Swash Ring, collective pitch, cyclic pitch

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kaos
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Swash Ring, collective pitch, cyclic pitch

Post by kaos » Tue Mar 13, 2012 4:50 am

any one figure out what exactly 'swash ring' is doing and how it is doing that?
from my trial and error, I found out it only affects cyclic pitch and that is how I set up my cyclic pitch now. It does not appear to affect the collective pitch at all. The collective pitch seems to be totally determined by the 3 mixes in ch11 in current heli template of eepe.


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Kilrah
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Re: Swash Ring, collective pitch, cyclic pitch

Post by Kilrah » Tue Mar 13, 2012 8:24 am

http://openrcforums.com/wiki/index.php/ ... Heli_Setup
3. Swash Ring: As the name implies. This limits stick movement just like a physical swash ring. Notice that this only works on AIL and ELE regardless of radio mode selected.
I'm not very heli-oriented, but it seems to be a standard as my Futaba TX has exactly the same "Swash ring" function.

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Re: Swash Ring, collective pitch, cyclic pitch

Post by kaos » Tue Mar 13, 2012 2:35 pm

AH, Kilrah, that is a start. At least now I know where that 'swash ring' is originated - Futaba. My guess is Thus was using Futaba Tx when he wrote the Thus code. :)

any heli piolt using Futaba Tx to set up their heli before?

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kaos
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Re: Swash Ring, collective pitch, cyclic pitch

Post by kaos » Tue Mar 13, 2012 2:45 pm

Can anyone confirm this:
It seems to me in er9x, the only place you need to level the swashplate is at mid stick , er9x seems to do a good job to level the swash plate at top stick or bottom stick. Not like the stock firmware you need to level the swash at mid with subtrim and level the swash at top and bottom stick with 'limits'.
Any one can confrim this? I set up 2 of my heli, it seems to be so. but this could be just the the servo and the type of heli I have.

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Re: Swash Ring, collective pitch, cyclic pitch

Post by Kilrah » Tue Mar 13, 2012 2:50 pm

I think the point is that ER9X's heli mix takes the AIL and ELE sticks as input for cyclic, without leaving you a chance to adjust the mixing amount and thus control sensitivity. Then the outputs are CYC1, CYC2 and CYC3 but as those are mixed with collective you can't act on the output mapping amount without screwing up everything.

So now if for example you find your heli too sensitive on the cyclic and want to reduce the amount of stick control, then the only way to do it is through that "Swash Ring". Or do the D/R and expos still work inbetween? Haven't tried..

On Futabas you can act on D/R and expo with helis of course, and that "Swash Ring" function also surprised me as logically I'd just have adjusted the D/R for AIL and ELE had I wanted to act on control sensitivity..


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kaos
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Re: Swash Ring, collective pitch, cyclic pitch

Post by kaos » Tue Mar 13, 2012 3:24 pm

Kilrah:
that is exactly what I have not figured out yet. Once we can get this straightened out. We are ready to put out a 'guide' for beginner as well as experienced heli pilot to use er9x for heli. Like Er9x for Dummies - heli version. :)

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Re: Swash Ring, collective pitch, cyclic pitch

Post by kaos » Tue Mar 13, 2012 3:50 pm

I think the sensitivity issue can be taken care of by D/R/ EXPO with the stick.

If what you are saying is correct, then my observation about the collective pitch and cyclic pitch is probably correct.
if true, there is no need to adjust the limit at top/bottom stick for leveling swash at those position. once swash is level at mid stick, 0 pitch, the collective can be specified by the % in ch11 mixes, and the cyclic pitch can be adjusted by the swash ring.

If you are not familiar with heli, we don't want the sum of collective + cyclic pitch >=20 or 21 degree. It will bog down the motor. we want higher collective pitch for hard core maneuver (usually tops out at 12,13 degree), and higher cyclic pitch for agility (usually tops out at 9 degree).

Out of the 2 heli I have set up , I set my collective pitch at + - 12 degree using ch11 mix % and cyclic at + - 8 degree using the swash ring.
the only thing i am not sure is leveling the swash, whether it needs to be done (or it may be unwanted like you explained) at the top stick/bottom stick.
Out of the 2 I have set up, it seems once the swash is leveled at mid stick, it is level at top and bottom stick without changing the limit.
If what you said is correct, then the mystery is solved. :)

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Re: Swash Ring, collective pitch, cyclic pitch

Post by Westy » Tue Mar 13, 2012 4:49 pm

Swash ring seems to give it linear decreased sensitivity.

