rrTV-PHOTO   New HD TV
HOME   rrTV-PHOTO   GALLERIES   MY GALLERY   HELP-FAQ
myHOME PM pmRR MEMBERS 585 ONLINE 42 EVENTS SEARCH REGISTER  START HERE
 
1 page457 viewsPOST REPLY
Real Raptors . Mikado Modellhubschrauber . GrandRC

.
.
Got Jet Fuel? Turbine Helicopters > Question about JetCat mech
 
 
autorotater
Heliman
Location: California

Heys guys I have a set of JetCat mechanics in the large Vario Huey fuse. I got it all set up and am only getting -4 degrees at bottom, 0 degrees at center stick, and +5 degrees at full stick. What am I missing here. The instructions don't give pitch link lengths. I set the swash with the jig from Vario and made all the links so that the heli is at 0 degrees at half stick. Any ideas what I could be doing wrong?

Thanks
Dan
03-17-2008 07:07 AM
 
 
PETER ROB
Key Veteran
Location: Devon UK

Blade set up

autorotater, that 19mm/20mm spacer is to make sure you do not bottom the swash plate on the top bearing block
Make sure the mixing arms are level at mid stick
For that type of machine and mechanics, pitch range will be around -2 degrees, +5 degrees, +9 degrees, that is for basic set up, you will have to alter the range to suit the individual machine and your own style of flying, remember it is scale and not Aerobatic
Take a look at your swash mixing percentages, on my 500 they are elev 60% aiel 60% pitch 76%
Hope this helps
Peter R
03-17-2008 09:31 AM
 
 
autorotater
Heliman
Location: California

Peter just to clarify you are saying my mid stick since this is scale should be +5? So then should I set my 0 degrees with my mixing arms level at 1/4 stick?

Dan
03-17-2008 05:41 PM
 
 
PETER ROB
Key Veteran
Location: Devon UK

Dan, No, your mixing arms should be level at mid stick,
(hover point)
Peter R
03-17-2008 06:39 PM
 
 
autorotater
Heliman
Location: California

Peter, don't mean to be difficult but I want to be clear on this so my set up is correct. I will have everything flat and level with servos at 90 degrees at half stick and +5 degrees. Is that correct? Sorry for the dumb questions.

Dan
03-18-2008 01:29 AM
 
 
PETER ROB
Key Veteran
Location: Devon UK

Dan, Not a dumb question, better to ask, than get it wrong,
Yes that's correct, that is your starting point you will need to fine tune later
Good luck
Peter R
03-18-2008 02:05 AM
 
 
autorotater
Heliman
Location: California

Thanks so much for being patient with me. I have never had a turbine or even a scaler of this size. It is very exciting.
03-18-2008 03:43 AM
 
 
PETER ROB
Key Veteran
Location: Devon UK

Dan,Tere are a few people I help with their Turbine/Scale, they all suffer from a strange condition called Turbine Fear, it takes me a long time to get accross to them that the turbine is just another power unit, one of these flyers, can fly competition class flying, as soon as he gets his turbine in the air he goes to pieces, consequently, he does not fly to his ability, and gets dis-heartened with his flying, and then blames it on the turbine
Scale your next big step will be different and something you will have to learn,( lots of stick time) try not to think like you are flying 3D, and learn to fly scale, like you learned to fly in the begining, one step at a time
Good luck with your turbine /scale, once that turbine gets in the air, you will be smitten,keep us posted
Peter R
03-18-2008 08:27 AM
 
 
chopper jockey
Senior Heliman
Location: uk

Quote 
I will have everything flat and level with servos at 90 degrees at half stick and +5 degrees. Is that correct?

If you don't mind me saying so, that is NOT a good set up. If you think about it for a moment, if you set it up that way, the pitch must travel from -2 deg to +5 deg on one half of the servo's travel(that's equivalent to 7 deg of pitch movement) but the top half of servo travel is only going from +5 deg to + 9deg. (that's only 4 deg movement). So you will need to reduce the transmitter high pitch end point.

