Dec 08, 2004, 03:51 AM
Registered User
Joined Jul 2004
1,537 Posts
Mixerboard, Gyro - for your info - PHA-01 or PHA-300

“Hovering” does not mean you set the mixerboard right.
Not only Mini Dragonfly does hovering but also flying like a pro.—Please see the link
http://users.telenet.be/homeflyerfor.../Dragonfly.mpg

First, only for Mixer, Main Rotor and Tail Rotor

In order to over come the torque of main rotor, the output of tail rotor is a function of a factor of Y, which is the output of the main rotor. Ideally linear function is what we are looking for. Rule of KISS. The discussion here only covers Mixer, Main Rotor and Tail Rotor.

X: the output or rpm of tail motor
Y: the output or rpm of the main rotor.
Blue dot is the point the chopper is hovering.

We assume that the f(X,Y) is a linear function. However, technically electronic components have their own characters due to temperatures, pressure, voltage and humidity etc, it is very difficult to have a linear relationship on a circuit board. Depends on how much \$\$ you would put in, you will more likely to have the chance to have a circuit function as “only” close to linear. Each manufacturer has its own design based on the target market segment and the cost of the product.

The mixer controls the slop of the line. By adjusting the mixer, we are looking for the best balance output between main rotor and tail rotor.

Line B : Ideally the best line č X= (M)Y M is the slope, which is a constant.
(We assume that Line B is the best equation for main rotor and tail rotor in this example. This line passes the origin. --- It means when X=0, Y also equal to zero. )

Chopper B will do the hovering and also when the main rotor stops, the tail rotor will stop.

Line D :The linear equation looks similar to X= (M’)Y M’ is the slope, which is also a constant. ---- However, it is a wrong constant. --- wrong slope.
(This line also passes the origin. --- It means when X=0, Y also equal to zero. )

Chopper D will not be able to do the hovering and but when the main rotor stops, the tail rotor will stop.

Line A : X= (M’’)Y + I M’’ is the slope, which is a constant. I is also a constant.

(This line does not pass the origin. --- It means when X=0, Y is not equal to zero.)
Chopper A will do the hovering and also when the tail rotor stops, the main rotor will still keep running.

Line C : X= (M’’’)Y + I’ M’’’ is the slope, which is a constant. I’ is also a constant.

(This line does not pass the origin. --- It means when Y=0, X is not equal to zero.)
Chopper A will do the hovering and also when the main rotor stops, the tail rotor will still keep running.

As you can see, Line A, Line B and Line C all cross blue dot. It means that even with different slope, all of them can do hovering without any problem.

On the other hand, Line D does not pass the blue dot. It also indicates that this Heli will have problem to balance when hovering.

Moving the trim of the rudder or moving the stick of the rudder are actually changing the constant I in the equation. --- Means you shift the line to the left or to the right.

Adjusting the mixer pot, you are changing the slope. In other words, rotating the line.

From Q to B : adjust the trim.

From D to B : adjust the mixer pot.

From C or A to B: Need to adjust both.

Now let’s bring the Gyro into our discussion with Mixer, Main Rotor and Tail Rotor.

Gyro, with the ability to keep the helicopter balance, will tend to keep the helicopter in the position of the way it is. I think to balance is not a good term to use. To stabilize the helicopter would be a better term to describe it’s function.

If you are flying Helicopter B (with correct mixer gain), you are sure will not have problem.

In order to adjust mixer correctly, it is better to turn down the gyro gain because the gyro will try to keep the helicopter balanced or stay the way it is. Helicopter A or C with wrong mixer gain, without any problem to hover, with gyro kicking in to stabilize the helicopter may still keeping flying without serious problem.

The input factors to the equation for the output of the tail rotor are, throttle, and rudder, Gyro. Turn down the gyro, you will have a better chance to get a correct mixing gain because you cut down the factor from the gyro.

Ray

--Thanks for many flyers feedback on this thread ---12/14/2004

Images

Last edited by RAY GWS; Sep 04, 2005 at 07:41 PM.
 Dec 08, 2004, 04:13 AM It will fly!!......oops! Finland Joined Apr 2004 186 Posts ... Last edited by pguss; Oct 07, 2006 at 07:16 PM. Reason: typo
Dec 08, 2004, 07:18 AM
Registered User
Joined Aug 2004
995 Posts
Quote:
 Originally Posted by pguss Yep, but if constant "I" changes during the flight you will go from line B to Q. In order to prevent this, you have to keep correcting "I" with trim during the whole flight. (Actually, isn't "I" a variable (not a constant ) that depends on temperature?) /Peter
LOL what Pguss said. 'I' will indeed change with temperature in the case of the PHA-01.

