Swashplate setup and subtrim

[Flybar-less]

I setup both of my Vbars with no sub-trim in the TX, use test mode and Vstabi to 90 degree servos. Then I check travel disparities with a swasplate leveler I had made for the Logo. Normally if one servo travels long or short, I'd use endponts to adjust, not sure if this is approriate with Vstabi. With nearly 100 flights, I have never had trim issues or had to re-trim.

I am very intrested in finding out what the appropriate method, according to Vstabi, for 90 degree trim and eliminating travel disparities is.

Does disconnecting the sensor help, classic mode...?

[OICU812]

If everything lines up pefect and you have equal throws why worry? Classic mode os for trimming if you find it is off in hover and has tendacies to drift in a particular direction. I myself as you did made sure everything was perfectly 90 with servo test and did my subtrims on the top panel of the servo page and never even trimmed anything after that part. In fact never even tried classic yet, straight to extended as I knew everything was perfectly 90 as I also ensured swash was perfectly level by having a level decvice under swash in the setup. I know this came up as someone said they had unequal throws, I checked this myself last night and mine were pretty much spot on so I would think this would pertain more to those that might not have the swash/levers 90 degrees at center sticks, etc.

Just my opinion, I did as Ulrich this, this was his answer.
"Trim:
The Vbar learns the real centers at startup. So a bit offset is ok. But to check that the travel is the same on both sides, it is good practice to first adjust the center with the zero positions of the channels. Then you can check much better if the travel is symmetrically and has the right amount. On the collective channel it is not learned, because you normally do not have an deterministic stick poition at startup. So at least here the center shall be near the middle"

[uragano47812]

Well i have done all the procedure servo arms 90° at center tx stick, swash leveled with trueblood swash leveler with the trims in servos panel with test on and trimmed with sliders on top of page.

I have set at this point upper linkage to obtain 0° it was near as the standard lenght given on logo500 manual.

But i have a question. I have the swash that is is not level during the movements of pitch is this due to the gyros or is something wrong on my servos setup?

[OICU812]

When it is not in servo test the swash can and will go all over, it is the Vstabi trying to stabalize it of course.

[cptsnoopy]

Hi Shawn,

Did you understand ulrich's response to mean it is ok to subtrim at the tx so the "live" screen is as close to zero as possible? I don't really see a problem doing this if that is what he intended. It my case there would be very little noticeable change and I could trim that out in the software. I would leave my servo centers where they are since I set those in "test" mode.

[OICU812]

Well I dunno , lol. Those guys are abit tough to understand what they really mean. I don't really understand the need of subtrimming period after you do your servo horns perfectly 90 with servo test mode. I mean that is true center if your sticks are at exactly zero, then you force the vbar to set zero and subtrim then accordingly on the servo page. I checked mine tonight as this is the way I did it and I have pretty much equal throws from what I can tell.

[Klinger]

Well I dunno , lol. Those guys are abit tough to understand what they really mean. I don't really understand the need of subtrimming period after you do your servo horns perfectly 90 with servo test mode. I mean that is true center if your sticks are at exactly zero, then you force the vbar to set zero and subtrim then accordingly on the servo page. I checked mine tonight as this is the way I did it and I have pretty much equal throws from what I can tell.

Yep, i would have to agree that the understanding the response part is confusing. I tend to agree that the vstabi should be able to handle all the subtrim, although i cant see the reason of subtrimming the Tx to zero axis on the live page dosent help either. I've done it both ways now and can really tell the difference but today's flight had more neg climbout than pos after i used tx subtrim. dont really know if i spent enough time in checking my collective settings and is is difficult to get a precise collective angle measured. I do mine by using a level on the main gear to get the heli and mast perpendicular and then use the level on top of the pitch gauge to try and find pitch ranges. I'll probably do it all again in a couple of weeks (after reading some more feedback here and on vstabi forum) but for now will have to wait as i'm off to indonesia this weekend on business. Sort it out guys and let me know :lol:

[OICU812]

Well I asked a few experienced Vbar peeps and they said they simple did as I did. Servo test mode, put all horns on as close to 90 degrees, then apply subtrim on the top for the 3 servos on swash. Perfect 90, then adjust swash to be perfect level mechanically then fly. I am just going to stick with that, my throws seem to be even. I will revisit when I can get a clearer translation from Ulrich and German gang on the wiki.

[Wenlock]

I don't really understand the need of subtrimming period after you do your servo horns perfectly 90 with servo test mode. I mean that is true center if your sticks are at exactly zero,

This is only true if your Tx sends true zero positions when the sticks are central. But it may not do that, due to errors in the pots or maybe the mid-stick pulse length could be off. In that case you would need to use the Tx sub-trims to get the Tx "zero" to match the Test Mode "zero". If you don't do this, then after you've spent time carefully setting the servo arms to 90 in Test Mode, they'll move somewhere else when you switch back to the Tx.

I read Ulrich as saying that it's ok to subtrim the cyclics and rudder at the tx to get zero in the Live screen with the sticks central. Not worth bothering about the collective.

However, I think we may be getting down to splitting hairs here.:dontknow

[jamesotron99]

This is only true if your Tx sends true zero positions when the sticks are central. But it may not do that, due to errors in the pots or maybe the mid-stick pulse length could be off. In that case you would need to use the Tx sub-trims to get the Tx "zero" to match the Test Mode "zero". If you don't do this, then after you've spent time carefully setting the servo arms to 90 in Test Mode, they'll move somewhere else when you switch back to the Tx.

