Improve stability in piro, better left turn and take off

[toys2cars2toys]

With a simple adjustment to 2 linkages, my msrx is much improved, it's much more stable in piro, now does better left turns and takes off with far less drift to the left



I was impressed with my msrx, straight away, I was using a basic TX setup 80% rates and 20 % expo. I was relieved as I'd read quite a bit about bad habits during rudder turns

Mine certainly turned better to the right, but I could do left circuits without drama

I wasn't very impressed by the very noticeable lean during hover, but this is very normal for little heli's particularly if the tail is a lot lower than the main blades

It was only after a bit more test flying, outside this time, that I did notice the very pronounced movement on hard piros, it would move to the left and rear, these could be corrected but were not exactly normal

I'd read on RCGroups of a couple of guys noticing that the cyclic starts to move to it's zero or midpoint as rudder is applied - hence the drift, this doesn't make sense to me because the AS3X should still be actively in control during a turn, not just moving to the mid point, this really didn't show up during normal flying - just piros in a hover

This got me thinking in conjunction with the noticeable lean and the thread on here about odd swash angles
https://www.helifreak.com/showthread.php?t=371693

I wondered if the AS3X was indeed bringing the swash to level during a piro, which would account for the move the the left, in a normal hover the swash does lean to the right

Someone of RCGroups beat me to it, read about it here
http://www.rcgroups.com/forums/showp...3&postcount=12

I'm calling it the MM Mod or MMM, after Martyn McKinney who first came up with it, I've since found out "Spainman" was working towards this fix too


The Modification....

To adjust the linkages
1- Zero all trims and subtrims, power on and make sure the battery is located properly
2- Test in an area with zero wind, take off and get into a nice stable hover
3- Apply a little rudder, observe which way the heli drifts
4- Repeat 2 and 3 a few times
5- Land, and adjust the swash linkages in the opposite direction to the drift
6- Repeat 2, 3, 4 and 5 until you are happy with the drift when rudder is applied

With a bit of testing I lengthened the Aileron servo to swash linkage by 3 full turns and shortened the Elevator to swash linkage by 1 full turn

This made great improvement piros in both directions were now very consistent - I'm not saying it spins on a dime like the original msr, you still need to control it

Take off's seem to be much better too, gone is that feeling of the heli shooting off and then taking a second to regain control

I'm now running 100% rates and no expo - lots of fun, I'll probably use some expo indoors though

My advice is to give it a go, but take the following precautions
- measure and note the lengths of the linkages before you change them, you may want to put it back to stock later
- be very careful with the swash balls, they do break off easily
- Only adjust the linkages by full turns, they only fit on one way and can break if you get it wrong
- If the linkage falls out, it it the TOP hole on the servo arms that are used

I would say that this is a work around for dodgy FBL programming and it goes totally against the grain to deliberately set a swash on the angle - but who cares, it works and it's so much better than mixes which do not work across all speed ranges

[ame]http://www.youtube.com/watch?v=Pe_dWT4ursY[/ame]

[Jakk]

I read that and tinkered tonight, +1 on the aileron 3 turns longer. Launches straight up now and no major left movement with left rudder (no mix) I worked with the ele also going 1 then 2 turns shorter but one turn is the best for me, at 2 turns I got too much forward movement with right rudder so I still indoors use some mix for ele but it's greatly reduced from what it was before the link adjustments. Great minds out there constantly thinking. Thank you !!!!

[t-heliflyer]

With a bit of testing I lengthened the Aileron servo to swash linkage by 3 full turns and the Elevator to swash 1 full turn

I'm a noob, but loving this heli, so is the Elevator in the front and the Aileron is the one on the left?

[Jakk]

Originally Posted by t-heliflyer

I'm a noob, but loving this heli, so is the Elevator in the front and the Aileron is the one on the left?

Yes you are right on both counts...

[toys2cars2toys]

Originally Posted by t-heliflyer

I'm a noob, but loving this heli, so is the Elevator in the front and the Aileron is the one on the left?

