Futaba CGY750 FBL install & review

[BenHeli]

Great videos John. Thanks.

I'm going to sit down this weekend to set the 750 with the 14MZ. Hopefully things will be smooth with the help of the videos.

[helidanno]

Building Trex 700LE

Can the CGY 750 be setup with 6203 and just function as heading hold tail gyro and gov? I wanna get the feel of this big beast with both setups and I havnt bought the FBL headset yet.

[HeliBenj]

Looks like you can, saw a post elsewhere from a Futaba guy saying that works by setting cyclic gains to 0. Then the unit acts as a tail gyro/gov and CCPM mixer
I have not verified that myself though.

[Zaaaguy72]

I am getting really frustrated with the swash setup on this thing. How the heck do I get the +/- swash throws equal? I get 13 degress + and my - will be about 16. On vbar and Microbeast there are very simple ways to equalize the throws for Cyclic and collective, but on the cgy I cant figure it out. I set the high/mid/low stick in expert menu, but that did not help. My hyperion atlas servos are setup very close to perfect, so I know my center points are correct. Since I am not supposed to mess with endpoints, how do I fix the difference between throws?

[Mercuriell]

The cgy750 is electrically perfect for equal throws and hence there is no adjustment on the unit. The unequal throws are due to your head geometry. You need to adjust the swash height till throws are equal and zero at mid stick. If you can't or don't want to do this then you can adjust the end points on your pitch curves. Don't try and use end points for this as this will change gyro gain. I know vbar has adjustment for this but this is electrically compensating for an imperfect mechanical setup!

[Zaaaguy72]

Thanks John, I will do some tweaking.

Chris

[Zaaaguy72]

Got it all dialed in, will test fly later today. Thanks for your videos and help John.

Chris

[orjanp]

Does the CGY750 have a built inn receiver for Futaba, like the VBar and TotalG have for Spectrum?

[raptorJoe]

Originally Posted by orjanp

Does the CGY750 have a built inn receiver for Futaba, like the VBar and TotalG have for Spectrum?

No not included. You have to upgrade your Rx to the sbus Rx.

Just ordered mine from tower, be here friday. Can't wait to transform the heli. I am using the fbl head from outrage fitted to my rap 50. I was going to order beastx but I have always put my trust into futaba. Plus with futuba's "sbus only" forces me to do away with my co pilot. No more training wheels!!!

Will update this weekend weather permiting.

[Zaaaguy72]

Well I thought I had it right, but I didnt. I still cant get it to be the same on +/- collective. I have messed with everything from raising and lowering swash, changing ball position on arms, center position of arms, and just about everything else in the book. The geometry is perfectly square. I am using a Mikado Trex 500 flybarless head conversion kit. How does moving the swash up or down change the throw ranges when you also have to fix your center point on the blades by the same amount? I am going to try to use the pitch curves to fix the problem. I called Futaba this morning and the tech said he did not know much about the 750 and asked that I email the question to them, which I did.

John, I saw you had the same problem on RR, how did you get rid of it?

[Zaaaguy72]

Ok, after much frustration and tinkering, I have all throw's within a degree in each direction. It will have to do!! I am so looking forward to flying this thing, should be very nice.

[Mercuriell]

Originally Posted by Zaaaguy72

John, I saw you had the same problem on RR, how did you get rid of it?

SAme as you - tinkering with the head geomtery !! THe head linkage on the Kasama Srimoik is very adjustable. I was surprised that very slight angular variations off the mixer arm on the blade grips gave such marked differerntial collective results - I had to use a digital pitch gauge but in the end got it exact. It may well be that the FBL Mikado head is not capable of being setup to give exact equal movements and that is why they incorporated the adjustment into the VBAR - I have never had a FBL Logo so you would have to ask ont he Mikado Forum.

I still think that adjusting the hi low of the pitch curve could be used to dial this out if you want. I think some people confuse this with adjusting endpoints of the pitch servo which is definitely not a good idea as this changes rate and will cause mixing interaction.

[Zaaaguy72]

I too had to use a digital pitch gauge!!! Funny that the same conclusion was found. Thanks for help man!! Happy flying.

[BOOGIE]

I cant get the 750 to switch threw the flight modes what the hell am I doing wrong Should I see it switch on the 750 when I move the switch?

[Mercuriell]

Originally Posted by BOOGIE

I cant get the 750 to switch threw the flight modes what the hell am I doing wrong Should I see it switch on the 750 when I move the switch?

You referring to different govenor settings ?? You need to setup governor gain on a receiver channel that outputs different setting depending on your flight mode. This is done in the transmitter and depends on what Tx you are using but can usually be done from the Gov menu in the Tx. You need to make sure your SBUS channel is set to the same Gov gain channel as your Tx !!

[BOOGIE]

I got it going thanks for the help!! It was very stable the tail was a little faster than I like Im guessing go down with the DR in the radio? Its not for me I was helping a friend thats just getting into helis from airplanes

[bmclaurin]

Thanks for the great videos, very helpful. I just received my 750, and I will be setting it up on my T-Rex 500 ESP w/ Align FBL head later this week.

