So spinning in circles on the ground is a good thing?

[northstar728]

Ok I think i need a little help. I just bought a raptor 30 and the following:
-jr xp7202
-gy401


Ok, so here is the problem. I start her up and get the blades up to speed ok but all of a sudden she does some kind of spinning manuver. I have been doing little adjustments for three days now and still the same thing. What am i doing wrong?

[chaos]

The "direction" switch (DIR, next to the LED light) might be backwards.

With the engine off, swing the tail by hand and see what the gyro does to the tail rotor pitch. I'm guessing it compensates backwards. Flip the DIR switch if so and try again.

[northstar728]

Originally Posted by chaos

The "direction" switch (DIR, next to the LED light) might be backwards.

With the engine off, swing the tail by hand and see what the gyro does to the tail rotor pitch. I'm guessing it compensates backwards. Flip the DIR switch if so and try again.

nope that wasnt the problem. do you think the gain may be to high still. the spinning happens in both modes.

[chaos]

Which way is it spinning... reference to the nose? (does the nose go left or right?)

From a position on the left side of the heli, which direction does the tail rotor spin; CW or CCW? I just mean the blades, not the whole heli. Turn the main rotor CW by hand and the tail rotor spins which way? It should be CW, but it's just as easy to go the other way if the belt half-turn is wrong.

When you say the heli suddenly starts to spin I assume this is because it's light enough on the skids to do this, as opposed to something coming loose? Like, is the belt tension tight enough?

An experiment: To eliminate everything but the gyro, bypass the gyro and see if you can rev it up to hover speed without this spinning thing happening. You can expect to have to hold some right rudder to do this. Make sure the TX endpoint limits don't try to drive the tail pitch slider farther than it can go. You will probably need to cut back on them. You might need a servo extention wire to bypass the gyro. If this works we can focus on the gyro. When you hook the gyro back up again be sure to restore the original endpoints.

Are you using a digitial servo for the tail, and is the 401 set for digital/non-digital as applicable?

Do you have any REVO mixing enabled? Generally it should not be enabled when using a gyro. Move the collective up and down and it should have no affect on the tail pitch.

If the heli works ok without the gyro then apparently something is not set up correctly with the gyro or possibly there is a problem with the gyro.

401 setup. Set the rudder endpoints to 100% and zero any trims. For the mechanical setup, with the tail pitch control slider centered, the pushrod connection to the servo arm should be at a 90 deg angle when the servo is centered. To center the servo put the gyro in the normal mode (the LED should be off) and zero any trims. Then carefully move the stick left and right and adjust the "LIMIT" trimmer on the 401 so that the pitch control slider isn't being pushed farther than it can go in either direction. Full left/right stick movement should just barely reach the end of the limit of travel on the slider. If this turns out to be uneven (hitting on one side and not the other), then the slider probably wasn't quite centered to start with, and you can slide the servo holder on the boom (or on the Raptor, change the length of the control rod) to get it centered. Make sure the left/right stick movement moves the tail pitch in the correct direction. If it isn't, then reverse the rudder servo at the TX, and recheck the limit.

Then put the 401 in the heading hold mode (LED on), and use the rudder stick to center the tail pitch slider. Then push the tail one way or the other to turn the nose and check to see if the 401 is giving a correction in the proper direction to the tail pitch. If not, then flip the "DIR" switch on the 401.

A crib for checking tail pitch direction: Park the tail rotor so that the blade holders are straight up and down (roughly). Then while holding the blade holders in that way, swing the top blade towards the nose. If the slider is centered then the blade will be parallel to the tail boom. Then when you move the stick to the right that top blade should point towards the right. And, if you swing the tail to the right (nose left) that top blade should also swing to the right (it's doing the thing you would have to do without a gyro).

If you're not using a digital servo make sure the "DS" switch is off. If you are using a digital servo then turn DS on and set "DELAY" to zero.

At the TX you should be able to get reasonable results out of a 50% gain setting in either mode. You may want to crank it up a bit once you get the thing basically working.