Yep, you got it, do make a note of how long they are before playing

Just realised that I made a typo, I shortened the elevator making it lean forward, I'll correct my first post

[toys2cars2toys]

Originally Posted by Jakk

I read that and tinkered tonight, +1 on the aileron 3 turns longer. Launches straight up now and no major left movement with left rudder (no mix) I worked with the ele also going 1 then 2 turns shorter but one turn is the best for me, at 2 turns I got too much forward movement with right rudder so I still indoors use some mix for ele but it's greatly reduced from what it was before the link adjustments. Great minds out there constantly thinking. Thank you !!!!

No problem, it was a combination of ideas and Martyn for RCG that got it

I guess it all depends on the starting point of the links, how much they need to be changed

[ebeing]

I bought two, a RTF and a BNF

The swash on the RTF was not level, whereas the BNF was.

WTF

[Ric66]

I had previously leveled my swash and this fix works well shortening the elevator link one turn and lengthening the aileron link three turns. I also tried two on the aileron link, but three seems to work better. Left turns are much more natural and it seems to take out most of the "wallowing" where the nose dips and rises in forward flight. Interesting!

[lamk]

Just bought the heli today. Found the heli drifting back and left during hover with a level swash and zero trim. Trimmed out the heli with forward and right trim, so achieving the same thing as shortening the elevator link and lengthening the aileron link. PIro and left hand turn way better after the trim. This is very strange. I have heli from 250 all the way to 700 size with beast x, skookum 720 and Vbar and none of them recommend using trim during set up. But whatever works. I'm very happy with the bird once it's trimmed out.

[tntburnett]

Originally Posted by toys2cars2toys

I was impressed with my msrx, straight away, I was using a basic TX setup 80% rates and 20 % expo. I was relieved as I'd read quite a bit about bad habits during rudder turns

Mine certainly turned better to the right, but I could do left circuits without drama

I wasn't very impressed by the very noticeable lean during hover, but this is very normal for little heli's particularly if the tail is a lot lower than the main blades

It was only after a bit more test flying, outside this time, that I did notice the very pronounced movement on hard piros, it would move to the left and rear, these could be corrected but were not exactly normal

I'd read on RCGroups of a couple of guys noticing that the cyclic starts to move to it's zero or midpoint as rudder is applied - hence the drift, this doesn't make sense to me because the AS3X should still be actively in control during a turn, not just moving to the mid point, this really didn't show up during normal flying - just piros in a hover

This got me thinking in conjunction with the noticeable lean and the thread on here about odd swash angles
https://www.helifreak.com/showthread.php?t=371693

I wondered if the AS3X was indeed bringing the swash to level during a piro, which would account for the move the the left, in a normal hover the swash does lean to the right

Someone of RCGroups beat me to it, read about it here
http://www.rcgroups.com/forums/showp...3&postcount=12

I'm calling it the MM Mod or MMM, after Martyn McKinney who first came up with it


The Modification....

With a bit of testing I lengthened the Aileron servo to swash linkage by 3 full turns and shortened the Elevator to swash 1 full turn

This made great improvement piros in both directions were now very consistent - I'm not saying it spins on a dime like the original msr, you still need to control it

Take off's seem to be much better too, gone is that feeling of the heli shooting off and then taking a second to regain control

I'm now running 100% rates and no expo - lots of fun, I'll probably use some expo indoors though

My advice is to give it a go, but take the following precautions
- measure and note the lengths of the linkages before you change them, you may want to put it back to stock later
- be very careful with the swash balls, they do break off easily
- Only adjust the linkages by full turns, they only fit on one way and can break if you get it wrong
- If the linkage falls out, it it the TOP hole on the servo arms that are used

I would say that this is a work around for dodgy FBL programming and it goes totally against the grain to deliberately set a swash on the angle - but who cares, it works and it's so much better than mixes which do not work across all speed ranges

I will try this myself. It makes sense .

Be blessed
Isaac

Sent from my NextBook Droid Tablet

[Cadfael]

thank you very much for this tip! Now my mSR-X is flying excellent without mixs too.

[ebeing]

Im not sure what you mean by turning the swash 1 or 3 turns.

What part to do turn?
Is there a video?

[toys2cars2toys]

Originally Posted by ebeing

Im not sure what you mean by turning the swash 1 or 3 turns.

What part to do turn?
Is there a video?

