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Old Dec 17, 2013, 12:36 AM
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"Vulcan-A": A prop in slot KF jet - PLANS available!

Hi all today i built the Vulcan A, a prop in slot flying wing based on the Vulcan bomber and reinforced with polystrap in an A-frame arrangement of spars and stringers that make it stiff without much added weight.

Wingspan is 20"
Beast Motor
Ar6410NBL brick
2 linear servos
300mah 2s gives around 10 minutes of fun
CG is 4.5-4.6" from nose, just in front of the prop slot.

Here's the maiden and some screaming around once it's trimmed out. What a fun little prop in slot, i love the noise!

Flight of the Vulcan-A (6 min 57 sec)


Check the pics, you can probably build one from looking at them and printing out a 20" span vulcan top profile. I'll probably post some plans soon though.

The plans are now up!
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Last edited by Rusty Mustard; Dec 20, 2013 at 03:44 PM. Reason: Added plans!
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Old Dec 17, 2013, 10:48 PM
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Canada, BC, Kelowna
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That’s an awesome plane Rusty! I love that Vulcan shape! This is the best looking simple “flat” foamie! imho. Seems like a great flyer as well. Please post the plans as I am very interested.
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Old Dec 17, 2013, 10:57 PM
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Plans are coming as soon as i get time to sit down and do some CAD.

If you're a moderately experienced builder, you could just print out a 3 view of a Vulcan and reference the pics i posted. Scale it to a 20" span, cut out the wing, step and two tail pieces

I just edited the post above to include pics. I attached them when i posted but for some reason they didn't appear.

Did i mention it's agile?

Through the trees (0 min 22 sec)
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Last edited by Rusty Mustard; Dec 17, 2013 at 11:09 PM.
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Old Dec 17, 2013, 11:56 PM
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What glue did you use for the pallet strapping?
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Old Dec 18, 2013, 12:14 AM
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Hot glue.
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Old Dec 20, 2013, 03:57 PM
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Okay i posted plans.

This is a simple build, 5 pieces of foam and no cut curves except for the prop slot. Sand all the straight cut edges to get the LE wing curves if you want 'em.

This is a great replacement for the Stryker if you had one and crashed it.

Use a 2.5-3mm CF rod as a motor mount. Run the CF rod straght up the centerline and glue in place between the two step panels for crashproofing.

Refer to the photo in the plans for polystrap placement. Polystrap is hot glued to the top and bottom. It's essential that the pieces on the top and bottom are aligned for maximum strength and stiffness.

Refer to the pictures attached to this post for radio gear installation location.

Fine tune the CG so it holds attitude in full throttle level flight with no reflex on the elevons. Rolls should be fast and axial with no down elevator input. If it wants to barrel roll move the CG back and trim the elevator down a bit until it flies level, rolls axial, and remains stable.

Have fun!

Vulcan-A Tree gap action! (1 min 19 sec)
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Old Dec 23, 2013, 01:20 PM
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This is cool, Rusty. Thanks for posting.
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Old Dec 25, 2013, 03:09 PM
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Okay, i've been flying this thing nearly everyday, and crashing it HARD!

It's absolutely indestructible,as far as flying, i must have over 100 hard crashes on it now, into trees, terrain, and even myself a few times. I pretty much crashed as hard as possible, downwind, full throttle in a dive right into solid rock, and it just bounced off. I've put it in inverted the same way, picked it up, tossed it back in the air, and kept trying to shoot the gap. Yesterday i clipped a wing on a rock ridge downwind at full throttle in a nap of the earth knife edge turn around a tree, it smacked the ground at my feet and cartwheeled down a rock talus slope for 30 yards or so. Dusted it off, put the battery back in place,and put it back up again. It's like it has a reset button, my crashproofing works!

So far i've cracked an elevon while beating it out of a tree with a stick, and i had a tailfin detach during another de-treeing. Both were easy fixes, and it still flew with one fin, although it was a bit loose and the wind really knocked it around.

The canted tail fins seem to be the thing that really locks this plane in, they're just as wide as the prop. I think the high velocity air passing through the fins like a duct creates a low pressure bubble between the airframe components and increases stability even at low airspeeds.

It also flies in pretty substantial winds. Yesterday i put it up in moderate slope winds and lift, and under power it punches right through. Gliding, i got it to stay up in the big lift zone, upright and inverted. As long as i maintain speed it's got a good glide ratio, and i found flying in the lift at around 10-20% power is enough to pretty much negate the windmilling of the prop and lets it act like a slope wing. It's a delta, so it's not the best on the slope, but it's got a high enough aspect ratio to fly decently.

If i had any FB's i'd build a few of these and fly full contact combat. They'd work for indoor combat as well, i can keep it in a pretty tight box , like the size of a basketball court at full throttle and some fancy stick wigglin'. A bunch of these screaming around indoors going full contact would be swarm-of-angry-bees awesome!

