RunRyder RC
 3  Topic Subscribe
WATCH
 1 page 655 views POST REPLY
Scorpion Power Scorpion Power
HelicopterMain Discussion › Mechanical Phase Lag corrected 450 ohh joy,,,,ohh pooh
07-01-2017 05:36 PM  81 days agoPost 1
icanfly

rrElite Veteran

ontario

My Posts: All  Forum  Topic

hehe, wonder what the meaning of the title is? I mechanically adjusted phase lag on my 450 at the swash plate due to switching over to dfc by Tarot on my 450, the other hub had a separate swash follower clamp that stripped one screw hole and the dfc head was all I had (crash repair).

When I first put the dfc on, after the other head was run at a reduced phase lag at the swash plate follwers, I had no option but to run it at the designed mechanical pl of 90°, wrongo. Damn thing was all wobbly as heck and couldn't hold a straight line if the gyro told it to. So what I discovered was this, as many of you would respond telling me the fbl takes care of it I say wrongo again, sure it does some correcting but it becomes overwhelmed with chasing a control circle of input and incorrect pl giving it too much work to do.

This morning I finished making a mechanical change to the swash guide by custom fabricating a tdr slot style (which I had already made a few years ago but was a 90° one, the new one took a couple of hours to make). Get the new guide thing on, plug the hei in on the kitchen table and take it out back. When 90°pl was sending the heli left and right and forward and back ON THE GROUND I knew it was bad, this time with less phase the heli was extremely well behaved and true in it's flight path so much so I became over confident and started to fly some bigger patterns in a backyard with a tree in the middle. A hard dive did not spare the perfect little beast from eating the tree a smidgen while breaking a blade and stripping a servo gear in the process, NOT A MINUTE INTO A PERFECT FLIGHT controlled session. I got livid because I spent all morning fabbing two guides because the first was not good, overshot let's say.

Any way, want to experience a 450 and any other heli like never before REDUCE PHASE LAG TO 80° PERIOD, that's all I got and man it's so good for the gyro I was pleasantly surprised, yet became unpleasantly flustered by the ensuing crash. Flying the heli in 90° pl must have caused my mind some confusion because this was the first flight without chasing the gyro and helis directional instabilities, it was terrible to control until the correction was made. No wonder people find it hard to learn on micros.

fun, it's been said before elsewhere even by extrapilot on hf several years ago who I got in a tangle with over some of this idea, then saw a topic he cleared up issued back in 2013 stating the fact. BUT YOU GUYS DON"T KNOW HOW TO FIX IT unless you go buy an expensive gyro, well, I do and I did mechanically at the lower swash all else being original, good for me huh.

I'd like to make it good for others, can be done if I show you how, after that it's all history in the making (I'll see what I can do to provide some solid product, it's that good and simple, not always do-able).

The inconvenient tree mishap was done without canopy and 1800mah lipo making it lighter and having less contrast against forest green, everything is grown in a bit. That tree has taken out a heli of mine many times in the past, many.

PM  EMAIL  GALLERY  Attn:RR
07-01-2017 07:56 PM  81 days agoPost 2
co_rotorhead

rrVeteran

Centennial, CO, USA

My Posts: All  Forum  Topic

Sativa or Indica?

PM  EMAIL  GALLERY  Attn:RR
07-01-2017 08:58 PM  81 days agoPost 3
Richardmid1

rrProfessor

Leeds, England

My Posts: All  Forum  Topic

Had this issue once on a flybarred Rave 450. I added washers to the washout arms to slightly rotate the inner swash in relation to the flybar and it flew so much better!

60% of the time, it works every time!

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR
07-01-2017 11:52 PM  81 days agoPost 4
icanfly

rrElite Veteran

ontario

My Posts: All  Forum  Topic

wow with all that fb junk in the way can barely make out the suggested mods.

Here's a discreet view of the matter of contention.

whatevar. Pictures are big so it's all out there clear and dear.

Couple of fine details I ran into were removing some cf to help the extended servo arm on the right not hit the frame, and on the left also removed some cf and one mounting screw it would hit and limit, and the ele servo is mounted inside the align bearing block with the ball on the outside of the arm to the far left (Some mount the ele servo on the left side). I gave it some consideration overnight before diving into completing the mod, breathed a sigh of relief when it super stable and I was in full control again.

