RunRyder RC
 18  Topic Subscribe
WATCH
 5 pages [ <<    <     1     ( 2 )     3      4     NEXT    >> ] 16356 views POST REPLY
Scorpion Power Scorpion Power
12-11-2008 03:08 PM  8 years agoPost 21
Wayne Mann

rrVeteran

United States of America

My Posts: All  Forum  Topic

Hi Dan,

The rotor head on the 700 has what we call uncorrecting delta, which means if a rotor blade tries to flap up due to a wind gust the rotor blade actually gets more pitch thrown into it via the delta. Delta in this direction makes the helicopter much more stable than the other direction. Basically in a nut shell; the rotor disk is stable in the wind (with the new carbon and fiberglass rotor blades) just like a frisby. It has virtually no tendencies to ballon up, it is the body or mechanics that it unstable and the mechanics are the unstable piece of the pie. When gust hits the model from the right side (clockwise rotating rotor) the tail rotor will try to fly up into the rotor blades and just the opposite will happen when the wind hits the left side of the model. I have done extensive testing with delta. So the model is sitting still minding it's own business when a gust hits the model. The body (mechanics) will try to ballon but because of the delta and the fact that the rotor disk is stable the push rods going from the swash plate to the bell mixers will create a push pull reaction between the blade grips and the swash plate holding the body still. How still depends on the amount of delta and how soft the rotor head is.

For this to work the rotor head damping has to be soft otherwise the dampers will drag the rotor head along when the body tries to ballon up. Unfortunately for this delta to work it's magic it requires head speed. When the model is running up or winding down the disk is very unstable, you basically get the opposite effect from the delta.

Your head speed must have been very slow when you touched down in the auto. Either land with a little more head speed, tighten up the rotor head damping a little bit or extend the pitch arm ball a little further in towards the center of the rotor head thus reducing the amount of delta. Any of these fixes will solve your problem.

If you have any other questions about this please ask.

Wayne Mann

PM  EMAIL  GALLERY  Attn:RR  Quote
12-11-2008 03:58 PM  8 years agoPost 22
F1 Rocket

rrKey Veteran

Melbourne, Florida USA

My Posts: All  Forum  Topic

Thanks for the input Wayne. I added a .5mm shim to both sides and went out and tried it. Only enough space to hover but it feels much better now. It's gusty as all heck but the machinne just rides it out. What are the effects of uncorrecting delta in FFF?

Danny

Danny - DemonAero Support Team

PM  EMAIL  GALLERY  Attn:RR  Quote
12-11-2008 04:31 PM  8 years agoPost 23
Wayne Mann

rrVeteran

United States of America

My Posts: All  Forum  Topic

Hi Dan,

Just like in a hover it makes the model track a lot better, depending on set up. In cross winds upstairs the model will hold pitch (elevator) heading a lot better.

Wayne Mann

PM  EMAIL  GALLERY  Attn:RR  Quote
12-11-2008 04:47 PM  8 years agoPost 24
F1 Rocket

rrKey Veteran

Melbourne, Florida USA

My Posts: All  Forum  Topic

Cool. Now I just need to learn to fly it

Danny

Danny - DemonAero Support Team

PM  EMAIL  GALLERY  Attn:RR  Quote
12-11-2008 05:13 PM  8 years agoPost 25
Wayne Mann

rrVeteran

United States of America

My Posts: All  Forum  Topic

Eaxctly.

Wayne Mann

PM  EMAIL  GALLERY  Attn:RR  Quote
12-11-2008 06:36 PM  8 years agoPost 26
Dr.Ben

rrMaster

Richmond, VA, USA

My Posts: All  Forum  Topic

I may as well complicate this discussion and get Wayne to describe how for all the benefits that noncorrecting delta has for cyclic stability, it can turn around and royally eff up collective stability.

Pick your poison. There ain't no free lunch here.