I use Expo for de sensitizing around the center stick also.

channel 11 with mixes on each curve to set up your max pitch on each pitch curve

so curve 4 id0 will always be less than curve 5 ID1

set your 5 deg at mid stick and if your mechanical nuetral throw points are the same then the swash will remain level all the way up and down the shaft when collective is applied

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Re: Swash Ring, collective pitch, cyclic pitch

Post by Kilrah » Tue Mar 13, 2012 5:00 pm

Hmm, what I'd do is:
1) Create new model, delete all mixes (all servo outputs will be 0).
2) With the servos centered like this, do all your mechanical 0° adjustments (servo horns straight, use ppmca if needed, swashplate flat at 0°)
3) Set your swash type in heli mix, set collective source to THR, assign CYC1,2,3 to the servo outputs in the mixes screen according to your connections, all at 100%
4) Move the throttle stick up/down, confirm all servos move in the correct direction and reverse if needed (individual servos on LIMITS screen or functions on the heli setup page), and check you've chosen the right holes on the servo horns to reach the highest up/down angles you want without having too much excessive throw
5) On LIMITS screen, adjust up/down limits of all 3 servos so that the swashplate is level at both the top and bottom end, AND you get the maximal pitch angles you want to ever reach (collective + cyclic), i.e the 20° you mentioned. Now if the mechanical part was done correctly you should have your swashplate perfectly level all along the throw of the throttle stick.
6) Now choose your first pitch curve, e.g. Curve 1, create a new mix for a free channel (e.g. CH11), assign source THR, curve 1, on heli setup change Collective source to CH11.
7) Edit the curve, starting by both end points, setting those to the max collective you want to reach (e.g. -2°/+12°), and filling in the midpoints how you'd like them
8) Center collective stick, set AIL and ELE D/R to reach the desired cyclic pitch (the 9° you mentioned) (I just tested in the simulator, D/Rs do work indeed).

In summary, now you'd have:
- Your collective range, set in 7), defined by the pitch curve
- Your cyclic range, set in 8), defined by the AIL and ELE D/Rs
- Your max angles (cyclic+collective) enforced by the LIMITS set in 5)

Now, I've had a look on the simulator and on my Futaba radio. Swash Ring actually crops the "square" nature of the AIL-ELE stick to a circle.
Let's say you move your stick fully left from the center, you did a movement with an "amplitude" of 100%. Same if you start with the stick centered and go fully down. BUT, as the stick can do a square, if you go to the lower left corner, your total amplitude movement is actually of 140%. This means that depending on the different adjustments and limits you have, even if you checked your cyclic angles at +/- 100% of every single control, you could have a servo that hits its limit earlier than expected if you bring the stick to the corner, and due to the cyclic mixing if one servo hits a limit it will affect all the 3 functions with unpredictable weird flight behavior.
Setting Swash ring to 100 will "round off" the corners, and never allow you to input more than 100% total deflection with the stick. Imagine a circle in the X-Y graph of the stick, diameter being the throw of the stick, and whenever you move the stick the output will be limited within that circle.

Actually I'll post screenshots of the Futaba, it's quite clear, I have the stick in the corner both times:
Swash_ring_off.jpg
Swash_ring_off.jpg (51.13 KiB) Viewed 12473 times
Swash_ring_on.jpg
Setting lower values for Swash ring will simply make the circle smaller, but IMO as it's a hard limit it makes no sense, as you lose use of some stick throw. Say you set Swash Ring to 20, then as soon as your stick is more than 20% off center the servo stops moving and the remaining 80% of stick motion do nothing. So I'd leave Swash at 100 if used...

