Gaui 550 Power Systems General Discussions

[dunkonu23]

13 is a lot, bro. Much more than me. I have 11 and 7.5 now... much more and I get too twitchy and can't hold a stable hover. I'm old, you know.

I had a strange accident today with it, too. I went through my usual do nothing first pack. I did put it completely vertical several times, though and that was fun.. timer went off and I did a powered landing.. no biggie. Second pack.. spool up, lift off in normal, switch to idle 1, the tail assembly spins almost 90 degrees on the boom. Hard landing, nothing broken, no parts lost.. I have video that I'm editing and will post it, but this is a first. I'll pin it in the morning.

Scott

[dunkonu23]

Here's the video...

[9sec240]

Very crazy Scott.

I tached my Gaui 500 today. 2300 RPMs. My Trex 500 with Scorp 3026-1600 was spinning 2800 RPMs for reference.

[Jerrymac]

Ivan, glad you got the spacers. I would have sent you a couple more, but still haven't found them yet. I must have made an unintended mistake on the 425 settings in the TX, as today I re-checked the blade pitch to increase it and found I only had 8 degrees. That must be why it feels a little mushy on collective even with the high head speed. I increased it to +- 11 to see how it flys.

Scott, glad to see that your heli didn't suffer any major damage. What tail assembly are you using? The stock Gaui tail units have a pin casted into them that fits into a hole in the boom. I couldn't spin mine on the boom if I tried to.

[dunkonu23]

Ivan,

That's interesting, re: your head speed. Before I changed gearing on my 550, I was turning 2300. Interesting. Then, Nexgen is running 1600 on his 550 with his insane motor, but as we know, he suffered a really bad grip failure possibly due to a defective part or vertical loading. I guess we'll never know on that. Dunno. I got frustrated with mine and killed it with head speed to mask my lack of collective skills.

Jerry,

It's a Sonix/CNC Heli assembly. Never had a lick of trouble with it before and I really don't anticipate any further issues now that it's pinned. It's funny, but when I first installed it I though it was odd it didn't pin. Well, it does now.

Scott

[9sec240]

Jerry, you should poop yourself a little bit when you bang collective now!! I think that the Gaui head design is weighted towards the collective side of things rather than cyclic. My 200s, 255 and 425 / 500 have all been rocket ships when I punched the left stick.

Scott, I thought it was interesting too. Based on the Gaui head speed calculator, I should be at 2277 RPMs on the Gaui 500. That is pretty darn close to what my optical tach said.

I have not flown my T500 ESP in a while and was shocked at how fast the head speed was when I lifted off. 2800 RPMs is probably why it flips and rolls so nice. The 425 flipped and rolled nice at that head speed too but lost so much head speed in the process. I really think cyclic was fighting corrections from the flybar.

I now have the paddles on the back hole which is the faster position. Hopefully it speeds it up a little more but I have doubts based on the head speed. Here is a video from Al's Fun Fly when I was testing the T600 flybar rod and small paddles.



Scott, you already watched it but Jerry might find it interesting.

[Jerrymac]

Ivan, looks like you got it flying pretty good right now. The flips looked nice and smooth.

Scott, I have read lots of posts over at Freak from others that are using that tail assembly too. Kinda odd that nobody else ever mentioned having it spin on the boom like that. Of course, nobody else seems to have the oddball things happen that you and I have over the last couple years. I don't think you will have any more problems with it now.

[dunkonu23]

Jun 21, 2010 13:24:01 GMT -5 Jerrymac said:

Ivan, looks like you got it flying pretty good right now. The flips looked nice and smooth.

Scott, I have read lots of posts over at Freak from others that are using that tail assembly too. Kinda odd that nobody else ever mentioned having it spin on the boom like that. Of course, nobody else seems to have the oddball things happen that you and I have over the last couple years. I don't think you will have any more problems with it now.