Regarding the unequal pitch range that others have noticed, it seems to me that, at least with the Align head, it is mechanically impossible to achieve *exactly* equal positive and negative range if the angle between your cyclic servo horns and their respective control rods is anything other than 90 degrees. I'm using the Align DS510 servos for cyclic, and the manual for my original FB-equipped 500 ESP recommends going all the way out to 19.5mm on the horns (presumably to avoid binding because the balls can bind against the servo casing in some cases if you move the balls in any farther on the horns). At 19.5mm, the control rods are angled in quite noticeably with respect to the main shaft at mid stick. Even at 16mm (or even 13mm), there is a slight angle--the rods are not parallel with the main shaft. If you follow the traditional setup procedure of getting your servo horns at 90 degrees with respect to the main shaft, it is a simple fact of geometry that you will not be able to achieve *exactly* equal positive and negative pitch, at least with the Align head, although you can certainly get it "close enough" or even so close that you might not be able to accurately detect it. You can, however, setup your servo horns to "point up" a bit such that they form a 90 degree angle with the control rods, and this will get you much closer to an equal pitch range. All of this assumes that you have equal servo travel in both directions (e.g., you have not adjusted your servo end points in your TX from their default 100% values, etc.).

I saw the following post a while back where someone did a simple drawing to illustrate this geometric fact:

https://www.helifreak.com/showpost.p...06&postcount=6

Sorry, didn't intend to hijack this great thread, but I thought this might be helpful for those that are frustrated with unequal pitch ranges.

[Mercuriell]

Very helpful comments re the geomtery - I agree and I suspect that is why the VBAR has an adjustment for unequal geometry - on the Kasama head with the links going up to a mixer arm rather than a pushrod it is possible to square up the geometery and make it equal though I don't feel this is a big issue

[Simone]

thanks thanks thanks great video

[recurry]

Originally Posted by Mercuriell

Very helpful comments re the geomtery - I agree and I suspect that is why the VBAR has an adjustment for unequal geometry - on the Kasama head with the links going up to a mixer arm rather than a pushrod it is possible to square up the geometery and make it equal though I don't feel this is a big issue

I know there are some who will vehemently argue but, in my experience of having built and flown 15+ FBL ships, having perfectly square geometry isn't necessary and trying to do so makes things way more complex than necessary. This fixation on making everything perfectly square seems to come as a result of taking a "guideline" to the extreme and causes people to waste a lot of time trying to make it perfect while losing focus on the more important things that make the ship fly well.

Yes, it's better that the servo arms be CLOSE to a right angle with the ball link because you want have the mechanical leverage and travel to be as close to symmetrical for each direction of servo travel as possible. Perfection is not required nor does it accomplish anything useful to make them perfect. In my experience plus or minus 5 or 10 degrees makes no perceptible difference. Maybe even 15 degrees is ok on some ships. Anything better than 5 or 10 degrees is wonderful but not worth spending a lot of time on. Basically whatever the best you can get with proper servo arm positioning on the servo shaft is what you should accept.

After building 20 plus FBL ships I've zeroed in on the following simple method that get's nearly perfectly setup mechanics every time. Simply center the servos using an Align servo tester or equivalent (1520us) and then install the servo arm in a way that get's it as close to 90 degrees to the ball link as possible. Then, using a swash leveler (the kind that go UNDER the swash without having to take the head off - like this: http://www.readyheli.com/CHP-L501-Cu...l_p_32311.html, not the CNC one's that require you to remove the head to use) make your ball links to exactly the length needed for a level, properly spaced swash with the servos at 1520us (center). After that, with servos still at center and a level swash, make your pitch ball links such that you get exactly zero degrees pitch. The easiest and most accurate way to do this is to lock the blade grips at zero pitch using one of these: http://www.readyheli.com/RDLohrs-Uni...l_p_37918.html (I made my own out of a ruler). After you've done this you can check for zero pitch by folding the blades to one side and when they line up perfectly that's zero pitch (which is the way Mikado advises). That's much more accurate than using a pitch gauge.

You can set the min/max collective pitch by moving the blades to one side and measuring the distance between the blades then using one of the iPhone, Android or PC programs (PC program here: http://www.rcgroups.com/forums/showthread.php?t=603927) where you enter the length of the blades and the distance between them to find the pitch. Again, more accurate than any pitch gauge and a heck of a lot easier. Mikado uses this method in their VBar setup software.

You can also set cyclic pitch this way. Instead of measuring the distance between the blades you find the distance the blades move from zero pitch, double it, and then find the pitch angle with one of the software tools above.

If you follow the above simple steps you'll be able to setup any FBL controller without having to trim anything and without trial and error. And, unless they are cheap blades, they'll also be nearly perfectly tracked most of the time. I've done this enough that I can do an entire servo/head mechanics setup in less than 30 minutes without rushing then I go through whatever setup the FBL controller requires and then go flying.

Hope someone finds this helpful.

Ron