JoeK
Member
Posts: 55
Reg: 06-18-03
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 06-19-03 06:48 PM - Post#21653
Picked up a Futura SS for a sweet deal on ebay , the former owner had the collective set to 0 at mid stick , 9 at top , -9 at bottom. I have moved it mechanically to -2 at bottom , 4 at mid and 9 at top . The throttle curve is 0/25/50/75/100 . Will these settings make the hover more stable? I see info for doing it both ways but when I was flying 8 years ago this was how my Legend was setup.
Your comments are appericated.
Joe
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larrytoelle
Full Time Senior Member
Posts: 3735
Loc: Fort Jones, California .....
Reg: 01-20-03
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06-20-03 05:52 AM - Post#21675
In response to JoeK
Hi Joe,
Congrats on obtaining your Futura ...
I'm not an expert, but ... in case an expert doesn't respond to you, I'll give you what I know ...
Seems that mechanical setup is best at -9,0,+9 ... the Mas Technique articles are posted on here somewhere and that's what most of the gurus are going with. Makes sense to me anyway ... and its as good advice as I've seen anywhere.
If you're seeking a mid-stick hover, then you can use your radio's pitch curve to dial in -2,4,+9 (normal mode) and still have -9,0,+9 available for idle ups (inverted & aerobatic). The Mas Tech goes for a 3/4 stick hover ... (try it, you'll like it).
Also, I'd guess that you'll find that you want to tweak your throttle a bit upward around mid-stick (maybe 70%) if you're going for a mid-stick hover, otherwise your throttle looks like a good starting point. You'll have to tweak to find the sweet spot ... normally, lower head speeds make the hover less stable ... mushier. Higher speeds make things more positive or crisp. I've found a bit (30-40%) of expo on the cyclics removes twitchiness ... but that seems to be a personal call. Lately, I've removed expo altogether, preferring a quicker stick.
Hope this helps ...
I'm relatively new to helis, but I'd guess that you'll find things have changed a bit in 8 years ... to the better I'd presume.
Let us know how things go with your Futura ... it's one of the birds that I've been lusting for.
LT
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TMoore
Senior Member
Posts: 1617
Loc: Cookeville, Tennessee
Reg: 10-16-02
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06-20-03 05:54 AM - Post#21676
In response to JoeK
You can do it any way you want. I still have several ships set up to hover at mid stick and on these machines the lower half of the collective stick travel is where the inverted curves begin. The more popular setup is to run -9 to +9 and use the throttle curves that you mentioned. This facilitates a real 3D setup and since you probably know how to hover and fly around this will not take much time to get used to.
Terry
| Your friendly neigborhood reality based Curmudgeonly Old Fart. |
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larrytoelle
Full Time Senior Member
Posts: 3735
Loc: Fort Jones, California .....
Reg: 01-20-03
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06-20-03 07:41 AM - Post#21680
In response to TMoore
Terry,
Thanks for the input. For those of us just getting into (or back into) this ... mechanical and radio setup poses a bit of confusion.
Personally, I've just started to fly inverted and having one heck of a time with it. I can't say that I'm totally aware of where the stick is ... 25% or 15% ... at inverted hover (well ... almost hover). Mike's setup ... logically ... seems reasonable, but I'd guess that I could've achieved the same result with a half-stick upright hover ... but perhaps later it'll make a difference, or at least I won't be wondering about it.
I'm coming to the conclusion that setup is not that big of a deal. As long as the engine remains within a reasonable range without bogging or stalling out, it seems that anything will work as long as you achieve maximum pitch in either direction and the engine supports the pitch and doesn't over rev. Am I wrong?
In your experience, are you aware of where your sticks are while you're flying? Would you notice the difference between a 1/2 stick hover or 3/4 stick hover? When I redid things to the Mas Tech setup, I initially thought I sensed a difference, but I'm not entirely certain what that difference was ... perhaps a different mental attitude more than a tactile experience?
As I become more proficient, perhaps these finer points will become important. For now, I find the linear set up easy, quick and consistent (a no brainer). Each of the birds has had to be tweaked a few degrees here and there to synchronize engine to pitch ... but that's not a big deal either ... just some fine tuning while checking out the rest of the bird.
Like the current discussion re: PPM v PCM, it may be an interesting discussion, but once the bird lifts off the ground, who cares or who is really aware? The real problem that most of us face, is how to gracefully keep the darn things in the air without violent contact with the ground. Right?
LT
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Tree_Top_Chop
Senior Member
Posts: 438
Loc: California
Reg: 08-14-02
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06-20-03 01:14 PM - Post#21692
In response to JoeK
You could go +7,0,-7 and still have a peppy machine and a easier time hovering with the new setup. If you change the setup from the "standard thing" to the "Mas thing" or vice versa then relevel everything. If you just change the pitch but don't relevel the swash, mixers, flybar links, and all that other stuff it won't fly right at all.