One thing about a fbl unit taking up the work of adjusting in flight problems, two days ago or so the heli had a bad enough vibe for a run with a 4s lipo that it was the worst control I've ever experienced with a heli except my 300 without any fbl unit two winters ago, too much fun. The fbl unit dealt with enough vibes to slow down control responses yet didn't flip over from a fbl unit upchuck thankfully

Nuther thing is that the balls are mounted closer to the servo at the third hole in on te servo arm when it could be better off at the second hole in and probably avoid filing the frames for extra clearance.

I really have to beef up the guide/servo arm for future sturdy use, it's still the m1.5 wire with a plastic tube for less friction.

PM  EMAIL  GALLERY  Attn:RR
07-01-2017 11:58 PM  81 days agoPost 5
Richardmid1

rrProfessor

Leeds, England

My Posts: All  Forum  Topic

Wtf

60% of the time, it works every time!

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR
07-02-2017 12:45 AM  81 days agoPost 6
JuanRodriguez

rrProfessor

The Villages, Florida

My Posts: All  Forum  Topic

Really !!

Been there, done that and old enough to know better.....

PM  EMAIL  GALLERY  Attn:RR
07-02-2017 01:22 AM  81 days agoPost 7
icanfly

rrElite Veteran

ontario

My Posts: All  Forum  Topic

lol

believe me when I did this it came with much examination of the end result mechanically to determine the outcome reasonably. PEAK AMPLITUDE of the blades happens less than 90°. Not going into details so as to avoid trying to describe what experts have already supported publicly (VTX blades pres Bill, extrapilot of hf, a certain book on helicopter engineering, my own happy accident experiences). There's also the gyroscopic effect of the disc the pl thing helps cancel.

Had my helis been phased this way from purchase I would be way ahead in terms of ability and self confidence, and I thought it was me.

I've gone public with this a few times in past, only up to you to somehow try it and support the result with your findings, can only suggest this much.

Let me contact my cnc guy and see if he can help with a product, must be a way to make this easy to do (on some helis yes and some no, this is the pooh pooh part)

winningy

I hope I've got my servos described correctly as ail/ele, will edit if it's not exactly as it should be.

PM  EMAIL  GALLERY  Attn:RR
07-02-2017 01:54 AM  81 days agoPost 8
Doublah

rrVeteran

USA

My Posts: All  Forum  Topic

Uhhhh...really???

PM  EMAIL  GALLERY  Attn:RR
07-02-2017 01:55 AM  81 days agoPost 9
Doublah

rrVeteran

USA

My Posts: All  Forum  Topic

I just lost 5 minutes of my life!

PM  EMAIL  GALLERY  Attn:RR
07-02-2017 01:56 AM  81 days agoPost 10
icanfly

rrElite Veteran

ontario

My Posts: All  Forum  Topic

really really

PM  EMAIL  GALLERY  Attn:RR
07-02-2017 02:08 AM  81 days agoPost 11
JuanRodriguez

rrProfessor

The Villages, Florida

My Posts: All  Forum  Topic

Really ?

Been there, done that and old enough to know better.....

PM  EMAIL  GALLERY  Attn:RR
07-02-2017 02:52 AM  81 days agoPost 12
BeltFedBrowning

rrKey Veteran

Kansas City

My Posts: All  Forum  Topic

Have you seen the interview with Arthur Young? He explains this same phenomenon in his original model helicopter. What was it like 1947?

perfer et obdura; dolor hic tibi proderit olim

PM  EMAIL  GALLERY  Attn:RR
07-02-2017 04:36 AM  81 days agoPost 13
icanfly

rrElite Veteran

ontario

My Posts: All  Forum  Topic

awesome really

PM  EMAIL  GALLERY  Attn:RR
07-03-2017 10:58 AM  80 days agoPost 14
Richardmid1

rrProfessor

Leeds, England

My Posts: All  Forum  Topic

Any way, want to experience a 450 and any other heli like never before REDUCE PHASE LAG TO 80° PERIOD, that's all I got and man it's so good for the gyro I was pleasantly surprised, yet became unpleasantly flustered by the ensuing crash. Flying the heli in 90° pl must have caused my mind some confusion because this was the first flight without chasing the gyro and helis directional instabilities, it was terrible to control until the correction was made. No wonder people find it hard to learn on micros.
There was definitely something wrong with your heli, but not the phasing!

Stick interaction is my guess. One of the reasons we have expo!

60% of the time, it works every time!

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR
07-03-2017 11:27 AM  80 days agoPost 15
icanfly

rrElite Veteran

ontario

My Posts: All  Forum  Topic

yah,,,,no,,,,when it's on the ground and it's moving in all directions other than the one your putting in from the tx then I go make the mod and it's crisp and defined, accurate and stable as ever,

EUREKA

It's a little hard to do on the 380 in the picture set background, altering pl angle by rotating the lower swash, but could be so easy, so easy (get the sense I've already re-engineered something here? yes).