For a more efficient set up, your servo travel should be over half way before you get to hover pitch, or in other words, the half travel point should be at the half way mark between -2 deg and +9 deg, that should equate to +3.5 deg at half servo travel position. Don't mix this up with stick position though. At mid stick (hover) position the mixing arms should be level and the servo arms should have already gone over half their travel (about 65%).

Setting the servo travel up this way makes the most of the available torque and travel, without having to reduce transmitter end points.
03-18-2008 09:16 PM
HOMEPAGE  
 
 
autorotater
Heliman
Location: California

Believe me I never mind getting advice from anyone. I was told the other day by Joe at East Coast Vario that the pitch range chould be +1 +5 +10. He said these larger heli shouldn't have any negative since they are so heavy they don't need it to lower altitude and the negative pitch can cause a resonance situation. So I have set it up with +1 bottom stick +5 mid stick with mixers level and +10 at top stick. How does that sound?

Dan
03-19-2008 05:49 AM
 
 
Turbinator
Heliman
Location: Nanticoke, PA

That is about the pitch range I run in my turbine EC135, +1/2, 5, 10, hover all levers center
03-19-2008 09:56 AM
 
 
PETER ROB
Key Veteran
Location: Devon UK

Dan,When you ask a question, on RR, the answere you get are varied but not incorrect, my first post said as a basic set up,
Chopper Jockey is 100% correct in his way of setting up, (I just find it hard to explain to a newbe)
Joe at East Coast, is correct with his set up for flying
Seattle Hello set me a link to someone who suffered so much ground resonance that his heli wrote itself off, not nice

At start up and on the ground if you have plus pitch, there is a possibility of a gust getting under your blades (Chopper Jockey's heli pad is on top of a cliff) and making the heli lighter on its skids, if ground resonance starts you have nowhere else to go but up
Whith negative pitch you can stick the heli to the ground, also a small amount of negative helps if you have to auto rotate

If you listen to all, it is then up to you, how you proceed
Good luck
Peter R
03-19-2008 10:19 AM
 
 
jamesmac
Senior Heliman
Location: Edinburgh

That is interesting what Chopper Jockey say's about set-up, makes sense form a mechanical point of view. I take it hover position on the stick can be altered by adjustment of the pitch curve position?

A couple of questions:

1. what is the preferred stick position for hovering a large machine such as the XLV [mid, or just above ctr?]

2. what is a recommended basic pitch set up for an XLV (wren turbine) with std blades?

James
03-19-2008 10:57 AM
 
 
MattJen
Elite Veteran
Location: UK,Gravesend, Kent

[B]1. what is the preferred stick position for hovering a large machine such as the XLV [mid, or just above ctr?]

In my opinion, i would say it is what ever you feel comfortable with or are used to..

I am used to a machine taking off at mid stick, and when i flew the XLV it was set slightly higher than mid stick, it felt weird to me and it felt as i was moving the stick a lot further before the machine lifted..

SO i adjusted the pitch curve so it lifted off at mid stick,

Matt

I bought mymother in law a chair for xmas, but she would not plug it in.
03-19-2008 11:06 AM
 
 
Coolrunnin
Veteran
Location: Manchester U.K.

I adjusted my hovering point to be at centre stick as that is how I am used to flying hovering maneuvers. It also makes a bit more sense, to me at least, to use as much of the throttle and pitch curves as possible for fine hovering control rather than just the top section of them. The XLV is quite precise for its size and it is not an aerobatic machine so set up this way suits it quite well for general cruising about.

Pitch wise my basic (simplified) three-point pitch curve on the XLV would be something like -1, 5, 10. I've found the blades will autorotate reasonably well at -1 too, no-doubt due to the reflex trailing edge Vario have put on the blades.
03-19-2008 03:49 PM
 
 
1 page457 viewsPOST REPLY
CanoMod . Futaba-RC . A Main Hobbies

.
.
Got Jet Fuel? Turbine Helicopters > Question about JetCat mech
  UPDATE SCREEN   PRINT TOPIC Advertisers 

Subscribe to This Topic

Sunday, September 7 - 1:13 am - Copyright © 2000 - 2008 runryder.com | email | link to rr | runryder needs cookie