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JoeK
Member
Posts: 55
Reg: 06-18-03
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06-20-03 05:17 PM - Post#21697
In response to Tree_Top_Chop
Why would I need to change the swash? It is all level and the bell cranks are at 90% when at mid stick with the new settings.
Joe
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JoeK
Member
Posts: 55
Reg: 06-18-03
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06-20-03 05:32 PM - Post#21699
In response to larrytoelle
Thanks for the info Larry , I need at this point for the ship to fly the way I am used to it to be. When you use -2 to +4 to +9 and you get into trouble you can set it down a lot easier than you can ( I think ) with -9 to 0 to +9 . I have read the MAS tech but I will not be doing inverted for quite a while. Have to get back to the basics for a while first.
With my Logo 20 ( Thats for sale ) it used -4 to +4 to + 9 and the one time I panicked and choped the collective I drove it into the ground, where if it had been a little less negitive it would have settled a lot slower. 
Joe
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Tree_Top_Chop
Senior Member
Posts: 438
Loc: California
Reg: 08-14-02
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06-20-03 08:31 PM - Post#21702
In response to JoeK
Well, it was 9,0,-9 when you got it for 18 degrees total throw. Lets say the Futura center for the swash is 20mm above the bearing block. That's 9 degrees down and 9 degrees up from that placement and everything centered. So now you want to change the setup.
If you just start cranking on grip rods you'll end up with 4 degree's positive at center (20mm swash height) giving you now -5 at the bottom, 4 at center, and 13 at the top. If you start playing with ATV's you think you could get -2,4,9 but you don't, the radio "smooths out" the curve and you wind up with something like -2,5,9. So you add in throttle to get the head speed up and you wind up with a model that isn't flying right. It's dogging on take-off and overspeeding on decents because the curves are crazy. If you're going from a symmetrical -9,0,+9 to a non-symmetrical -2,4,9 you need to relevel everything. Something in the linkage will be wrong, either the mixers, the flybar links, or the swash. That's why I was saying relevel the swash and everything. Start with the bellcranks at 90, swash level at the recommended height, then level everything above that out with 4 degree's at midstick. Then see what the range looks like.
I'm assuming here you're heli has a flybar mixer and isn't connecting the grips straight to the swash or a mixing base and has the "System 88" swash, right? All that has to be level or it'll behave strangely. It'll still fly, but you'll be fighting it all the time as mixers flip past center on one side but not the other, etc.... It's strange and hard to believe but taking away that 1 degree in the scheme of things can really mess the handling up (if it was set up right for -9,0,+9). It all depends on what part had to "eat" that 1 degree change. If you level everything out perfect, make sure the flybar paddles are perfect, make sure the throws are as symmetrical as possible, it'll darn near hover itself. A little flybar weight and it'll really be rock solid in the air. Then ditch all those bushings and get some ball-race replacements and it'll be soooo smooth and a pleasure to fly.
Course, the other guy could've just cranked on the rods and then sold it because he couldn't get it to fly right 
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JoeK
Member
Posts: 55
Reg: 06-18-03
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06-20-03 08:47 PM - Post#21703
In response to Tree_Top_Chop
I understand what you are saying, ( I think ) but I set this up using the Vario pitch gauage and the flybar level, I cranked in more pitch by lenghting the pitch servo control arm. Yes it is a System 88 head. At mid stick all bell cranks are at 90 % , the flybar is level using the float level that comes with the Vario pitch guage. Again at mid stick I have 50 % power and a stright linear curve to the throttle. I may have to add a bit more throttle to the hover position. The hover control on the 8103 gives me an additional 1 degree of pitch at mid stick. So at the mid point I am at 4 to 5 degrees with a throtle setting at 50 % and the swash plate is level.
That is part of what I am having trouble understanding, all appears to be level with both sticks at center. Is that not what I want to have ? I mean the cyclic is at center and the swash is level and the bell cranks are at 90 degrees.
Joe
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Tree_Top_Chop
Senior Member
Posts: 438
Loc: California
Reg: 08-14-02
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06-20-03 09:53 PM - Post#21705
In response to JoeK
Yep - and the flybar mixers (swiveling arms on the grips) are level? and the flybar link arms are level, too? The paddles are level with the flybar link arms?
Also, when you tilt the flybar watch the mixing arms and they both break center at the same time? And they both travel the same distance (one up and one down). You don't want one lingering around center or needing to pass through center after the other one has already gone on it's merry way or the heli will be "jumpy". The key is to have everything parallel (level) and breaking any center points at the same time. It's kind of a complex system but it works extremely well - you'll love it.
Also, pull the blade grips and check the bearings and shaft. Check the 0-ring dampers in there, too - they can get tore up. You'll get the "Wah-Wah's" if that stuff is buggered up. Last thing is to pull up and push down on the mainshaft, it should be solid (doesn't "give" or rock).
