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Oct 05, 2018, 10:52 AM
flyin' fool
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I've had a few Pizza Box Flyers and a Simple Delta do the same in a turns. I think I corrected it with a CG change.
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Oct 06, 2018, 12:26 AM
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davereap's Avatar
I had a triplane that went weird in the turns.. due to vertical areas.. the scale fin was too small, the fuz had as much area and when banked the nose would rise , or tail fall, and had to be corrected with rudder.. A bigger fin increased the rear area and allowed the body to track better when in the bank..

A more balanced vertical area is needed.. so when banked it neither rises nor drops.. the rolls get more axial..
That's why the rear tip fins got added... my best guess..

In construction I did work out the COG for the vertical areas, and for best results I should have matched the vertical areas COG with the horizontal wings COG..
however it didnt match, the nose area was %age wise to big....and I didnt worry...

Reworking the new numbers with the tip fins added, the vertical COG calculations are now very close to the horizontal ones.. so a good guess....

latest sketchup file added
Last edited by davereap; Oct 06, 2018 at 01:28 AM.
Oct 07, 2018, 09:20 PM
flyin' fool
goldguy's Avatar
Maybe too much side area forward of the CG could be the culprit.

Oct 08, 2018, 01:32 AM
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davereap's Avatar
Thats what I thought.. By adding the fins I changed the %ages , it should be better now...
testing thursday eve..

changes V1, V2, V3. and ratios..

I fly my V2 at a 22.5% COG ... that seems to be perfect..
Last edited by davereap; Oct 08, 2018 at 03:22 AM.
Oct 10, 2018, 10:51 PM
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A new sketchup drawing for all three versions
Oct 12, 2018, 12:52 AM
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davereap's Avatar
The addition of the tip fins sorted out the problems...the V3 is perfect now, as it should be.. all Q-versions fly great...I cant really tell much, if any, differences in their flight... Its only the wing loading that has made a difference in the slow speed end of the flight envelope...

My front end strengthening is working, post 5, I had a few bash and crash moments , and no damage resulted..

So it was definitely the vertical balance causing the weird behaviour.. Its a design aspect of our foamies that is often overlooked...
modified V3 testing (6 min 15 sec)

more videos on the quasar thread....

The only thing now remaining is to build a light weight version..
Last edited by davereap; Oct 12, 2018 at 04:33 AM.
Oct 12, 2018, 07:55 PM
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I wouldn't mind scaling this up to run a 3s 1000may setup.
Oct 13, 2018, 01:26 AM
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davereap's Avatar
this bigger one is 26" span... using a 150W motor on a 3s 600-800

a 150% size would be good with a 200W motor... in either the V2 or V3 shape..

Going bigger a KFm2 wing like seen on the 26" version is a good idea for better strength..
I used a 30% KFm2 step rather than a 50% step to keep the weight down,
and the step area is covered in laminating film above and below the wing ...
No spars, the film does that job..
Last edited by davereap; Oct 13, 2018 at 01:37 AM.
Oct 13, 2018, 06:44 PM
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How would I print this ie tiles. Did a search on sketcup and it kinda looks like it's a nightmare
Oct 13, 2018, 07:59 PM
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davereap's Avatar
Download and use adobe reader DC..
open the pdf file ..print as a poster..use actual 100% scale size for the standard size or 150% ( pick your scale percentage) for bigger.. have a suitable overlap set and have the cutting marks checked

With a V2 the wing is easily drawn up directly onto the foam..So only print the fuse..
V3 print out both..fuse and half wing... join the tiles and cut out the stencil shapes... trace out the half wing, turn over the stencil for the other half..
Oct 13, 2018, 08:03 PM
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dimensions clips from sketchup
Oct 13, 2018, 08:29 PM
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Looks like I might have to join 2 pieces of board together. Aiming to get 40"x40"
Oct 13, 2018, 08:33 PM
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davereap's Avatar
printing or exporting from sketchup is easy enough...
note...1.. camera must be set to parallel
2..item or whatever must be framed in the window tightly...
because what you see is what you print or export , all to scale, including all the white areas..blank paper..
Oct 13, 2018, 08:46 PM
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davereap's Avatar
40is big... scale up at 1.8181 recurring ...181%

If its going to be too fragile or bendy think about doubling the layers... and the use of laminating film as stiffening on the wing..
Last edited by davereap; Oct 13, 2018 at 09:02 PM.
Oct 13, 2018, 08:54 PM
Registered User
Originally Posted by davereap
40is big... scale up at 1.8181 recurring ...181%
Yep a bit more outdoor friendly. I have a dst 1200 motor sitting with 1000may batteries. 8x4 should do OK... I hope

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