Ben

PM  EMAIL  GALLERY  Attn:RR  Quote
12-11-2008 07:02 PM  8 years agoPost 27
Wayne Mann

rrVeteran

United States of America

My Posts: All  Forum  Topic

I can't imagine why you or Dan would be having collective issues Ben? I just assumed that everyone used the same collective "auto pilot" control that I use. Yes Dan the uncorrecting delta will cause the model to be less stable on collective. You can counter this by using a delrin ball on the center of head axle to support the lifting loads placed on the axle which will greatly reduce collective problems, however this will not be necessary with his set up as he has limited delta and the damping is probably to tight to allow much vertical movement in the axle. Remember this head has a 10 mm cross shaft. How much room can there possibly be in there for movement in any direction! Besides he has been away from this for a long time. He has much bigger fish to fry.

Wayne Mann

PM  EMAIL  GALLERY  Attn:RR  Quote
12-11-2008 09:55 PM  8 years agoPost 28
F1 Rocket

rrKey Veteran

Melbourne, Florida USA

My Posts: All  Forum  Topic

I can't imagine why you or Dan would be having collective issues Ben?
Hey Wayne, Thanks for providing an excuse for my poor collective control. "It's not ME, it's the &@*#&%* head design."

Danny

Danny - DemonAero Support Team

PM  EMAIL  GALLERY  Attn:RR  Quote
12-12-2008 12:02 AM  8 years agoPost 29
NormanD

rrNovice

chattanooga, tn - usa

My Posts: All  Forum  Topic

For what it's worth, when I switched my Trex 600 to correcting delta I noticed a sizeable improvement in collective management. Before it was smooth in idle wind, but a bit of a handfull once wind came into the picture. Throw 10-15mph winds at a 600 with the uncorrecting delta and it can be a handful and sometimes a headache to maintain collective stability. But that's coming from a relative new guy, I guess I've picked my flavor. The instrument holding the gimbals needs a lot of work too. I can only speak to how my particular helicopter responded, which was very well in the way of collective with positive delta.

PM  EMAIL  Attn:RR  Quote
12-12-2008 02:47 AM  8 years agoPost 30
Santiago P

rrProfessor

South West, Ohio

My Posts: All  Forum  Topic

Ben, Wayne,
I was starting to fell like the guy with both feet in his mouth , (instead of the typical one footer) when I have been preaching on the benefits of positive delta. All along I kept thinking that it benefited both the cyclic and pitch stability, and then found myself asking why (in this case my Raptor) it wonder around sometimes, and blamed something else.

Presently I have one Freya on uncorrecting the other correcting. Can't wait to fly both back to back in some wind to see which I prefer. I guess I have really liked the one on correcting, but frankly, the best heli I've ever flown in heavy winds was a friend's bone stock Vigor CS. The thing felt like it had an autopilot it hover and piro so well. Its head was set on uncorrecting as well. Hum

Team Minicopter - PeakAircraft.com
bavarianDEMON- Team Kontronik - Scorpion Motors-

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
12-12-2008 03:01 AM  8 years agoPost 31
spencer737

rrApprentice

Canada

My Posts: All  Forum  Topic

Hey Danny your 700 is looking SICK, post up some vids!!!

Spencer
Esprit Model Flight Team

PM  EMAIL  GALLERY  Attn:RR  Quote
12-12-2008 01:14 PM  8 years agoPost 32
NormanD

rrNovice

chattanooga, tn - usa

My Posts: All  Forum  Topic

Actually Santiago, you may not be far off base. Our full scale counterparts benifit from what is being called correcting delta in both hover maneuvers and brisk forward flight. Either by way of such things as delta-3 hinges or offset pitch horns. In FFF on these big birds it has a lot to do with reverese flow and the size of the stalled region of the retreating blade, and some other factors I will leave out for simplicity. It is termed "retreating blade stall", and will cause the helicopter to pitch up in FFF and possibly roll. It starts hapenning on the retreating blade but because of precession it is felt when 90 degrees of that, or the tail. The nose can pitch up and possibly roll.