I've got a 5 piece F-15 in the works now using the same crashproofing principles, and i'm also working on a F-15EZ variant that looks like a jet but flies like a primary trainer. A few more design tweaks in CAD and i'll be ready to commit the F-15EZ to foam. I'm going to build the first F-15 today hopefully, and if it all works out i'll adapt it to the EZ variant and hopefully noobs can have a 'cool' jet to fly instead of a 'boring' trainer.
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Old Dec 26, 2013, 11:51 AM
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Joined Dec 2009
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Quote:
Originally Posted by Rusty Mustard View Post
Okay, i've been flying this thing nearly everyday, and crashing it HARD!

It's absolutely indestructible,as far as flying, i must have over 100 hard crashes on it now, into trees, terrain, and even myself a few times. I pretty much crashed as hard as possible, downwind, full throttle in a dive right into solid rock, and it just bounced off. I've put it in inverted the same way, picked it up, tossed it back in the air, and kept trying to shoot the gap. Yesterday i clipped a wing on a rock ridge downwind at full throttle in a nap of the earth knife edge turn around a tree, it smacked the ground at my feet and cartwheeled down a rock talus slope for 30 yards or so. Dusted it off, put the battery back in place,and put it back up again. It's like it has a reset button, my crashproofing works!

So far i've cracked an elevon while beating it out of a tree with a stick, and i had a tailfin detach during another de-treeing. Both were easy fixes, and it still flew with one fin, although it was a bit loose and the wind really knocked it around.

The canted tail fins seem to be the thing that really locks this plane in, they're just as wide as the prop. I think the high velocity air passing through the fins like a duct creates a low pressure bubble between the airframe components and increases stability even at low airspeeds.

It also flies in pretty substantial winds. Yesterday i put it up in moderate slope winds and lift, and under power it punches right through. Gliding, i got it to stay up in the big lift zone, upright and inverted. As long as i maintain speed it's got a good glide ratio, and i found flying in the lift at around 10-20% power is enough to pretty much negate the windmilling of the prop and lets it act like a slope wing. It's a delta, so it's not the best on the slope, but it's got a high enough aspect ratio to fly decently.

If i had any FB's i'd build a few of these and fly full contact combat. They'd work for indoor combat as well, i can keep it in a pretty tight box , like the size of a basketball court at full throttle and some fancy stick wigglin'. A bunch of these screaming around indoors going full contact would be swarm-of-angry-bees awesome!

I've got a 5 piece F-15 in the works now using the same crashproofing principles, and i'm also working on a F-15EZ variant that looks like a jet but flies like a primary trainer. A few more design tweaks in CAD and i'll be ready to commit the F-15EZ to foam. I'm going to build the first F-15 today hopefully, and if it all works out i'll adapt it to the EZ variant and hopefully noobs can have a 'cool' jet to fly instead of a 'boring' trainer.
Wow, Rusty. From your report I'd think you were flying a foamie! I spent Christmas on the Phoenix Sim. I tried my best to pare down the model of The Beast on there. I plugged in all the dimensions I could to make it similar in size, cg, etc. I was pretty proud of what I ended up with and thought that it was flying how I thought it should. Then, I went to adjust it one more time and, I guess, I copied over everything I did. Anyone else use Phoenix and would like to share their sim program for the E-flite Pitts M12?
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Old Jan 19, 2014, 01:29 PM
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United Kingdom, Pardshaw
Joined Oct 2012
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This looks like a great flyer.

I've got some Blue Wonder 1300 kv motors which give me 17 ounces of thrust on an 8 x 3.8 prop.

So, I thought I'd scale it up from 20 inch wingspan to 29.5 inches. Based on some rough calcs......

Any mistakes, of course, are mine not Rusty's !

First step.....cut the base layer from 6 mm Depron.
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Old Jan 19, 2014, 01:55 PM
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Wow, 17oz of thrust?

With the right prop that thing should be a rocket! Can't wait to see it finished, i might scale one up like yours.
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Old Jan 19, 2014, 02:09 PM
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Joined Oct 2012
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Hi Rusty,

Yep...17 ounces. I built a thrust meter which gives fairly accurate measurements. Also use a Wattmeter with it. Helps size the prop. to get max thrust for min Watts.

Second step.......

I use a 6 mm square section carbon fibre tube to make lightweight motor mounts for Blue Wonders. This fits perfectly flush into a slot cut into the 6 mm Depron. I epoxy the tube in. The Pallet Strapping then fits perfectly flat over the top (thats the third step).
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Old Jan 19, 2014, 02:46 PM
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Here's the home-made thrust meter.

The vertical arm is the same length as the horizontal arm, so there is no amplification or reduction of thrust transferred to the kitchen scales.
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Old Jan 19, 2014, 02:59 PM
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Cool setup, i need to get one going as soon as i get a scale and a wattmeter.
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Old Jan 20, 2014, 01:29 PM
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United Kingdom, Pardshaw
Joined Oct 2012
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Some more progress.......

I've been very impressed with the thought that has gone into this design. Its gone together very well and is very light and stiff thanks to the clever use of pallet strapping, tape and the KFm panels.

The techniques could be adapted to other designs, so if anyone is interested it may be worth checking out Dave Reap's excellent thread on Pallet Strapping reinforcement here:-

http://www.rcgroups.com/forums/showthread.php?t=2047264
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Last edited by pardshaw; Jan 20, 2014 at 01:35 PM.
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