X-Plane build thread

[Ededge2002]

This will be a build thread of my latest project a Yuri Models X-Plane.  The model is a full carbon molded Hotliner/sport model and there isn't any "construction" left to do.  Its more of an assembly thread really but I will be going over the components ive chosen and why along with how the pieces are installed.  There are a few goals I have for this plane but the main point is to go quickly AND quietly.  Instead of a tiny screaming prop I will be using a geared motor and a larger high pitch slower turning prop.  This is a way the power limited class F5D racers have been using to gain a little more efficiency over the small prop setups.

http://yuricomposites.com/

This video is an example of the of sound of the two different setups.

http://youtu.be/8-Kr77lZ90c

[piker]

Very cool, Ed.  I'm looking forward to learning more about this new approach to speed.  But you know the routine.  We need pictures 

[sihinch]

Thanks so much for doing this Ed.  I cant wait to learn from your mistakes! 

[battlestu]

Very cool, Ed.  I'm looking forward to learning more about this new approach to speed.  But you know the routine.  We need pictures 

agreed pictures with beer bottles are need 

[Ededge2002]

There will be photos I have an appointment to get waxed this afternoon!

[battlestu]

There will be photos I have an appointment to get waxed this afternoon!

Please say that is a typo and you mean to say "There will be photos I have an appointment to get the plane waxed this afternoon!"

[thehaze]

 

[Ededge2002]

Airframe and the equipment list.

Initial empty airframe weight is 13.8oz(392g) with a wingspan of 52"(1320mm)

Neu 1115/1.5D(3500kv)
Kontronic KPG27 5.2:1 gearbox
Georgi Mirov GM 10 X 23 F5D carbon folding prop with 30mm spinner
Castle Creations ICE LITE 100 esc
Hyperion DS09 servos (metal gear for flaps carbon poly for remainder)
Castle Creations 10 amp bec
Futaba R617FS receiver
ThunderPower 5S 1800mA 45C battery
undecided RX battery power (likely 2s LiFe)

[Ededge2002]

Firewall installation.

I used two layers of 2.5mm G10 to make the firewall.  Time consuming to make the pieces by hand but im happy with the end result.  Glued in with 30minute epoxy thickened with ground fiberglass(there was lots of it made making the firewall!). 

[Ededge2002]

Motor/Esc assembled and cooling hole cut in fuse above Esc. Theory here is that the air will go in the hole and exit out behind the spinner.  A little graph with an actual test of the motor/prop combo I have measured with a pitot tube and data logger to give an idea of where this is going.

[sihinch]

Love this thread! Thank you. Offers great insight in to specifying a high-performance power system and some build techniques and little quirks that you need to watch for.

2 questions - can you explain some more about how you sized the diameter of the firewall and then how you went on to cut the fuse length?

And secondly do you have any more details on the ESC cooling theory? Like, does it really work?

Cheers
S

[Ededge2002]

2 questions - can you explain some more about how you sized the diameter of the firewall and then how you went on to cut the fuse length?

And secondly do you have any more details on the ESC cooling theory? Like, does it really work?

S

Im using a 30mm spinner and no fuse portion was removed as the minimum diameter is 30mm.

I used a 30mm spinner and pushed it up inside the nose cone of the fuse and measured how far back this sat from the lip of the nose.  I measured the motor (or in this case gearbox) output shaft length and figured the maximum back I could position it and still have the required amount of the shaft sticking out.  I took the numbers and made a drawing showing the thickness of the firewall and the inside diameter of the lip of the fuse nose and mapped out the taper.  I made a little wood template the diameter that I had calculated would put the motor the right distance back and tried it.  It was very close.  I made the G10 pieces a TINY bit smaller so If anything I could position the spinner slightly further back on the shaft if any fudging was required.  More time figuring it out and making the firewall than you would think looking at two little pieces of plastic!

Cooling?
I did a LOT of reading about this and the common thing encountered when an esc went up in flames was that regardless the vents the smoke and soot usualy came out the back of the spinner with burn marks going forward in the fuse to this point.  The thinking is that with bernoulli's principle the air going around the nose of the plane accelerates the airflow developing a low pressure area.  Further back on the fuse the airflow should be reattaching to the fuse slowing the air and making a high pressure area.  This leads to the thinking that the air will enter the fuse at the high pressure area and proceed to the forward low pressure area.  I will admit this is ALL experimental!  The other thing in play here is how much drag is worth compared to how much cooling??  This will be a two minute maximum cooling situation so there will be no time to heat soak much and the system Im using is hopefully not operating over its capacity at approximately 75amps.  I can after all add more holes if needed but my Enigma is set up this way and nothing is hot at all in there.

(sorry I tried to explain it as well and as briefly as I could.)

[sihinch]

Thanks Ed. I think I get it.

So how are you cutting the carbon? What tool are you using? I see you are using masking tape to reduce splinters or wandering of cuttitng tool, is that right?

[piker]

That's a hot looking plane!  Thanks for all the details.

[Ededge2002]

Installed a couple of control horns tonight....