I'm assuming here that you have the 401 mounted such that the LED and pots/switches are on the top. It doesn't matter which way the thing is aimed, front/back and left/right don't matter. It is only sensitive on a axis running from top to bottom.

[northstar728]

thanks chaos. i will try this. i am new to helis and would really like someone that has flown before to look at it to make sure everything is setup correctly. i live in az does anyone live close that can help me?

[chaos]

There are quite a few pilots around Phoenix, as you might imagine. There is a pilot locator here. It's pretty slow to respond, but if you hang in there you might zero in on somebody near you. Also check for a hobby shop. You might hook up with a fellow pilot there. But if you can't find anybody you can learn what you need to learn to enjoy your heli.

Here are some videos that will help.

Whatever questions you have there's bound to be somebody who can give you the info. I don't know anything about your radio except for what advertisements say but surely somebody here does. I see that it has 5-point pitch and throttle curves. I see a lot said about that subject but for a new person there might be some fuzz around the understanding of it. So, I'd like to rattle just a bit to give you some gerneral info.

Let's consider the 5-point pitch curve... collective pitch is what we're talking about. These 5 points correspond to 5 positions of the control stick. Point #1 refers to the stick being all the way down, or back, towards you. Point #5 is all the way up. Point #3 is where you're at when the stick is centered. Points #2 and #4 are quarter and 3/4 stick positions, respectively. Each of those points (stick positions) can be set to a value ranging from 0% to 100%. This percent refers to the percent of available servo motion, and that is affected by the endpoint settings.

Let's pick a point, say, point #3. That point is selected when the stick is in the center. In your TX programming you can select point #3 and edit the value of it to whatever percent you want. If you set it to zero then the servo is all the way as far as it can go in one direction, which depends on how the endpoint is set. If you set it to 100% then the servo is all the way at the other end, depending on that limit. You wouldn't want to set point #3 to either of those, generally, but you could. If you set it to 50%, which is more likely what you would want, then the servo is in the middle of its range of motion.

These 5 points allow you to adjust how the stick movement affects the collective pitch. For starting the heli, I like to set all 5 of them to 50%, which centers the servo, and I set the mechanics to give zero pitch when the servo is centered. This way, the heli won't take off, but I can start the engine and get the head up to speed because the throttle has its own curve that works exactly like the pitch curve. I set point #1 of the throttle curve to enough to give me a decent idle. I use the throttle cut switch to close the throttle fully. I set point #3 to give me around 1800 rpm, and point #2 between those two. I set points #4 and #5 to the same value as #3. In this way I won't overrev the thing. Once I get it started and up to speed, at half stick (point #3), I switch to idle-up, which selects a whole different pitch and throttle curve pair. On that one I set a linear pitch curve, point #1=0%, #2=25%, #3=50%, #4=75%, and #5=100%. I use that curve to set up the mechanics on the heli. At mid stick, point #3, the servo is set to 50% and I want the swashplate to be in the center of its range of motion at that setting and the blade pitch to be zero. When the stick is full back, point #1, which is set to 0%, the swash is full down (endpoint limit set as needed) to give max negative pitch. That's for inverted flight. And with the stick full up, selecting ponit #5, which is set to 100%, the swash is full up (with that endpoint set as needed) to give max positive pitch. So, this linear pitch curve makes the full range of pitch available. Once the mechanics are set up this way then you can make the heli more docile just by changing the values at the points. For example, you could set point #1 to give +1 deg on the blades. That way, if you panic and slam the stick all the way down you won't be trying to penetrate the earth with your heli.

Anyway, my only point here is to say that these curve points correspond to positions of the stick and each of those points can be adjusted to give any percent of servo input from zero to 100%. Exactly where the servo ends up at zero percent or 100 percent depends on the setting of the respective endpoint adjustment. If a point is set to 50% the servo will be at the center of its possible range of motion, and the possible range of motion is determined by the endpoint settings. The idle-up feature provides a separate set of curves. You can set any of the curves whatever way suits you. The throttle curve, however, should normally be set so that the engine holds the rpm steady during flight.

I think this is too long... hope I haven't confused you with this piece of ramble. It's late and I'm tired. That's my excuse.