How about a piYak??!! - Page 17 - RC Groups
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May 10, 2012, 01:02 PM
flyin' fool
goldguy's Avatar
Don't forget to place the equiptment in a fashion so as to balance it nose to tail as well.
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May 11, 2012, 06:18 AM
“There’s no place like Foam”
gpw's Avatar
With disk planes the acceptable CG range is very narrow , and although we try our best, sometimes the CG does not end up where exactly we want it (or where the plane wants it) ... So we always resort to the old “lump of Clay”on the nose (no, not our nose, the plane’s ) ... an ample supply carried in the field box for just such occasions... Perfect for “fine tuning” of the flying properties ..
The small bit of added extra weight is much offset by the improved flying qualities...

Just thinking that if one did extend the nose a bit for better balance , the side area should be kept to a minimum (no implied radials /cowlings ) ... or maybe even just an extended motor stick ... but then it wouldn’t be a Yak , not that it’s even close now ...
May 12, 2012, 02:09 PM
Victoria Super Mortem
UBILDIT's Avatar

Ahhhh! That's Better

O.K. the picture is just an edited version of the first one.. Rudder servo is now forward. The dark shaded areas on the rudder itself ... I milled 3mm of foam out of each side in the shape of the shaded area... but after all that.. the best thing I did was glide test it , only to find that in a glide it was quite nose heave... so I unglued the two bamboo skewers holding the upper part of the motor in place and gave it a bit of down thrust, which apparently was actually level or maybe slightly down.. and it will now fly with a 450 mah battery instead of an 800 and the handling with all input... especially rudder is outstandingly better... thanks for ya'lls input...


Oh, also.. moved receiver and esc forward as suggested... rock on...
Last edited by UBILDIT; May 12, 2012 at 02:10 PM. Reason: forgot other stuff.
May 12, 2012, 05:30 PM
Registered User
That sounds much more fun now!
May 19, 2012, 05:31 AM
Foam is where the heart is
brett.c's Avatar
I've had about 8 flights with my 18inch piyak and I'm starting to get the hang of it.
I ditched the landing gear because it flew much better without.
Throws are now set to the maximum for maximum fun.

Down elevator is a little savage but up and roll controls are fine.
Rudder travel may be a little too much because she'll corkscrew towards mother earth on full travel. However that does make for some rather interesting manoeuvres.

Pretty tough too. I've doinked a few times with no ill effects.

Great little plane
Feb 28, 2013, 11:29 PM
Registered User
I thought this needed a little bump as many may have not seen one of the best designs on the planet...
Mar 01, 2013, 07:06 AM
Registered User
philipa_240sx's Avatar
Although most of my fleet is balsa, there is always a piYak raring to go. Still one of my most favourite fun planes.

If you haven't built one, what on earth are you waiting for?
Mar 01, 2013, 09:02 AM
flyin' fool
goldguy's Avatar
I'm still flying an EPP Pi. It's a bit shabby now, heavier and needs to be replaced after hundreds of flights and hours of fun.

A wonderful design.
Dec 18, 2013, 05:18 PM
Registered User
tallflyer's Avatar
You Guys were holding out on me I just found this thread after My Friend Tim on facebook told me about it
Latest blog entry: Yunnec Typhoon H Review
Dec 18, 2013, 06:55 PM
flyin' fool
goldguy's Avatar
Look here ................ and here too ................
Last edited by goldguy; Dec 18, 2013 at 07:03 PM.
Dec 22, 2013, 05:06 AM
Registered User
davereap's Avatar
here are two ideas Ive been using on my smaller squarer bodied Pi yak
This is a 15.25" version from 6mm EPP

another idea for a new build is to use pallet strapping to replace spars.. Its a cheap material and very strong....two strips glued in a sandwich above and below a wing makes it very stiff.. the strapping can also be split down its length and glued round any flat leading edge for further stiffness and damage protection
Last edited by davereap; Dec 24, 2013 at 02:01 AM.
May 31, 2014, 03:16 PM
Registered User

Thrust anle?

I'm pretty sure I read that the PiYak needs no thrust angle - down or right - is this correct? I'm getting ready to put my 18" er together and sometimes I just build the thrust angle into the motor mount. I sure would appreciate some input on this please! Thanx
May 31, 2014, 03:27 PM
'Lectric Aficionado
aeronot's Avatar
With all the hovering, torque rolling, etc u can do with a pi yak, a zero thrust line has always been best for me.
Jun 01, 2014, 02:11 PM
flyin' fool
goldguy's Avatar zero
Jul 24, 2014, 12:53 PM
aeronot.......... very fun plane..........thanks.

just gave u and the pi some kudos over on the nut ball thread to see if i could send some of the n/b er's over here for a look. this design does not get the interest it deserves .


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