Setting Up the GP-750 gyro in T-Rex 250 kit

[crash1000]

are the upgrade parts included in that pakage?

[Ozydego]

Setup per manual
11. Now Limit LED lights up.
12. Move the rudder stick and observe your tail pitch travel. Move the rudder stick left until the tail pitch slider reaches the end, then move to the right until pitch slider reaches the other end.
13. While holding the rudder stick, press SET button on gyro.

Setup per Assurance

11. Now Limit LED lights up.
12. Move the rudder stick and observe your tail pitch travel. Move the rudder stick LEFT until the tail pitch slider reaches the end,
13. While holding the rudder stick at that spot, press SET button on gyro.
14. Finish the setup, then go BACK through the setup process again, but this time, Move the rudder stick RIGHT until the tail pitch slider reaches the end,
15. While holding the rudder stick at that spot, press SET button on gyro.
16. Now finish the original instructions


A customer was having issues with his tail limits, he was always having binding with the servo. We went through the setup a few times without luck and finally called Assurance. They corrected the setup procedure over the phone and that fixed the problem. The real issue in the end that caused the binding in the first place was the ball end being 12mm out from center instead of 5mm like the manuals states. This caused the limits to be out of whack and thats when we noticed the original procedure to not work.

[butters149]

so it will set limits for both end points?

[Ozydego]

From what I understand, not at the same time, you have to go through the setup twice to set both points

[cloudbase73]

So, is it recommended to use the setup per the manual or use what Assurance has suggested. How can I confirm that the limits for both end points have been setup correctly.

[Ozydego]

I would say that when you are done, you dont get binding and the slider goes all the way out...

[Rgoh]

I am unable to set the limit of my GP750. After setting 1520, DS, NOR. I press SET to come into Limit. According to the latest instruction in page 2, I should hold left stick then press SET, exit the setting, enter again to do the right stick.
When in limit menu, my status led is green and blinking, while the limit led is green and solid. When I put left rudder, both the status and limit led is green and solid. While holding left stick, I press SET. Then it goes into delay. I did the same thing for right rudder, but this time status is red and blinking while limit led is still green and blinking. Exit the setting. Check my limit, it's still the same as before.
Am I missing something? This is my first experience with Align gyro. Im using Ino-Lab 201 BTW.

[Grant_beltcp]

I set mine today with a new servo (it was binding at both extremes) and it the way it said in the manual. Give left rdder untill it gets to the right point, then give right rudder to the right point and then keeping it there pressed the button. It seemed to set both limits fine.

[Rgoh]

I forget to set the ball 5mm away, put it right at the last hole. It was already the min. limit the gyro can go. My bad...

[steves]

I'm having PROBLEMS:

I have everythign set up properly...
but when I go to spin up, the tail spins hard right, when it gets up to headspeed
or the HEAD will tilt hard to the right, just before lift off?

Also, what should the Gyro be set to in the DX7 radio? 60-70%?

[Ozydego]

Sounds like you need to change the direction of the gyro, dunno about the head,

[dkpodder]

I've got a wierd tail-issue too.

Super combo, stock setup. Initially I had the binding issue, but now I've sanded the hub down, and it seems to be better. I can change tail pitch by hand, allthough it needs high amount of force...

Gyro set up as per instructions in this thread, and full delay, small heli, 25-35 % gain in futaba AVCS mode, ball is aprox. 5 mm. from center. Tested with a 3154, but same issue.

The problem:
When hovering, I push the rudder stick, and turn the heli just 1/8 - 1/4 turn, it starts wagging, and i 5-10 wags it settels down again. The problem increases by increasing the gain, but i've got a very bad-holding tail at 25% gain, and the problem is still there.

I'm allmost at the point of trying the spartan-cure, but normally I do not quit when it should be possible to work it out.

Any suggestions to this problem ?

[gixxerjeff]

Try cutting down your spare tail blades down to 30mm bolt hole to edge.Works well to get rid of the wag,but I dont know about the 420 servo,Im using a JR290....

[jwtje]

I got rid of the gyro and servo all together replaced it with my trusty 401 and futaba 9257 servo i took the tail apart sanded everything and made it as smooth as possible, for me this was the cure it flies wonderfull now tail holds great.

[Ozydego]

You stated full delay??? The gyro should have zero delay in it, or center stick with the top LED blinking red. That would cause a wag. What aso concerns me it that it takes a lot of force to move the tail by hand, it should be smooth as butter, I have seen tails get gummed up by locktite getting in the brass bushing going from the slider to the hub, I would start taking things off starting at the hub and find out where the tail gets easy to move back and forth... then work your way back making sure everything is smooth

[ndoren]

Bert Kammerer states somewhere on this site that he uses FULL (max) delay on all his gyros, which allows him to increase gain/holding without wag. Interesting.

See: https://www.helifreak.com/showthread...=102326&page=6
Posting #53

[dkpodder]

Without the motor running, the tail is silky smooth, but when I test with 70% throttle, it takes a lot of force to move the pushod.

[GaeGuu]

Hi,

I got one of those 250 super combos today .. and I already thought there must be something else in that small box but not my awaited 250

The build went pretty smoth but while setting up the tail I got stuck!
I tried all of your ideas and recommendations but I think there is no one who could make this DS420 holding the tail.
I really tried the whole afternoon even with sanding and and and .. messed up radio and everything.

Finally I went to an expensive electronics shop and got one of those S3154 .. and guess what: It just worked!!

So GP750 is fine and works like explained in this thread but you have to replace this DS420 with something else like S3154 or 290 (which is not available in switzerland) and your tail will just be fine.

Cheers,
Alex

[mipo]

11. Now Limit LED lights up.
12. Move the rudder stick and observe your tail pitch travel. Move the rudder stick left until the tail pitch slider reaches the end, then move to the right until pitch slider reaches the other end.
13. While holding the rudder stick, press SET button on gyro.

This is the part where I'm stuck at. So, the limit led shows up, then i move rudder stick from left to right then in the middle and press SET button. But nothing happens. I also tried to move to the left then SET button, to the right then SET button but it just won't work. Any ideas how to make it work?
Thanks in advance.

[johnnychimpo]

No, move far left until pitch slider at end of travel and then right and HOLD the stick and press the set button.