RunRyder RC
WATCH
 2 pages [ <<    <    ( 1 )     2     NEXT    >> ] 2813 views POST REPLY
10-22-2011 12:12 PM  8 years ago
Topic Vote0Post 1
AnneThe Man

rrApprentice

Ireland

MyPosts All Forum Topic
Bouncing in the wind
I have just completed a new 90 size model. I have used a shorter flybar but heavier, SAB, weights. It sits in the hover very well but is verticaly very jumpy. It is very windy at the moment.
What aspects of the hardware affect vertical movement in the hover?
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
10-22-2011 01:05 PM  8 years ago
airdodger

rrElite Veteran

Johnston USA

MyPosts All Forum Topic
http://www.w3mh.co.uk/articles/html/csm9-11.htm

The above may be some help. Blade weight, blade design, flybar paddles and weight, flybar length, position of sliding flybar weights, headspeed, mixing ratios , curves, and you affect the outcome. If you give a lot of info I would think some of the contest pilots will try and help with specific problems or maybe even have close to the same setup.
Chris
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
10-22-2011 01:31 PM  8 years ago
ttrip06

rrApprentice

Central Pa

MyPosts All Forum Topic
What model are we talking about? If you already are using heavy paddles and blades, then it comes down to flybar ratios and pitch curve setting you are hover with.Tim Tripoli

Team Futaba, Rail Blades
Team Crash
ProggressiveRC
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
10-22-2011 01:58 PM  8 years ago
AnneThe Man

rrApprentice

Ireland

MyPosts All Forum Topic
ENV with V2 Radix FAI blades, but I don't have a headspeed yet as I'm using Kontronik and I haven't had anyone to tach me. My feeling is it is fairly low as I have modified the standard dampners but I am still getting a very small amount of tail nodding.
There was a thread not so long ago that adressed vertical bouncing separately, but I can't find it.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
10-22-2011 04:08 PM  8 years ago
Dr.Ben

rrMaster

Richmond, VA, USA

MyPosts All Forum Topic
Two things to consider:

1. Delta angle. Some correcting delta improves collective stability at modest cost to cyclic stability.

2. Blades and headspeed and pitch curve. Most symmetrical blades have a definite sweet spot for headspeed in hover. If you get below it especially or much too far above it, the model will not react well to wind gusts. You need to carefully assess whether the slope of your pitch curve is correct. You need a steeper curve for the wind, but no so steep you can't settle the model down with precise corrections for the wind. ALSO, do not assume the pitch curve will be symmetrical above and below half stick. Balance the feel of the model for collective input above half stick and below half stick.

Ben Minor
Peak Aircraft/Team Minicopter Team Futaba Team Kontronik USA
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
10-22-2011 08:12 PM  8 years ago
Heimypilot

rrApprentice

Hengelo Netherlands

MyPosts All Forum Topic
Hello Ben,

Can you more or less explain why a bit correcting delta could dampen the bouncing?

To me getting rid of a portion of bouncing would be very helpful. I actually never had a heli that did little bouncing. It always went up and down 2 feet in a gusty windforce 4.

Steven
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
10-23-2011 04:13 AM  8 years ago
Dr.Ben

rrMaster

Richmond, VA, USA

MyPosts All Forum Topic
With correcting delta, when the head gets hit by a gust and the axle deviates from its neutral state, the axles's movement acts to effectively twist the pitch angle of the blades to counteract the lifting tendency of the gust.

I've flown models set up both ways. You can put enough noncorrecting delta so that the darn thing is almost unmoveable laterally (cyclic) when hit by a gust, BUT the model becomes virtually uncontrollable on collective in gusty winds. When being judged, it's much easier to hang onto the model cyclically (less obvious to judges too) when hit by a gust, than to try to supress the model as it jumps 2 feet in the air when hit by a similar gust.