The next step will be to set up a throttle curve, so on the channel your ESC/throttle servo is connected to you'll want to create a mixer line with source THR, choose a curve (e.g. curve 4), long press MENU to go to the editor and enter the curve settings.
You can then add more throttle or pitch curves for your different idles the same way, just insert new mixer lines below the existing ones, again with 100% THR source, another curve do you can make it different, a switch to activate it, and Multiplex type "Replace" so that it overrides the previous one(s) when active.
There we go, only step left is setting up a gyro mix - depends on the gyro but usually easy, you typically simply would set gain adjustment on a pot (with a 100% P1 mixer line on your gyro channel) as a first step, fly and find the correct setting, look at the output monitor to see the value your gyro channel is set to, and if it's for example -42% then replace that 100%P1 line with -42% MAX. Gain will now be locked there. If you wanted a second setting sleectable by a switch - you've probably understood by now, but you'd simply create a second MAX line below the first one with the other % value, set type Replace, and select your switch.
Last edited by Kilrah on Tue Mar 13, 2012 5:11 pm, edited 4 times in total.

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Re: Swash Ring, collective pitch, cyclic pitch

Post by kaos » Tue Mar 13, 2012 5:02 pm

Westy wrote:Swash ring seems to give it linear decreased sensitivity.

I use Expo for de sensitizing around the center stick also.

channel 11 with mixes on each curve to set up your max pitch on each pitch curve

so curve 4 id0 will always be less than curve 5 ID1

set your 5 deg at mid stick and if your mechanical nuetral throw points are the same then the swash will remain level all the way up and down the shaft when collective is applied
Swash ring only affect the cyclic pitch on my model.

D/R, expo both affect the sensitivity for the sticks . D/R will affect the collective pitch, expo will not affect the max pitch but reduce sensitivity.

I set all my heli at -1 , +1, +12 degree for ID0/norm for normal flying. for ID1,2 it is the max + - 12 dgree for 3D/stunt flying.

the mechanical neutral is really the question. If er9x does well keeping the swash level by adjusting the swash at mid stick with 0 pitch and maintain it throughout the stick range without adjusting the 'limit' (which the stock frimware has to be done to have a leveled swash all the way up or down), then the mystery is solved.

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Re: Swash Ring, collective pitch, cyclic pitch

Post by kaos » Tue Mar 13, 2012 5:37 pm

kilrah:
that sounds great on the 1st look, after I get home I will check on those.
so you are saying you still need to level the swash at top and bottomsticks for the swash (which I did not need to do for my trial model/heli, and that is my question too). then use ch16 to do the actual pitch curve. :) that sounds good. will check on that.

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Re: Swash Ring, collective pitch, cyclic pitch

Post by Kilrah » Tue Mar 13, 2012 7:00 pm

kaos wrote:so you are saying you still need to level the swash at top and bottomsticks for the swash (which I did not need to do for my trial model/heli, and that is my question too).
That has nothing to do with the radio, but with your mechanical setup. The radio will give the same -100 / 0 / +100% signals to all servos. IF your mechanical installation is clean, all servo horns are nicely aligned at 0°before setting the limits then they'll be in sync along the entire throw. If your servos have different neutrals (for example one has the servo horn one "click" of about 5° downwards, while another has the same 5° but upwards due to the servo horns' fitting) and you don't correct them with subtrim, you'll get differences along the way because servo movement is non-linear (with rotary servos, every % of input gives the largest amount of linkage movement at the center, and decreases the further you get).

So, to avoid that, you'll want to align your horns with subtrim. Fine. Let's say you need +20 subtrim (huge, but for the illustration) on one servo to align it to the others. Now, with the sticks centered that servo will be at +20 on your 9X's servo monitor screen. But, its limits will still be +100 and -100, which means that on one side it will only move by 80%, while on the other it will move by 120%, creating asymmetric movement, and your swashplate will gets skewed along the throw... to correct that, and reach the same mechanical servo movement as the other servos, you'd have to set limits to -80 / +120!

So in conclusion, the better your mechanical setup the better for the radio setup and precision. Most important is to have all servo horns as close as possible to the other at neutral to require as little software correction as possible.

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Re: Swash Ring, collective pitch, cyclic pitch

Post by kaos » Tue Mar 13, 2012 7:51 pm

Kilrah:
I think you just hit the nail. that is exactly what my question is. and Yes, we do need to do adjustment on 'limit' for the 3 cyclics. it is just happened that my 2 heli, some how, after I level them at mid stick, without any adjustment on the limit, they seems to be 'pretty level' - eye balling at top stick and bottom stick.
and yes, rarely I get a 0 subtrim on set up. those linkage rods are hard to get to 0 subtrim at mid stick, I would rather see those ball link connector to be 90 degree inside the connector, instead of getting a 45 degree linkage connector to the ball and when you move the swash they eventually straighten out which will throw the swash off a few clicks.

