2013 @ 12:10 AM | 7,278 Views
Since I lost my original B-58 in a tree several years ago, I've been missing it.
So, I broke out the plans, made some modifications, and decided to save a bit of weight, would just keep it in the white, which also allowed me to do panel line detail.

It is 12 oz so far, without esc, motor and battery. 32" ws and 49" long. I doubled all the way to the fuse nose this time, and used 6mm doubled on the motor pods in this version.

I didn't want to splice that much so I used four compete 27.5x39" depron sheets and there was a lot left over, I only spliced the center section nose about 10" or so. Not much carbon needed, just some strip in each engine pod, two wing spars and a tail strip for stiffening. I did use some leftover spar rod in the tail to secure the motor plate to.

Here's the new video...

Scratch Built RC B-58 Hustler pusher parkjet (1 min 54 sec)

Posted by burkefj | Oct 14, 2013 @ 01:23 PM | 7,100 Views
I had two very successful flights this weekend in Brothers, Oregon, and a bit thanks to the John Lyngdal, Gary Goncher, Tim, the other Tim, and Robert for helping out, and to all the OROC folks for putting on a great launch, and providing a great dinner, and to my wife, Sophie for helping out in the cold.

First flight was on a J-570 and was perfect, just a slight 5 degree angle caused by wind about 100 feet up, missileworks micro altimiter worked perfectly, 1300', no damage. Second flight was on a J-510, slightly more tail heavy, video will show a slight wiggle then it straightens out, again, perfect altimiter deployment with motor backup, 1700' and zero damage on landing. Very rewarding project and looked very good flying.

...Continue Reading
Posted by burkefj | Oct 11, 2013 @ 02:08 PM | 3,406 Views
Here is my X-2 rocket boosted RC glider kit assembly instructions, 39" long and 34" wingspan, weight RTF is 13.5 oz for the aerotech reloadable 24mm D-7, E-7 and E-6 rc reloads.

Flight instructions and items for completion at


Airframe with carbon spar and full flying tail surfaces with torque tubes installed.
Nose weight
Motor mount
Rail buttons and screws or launch lug(your choice)
styrene strip for reinforcing
velcro for mounting rx/bec/battery
blenderm tape(for taping wires and reinforcing joints)

Flight video is at:
X-2 rocket boosted RC glider Kit (0 min 57 sec)
...Continue Reading
Posted by burkefj | Jan 08, 2013 @ 04:59 PM | 6,743 Views
My name is Frank and I'm a cat-a-holic....could even be called a hoarder of cats....they all came to me in different ways and I love them all. Below are 5 of the 7 I currently take care of....

Current collection........

Tommy: He's my secret favorite and my good buddy, he is the sweetest cat you could imagine. My daughter and I picked him out of shelter with his sister, Coco.

Baby: He wandered in to our house last thanksgiving day, and went to sleep on the couch. He's small but doesn't take any crap from the others. He is quick to talk to you and purr loudly, he always wants a snack....I don't know why he doesn't weigh 40 pounds....

Mischa: He reminds me of a meercat.......We got him from a shelter with his brother Sascha, they were the cutest twins....we had to use colored collars to tell them apart...Mischa sleeps in the strangest positions.....He is like a coiled spring. He sits outside the patio door at night and jumps up to catch bugs, he can jump about 5 feet high.......dude has air...

Sascha: He likes to sleep in the sink or any other small confined space....

Cubby: He was dropped off at our neighbors house when he was 5 weeks old in a paper bag....we took him in.....He's got the biggest eyes...if anyone could give you that helpless look like puss in boots does in Shrek, Cubby can do it..he could give you that look and you'd do pretty much anything for him....

Passed Friends no longer with us...

Cairo: He's was big doofus and...Continue Reading
Posted by burkefj | Dec 25, 2012 @ 09:46 PM | 9,935 Views
Thanks to my lovely family who got me enough foam, and electronics to make another rocket glider. They also gave me a half a day repreive yesterday and today to work on it. I've been wanting to try a spaceship one , but have been worried about CG, twisting and stiffness of the tail booms. It came out ok, I wound up having to put some parallel stiffeners on the bottom of the wing to help prevent twist.

I couldn't find a decent 3-view that I liked or thought was right, so I just did this freehand from a book I have from pictures and relative sizing. I think it captures the look if not perfect scale. The full flying control surface placement was dictated by the fact that I wanted to put the pivot rod accross the fuse and tie it in just in front of the rocket motor mount. This helps reduce the twist of the tail booms and worked well, and actually came close to where they are supposed to be. Since I was doing a cruciform structure, I had to move the wing placement to the middle of the fuse instead of the upper portion, but I don't think it makes that big of a difference in look. I did not add the later stub strake fins in front of the control surfaces yet till I fly it and see how it does without them. Due to the lack of stiffness of the booms, I glued in carbon tubes in each one and laminated a 3mm cover over the tube, that made them very stiff. The wing still had some twist so I used two carbon tube spars as well.

I mounted the servos as far forward as I could to...Continue Reading
Posted by burkefj | Dec 20, 2012 @ 11:47 PM | 9,776 Views
I decided I wanted to try doing one of the proposed Delta wing configurations for the X-15-3 plane, I chose the one normally modeled with the diamond wingtips...I made it simply by taking my X-15 plans, stretching the fuse the scale amount(about 10 inches) and changing the top view to a delta with wingtips. I added some 3mm covers on the sides of the fuse to sort of give it a look like the fairings had. It gives it a bit more body. It's all completed except for painting now, and the fairings added quite a bit of stiffness to the body. It came out at 55.5" long and about 21" wing span which is slightly oversized just for wing loading. Weight is right at 13 oz rtf, but without paint, so assume about an ounce more finished.

Update 12/21/12 Since the world didn't end yet, i had enough time to paint the Delta X-15 and do the markings. Came right out at exactly 14 oz rtf. Pictures show it next to the X-15-2

Update 12/27 Good maiden this morning. CG and throws were spot on as was glide trim, very nice!
Here is the cg calculator I used:

Flight video:
X-15-3 Delta Configuration RC Rocket boosted glider (0 min 41 sec)

Here's a scaled down version with CG location