It's the linkages between the servo and swashplate that need adjusting

They are thin metal rods with a black balljoint at the top end, you have to carefully pop the balljoint off the swash plate (careful - easy to break the swash)

Screwing the balljoint further onto the shaft reduces it's overall length
Screwing it off, lengthens the rod

For me, it took 3 full turn out or longer on the aileron linkage - to the side of the mainshaft
and 1 full turn in or shorter on the elevator pushrod - the one in front of the main shaft

The amount may be different, heli to heli, 3 and 1 is a good starting point

Only use full turns as the balljoint should not go back onto the swash backwards - it may with lots of force

[Flatearthman]

Toys2,
it looks like you have your rotorhead to swash links on the short balls is this correct?

[toys2cars2toys]

Originally Posted by Flatearthman

Toys2,
it looks like you have your rotorhead to swash links on the short balls is this correct?

Sorry, I stole the pick off the net and added my scribbles!

I've just checked mine, they are on the longer balls

[Dasfriek]

I think this is gonna be trial and error for some people depending how far from stock they have taken thier heli and battery size and placement.

I say this as i had previously leveled my swash so counting turns was off for me.
Also mine has so much weight and far from stock i spent a TON OF TIME finding the sweet spot, I found it once but lost it by trying to dial it in better.

BUT, This does 50% help my heli. But with better dialing in and consistent battery style and placement it does help.

In order for it to fully work it in flight you need to be close to ZERO cyclic before starting the rudder turns or the swash will be out of place and the changed swash angle will mean nothing.

IMO you goal will be to get as close to a hands free hover with level swash settings and then add the 3 turns and minus 1 turn and then it works much better.

Im in no way saying this dont work, It helped my heli and im gonna keep working with it.
But it works best with bone stock MSRX's and not so much with ones like mine that have been so adjusted and tweaked it is much harder to dial in.

[prairie ville]

I just tried this, and it really does calm down the left piros. Thanks for the info.....

[toys2cars2toys]

Originally Posted by Dasfriek

I think this is gonna be trial and error for some people depending how far from stock they have taken thier heli and battery size and placement.

I say this as i had previously leveled my swash so counting turns was off for me.
Also mine has so much weight and far from stock i spent a TON OF TIME finding the sweet spot, I found it once but lost it by trying to dial it in better.

BUT, This does 50% help my heli. But with better dialing in and consistent battery style and placement it does help.

In order for it to fully work it in flight you need to be close to ZERO cyclic before starting the rudder turns or the swash will be out of place and the changed swash angle will mean nothing.

IMO you goal will be to get as close to a hands free hover with level swash settings and then add the 3 turns and minus 1 turn and then it works much better.

Im in no way saying this dont work, It helped my heli and im gonna keep working with it.
But it works best with bone stock MSRX's and not so much with ones like mine that have been so adjusted and tweaked it is much harder to dial in.

That makes sense, I think that the angle of lean in hover is related to how much the links need adjusting, I'm running 160mah batts where I believe yours are heavier, so it will probably hover more upright

Mine flew a pretty good hover out of the box, no trims, then I adjusted the links and it hovered the same - also no trims, of course the AS3X had compensated for the linkage change, probably the only visible difference is that sat on the ground after adjustment - the swash would be at an angle, and in hover it would be at a similar angle

[Flatearthman]

in the same post Martyn said:
I also highly recommend using cut down stubby mSR blades for flying in the wind.
anyone try this yet? Don?

[Dasfriek]

Yes, The weight and mods to mine make it about the worst heli to try and do this mod too. But even i did see improvement so i will continue to keep adjust with the same principle in mind. My heli pig has weight added everywhere along with the extended tail which again mess's with this mods functionality.

My mSR parts bag is low, But i have one spare used set of blades and two sets of SYMA S107-02 R/C Helicopter S107G Rotor Blades that i already cut to mSR sized blades and i dont mind chopping them further.
these are the ones.
http://cgi.ebay.com/ws/eBayISAPI.dll...m=250960184349

The extra torque needed to spin these up will be much more than the stock MSRX blades as they rely on speed more than blade area and pitch. So ill have to keep an eye on main motor heat, But i have two heatsinks on it so it should be ok.

Ive got quite a bit of work to do on my heli's today so hopefully i can fit in some flights as i can only fly at certain times of the day which is when no one is using the living room as its the largest area in the house.