But thanks for the info, it is a useful and well written explanation of how the PHA-01 works and how to fine tune it. Its just a shame it wont stay 'tuned' for long.
 Dec 08, 2004, 08:37 AM Houng-wen Lin Shijr, Taiwan. DungGwan, China. City of Industry, California. Joined Sep 2001 19,449 Posts Ray and me on the way to USA. GWS RD and artwork section had shot some videos. Hope will post the link as soon as Debby get them on GWS web. I will be GWS USA for a few days. Who want to give a ton of fertilizer for my 3 acres yard?
Dec 08, 2004, 08:42 AM
Houng-wen Lin
Shijr, Taiwan. DungGwan, China. City of Industry, California.
Joined Sep 2001
19,449 Posts
Quote:
 Originally Posted by Willard LOL what Pguss said. 'I' will indeed change with temperature in the case of the PHA-01. But thanks for the info, it is a useful and well written explanation of how the PHA-01 works and how to fine tune it. Its just a shame it wont stay 'tuned' for long.
Thanks. Will instruct GWS RD also doing temp test by hot air blower and measure by infrared temp meter.

Let's see what's cooked?
 Dec 08, 2004, 08:44 AM Houng-wen Lin Shijr, Taiwan. DungGwan, China. City of Industry, California. Joined Sep 2001 19,449 Posts Welcome to post what's problems you had? So, we can keep the next one better. Make it more easier to be set up by any one, not just by GWS RD. They are too much skilled, always told me: No problems.
 Dec 09, 2004, 07:47 PM Houng-wen Lin Shijr, Taiwan. DungGwan, China. City of Industry, California. Joined Sep 2001 19,449 Posts I hope every one who had "problems" with PHA-01. Pls spend a little time to read through this thread, should be help.
Dec 09, 2004, 08:30 PM
NON PayPal Member
Sacramento Metro, California, United States
Joined Nov 2001
373 Posts
Quote:
 Originally Posted by GWS4CEO Ray and me on the way to USA. Who want to give a ton of fertilizer for my 3 acres yard?
"Deleted as inappropriate by moderator."

Your stupid and long gone customer
Last edited by Michael Heer; Dec 10, 2004 at 05:13 PM.
 Dec 09, 2004, 08:46 PM Houng-wen Lin Shijr, Taiwan. DungGwan, China. City of Industry, California. Joined Sep 2001 19,449 Posts I am keep monitor this matter proceed. Deleted quote of previous post. ModeratorWhat's up? Why you said likewise? I am keep monitor this matter proceed. Last edited by Michael Heer; Dec 10, 2004 at 05:16 PM.
 Dec 10, 2004, 04:58 PM Registered User Joined Jul 2004 145 Posts This is good information on how a gyro works but you are NOT taking into acount TEMPERATURE!!!!! this chip DRIFTS as temperature increases....and its apparently not linear, or the gyro would self correct....
 Dec 10, 2004, 05:33 PM Registered User Maryborough Qld Australia Joined Jul 2003 511 Posts Mr Lin, That was a joke by Wildbill. Not to be taken too seriously ( but there is a message there). What he was getting at was that you could spread some of the Initials deleted by Moderator that appears from time to time here -- depends on what side of the fence you are sitting on which is which Just light a fire under the tail of your R&D to get the PHA-01 fixed and get the replacement out. There is too much 'bad press' which reflects on all GWS products Last edited by Michael Heer; Dec 11, 2004 at 11:54 AM.
 Dec 10, 2004, 06:01 PM It will fly!!......oops! Finland Joined Apr 2004 186 Posts *** Last edited by pguss; Jan 02, 2005 at 02:37 AM.
 Dec 10, 2004, 06:04 PM It will fly!!......oops! Finland Joined Apr 2004 186 Posts ... Last edited by pguss; Oct 07, 2006 at 07:16 PM.
Dec 10, 2004, 06:27 PM
Houng-wen Lin
Shijr, Taiwan. DungGwan, China. City of Industry, California.
Joined Sep 2001
19,449 Posts
Quote:
 Originally Posted by frodus This is good information on how a gyro works but you are NOT taking into acount TEMPERATURE!!!!! this chip DRIFTS as temperature increases....and its apparently not linear, or the gyro would self correct....
GWS are working on a tiny size heat-sink.

All the GWS Dragonfly with PHA-01 or indevidual PHA-01 owners pls contact GWS USA: usa@gws.com.tw fill a customer datas form with the copy of puchased invoice. You will receive this micro heat-sink free of charge.

Out-side USA, pls send to GWS HQ: service@gws.com.tw

Incase you like PHA-01 size better than the new device. I am sure how many grams will be increased? Since we need to add on a larger BEC, yet the PG03 linear circuit will be bigger than micon!