With that explanation, I think I don't even need to check for real any more. :) It is done deal. :)
Next wk or so, time allows, I will try to come out with the Er9x for Dummies - heli version with a template that any one can use. :)
then we can all fine tune it to put up here for any one using er9x for heli flying. :)

After all, er9x is not an 'easy' programming for most flier. My guesstimate is probably 90 percent heli flier never get into mixes. Just follow the subtrim, travel limit to set up their heli and fly. And unless you are at least intermediate plane flier or advanced plane flier, you won't get into too much with these mixes either.

I probably won't use er9x flying helis (stock FW is good enough for heli flying) until I get into problem to program my fancy night lights on the heli. I found er9x can do what I want but not the stock firmware. :)

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Re: Swash Ring, collective pitch, cyclic pitch

Post by kaos » Tue Mar 13, 2012 10:21 pm

Kilrah wrote: Setting lower values for Swash ring will simply make the circle smaller, but IMO as it's a hard limit it makes no sense, as you lose use of some stick throw. Say you set Swash Ring to 20, then as soon as your stick is more than 20% off center the servo stops moving and the remaining 80% of stick motion do nothing. So I'd leave Swash at 100 if used...
There we go, only steps left are setting up a throttle curve and gyro mix, but those depend a lot on the equipment, and other curve sets if needed...
hmm, on my 2 heli set up , I found the swash ring did not affect the collective pitch, but it does change the cyclic pitch.
and yes, I did use curve to set up the collective pitch I want (+ - 12) and one of them end up with a weird curve in ID1. like -38 -19 0 50 100.
Any way, I will check both to see how these 2 interacts each other. Now we got the swash leveling with limit out of the way.

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Re: Swash Ring, collective pitch, cyclic pitch

Post by Kilrah » Tue Mar 13, 2012 10:30 pm

kaos wrote:I found the swash ring did not affect the collective pitch, but it does change the cyclic pitch.
Yep, correct. It only prevents you from overdriving cyclic pitch by combining longitudinal and lateral.

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Re: Swash Ring, collective pitch, cyclic pitch

Post by kaos » Thu Mar 15, 2012 2:44 pm

Well, got everything checked up. Kilah, you are dead on. Those steps you describe is good to go.
and the swashring does not affect the collective, and collective does not affect the swashring/cyclic either.
It was interesting to see how the max + and - pitch are different. although I used very little 'offset' to adjust the servo centering, but left the servo arm not exactly 90 degree, there is about 5 degree more - pitch than + pitch. I think leave the max pitch in the weight and use curves to set the max pitch angle desired is the way to go.
got the timer fixed as well. The THs and TH% really don't work for heli flier. It will stop the timer with THs when left stick is down but for heli in ID1,2 that is max throttle. as for TH% is worse, because the heli ID1,2 below the mid stick the throttle increases not decrease. So I did a switch in SW1 v>ofs ch3 -100 to make the timer triggered by power output. this will also make the THR switch working properly to stop the timer.

Got a template made with a guide. Modifying the wording in the guide so it can be used for new user or anyone is using the er9x 1st time.
Will upload the eepe file and guide tonight. Forgot to bring my flash drive with me today. :x

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Re: Swash Ring, collective pitch, cyclic pitch

Post by kaos » Fri Mar 16, 2012 6:43 am

OK, here is the eepe file for setting up a cp heli, using a 120 swash and a Gy401 gyro as basis.
We all know er9x has many ways of achieving the same thing. this template is especially geared for heli pilots making transition from T9X stock FW to er9X before they are fully familiar with the er9x's bits and pieces.
The outline of the setup procedure is already described by kilrah in previous post. The detailed guide will be up soon after some changes to be made. Still debating how detail the guide should be. For people who already flying cp heli or for beginners as well.
One thought is, send the guide to Erazz, if he can follow the guide to set up a cp heli correctly, then it should be good enough. :mrgreen:

some key points:
-> the Rx ch line up is kept the same as the stock T9X:
ch1: right cyclic/Ail
ch2: ElE
ch3: ESC
ch4: gyro/tail servo
ch5: gyro signal
ch6: left cyclic/pitch

