Update on the new Gaui 255.

Man this thing is going to be tough to build. Finding servos that "fit" is proving to be difficult.

The first set of servos I tried were too wide to fit between the AIL / PTC servo mounts. The second set fit between the mounts but the way the heli is designed, they hit the upper frame. Not too sure what servo is going to have an overhang that is going to work with this frame. May have to dremel the frame or space the servos back.



Hitec HS45HB does not fit.
MKS DS480 does not fit.
Hextronic MG14 does not fit.
Futaba S3103 does not fit.
Hitec HS65MG does not fit
Hextronic HTX 900s do not fit.

Hitec HS55 fits but is a crappy servo.
E-Flite DS75H fits but is worse than the HS55.

I am tempted to take the Hyperion DS09 SCD servos out of my FES and put them in the 255. I don't fly the FES because of the auto tip feature... hmmmmm..

Later that night..................................

I did get the DS09s in the frame but they are not an ideal fit either. Even with spacers, the servo horns are nearly touching the frame. This also puts the linkages on a slight angle. I could run a thicker spacer but I am maxed out on the bolts they provided. I am not sure why they did not make this mount adjustable like the Beam E4 or Furion.

I will be really interested in finding out what servo they did design this heli around.

After getting the DS09s in the frame I was a bit worried about having full travel on the front servos without hitting the frame when the arms are in their full up position. I set the pitch to 10° and then tried setting cyclic to 8° but the swash itself was binding on the main shaft. The swash will not physically tilt more than probably 7 1/2° before the main shaft and bottom of the swash contact each other. To insure no contact with the swash and main shaft, I set cyclic for 7°. With those settings, at full pitch and full back cyclic, the front servo arms hit the frame pretty hard. I do realize that this is an area that will probably not get used that much but it can still happen. I reduced pitch to 9° and it is a little better but still contacts. The frame or servo arms will need to be clearnaced.

Here is a picture of the area in question at 10° pitch and 0° cyclic. Add any cyclic to the mix and you are hitting.



Here is a picture of the DS09 installed. Notice how close the servo arm is to the frame even with the spacers behind the mounting tabs. This complicates the issue in the last post. If the servo sat further back, the arm would be further away from the upper radius in the frame and would have more clearance.



I am currently setting the tail up on the Gaui 255 with a Gaui GU210 gyro and Hyperion DS09 GMD servo. The tail control linkage on the 255 is pretty aggressive. Small inputs make large changes in the tail blades. I moved the ball all the way in on the servo horn (6mm I believe) and adjusted the limit pot on the gyro. It will not let me run beyond about 75% on limit.

.................................................. .....

IT IS ALIVE!!!!!

It is VERY reactive.

It is VERY fast.

It does mild 3D like crazy!

I got none of it on video...

As usual, I had camera issues. I grabbed the good video camera too but got three pitch pumps into the flight and ran out of tape.

[youtube]http://www.youtube.com/watch?v=g4XRSONzEuI[/youtube]

I ended up reprogramming the tail servo to 45° from the default 50° which helped get the gyro limit just above 80%. I need to get some more flights on it to evaluate the tail control and piro speed. IMO, the tail is a bit fast right now. Gain is set at 40% on my DX7 using gear end points.

Swash mix ended up at 50% AILE, 57% ELEV and 37% PIT for 7° cyclic and 9° pitch.

Right now I am tail heavy with a Zippy Flightmax 800mAh 3S 20C. When I get the XT60 connectors, I can get the Turnigy 1000mAh 3S 30Cs installed and it will balance out very well.

I was not allowed to fly it any more at the dome last night due to the carbon blades. I am going to try to paint those white today and fly it again tonight.

A couple other things to note. The blades were labeled stating that you NEED to balance them. I popped them on my scale and found one blade weighed 9.01g and the other 8.90g. There was a lot of flash on the heavy bladed that I removed with some 300 grit sand paper. This dropped the weight to 9.00g. I cut a piece of electrical tape that weighed .1g and found it needed to be at the very tip of the light blade to get it to balance like the heavy one.

The head spools up crooked but straightens out once at speed. I am not sure if the dampeners settled in transport or what. They did provide hard spacers or replacements for 3D which I might have to try.

There is a small vibration that I need to chase down which is likely in the head due to the above mentioned issue.

Things got warm after a 4 min flight. The Zippy 800mAh 20C was quite warm. I think the 1000 mAh 30C should do better. The motor and ESC were both warm but not to the point of being too concerned. It ran cooler at 100% than it did at 80% throttle.... although this could have just been the heli breaking in and getting loose.


As you can hear, the motor is LOUD!! Mine came with the mesh a little loose which I tightened up a bit after the first flight. The noise was still there. The motor appears to have the same dimensions as the 4800kv and 5600kv motors. It is the same colors and has the same laser etched logo on the bell.... but instead of having the kv of the motor etched under the Gaui logo, there is a sticker covering that area that says 3400kv. I wonder what it says under that sticker... hmmm...

The landing gear is nice and soft... It looks a lot like the 200 landing gear but larger... the big difference is in how much it flexes. I think it is going to be very resistant to breaking.

The carry case is SWEET. The canopy is so awesome looking from the front. a cross between a Beam E4 and Vibe 50 canopy. There were several guys at a time last night that would come over and ask "what heli is that???" Everybody liked it. I cant wait to get it out tonight.