Ben Minor
Peak Aircraft/Team Minicopter Team Futaba Team Kontronik USA
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
10-24-2011 03:37 PM  8 years ago
AnneThe Man

rrApprentice

Ireland

MyPosts All Forum Topic
Thank you for you help. I was hoping to check the headspeed but we have had non-stop rain.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
11-02-2011 01:22 PM  8 years ago
GM1

rrElite Veteran

Tallahassee, Florida US

MyPosts All Forum Topic
Delta
Dr Ben gave about as concise a description of delta as I have ever seen. Some guys prefer too make manual corrections in collective and others in cyclic. A few years ago we experimented a lot with this and, I like a little correcting delta so the collective isn't quite as jumpy but not so much as to make the cyclic wander all over the place. It depends on what you like and once you get the "feel" you want, it's much easier to practice and learn what is going to happen when the wind hits the model from different directions.
The Radix V2s are much better in hover than the older ones BUT theyare rpm sensitive so move the hover rpm up and down to find where they are happy on your model. Mine is about 1525.
On a dog sled team, if you're not the lead dog, the view never changes.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
03-27-2013 05:28 PM  6 years ago
Heimypilot

rrApprentice

Hengelo Netherlands

MyPosts All Forum Topic
Hi!

Anyone of you guys having some experience regarding the hirobo SSZ-5 head? I'm very slow reacting to bouncing so I need the head to compensate for me. But the SSZ 5 head has only 2 holes for setting the delta. One looks a very little bit uncorrecting and the other is correcting. I tried both and the correcting hole is worse over the other. However both unsatisfacory.
Is there a way to make it perfect or will I be ending up making a slot in the pitch arms?
I use the red dampening rubbers from the SDX head.
How about the centre teetering in this head, if I remove it what can I expect. Wil it affact the bouncing?

Lots of questions , I hop you can shed a light!

Thanks!

Steven.
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
03-27-2013 07:13 PM  6 years ago
Christian Rose

rrNovice

Tengling, Germany

MyPosts All Forum Topic
Hello Steven,

as you know i have done very much setup attempts for the SSZ-5 in my old Hirobo Times. The Setup i like the best is the one i told Holger two years ago.

First: Get a pair of SSZ-4 blade holder arms, so you can run the center position without getting the control rods touching the blade holder arm itself at high pitch ranges.

Then take a 520mm flybar (JR one) and a pair of K&S FAI V2011 or FunTech FAI Paddels.

At the seesaw you take the side with the two holes for the balls. Mount it at the outer position (pointing to paddle side)
Here i used a little shorter one balls (7mm if i remember correctly)

At the mixing arms i use the outer hole on the right (Seesaw - Blade - Link) and the middle position on the left side. As for the inserts i use the SDX one with only a bit offset. Beetween the Mixing arms i use a additional 1mm shim.

Then fly and be happy

All the best
Chris
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
03-28-2013 02:59 AM  6 years ago
Chris.C

rrVeteran

Hong Kong

MyPosts All Forum Topic
Have you try the white damper rubber (#70)- 0414-545? and the main blades 0414-538?
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
03-28-2013 07:53 AM  6 years ago
Heimypilot

rrApprentice

Hengelo Netherlands

MyPosts All Forum Topic
Thanks Christian, your modification will be very good I'm sure but in what way wil that stop my heli from bouncing? Is it the paddles ? The rest of your setup is not so much off as I have it right now. And I'm trying to get the best out of the original head as the blade arms and the paddles are quite an investment for me now.

Chris C: Do you know where to scale the red SDX dampeners? The original black ones are #80 and have a metal bush inside. The red SDX rubbers are somwhat softer and don't have a metal bushing inside, but mounted in the head they are still quite hard I think. I still have a set of the blades that came with the OPIII kit and these blades (0414-531) bend more than the dampener rubbers.......

Will I already be better of using softer dampener rubbers? I can easily trim a ring from the dampener rubbers in the lathe..

Steven
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
03-28-2013 12:35 PM  6 years ago
nighttrain

rrApprentice

Louisville KY

MyPosts All Forum Topic
Steven,
For delta to work, the spindle has to be able to move. If no movement, then no effect. Dampers are cheap. Buy several sets and experiment by making the damping softer and softer. I think you'll soon be very happy!
SHARE  PM  EMAIL  Attn:RR  Quote
03-28-2013 03:45 PM  6 years ago
Christian Rose

rrNovice

Tengling, Germany

MyPosts All Forum Topic
Steven,

sorry i forgot to mention: i use the standard black SDX damper rubbers, not the red ones. Only the one out of rubber, no brass insert. The 80° Shores are way tooo hard, i never understand how Hirobo sell such hard dampeners together with a f3c heli.

