Finished her up at 4 AM this morning . AUW with 3S 520 is 8.1 oz.
Ran it up a few times and although it feels like it will hover OK it's not exactly
trying to rip outta my hand . Maybe need to play around with the
pitch and throttle curves and see what kinda currents we're drawin'. Motor
is just barely warm after playin' around so sounds like it has plenty of reserve
power if I figure out how to use it. I'll play with it some more this evening.
Good news is it balances very close to the rearward CG point without the
battery. That means I'll be able to use the stock battery holder .

Steve

Video?!?

Hey Steve,
Great looking YAK! Have you flown it yet? I finished mine up last week and have flown it 3 times. The first flight was disapointing, too much vibration not enough reverse pitch. Second flight was better and the third flight today was the best! For the first time today the plane went backwards. Watching it stand still for a moment was a trip! It was really doing some strange stuff. I will continue to work with finetuning the pitch setting until I get it right for me.
I installed the VP setup on my Shockie YAK using the recomended setup included with the VP prop unit. I did use a servo saver to avoid stripping the pitch servo in case of a prop strike. I used a lite ply servo mount to tightly hold the servo and used the servo screws so that removing the servo for service would be easy. I added very thin cf rod struts on the tail feathers to stop the flutter. It fly's heavier but well. I also added counterbalanced ailerons and the roll rate is crazy!!!
I included pictures to show what I've done. Setting up a VP plane is tough but I think it'll be worth it. One things for sure, I've learned a great deal from this experience already!

Harry

That's great Harry . I still have issues with mine though . Flew it
again today with less than impressive results. There's no way it even comes
close to stopping with the nose down. What I think is happening from the
sound of the prop is that it's not holding the pitch. I believe there is still
too much flex in my pitch rod/servo setup. I think the pitch is flattening
out under load. Guess I'll have to move the servo up close like yours.
What servo are you using?

Steve

Hey Steve,
I'm using an HS-55 servo for pitch. And there is no flex on the pitch control rod. I did have to add more reverse pitch than was called for in the directions though.

Harry

Originally Posted by harrymc

Hey Steve,
I'm using an HS-55 servo for pitch. And there is no flex on the pitch control rod. I did have to add more reverse pitch than was called for in the directions though.

Harry

Thanks, I'll go ahead and use the same servo then but move it up closer
to eliminate all flexing. I just thought of another issue that I wonder if
we need to be concerned with, the extra strain on the BEC caused by the
fourth servo .

Steve

Steve,
I've been flying several planes with 4 servos (2 on ailerons) with no problems for some time now. The cc10 does get hot sometimes, but does seem to be holding up well so far.

Harry

Originally Posted by harrymc

Steve,
I've been flying several planes with 4 servos (2 on ailerons) with no problems for some time now. The cc10 does get hot sometimes, but does seem to be holding up well so far.

Harry

OK, that's encouraging . I moved the servo from the fuselage down onto
the wing. The Depron is double thickness there. I was getting a lot of
flex in the single thickness where it was mounted before. Also I'm using
a thicker piece of rod to the servo. Still have a slight amount of flex but
MUCH BETTER than before. I'll see how this works before I try to tear into
the nose to mount it up there.

Just got back from a test hop and things are much improved. I actually
got it to hover nose down a couple a times . Now I think I need a slightly
longer arm on the servo to get just a tad more pitch. I have to say it's
a kick to be able to stop and change directions in a blink of the eye .
Motor and pack were just warm after running out a 3S 520 pack. My
next thing will be to check the current draws and see if I can get in the
sweet range with my pitch settings.

Steve

Cool, Im putting that setup on a Axi 2208/34 as that little motor had me wondering about being enough power.

Harry, is that the same servo saver as Scott was recommending?
Thanks for the pics!

Yes it is RC, and you're very welcome. I hope they help!

Great job on the last flight Steve! I think I'm going to try lighter batteries as you've done and see what happens.

Harry

.....if the S2 motor is a good match for the VPP on a YAK-54. . I
did a LOT of experimenting in the shop with different pitch and throttle
settings and never did really find anything that gave the kind of thrust
needed to aggressively 3D a model of this weight. Ya, I've gotten it
to hover nose down but only in the first few minutes of a pack. And
even regular hovers take about 3/4 WOT. Also if the plane is on a
down line with any speed you can only slow it slightly with neg. pitch.
Measurements with the Whattmeter show around 6.5 A when thrust
maxes out. Since I,m using a 520MAH pack that's taken it way down in
voltage. I've played with the pich setting in the radio while the motor is
running full throttle and you can really see and hear the difference in rpm's
as you go from low to high pitch. You can also feel the change in thrust
and it seems like that 6A range felt like max thrust but even then it wasn't exactly tearing the plane outta my hand . Now if I use an 830mah pack
I gett mor thrust but not enough to make up for the batteries extra weight,
so that just makes matters worse. Maybe I need to geat a hollow AXI 2208/34 for this thing. Anybody got any ideas

Steve

Steve,
Good timing for your questions. I'm working right now on removing the S2 motor and plan to replace it with the hollow shaft AXI 2208/34 that I have. I'll use the prop hub that came with the Ikarus vp unit. I'll need a longer pitch control rod, so it's off to my lhs in the morning if the hurricane is gone by then. I hope the extra power will allow the kind of response I've seen on the videos.

That is bad news! I'm waiting for the 7 channel CC/Berg receivers to come out to finish mine.

The good news is that I've been flying the S2 with a 8x4 GWS HD prop on my Ikarus Yak on 3s lipo packs, and it does fine. It seems to have a bit more thrust than my Axi 2204/54 with the same prop and battery.