I would like to share my setup with you guys,and hope you will do the same.
*disclaimer*
1.This is in no way an absolute setup.It is a combination of my two years chasing this setup with the V-Stabi,along with information sharing with Chuckie and other forum users.
2.In my opinion,it's better to do the mods to a second heli,as it flies similar,but different than the flybarred version.I enjoy my std.N9 just the same.
3.After the modifications that I have done,this helicopter has revealed itself as very powerful and should treated accordingly.It's not for the faint of heart,especially mine.
4.Your flying buddies will be extremely envious of your new heli
The goal with the V-stabi in the N9 is to get the program to run like the Logo series.We all know these babys rock the house.The Logo utilizes direct linkages at 16mm from the servo horns.
This is the starting point.The antirotation guide top hole is drilled tapped for 4mm. The bellcranks are changed from the 18mm by 30mm high ratio to 18mm by 20mm Next,the servo horns themselvs need to be at 16mm or thereabouts. Mine is at 16mm.I powered up,center,measure,drill. Used the JR adjustable servo horns ,welded the holes closed,redrilled and tapped them at 16mm Now that the servo horns are moved from the stock 13mm to 16mm,there is contact with the ball links.I cut some spacers.4mm on the pitch side,3mm on the aileron side.The canopy still fits fine with a little room to spare for padding of some sort. Also milled the center servo mounts down 1 1/2 mm. Frame at guide is opened at the top hole.Guide is fitted with modded bellcrank. Rear frame (elevator) is drilled 10mm foward from stock location.This one is not exactly strait,as it took a couple of revisions. Modded the guide and put carbon on the elevator rod.
This is my electrical layout.It balances a little tailheavy with the 2 cell.I have other packs coming to try. Balance with half tank. Engine has to run smooth,as well as the rest of the model. Achieved +,- 12 1/2 degrees at 90 collective common in the program.
With the new ratios and revised horn spacing,the heli flies very stable and predictable even though it's extremely fast.
There's still a few holes in it,it's a work in progress.
I have the Fueled by Hate frame setup with the "Bonita" (Bonta) head. I call it that cuz' it's so damn pretty.
No. At 20/20 the pitch with 80 collective common is less or about +-10. Bart tried 1 to 1 bell cranks and the pitch was too low.
Something like 16/20 would get the N9 closer to +-12 with 80 CC but the 16mm height is a problem. The links and balls on the bell cranks would get too close or be driven below the top of the side frame. In my setup the top ball rubs against the frame at the elevator bell crank. You would have to change the elevator bell crank mounting spacers to move the bell crank in toward the center of the frames. The front two bell cranks are not a problem as you simply add a shim to move them further out.
Some high speed passes and straitline flight.I detuned it a little,it was a little too wild.It's coming together.Needs stiffer dampeners,you could hear the blades coming out of track at high speed.J-Rock on the sticks.
Adding my experience flying the same setup this past weekend I'd say the vbar N9 flys great with the mods to the bell cranks and running 16mm servo arms. I’m getting +-11 at 80 collective com and 85 CC gets me +-12 degrees. The cyclic gain is set for 97 as recommended by Mikado to match the swashplate measurements.
My setup differs from BartB’s in the servo layout; I reversed the servo mounting position so the link balls and links would clear without having to run too much spacer under the servo mounts. I also eliminated the spacers underneath of the outer two servos and added a set to raise the elevator servo. See the new pictures in my gallery.
I am running the same modified guide versus the plastic anti rotation guide in the pics. The plastic guide is not strong enough for fbl especially when drilling the guide to accept 4mm screws.
When turning around the elevator servo the long elevator rod needed to be longer even though the elevator bell crank is 10mm closer. I picked up a 4-40 threaded rod (2.7mm) and carbon rod from a local hobby shop. The rod is 175mm or so. As noted in the pictures I raised the link ball on the servo arm. I also raised the swash by adjusting the three rods from the bell cranks a few turns so it wouldn’t contact the long elevator carbon rod. This didn’t cause a problem with the swash driver arms on the fbh head.
For the metal servo arms on the JR 8717 I'm running ½ servo arms made by Dynamite, part # DYN2535. Use RED loctite to secure the 3mm link balls. Trust me blue doesn’t work. After the 5th flight the heli flew a bit oddly and after inspection I found one of the link balls loose.
On the swash I measured the distance from the side of the main shaft to the center of the link balls on the outer ring and noticed the elevator ball was 1mm short. I added 2 of the small 3mm washers underneath to move the ball out 1mm. Or if you use the vbar you can adjust this in the Distance setting, set to 97 instead of 100 (97=100*34/35).
I think that’s it for how my setup differs from Bart’s. I’ve been playing with the settings for gain, agility, rudder rate, etc. So far I feel the fbl N9 tracks better than ever and the heli is by no means slow in any direction; it flew great in 10 to 15 knot winds. The aileron and elevator response is much better as compared to running the servo arm link balls at 10mm. Stationary rolls were better and required less input. I never felt any delay from when I gave a command to seeing the model move, like doing fast stationary tick tocks, and only at a few times did I see the model react unexpectedly. This was probably due to the vbar trying to keep up when the wind was pushing against the rotor disk and model was a little slow to respond. The N9 is so much bigger than my T600N but yet it flew even better than my well tuned fbl 600N.
The autos with the fbl N9 were defiantly different and interesting. The control response never gets soft when the rotor speed falls so I need to practice my autos a bit more. I have no problem with my fbl 600N but I guess I need to recondition myself with the N9. On one of my last flights on Sunday I took the heli up to several hundred feet and did very fast inverted auto. The model took only a few seconds to come down and was flying faster than I have ever seen. I quickly pushed up into the vertical and it went up forever. The headspeed went though the roof and must have been over 2200 or something. This setup has new possibilities and I’ll have fun exploring them.
LOL...You guys give "clearance"to anyone We both agreed we're gonna need a turbine waiver for this damn thing I'm using 690 Curtis blades. What are you running?
I was thinking of trying 0.4mm shims instead of 0.5mm. The axle doesn't move at all and the double O rings are new so when the rotor speed is very low I get a bit of shaking.
If you're using the V-stabi,you would be best suited to emulate the Logo lengths which are 16mm from servo center. This is my L500 swash.The L600 is exactly the same. The N9 swash has different dimensions,but there's enough adjustability built in the program. If you're able to pull this one off,you're going to have a very stable and predictable platform to build on.
Chuckie
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On the swash I measured the distance from the side of the main shaft to the center of the link balls on the outer ring and noticed the elevator ball was 1mm short. I added 2 of the small 3mm washers underneath to move the ball out 1mm. Or if you use the vbar you can adjust this in the Distance setting, set to 97 instead of 100 (97=100*34/35).
I need to put the spacer on mine as the swash is 1mm short on the elevator side. The Logo is 31 mm from od of 10 mm mainshaft for all three balls on swash. That explains my flips being faster than rolls.
Weather your flying FBL or not ,that carbon tube over the long elevator push rod is an absolute must IMO. It cured all the up\down nose movements in hard pitch changes and some other maneuvers I was having problems with.