-> in er9X right cyclic(Ail) servo is cyc2, left cyclic(pitch) servo is cyc3, and Ele is cyc1
-> The timer switch in er9x , THs and TH% does not work for heli inverted fly. a SW1 is in there using throttle output as trigger. The timer is started when throttle is not 0% can be stopped with THR if it is programmed to 0% throttle.
-> The last line ch11 is in there for convenience during set up, using RUD switch to achieve a 0 pitch swash position when needed. After setup this line should be deleted.
-> a gyro mode switch using GEAR, on is Rate Mode, off is HH mode with P3 to adjust the gain in either mode any time. The initial gain for either mode can be set based on individual gyro/set up (the initial number is based on a gy401 gyro).
-> to set the throttle in er9x: the throttle scale in er9x is from -100 to +100, 200 unit, while the stock T9X is 0-100, 100 unit. T9X user should be aware 0% throttle in T9X is going to be -100 in er9x. 100% throttle is still +100, but 50% throttle in T9X would be 0 in er9x.
in curve c1 mid stick is actually 60% throttle , c2 mid stick is 70% throttle , c3 mid stick is 80% throttle
-> in er9x the max collective pitch is entirely determined by the weight of ch11, the numbers need to be the same for all 3 mixes in ch11. the pitch angle for each fly mode can then be adjusted in associated curves.
-> the max cyclic pitch is determined by 'swash ring' in heli set up menu.
-> D/R can be further used when needed for either cyclic or elevator pitch

ONe more thing,the timer needs be changed based on individual need. initial timer is set at 45 min for setup. If the timer alarm starts to beep before you finish the setup. You need to study more about how to set up a cp heli. :)
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Heli setup model.eepe
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rharms
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Re: Swash Ring, collective pitch, cyclic pitch

Post by rharms » Sun Apr 22, 2012 9:26 pm

I read thru this post quickly, so may have missed this, but here goes.
Are you aware of the origins of the term "swash ring"?
When radios lacked the programming functions of today's radios, there were available physical rings.
The ring was attached to the radio at the base of whichever stick had the elevator and aileron functions.
The ring allowed full left/right and full fore/aft movements of the stick, but prevented it from going into
the corners. You then had to set the physical collective and cyclic such that you could get maximum throws in the left/right and fore/aft directions,
but the ring then prevented binding of the linkages when you performed combined movements.
This may have been obvious to everyone, but I add this in case you were not aware.
Rick Harms

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kaos
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Re: Swash Ring, collective pitch, cyclic pitch

Post by kaos » Wed Apr 25, 2012 4:19 am

Thx, Rick. I always wondered where that 'swash ring' came from. but did not find anything about it. I 'guessed' it was a ring on the swash in the old old days. :mrgreen:
Now I know it was actually on the control stick of the Tx. good to know these history. ;) My 1st RC Tx is 2.4 GHz. have no idea what the old Tx was.

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Re: Swash Ring, collective pitch, cyclic pitch

Post by pmackenzie » Wed Apr 25, 2012 10:06 am

FWIW, erazz developed the heli specific mixers, including swash ring feature, not Thus.

Starting about here:
http://www.rcgroups.com/forums/showthre ... g&page=259

Pat MacKenzie

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Re: Swash Ring, collective pitch, cyclic pitch

Post by Crashj007 » Wed Apr 25, 2012 1:22 pm

--
FS-TH9X 2.4GHz 9CH from Nitroplanes
Smartieparts board & backlight
Stock Flysky RF and mainboard
er9x FW V 744

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kaos
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Re: Swash Ring, collective pitch, cyclic pitch

Post by kaos » Wed Apr 25, 2012 2:38 pm

pmackenzie wrote:FWIW, erazz developed the heli specific mixers, including swash ring feature, not Thus.

Starting about here:
http://www.rcgroups.com/forums/showthre ... g&page=259

Pat MacKenzie
Gee, I did not realize Erazz is THAT old. :mrgreen:


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