RE: Who wants a scale pusher prop jet?  
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RE: Who wants a scale pusher prop jet? - 2/9/2005 6:58:20 PM   
Mike James



Posts: 2431
Joined: 1/19/2002
From: Anchorage, AK, USA
Status: offline 		Bob is right. (Thanks, Bob.)

From the early CAD stages, both the rotation issue and engine cooling were addressed. With a 12-inch propeller, the plane can rotate to 10 or 11 degrees on the ground without a prop strike. Simulation testing has convinced me that this is enough. 10 degrees is actually more than most people think, visually. (image attached) Note that since this image was created, we've decided that the lower ventral fins aren't required, so we won't be using them. (The outward canted vertical fins accomplish the same purpose... decreasing Dutch roll tendency, and preventing over rotation at high AOA.)

If someone really wanted to take off and land at extremely high angles, they could just modify the landing gear a bit, and/or use smaller diameter props.

PS> If you go to the first page in the article, ( http://www.nextcraft.com/j47_sportjet01.html ) you'll find links to two pages that may interest you...
First, there's a page that shows the whole development cycle of the plane, at http://www.nextcraft.com/j47_development.html and then there's a page showing the simulation testing we did in X-Plane, at http://www.nextcraft.com/j47_sportjet_x-plane.html

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< Message edited by Mike James -- 2/9/2005 7:05:52 PM >


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RE: Who wants a scale pusher prop jet? - 2/10/2005 7:22:18 AM   
LGM Graphix



Posts: 2330
Joined: 4/20/2003
From: Abbotsford, BC, CANADA
Status: offline 		This may be covered in this thread already, but it's a long thread LOL!!!! any idea on projected price for this kit? It looks like it might be really cool and useful for the 12lb thrust turbines as well.
Jeremy

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RE: Who wants a scale pusher prop jet? - 2/10/2005 8:09:44 AM   
Mike James



Posts: 2431
Joined: 1/19/2002
From: Anchorage, AK, USA
Status: offline 		For pricing info, it's best to email me, or this begins to look like a commercial thread. (and we're not even selling kits yet.) And... We are researching a turbine conversion.


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RE: Who wants a scale pusher prop jet? - 2/11/2005 1:03:33 AM   
Mike James



Posts: 2431
Joined: 1/19/2002
From: Anchorage, AK, USA
Status: offline 		Hi everybody,

The top fuselage half is done, and the bottom is in the vaccum bag now.

Bonus, from painting in the mold...
i was wondering how I'd align the gear door reinforcements (1/32" balsa) and the paint allowed me to simply make reference marks where they needed to go, then epoxy them in between the two layers of glass. Same procedure for the lite ply spinner ring.

I've also got one of the tailerons done, and some other small parts, such as separate landing gear doors, NACA inlets, etc.. Coming along nicely now, and this is a LOT more fun than sanding the plugs.

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RE: Who wants a scale pusher prop jet? - 2/12/2005 3:10:41 AM   
ewstap


 

Posts: 20
Joined: 10/16/2002
From: Kannapolis, NC, USA
Status: offline 		Enough already! I'm ready to go to Pat'S place to see it fly. Can't wait much longer. Do you know Phil Kimbrell? Flys at Triple Tree often. Let us know when it will happen!

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RE: Who wants a scale pusher prop jet? - 2/12/2005 3:57:08 AM   
Mike James



Posts: 2431
Joined: 1/19/2002
From: Anchorage, AK, USA
Status: offline 		We're getting there.

Yes, I've met Phil. In fact, he has come by to visit a couple of times, and spent a few hours. He's working on some composite projects of his own, and doing a very nice job, too.

Since I don't have a buyer-type "kit" in front of me, you can expect that it will take a couple of weeks to finish the assembly. Tonight, I've waxed and PVA'd the wing and vertical fin molds. Tomorrow, I'll spray them with the white primer, and expect to vacuum bag them tomorrow night.


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RE: Who wants a scale pusher prop jet? - 2/16/2005 1:54:35 AM   
Mike James



Posts: 2431
Joined: 1/19/2002
From: Anchorage, AK, USA
Status: offline 		Hi everybody,

Ta da!
Here's the first fuselage, joined and out of the mold Production fuselages will have the formers installed in the mold, and this one didn't, so I dinged it up a little getting it out of the mold. Still, it will be fine for flight testing, and it looks good. The second photo shows the (unpainted) hatches and the canopy test-fit. Everything looks good.