They probably pinned it like all good pilots should do! LOL! That kind of makes me a bad pilot... I'll own up to it! I suck! LOL!

I sure hope I have no other problems. I was going to fly it today after work, but my pop-up canopy for IRCHA came in so I set it up in the living room. Man 10X10 is big! I took it down, though... freaked out our dog!

Scott

[dunkonu23]

Ivan, I bet it's because the Gaui calculator is at 22.2 volts... you're probably running anywhere from 25.2 to 23.8 so you're bound to be higher in my way of thinking. I checked mine at 25.9 volts and got 3116! LMAO!!!! If that's the case, holy crap!!!!

Scott

[dunkonu23]

Turns out the tail output shaft was bent. Dunno if it bent during the landing or it bent when I tried to straighten things out. I have another, though. Pinning worked, though.

[Jerrymac]

Jun 21, 2010 14:31:49 GMT -5 dunkonu23 said:

Turns out the tail output shaft was bent. Dunno if it bent during the landing or it bent when I tried to straighten things out. I have another, though. Pinning worked, though.

Probably got bent during the landing. Good thing you found it now, or you would have been scratching your head on the next flight wondering where the vibration was coming from.

I didn't get to fly today. Been tinkering around with both the 425 and the 550 making some gear changes and set-up changes to both of them. Hope I don't make them fly worse,lol.

[olddutch]

Update from Ol Dutch. In my last note I mentioned putting my friends GY 401 in place of my 210. I was shocked on the first flight test when no change was seen. Another pilot entered the scene and made some observations. Increase tail pitch until we get results even though it looks like we added a lot. Then he noticed that the rudder servo was actually moving in a narrow arc. Funny that we had not noticed. Cranking up the gyro limit added servo travel, and we took to the air. WOW! It held just great. I then took the Tx and proceeded to fly it. I had done a little hovering only and it was over a year ago. I hovered for awhile and then took it around a couple of circuits and a fig. 8. It was just like I do on my sim. I am thrilled. That was yesterday and today I went back out and flew out 4 sets of battery packs. It is one smooth, solid bird.

But now.....what was the real problem that gave us so much grief. Was the G 210 really OK after all? Would it have worked with adjusting the gyro limit as we did to the 401? Or was it a combo of things. However, I bought a 401 and that's that.

My thanks to each of you for your concern and advice. I feel that I have gained a fair amount of knowledge from you. I appreciate you guys very much.........THANKS......Rich

[Jerrymac]

Rich, my guess would be that the 210 was probably OK. It seems that the problem was a set-up issue to me. In an earlier post you mentioned that you had an experienced pilot helping you, so I myself did not mention a set-up issue as I did not want to step on any toes.

I set the servo limit pot on my JR gyros at around 80%, then move the ball on the tail servo arm in or out till I get full travel on the tail pitch slider with no binding in either direction. I do this with the Rudder ATV's at 150% on my DX7. If it needs a minor adjustment to get full travel, or to prevent binding, I then adjust the limit pot only very slightly to get it right. If I have to move the limit pot too much, I go back to the mechanical set-up and re-adjust it first.

Anyhow, glad you got it sorted out and are enjoying your flying time. It is a real stable and fun heli to fly. Keep in touch.

Jerry

[9sec240]

Rich, you can't go wrong with a GY401. The gyro just works!! If you don't mind, let me give you a few hints on setting it up for excellent performance.

Put the gyro in rate mode. No trim or sub trim on the radio. Make sure the servo arm is at 90°. Move the tail servo on the boom till the tail pitch slider is centered. Adjust your limit pot up till your servo just begins to bind / buzz in both directions. If it only buzzes on one side, you are not centered. Turn the limit pot down till there is no bind / buzz.

Look at where the limit pot is adjusted. It should be between 80% and 120% but preferably as close to 100% as possible. If you are above 100%, you can move the ball further out one hole on the servo arm and reset limits and check limit percentage again. If you are less than 100%, you can move the ball one hole further in on the servo arm, reset limits and recheck limit percentage. Use whatever ball position gets you closest to 100%.