I read Ulrich as saying that it's ok to subtrim the cyclics and rudder at the tx to get zero in the Live screen with the sticks central. Not worth bothering about the collective.

However, I think we may be getting down to splitting hairs here.:dontknow

Wenlock, just like a heading hold gyro the vstabi learns the center positions of all channels while it's initialising. So if you program in subtrim on the TX the next time you power on the vstabi it will learn the new position as zero. It really makes no difference whatsoever. I guess this also means that just like a tail gyro, don't wiggle the sticks when the unit is initialising.

[uragano47812]

I have try the new wizard to check my setting. Well i see that the servos centering values are the same as i had obtained by doing the servo centering non in test mode.

i see also that doing the servos and swash centering in test mode, when i turn off the test mode the swash is heavy out of center instead of slightly (normal for gyros compensation) as not in test mode.

I havealso used in the wizard the TX subtrim to match the center of each channel. But when i use subtrim on collective i have at middle stick 0° of pitch but when i move full collective up i have 11° and when i put all down have 14°. Instead without subtrim on collective i can reach +/- 13°.

So what can you suggest? Can i do the first fly?

Thanks

[Flybar-less]

If the 3 cyclic servo arms ar at 90 degrees in test mode, you should only need to adjust pusrod length to get everthing to 0 degrees. On my helis, this gives 8 degrees cyclic and 12 degrees collective with endpoints set to 100% as well as Commmon collective. You can add further travel in Vstabi through the Servo Common collective or Expert Swash individually.

[OICU812]

If the 3 cyclic servo arms ar at 90 degrees in test mode, you should only need to adjust pusrod length to get everthing to 0 degrees. On my helis, this gives 8 degrees cyclic and 12 degrees collective with endpoints set to 100% as well as Commmon collective. You can add further travel in Vstabi through the Servo Common collective or Expert Swash individually.


That is exactly how I did mine, I am leaving it. I really do not understand how or why they put that into the SW. It was always told to me to not put any trim in radio, and doing it just as you discussed makes more sense to me, I wish the translattion with those guys was not so difficult, even when they speak English it does not make sense half the time. They need to hire a full time translator stat! LOL:rolling

[cptsnoopy]

I have try the new wizard to check my setting. Well i see that the servos centering values are the same as i had obtained by doing the servo centering non in test mode.

i see also that doing the servos and swash centering in test mode, when i turn off the test mode the swash is heavy out of center instead of slightly (normal for gyros compensation) as not in test mode.

I havealso used in the wizard the TX subtrim to match the center of each channel. But when i use subtrim on collective i have at middle stick 0° of pitch but when i move full collective up i have 11° and when i put all down have 14°. Instead without subtrim on collective i can reach +/- 13°.

So what can you suggest? Can i do the first fly?

Thanks

If you are getting the swash heavy out of center when you are not in test mode then try a "cold restart" on the overview tab. if the swash does not center then you have a problem and do not fly.

if the swash does center you may be ok.

when checking your pitch it is very difficult to determine exact angles because there is no flybar to compare angles to. if your reference is off 1 to 2 degrees then you can get errors similar to the values you posted.

what are the values that you show in the live tab for rc when the sticks are centered? how about when the sticks are in the full up position? mine were near zero roughly +/- 50. at full travel with the sticks mine were near +1620 and -1560. This was with my endpoints at 100% on a DX-7 transmitter. My subtrims are at zero.

[uragano47812]

Ulrich write to me that my procedure with wizard is right.

As i said i have done the wizard including the subtrim procedure to match TX zero to vstabi zero when i was doing the wizard. At the end of wizard the swash was a little little bit out so i click to Coldrestart and the swash was perfectly at zeros.

About the pitch i have corrected my linkages so now i have +/-13°. About the cyclic i have reduced to 70 the value on cyclic ring so i haven't any binding (expecially on elevator because servo horn touch the frame plastic).

Now all seems ok but i don't understand the meaning of proportional on elevator and aileron expert menu.

I see that some people use 60-70 as value other have it to zero.

I will fly for the first time tomorrow and i have ready two banks one in classic mode to verify trims and another in extended started from Ulrich Logo500 sport setup (proportional to 60).

Anyone has try this setting from Uli or the standard Logo5003D setup from software CD? (a friend has try it but it say that the heli was super nervous and difficult to fly... But i'm not sure if he has done well the swash setup correctly)

How much EXP is better to put on TX on cyclic and tail?

Let me know, because i'm a little worried...
Thanks

[Flybar-less]

I fly 60 to 85 proportinal on cyclic depending upon the setup. 60 should be fine. For expo I use 15% on cyclic and tail.

[Flybar-less]

One characteristic of the Vstabi is the fact that cyclic authority remains high at low headspeeds. This can make the heli appear unstable on the ground or in aerobatic autos. Flybar helis get mushy when the headspeed drops.

[Taipan]

When setting the TX channel directions to match the vstabi ones, elevator has me confused. It says up or down, but what direction does that refer to on the swash?? My guess is UP elevator means the elevator being up on a PLANK and therefore it pulls UP or BACK. So for UP elevator the swash should tilt BACK?

[cptsnoopy]

So for UP elevator the swash should tilt BACK?

correct

[Wenlock]

Wenlock, just like a heading hold gyro the vstabi learns the center positions of all channels while it's initialising. So if you program in subtrim on the TX the next time you power on the vstabi it will learn the new position as zero. It really makes no difference whatsoever. I guess this also means that just like a tail gyro, don't wiggle the sticks when the unit is initialising.

Fair enough. In that case all my waffling on about using the Tx sub-trims is irrelevant.