Here's the Aurthur Young piece;

Watch at YouTube

Can anyone be of help and point out the minute he goes into pl?

Have a wonderful flight.

PM  EMAIL  GALLERY  Attn:RR
07-05-2017 01:16 PM  77 days agoPost 16
icanfly

rrElite Veteran

ontario

My Posts: All  Forum  Topic

well, just a little vested update to prove I'm not the only one with this knowledge, this quoted from another site who's members have run a topic of the matter,
Helicopter physics question
and it's been said clearly to back up what I stand by 100%,
There is a small component of precession, around 10% of the observed effect,
then on to
As a rule of thumb stiffer blades and dampers = less phase lag. If you could have an infinitely stiff rotor system with no teeter or blade flap then there would be no lag.
now if you really have cursed and gone on a temper tantrum because you believe helis are HARD TO FLY or at least hard to learn to fly your doing it because they are engineered WRONG at the swash plate, PERIOD.

Hey, this 80 number didn't come to me for nothing, something hinted on however for two years I didn't listen or do something about it. When I did try the change on another heli I was shocked at how ultimately stable the heli was like ever and in wind too.

Here's a video I found on hf. I'm only here to keep beating my drum about it, you're all big boys and can decide for yourself. Doing something about it may be difficult I understand.

Watch at YouTube

Imagine, with all the technological advances in the rc heli of late there's still been an old engineering flaw that is more than an annoyance and hindrance to learning flying a heli and performance control, phase lag offset.

and to be certain I actually had once reduced pl offset to 70° in an experiment on a 450 but it started to compensate slightly later than it needed, just to let you know about that attempt, the heli flew no problem otherwise.

PM  EMAIL  GALLERY  Attn:RR
07-05-2017 01:22 PM  77 days agoPost 17
Richardmid1

rrProfessor

Leeds, England

My Posts: All  Forum  Topic

But todays fbl rotor heads are stiff with no teater or blade flap! I think phase lag issues are a thing of the past my friend. Today's fbl helis fly 100% true and precise, you pull back on the elevator and the heli will do a perfectly straight flip or loop for example.

60% of the time, it works every time!

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR
07-05-2017 02:08 PM  77 days agoPost 18
icanfly

rrElite Veteran

ontario

My Posts: All  Forum  Topic

fair enough but still there have been questions about this from 3d flyers who when flipping a heli see the tail has moved from it's original direction of intended orientation, that answer was to correct pl in the fbl unit.

So either the fbl units have got to have a rotating swash tuning or it has to be done mechanically.

You guys will wake up more to it one day, incorrect pl has been the cause of more than one tip over on takeoff or landing in my experience and an aweful offset of stick direction to heli reaction.

Because a heli is good from the factories doesn't mean it's great or perfect.

You won't trust me until you try it, that much I know.

PM  EMAIL  GALLERY  Attn:RR
07-05-2017 03:34 PM  77 days agoPost 19
Richardmid1

rrProfessor

Leeds, England

My Posts: All  Forum  Topic

You guys will wake up more to it one day, incorrect pl has been the cause of more than one tip over on takeoff or landing in my experience and an aweful offset of stick direction to heli reaction.
99% of the time the tip overs were due to vibration getting to the gyro sensors or the FBL unit over correcting on the ground.

60% of the time, it works every time!

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR
07-06-2017 06:17 AM  77 days agoPost 20
icanfly

rrElite Veteran

ontario

My Posts: All  Forum  Topic

10° isn't much if you consider it, I'm now checking out how to make a similar alteration on my dfc700 and it's a little trouble when the servo horn balls and links there hit the frame sides, the plastic part. Don't know if I'm up to grinding some plastic away to make it work or finding another way around this on a 700. The earlier 700e model will be easier to make the mechanical mod except a new support arm in back will have to be made up with the offset for that one to work. Those are just Align product and dfc units.

btw it is co-incidence the other forum has a topic on this matter, and to reference them here is not by design but only in the name of info sharing.

PM  EMAIL  GALLERY  Attn:RR
WATCH
 1 page 655 views POST REPLY
Scorpion Power Scorpion Power
HelicopterMain Discussion › Mechanical Phase Lag corrected 450 ohh joy,,,,ohh pooh
 Print TOPIC  Make Suggestion 

 3  Topic Subscribe

Thursday, September 21 - 11:27 am - Copyright © 2000-2017 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online