Delay is used to reduce bouncing when stopping quickly from a pirouette. Fast digital servos designed for gyro use will require little or no delay. I run a Futaba S9257 tail servo on my 450s and a Futaba S9254 on my Gaui 500 and Trex 600 with the GY401. These require no delay. I have not had to try to adjust out a bounce so you are on your own if you need to do this. On cheaper gyros, I have adjusted delay and it helped with the bounce but never eliminated it before compromising the performance of the gyro. I would suspect the Futaba would not be as bad though.

Fly in AVCS mode (heading hold) and adjust the gyro gain so the tail holds during your most aggressive moves without wagging.

Adjust your piro rate by increasing or decreasing your rudder end points.

Adjust rudder expo to get the tail to track / feel like you want.

Fly and enjoy.

[dunkonu23]

Jun 21, 2010 18:41:37 GMT -5 Jerrymac said:

Jun 21, 2010 14:31:49 GMT -5 dunkonu23 said:

Turns out the tail output shaft was bent. Dunno if it bent during the landing or it bent when I tried to straighten things out. I have another, though. Pinning worked, though.

Probably got bent during the landing. Good thing you found it now, or you would have been scratching your head on the next flight wondering where the vibration was coming from.

I didn't get to fly today. Been tinkering around with both the 425 and the 550 making some gear changes and set-up changes to both of them. Hope I don't make them fly worse,lol.

Got the tail output shaft fixed. 40mph wind gusts today in the back yard, it held great! So, if the winds die down, I'll go fly at the field.

Scott

[9sec240]

Cool beans Scott. What tail blades and gyro are you running? I have been extremely impressed by the 84.5 mm KBDDs with the 401 on my G500

[dunkonu23]

Jun 22, 2010 19:09:59 GMT -5 9sec240 said:

Cool beans Scott. What tail blades and gyro are you running? I have been extremely impressed by the 84.5 mm KBDDs with the 401 on my G500

Thanks, man. I was relieved. You should have heard the horrible noise it made yesterday. It sounded like something was rubbing on the canopy. Ugly.
I plan on taking the Gaui to the fun fly this weekend, so it was kind of important to me to be right on the fix. I also found one of the boom supports had lost a screw, so that's a good thing.

I'm using a Spartan DS760 with a Hyperion DS20 GMD and 92mm KBDD blades. The area behind my house is kind of like a venturi (smaller version of streets lined with sky scrapers, like in Manhattan or Chicago) in that wind blows down between the houses and trees in the back, so it's difficult to hold a steady height. Throw in the space between houses that cause a bunch of cross winds. The tail blades were singing big time but absolutely no weather vane action at all. It was cool as all get out to break the area between houses and get swirling side gusts!

Scott

[olddutch]

Hi guys....just keeping in touch. I have a bit of stick time with the Hurri now and have tried different gear ratios and blades. I am very pleased with gearing of 14-42-20-61. I am running 550 FG blades at this time. Oh how I like this compared to my earlier trials with a T-Rex 450. This Hurri is just right for this ol newbie. Thanks again for the help you have been to me!.....Rich

[Jerrymac]

Hi Rich,
Glad to hear that you are enjoying your new heli, and nice of you to pop in and let us know. I sorta know what you mean with the Trex450. I don't have a Trex, but I started out in this hobby with a 450 sized heli and never thought I would learn to fly.
Getting the Hurri 550 was a big help in learning, and now I can fly my 450 much better too.

Nice to hear from you again. Keep in touch.

Jerry

[dunkonu23]

Hey Rich,

What motor are you using with that gearing? Just wondering because it's the same gearing I'm using with an 1100kv Scorpion and it's about the most intense pitch pump bird I've ever seen. Head speed is at LEAST 2600rpm.

Scott