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Old Mar 09, 2011, 08:31 PM
in persuit of low wing loading
Gordon Johnson's Avatar
Boston, Mass
Joined May 2001
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Skeleton Toon Jet

Finally after a couple of months not touching it I got some time to work on my Skeleton Toon Jet. All that is left is to install the Vapor brick and control rods, and shorten that way too long prop shaft.

Wing span is 11 inches, weight looks likely to come in around the 13.5g range, and wing loading should be about 0.75 oz/sq.ft or so. Propulsion is PZ Cub 6mm gearbox and motor.

Covering is RA Microlite with painted on decoration using paper templates. It looks like the paint added about 1 gram, but worth it I think.

Airframe with CF wing brace weighs 4.35g.

Gordon
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Last edited by Gordon Johnson; Mar 09, 2011 at 08:56 PM.
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Old Mar 09, 2011, 08:37 PM
in persuit of low wing loading
Gordon Johnson's Avatar
Boston, Mass
Joined May 2001
6,438 Posts
Here are some earlier pictures during construction and creating prototype skeleton pieces.
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Old Mar 09, 2011, 10:01 PM
Fly long and land softly
Jim_Marconnet's Avatar
Madison, Alabama USA
Joined Oct 2005
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Gordon, that's a Beauty! And with a wing loading lower than an Vapor (unbelievable!), it should fly wonderfully.

I love the way you ran the wing back into the tailfeathers. I'll guess that gave you some more wing area and a lot more stiffness than if the wing and tail were completely separate, joined by just the fuselage.

I look forward to hearing how it flys.

Jim
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Old Mar 09, 2011, 10:04 PM
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I R Irv's Avatar
United States, IL, Washington
Joined Nov 2008
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Gordon I don't know how much of an improvement this would be, but I would be happy to make you one. (it's the least I could do for you) Also I don't know if it was me but I broke my shaft on the first prop strike. Had to replaced it with either a Vapor or Ember shaft.
TODD
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Old Mar 09, 2011, 10:25 PM
in persuit of low wing loading
Gordon Johnson's Avatar
Boston, Mass
Joined May 2001
6,438 Posts
Jim,
Glad you like the way it all flows together. It's not a new design. There is a thread on the larger non-skeletonized version that my son flies. It's my version of a pizza box flier, except I've attempted to make it look like a cartoon plane.

Todd,
I may take you up on that. I've seen that you put bearings in your PZ gearboxes. Or, I might do it my self. I have another Cub gearbox and will look at putting bearings in it. I haven't even looked at it closely enough to see if I need to bore the holes out larger. But, I tested this motor and gearbox with the 4" MCF prop and got 18.7g of thrust, so it should be sufficient for this plane. And, putting ball bearings in it would slow down getting it finished. But, I may use this GB in another plane, and for that one I've been thinking about BB.

Gordon
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Old Mar 14, 2011, 08:51 AM
in persuit of low wing loading
Gordon Johnson's Avatar
Boston, Mass
Joined May 2001
6,438 Posts
I got the equipment installed in Skeleton Toon Jet over the weekend. It came in at 13.45g. My estimate before beginning was 12.9g, so I'm happy with how close it came to the original estimate.

First flight won't be till the end of March at our next indoor. I'll try and get video.

Gordon
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Old Aug 16, 2012, 10:23 PM
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Pete P's Avatar
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Massive bump!

I stumbled across this thread, and built up a semi-skeletonized version myself.

The fuselage is 1.2cm thick- That's a 1CM foam block, cut out, with 2 of 1mm sides glued on.

The wing is a single piece of 2mm foam, home-planed and rather light.

My bare airframe with a wingspan of 25cm came in at about 5g, a bit heavier than Gordon's here, but I'd assume a bit easier to build It weighed 4.1g before the tail feathers and propulsion reinforcement.

Inside, I have a Mosquito brick (just because I had it lying around), an Ember 6mm motor, gearbox, and prop. AUW is 16.8g with a 120mAh cell. It could use a 90 or 70mAh cell, and likely prop hang.

Fantastic plane, thanks Gordon! I've done my test flights, I can't wait to take it to the park tomorrow.
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Old Aug 17, 2012, 06:48 AM
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Oxford, Michigan, United States
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Epp?
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Old Aug 17, 2012, 08:36 AM
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No, it's some composite recycled foam. It's porous (not quite air-tight), but strong enough and certainly light enough. The wing alone weighed about 1.6g without flaps. The unglued foam components for the fuselage weighed 1.75g.
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Old Aug 17, 2012, 11:41 AM
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wall foam it appears
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Old Aug 17, 2012, 11:55 AM
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Again, it's recycled foam. It was used to pack electronics- I forget the exact source, I scrounge so much foam with which to make sheets. It came in a large block, I have a hot-wire planer I use quite a bit.

I do have some wall foam left- That's pressed closed-cell foam, the adhesive used between the 'balls' is springy and elastic. My foam here uses less adhesive, and tends to tear between the foam balls. It doesn't spring back when squished, but it sure is light.
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Old Aug 17, 2012, 01:26 PM
in persuit of low wing loading
Gordon Johnson's Avatar
Boston, Mass
Joined May 2001
6,438 Posts
Pete,
Nice job.

Believe it or not, my Skeleton Toon Jet has still never flown. Although my second clear and larger Skeleton Toon did fly. I put the opening for the brick under the wing (for esthetics reasons) before I figured out that the channel mapping won't work with it in that position, or at least I couldn't figure it out. It's on my list prior to NEAT this year to carefully remove it from under the wing, and put it on top. I just haven't gotten around to it yet.

Gordon
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Last edited by Gordon Johnson; Aug 17, 2012 at 05:44 PM.
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Old Aug 17, 2012, 01:37 PM
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I would love to see a video
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Old Aug 17, 2012, 01:42 PM
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Oxford, Michigan, United States
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Quote:
Originally Posted by Gordon Johnson View Post
I put the opening for the brick under the wing (for esthetics reasons) before I figured out that the channel mapping won't work with it in that position, or at least I couldn't figure it out. It's on my list prior to NEAT this year to carefully remove it from under the wing, and put it on top. I just haven't gotten around to it yet.

Gordon
Is it just a matter of programming mixes Gordon? Or do you not have at least a DX7? With less than a 7 you run out of mixes real fast trying to rearrange things.
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Old Aug 17, 2012, 01:45 PM
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I built mine up having forgotten the best radio position, and then figured it out and cut in the slots. I'd imagine you used a laser cutter- I did all mine freehand with a hot wire!!

I'll post a video once I take it to the park.

I'd love to have mine as light as yours, Gordon, but the foam I used here is too flimsy to be cut thinner/skeletonized along the wing. The body provided ample structure for a thin cut, however. Would you have a components weight breakdown? I'd just like to compare the foam portions. Maybe once my Deltang RX arrives, I'll make another with some actuators- Super light!
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