Spinning BR 450

[Warp778]

After a small crash, I was still able to hover my BR 450 PE but noticed that the tail control bushing was sticking on the tail shaft a bit.  At the last hover for the day, the tail was quite stuck and the tail servo was buzzing quite a bit.

I replaced the tail shaft that was a bit bent and realized that the servo was also damaged. I replaced the old standard tail servo with a new EXI 18H53 9g digital metal gear servo.

When trying to spin up and fly today, the heli spins in a counter clockwise direction very fast, out of control, and will not stop - it spins faster as more power is given and does stop when power is off. 

Everything seems to check out in static mode but it spins when the motor is connected and trying to take off.  This happens in both the HH or rate mode.  When testing with the motor unpluged, everything tests out apparently fine - the tail slides right and left with no problem and centers OK.

Did I also damage the gyro or do I need to do some adjusting of the gyro gain because of the new servo (I haven't touched the gain screw on the gyro itself at all)?  Do I need to set something different in the Transmiter (standard Exceed TX) and the 6tConfig program?  Does just changing to a new servo change something in the gyro and/or TX that I am not aware of?  Please help.  Thanks.

[bad007]

That sounds like the servo needs moved on the tail boom after being replaced. First check the direction of travel with the gyro,  Initialize the gyro and switch to normal mode ( light off ) pick up the heli and rotate it counter clockwise, the slider should move left if not direction needs switched, thats the other setting on the gyro besides the gain. If ok set trim for the tail to 0 and make sure the slider goes full left up against the boom with right stick. If not check  the ball and link at servo and make sure they are not getting up against the servo housing and stopping it from a full travel. That sometimes happens if you use the first hole on the horn. If adjustment is needed loosen servo straps on boom and move servo so slider travel is centered out making sure you get full travel right and left, If you cannot get full travel up the gain on gyro until full travel is obtained. Slider must slide full left with right stick. If to much right trim is still needed to keep heli from rotating left shorten linkage 1 turn at a time until proper trim can be obtained. Alway trim the tail in normal mode ( light off on gyro )

[Warp778]

(I have checked the direction of the servo and the amount of movement.  Both check out fine. Right stick makes the slider go left and when I pick up and move the heli to the left (nose left - CC) the slider moves to the left. Everything appears to be centered in normal/rate mode - but------

However, when I spin it up the slider moves all the way to the right and stays there - the tail will not compensate for any movement with the slider to the right as far as it can go and the heli just spins out of control.  Even if I move the stick while it is running up, it won't change the spinning.)



After a small crash, I was still able to hover my BR 450 PE but noticed that the tail control bushing was sticking on the tail shaft a bit.  At the last hover for the day, the tail was quite stuck and the tail servo was buzzing quite a bit.

I replaced the tail shaft that was a bit bent and realized that the servo was also damaged. I replaced the old standard tail servo with a new EXI 18H53 9g digital metal gear servo.

When trying to spin up and fly today, the heli spins in a counter clockwise direction very fast, out of control, and will not stop - it spins faster as more power is given and does stop when power is off. 

Everything seems to check out in static mode but it spins when the motor is connected and trying to take off.  This happens in both the HH or rate mode.  When testing with the motor unpluged, everything tests out apparently fine - the tail slides right and left with no problem and centers OK.

Did I also damage the gyro or do I need to do some adjusting of the gyro gain because of the new servo (I haven't touched the gain screw on the gyro itself at all)?  Do I need to set something different in the Transmiter (standard Exceed TX) and the 6tConfig program?  Does just changing to a new servo change something in the gyro and/or TX that I am not aware of?  Please help.  Thanks.

[bad007]

Ok, so you replaced the shaft for the tail, you don't supose you have the tail spinning backwards, looking at heli from the left side it should spin clockwise.
The belt has a 1/4 twist in it and if you got it flipped when replaceing the shaft the tail will spin backwards. It sure wont correct even with the stick if so.

[Warp778]

Ok, so you replaced the shaft for the tail, you don't supose you have the tail spinning backwards, looking at heli from the left side it should spin clockwise.
The belt has a 1/4 twist in it and if you got it flipped when replaceing the shaft the tail will spin backwards. It sure wont correct even with the stick if so.

I did check that.  When the main blade moves clockwise (looking from the top) the tail moves counterclockwise when looking from the right side (or clockwise if looking from the left side.). 

I forgot to mention that I did have to change the tail servo reverse function (in the T6config program) when I put on the new servo.  The old servo (original equipment) had the reverse button checked and that made the new servo move in the wrong direction.  I changed the check to normal so that now the new servo moves to the left with a right stick move. Given that I had to change the reverse function of the servo (channel 4) should I also do the same for the gyro (that is, change the gyro channel 5 from reverse to normal)?  Is there a connection between the two? The gyro does react properly in static mode when I move the tail to the right (the slider moves to the left).  It still goes all the way to the right as soon as I spin up and will not adjust - that makes the heli spin out of control.

[AKPhill]

Try it  i had one that was giving me some greif and when i reversed the gyro the tail started behaving again if it works then  you have fixed it yourself

[bad007]

I also had a problem with the tail spinning out of control and discovered the reversing adjustment on the gyro itself vibrated to mid point.
also in normal mode ( light off ) does the servo go to the trimmed point and act properally?  I had the T6 just for a short time and I found adjusting the v knob for the gyro had a small range to work with. If the knob was turned too far left the gyro would not initialize properally and had no tail control.

[Warp778]

I also had a problem with the tail spinning out of control and discovered the reversing adjustment on the gyro itself vibrated to mid point.
also in normal mode ( light off ) does the servo go to the trimmed point and act properally?  I had the T6 just for a short time and I found adjusting the v knob for the gyro had a small range to work with. If the knob was turned too far left the gyro would not initialize properally and had no tail control.

Thanks, I'll try stitching the gyro reverse tonight.  I am using the stock gyro MKS292 - is there a switch on it for analog versus digital servo use?  The new servo (18H-EE0089) is digital whereas the old original one (18H-EE0084) was I believe analog.

[dditch66]

99% of the time, violent spin is reverse settings in the gyro and/or the Tx.
If you replace your gyro, you gotta check it.
If your servo is different than the stock, most likely your changing the Tx reversing AND the gyro.

Read this:
http://www.mycoolheli.com/gyrobenchtest.html
Do the pinch test. that tells you Gyro reversing.
Moving stick right and slider moves left tells you Tx reversing.
If you have the latest BR gyro, it's the MKS292 that has a reverse "dial" on it. Older ones you have to flip it around (180 degree rotation about the boom axis)
http://www.mycoolheli.com/mks292.html

[Warp778]

99% of the time, violent spin is reverse settings in the gyro and/or the Tx.
If you replace your gyro, you gotta check it.
If your servo is different than the stock, most likely your changing the Tx reversing AND the gyro.

Read this:
http://www.mycoolheli.com/gyrobenchtest.html
Do the pinch test. that tells you Gyro reversing.
Moving stick right and slider moves left tells you Tx reversing.
If you have the latest BR gyro, it's the MKS292 that has a reverse "dial" on it. Older ones you have to flip it around (180 degree rotation about the boom axis)
http://www.mycoolheli.com/mks292.html

Just to bring a closing to this thread.  I reversed the gyro and that did the trick.  Everything runs as it should now.  When reversing the servo I obviously should have also reversed the gyro at the same time.

Thank you all for your help.  May the force be with you.