As far as the Trex's go, they are a unique animal among their counterparts. They were mostly designed tail heavy and for hard kick, which is great for 3D, but being the head design tuning options are limited,it does pose some unique challenges to feel a good difference.

This is only my opinion and studies, and I certainly do have respect for the testing and experience of the others that have spoken here.

Norman

PM  EMAIL  Attn:RR  Quote
12-14-2008 02:17 PM  8 years agoPost 33
F1 Rocket

rrKey Veteran

Melbourne, Florida USA

My Posts: All  Forum  Topic

Thanks for the help

I had a great time hanging out with the F3C gang at the Orlando fun fly. Many thanks to Erich, Gordie, Nob, and Cliff for flying my machine and giving me feed back on my setup. I'll try some of the suggestions over the next few weeks and start practicing.

Danny

Danny - DemonAero Support Team

PM  EMAIL  GALLERY  Attn:RR  Quote
12-14-2008 03:55 PM  8 years agoPost 34
Wayne Mann

rrVeteran

United States of America

My Posts: All  Forum  Topic

Hi Dan,

Did Cliff fly it around? What did he think about the electric upstairs? I will give him a call after lunch.

Wayne Mann

PM  EMAIL  GALLERY  Attn:RR  Quote
12-14-2008 04:08 PM  8 years agoPost 35
F1 Rocket

rrKey Veteran

Melbourne, Florida USA

My Posts: All  Forum  Topic

Cliff flew it a bit upstairs and It seemed to be going good although his Caliber was a rocket ship. The packs I currently have are only 17C and have a lot of time on them so I know there is much more power available if needed.

Danny

Danny - DemonAero Support Team

PM  EMAIL  GALLERY  Attn:RR  Quote
12-14-2008 05:37 PM  8 years agoPost 36
Wayne Mann

rrVeteran

United States of America

My Posts: All  Forum  Topic

OS engine = rocket ship, that is an oxy moron. Wait till you see one of my full fuse YS powered Calibers go.

Wayne Mann

PM  EMAIL  GALLERY  Attn:RR  Quote
12-14-2008 06:14 PM  8 years agoPost 37
F1 Rocket

rrKey Veteran

Melbourne, Florida USA

My Posts: All  Forum  Topic

You should see my 700 go on 12s

Danny

Danny - DemonAero Support Team

PM  EMAIL  GALLERY  Attn:RR  Quote
12-14-2008 06:18 PM  8 years agoPost 38
Wayne Mann

rrVeteran

United States of America

My Posts: All  Forum  Topic

I have seen what an electric is capable of. Curtis's machines are very impressive when he gets on it. Now if he just had enough battery to make it to the end of a flight using that much power.

Wayne Mann

PM  EMAIL  GALLERY  Attn:RR  Quote
12-14-2008 10:32 PM  8 years agoPost 39
Santiago P

rrProfessor

South West, Ohio

My Posts: All  Forum  Topic

OS engine = rocket ship, that is an oxy moron. Wait till you see one of my full fuse YS powered Calibers go.
Wayne Mann+anybodys heli=rocketship
Now thats an ozy moron. Smooth hands equal extra HP.
Not to take anything on how good the the YS SRs are.

Team Minicopter - PeakAircraft.com
bavarianDEMON- Team Kontronik - Scorpion Motors-

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
12-14-2008 10:37 PM  8 years agoPost 40
ErichF

rrElite Veteran

Sutton, NH

My Posts: All  Forum  Topic

I gotta say, having spent the weekend at the Orlando fun fly, by far the most powerful nitro helis out there were YS91 SR powered. No flameouts, either.

Erich

PM  EMAIL  GALLERY  Attn:RR  Quote
WATCH
 5 pages [ <<    <     1     ( 2 )     3      4     NEXT    >> ] 16356 views POST REPLY
Scorpion Power Scorpion Power
 Print TOPIC  Make Suggestion 

 18  Topic Subscribe

Saturday, October 21 - 1:19 pm - Copyright © 2000-2017 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online