The last image is the prepped wing molds, and the wings are next, starting tonight. Latest updates are at http://www.nextcraft.com/j47_sportjet11.html

Closer all the time...

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RE: Who wants a scale pusher prop jet? - 2/16/2005 3:20:22 PM   
smchale



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Joined: 6/19/2002
From: Malvern, PA, USA
Status: offline 		Looking great Mike! Don't let any of the boat guys see it!

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RE: Who wants a scale pusher prop jet? - 2/16/2005 3:48:35 PM   
bob27s



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Joined: 4/9/2002
From: Cleveland, OH, USA
Status: offline 		Mike,

How are the fuselage pieces joined? Do you just tape the seams in the mold? Just foamie-glue (aeropoxy)?

That is one thing I do not see mentioned much on some of the composite threads. I know the wings are not taped (cant get inside), but what of the fuselage and larger structures?

Bob


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RE: Who wants a scale pusher prop jet? - 2/16/2005 4:39:23 PM   
Mike James



Posts: 2431
Joined: 1/19/2002
From: Anchorage, AK, USA
Status: offline 		Thanks, smchale. Yep... Put a big "bat fin" on the back, and let 'er rip.

Bob,

In this case, I used fiberglass cloth strips ( "tape" ) around the rear of the fuselage, approximately from the leading edge of the wings to the tail. It really wouldn't have been necessary except that without formers installed, it was a little fragile. With formers installed, whatever you do on the seam is strictly cosmetic, as the internal structure takes the loads.

If we were making Pattern-type airplanes, using left/right molds, I'd use tape to join the pieces, because the skin itself takes more load. On this airplane, the seam is hidden at the bottom part of the fuselage's curves, where the bottom of the tailerons, wing, and the nose's chine go.

I vacuum bagged one wing (2 halves) last night, and will be doing the other one today, along with some tail parts. In the next few days, you'll see the engine, retracts, etc., installed, and it will look like a plane. I'm excited.


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RE: Who wants a scale pusher prop jet? - 2/22/2005 3:22:52 AM   
Mike James



Posts: 2431
Joined: 1/19/2002
From: Anchorage, AK, USA
Status: offline 		Progress this week...

Fuselage is together, gear doors are installed and functional, and I'm finalizing details to be sure engine access, hatches, etc., are all right. Internal parts are installed in the wing molds, which will be joined tomorrow, and pulled the next day. Latest updates are at http://www.nextcraft.com/j47_sportjet11.html which include some more photos.

Closer every day...

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RE: Who wants a scale pusher prop jet? - 2/22/2005 2:24:07 PM   
Neil Guildford


 

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From: Guildford, UNITED KINGDOM
Status: offline 		I think that because of the nature of a Prop/Pusher jet being almost impossible to hide everything that makes it run, most importantly the sound, should be designed to be very fast. To me that is what makes an RC jet. Therefor I would want something with a thin wingsection and as little drag as possible. For instance avoiding large "Scale" air intakes on the front as they slow the plane down something chronic, look at the Cermark F16.

I think Sport, slim with retracts and flaps...

I would also prefer a wooden fuz for ease of repairs.

Neil

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RE: Who wants a scale pusher prop jet? - 2/22/2005 2:58:11 PM   
bob27s



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Joined: 4/9/2002
From: Cleveland, OH, USA
Status: offline
quote:

ORIGINAL: Neil Guildford

I think that because of the nature of a Prop/Pusher jet being almost impossible to hide everything that makes it run, most importantly the sound, should be designed to be very fast. To me that is what makes an RC jet. Therefor I would want something with a thin wingsection and as little drag as possible. For instance avoiding large "Scale" air intakes on the front as they slow the plane down something chronic, look at the Cermark F16.

I think Sport, slim with retracts and flaps...

I would also prefer a wooden fuz for ease of repairs.

Neil


Neil......

Its a tough balance.

If you want sport, slim, retacts, thin wings, wood, very fast...... you want this
http://www.rcuniverse.