It is a connection of all the factors: Dampenig, Zero Delta, position of the balls, bell-hiller mixing and so on. It took me a great effort of time to find this setup, which was working for me perfectly and Holgi also likes it.

The bouncing is mostly a combination of a too hard dampening, with to much bell-mixing and wrong (to less) rpm and or pitch curve. The most of the F3C Blades are very good. Quit very good results i got with the SAB 0208 (out of production now because of Goblin / 3D Blades etc)and the RADIX FAI V2. With my sylphide i fly the Radix F3C and the original (very expensive) JR Blades with best results but i want to try the DH F3C Blades sometimes.

If you want you can call me, english is no problem.

All the best

Chris
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
03-29-2013 12:37 PM  6 years ago
Chris.C

rrVeteran

Hong Kong

MyPosts All Forum Topic
The reason I asked if you have try the dampers and the blades is that these two items are part of the equation in their design for an optimum FAI machine, even though they do not necessary include these in the kit.

So I guess it worth a try of using the manufacturer's recommended items and set it up from there.

I may be wrong but the white dampers are new item and usually the Japanese FAI blades have a little flex lengthwise.

Just my opinion.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
03-30-2013 10:37 AM  6 years ago
GootyS

rrApprentice

Gauteng South Africa

MyPosts All Forum Topic
His use a kontronic 120 camp with kontronic motor. With the 8fg radio and through curve in a straight line at 53.5% i get 1550 in hover. Going the .5 took the head speed from 1520 to 1550. Hope this helps a little.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
03-30-2013 07:55 PM  6 years ago
Heimypilot

rrApprentice

Hengelo Netherlands

MyPosts All Forum Topic
Sorry GootyS, I don't understand where you're aiming at.

Christian: I thought I had the red dampeners, but as I took them out today to trim them to make the dampening softer I noticed I have the black ones too. Do you know wheter the red ones are harder or softer than the black ones?
I'm very sad to hear that the SAB 0208R is out of production. I have 2 sets of these for either one of the Freya's a set. A really nice blade with a very nice price. I hope that I wil not crash them....

I hope to test the softer supension tomorrow or monday, but the forecast states a windforce 3 on both days, so I will not have a good comparison......
Another option for me to try is a set of Fun-key 680 blades. Unfortunately they are rather lightweight, but any experience is another experience.

Thanks for the input so far, I take everything you al mention seriously, but I like to change only one thing at the time...

Steven
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
03-31-2013 08:49 AM  6 years ago
Christian Rose

rrNovice

Tengling, Germany

MyPosts All Forum Topic
Blades and so on
Hello Steven,

happy easter at first to you and your family

As for the blades: Get a pair of Radix F3C V2. They are superb blades. Also get some K&S V2 F3C or FunTech F3C Paddels and mount them on a 520mm - 530mm Flybar. Flybar weights approx. in the middle of the flybar.

The black dampening 50° Shore hard do not need any modification, just ad enough grease. I liked the center bearing of the blade holder spindle, but in the Sylphide i have no one, and it also flies very good.

Best wishes

Chris
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
04-01-2013 02:52 AM  6 years ago
allegro16

rrNovice

Kuala Lumpur, Malaysia

MyPosts All Forum Topic
Hi Guys,

I'm currently using Rotortech 720 (non SGs) on my Freya with SSZ-V head. I noticed that it is really bouncy in the wind. Headspeed for hovering is 1500 RPM. The mixer settings is stock according to the manual and I'm using the new 70D white damper

I'm considering switching to Radix V2 F3C blades. Will the Radix handles the wind better than the RTs ? What about the aerobatics segment - any differences between the 2 blades ?
SHARE  PM  EMAIL  Attn:RR  Quote
WATCH
 2 pages [ <<    <    ( 1 )     2     NEXT    >> ] 2813 views POST REPLY
 Print TOPIC  Make Suggestion 

 10  Topic Subscribe

Monday, December 16 - 8:15 am - Copyright © 2000-2019 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online