Everything else is pretty straight foreward.
Do you know what height the swash is supposed to be leveled from the bearing block? Should be in the instructions - I think it's 20mm.
Couple checks to double check you're setup - move the left/right fore/aft cyclics and watch the swashplate. It shouldn't move up and down (though it may just a wee little bit). It should just rock around. Also, on the head, they didn't seem to leave alot of bite for it on the main shaft so they can rock and wear. Try rocking it back and forth on the mainshaft, it should feel tight and resist being rocked, it shouldn't click or feel like it's worn itself.
That's about all I can think of to watch out for. Robbe/Schluters are real nice, but the whole system 88 thing takes a little longer to setup right. The more time you put in to getting it exact as possible the better it'll work for you.
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JoeK
Member
Posts: 55
Reg: 06-18-03
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06-20-03 10:04 PM - Post#21706
In response to Tree_Top_Chop
Going to hover it this weekend, will check all the point's everyone mentioned and will report back next Moday ! Thanks all.
Joe
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JoeK
Member
Posts: 55
Reg: 06-18-03
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06-24-03 04:12 PM - Post#21955
In response to JoeK
Well almost got it up to hover, I was flying in my backyard which is not real enough room even to hover as I have a fence all the way around. I always feel closed in , no way to try to fly out of a bad situation. Anyway , took it up light on the skids and it seemed pretty responsive. Good head speed, cyclic seemed pretty crisp. Will take it to one of our local parks this weekend and see how well it will do with enough room to fly it.
Also I ordered the FMA Co-Pilot , the reviews I read seem to make it ideal to get back into flying again. Anyone else read about this or tried it?
Joe
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larrytoelle
Full Time Senior Member
Posts: 3735
Loc: Fort Jones, California .....
Reg: 01-20-03
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06-25-03 01:41 PM - Post#22008
In response to JoeK
Joe,
Good luck and good flying!
I'm curious ... Why would you think that you'd need a co-pilot? It has seemed to me that if you get into trouble, it's just as quick ... or quicker ... to fly out of it than find a switch to turn on the co-pilot. In all of my crashes (too many) ... by the time I knew I was in trouble, there wasn't time to "think" about throwing a switch. I can't see how a co-pilot would help out "dumb thumbs" or poor judgment ... but maybe I'm missing something.
LT
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JoeK
Member
Posts: 55
Reg: 06-18-03
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06-25-03 06:16 PM - Post#22018
In response to larrytoelle
As I understand how the Co-Pilot works you just release the cyclic stick and it will right it self and go to a stable hover, no switch to throw and I agree with you when you have dumb thumbs it is hard to hit the right switch sometimes. You set Co-Pilot at say 50% , then bring it down as you get more comfertable with the ship.
Joe
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Tree_Top_Chop
Senior Member
Posts: 438
Loc: California
Reg: 08-14-02
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06-25-03 06:40 PM - Post#22022
In response to JoeK
Flybar weight, too. Don't know if you have any. But it'd probably be a good idea to put weights on and slide them all the way out to the paddles. You can always move them in if the heli isn't snappy enough for you. No idea on the co-pilot, just what I've read. Like you said, levels out the heli if you release the sticks but it'll still drift (it doesn't just stop it dead and hold it in a perfect hover).
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larrytoelle
Full Time Senior Member
Posts: 3735
Loc: Fort Jones, California .....
Reg: 01-20-03
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06-26-03 02:34 PM - Post#22065
In response to Tree_Top_Chop
Re: Co-Pilot - Oh ... Ok ... That makes better sense. That would however, go against instincts to just let loose ... but it might work. I had one serious crash where the bird was beyond where it should've been and I managed to get disoriented ... a co-pilot might have saved that one. I've since striped the blades top and bottom differently and haven't had the problem since.
re: Flybar weights ... yes. I've moved them inboard and they do liven things up a bit. Eventually, I'll try them removed altogether. They do make a difference. I've also found that about 30% expo on the cyclics removed some of the twitchiness when they're moved inboard and makes things easier to maintain a smoother hover or transition.
LT
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JoeK
Member
Posts: 55
Reg: 06-18-03
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06-26-03 07:19 PM - Post#22077
In response to larrytoelle
Revo mixing , are there any rules of thumb about reveloution mixing for the tail? 10 % more right during hover and so on? I know I always seem to fight the tail in lift off at this time.
Joe
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TMoore
Senior Member
Posts: 1617
Loc: Cookeville, Tennessee
Reg: 10-16-02
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06-26-03 08:54 PM - Post#22079
In response to JoeK
If you are using a HH gyro, no Revo is necessary.
Terry
| Your friendly neigborhood reality based Curmudgeonly Old Fart. |
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JoeK
Member
Posts: 55
Reg: 06-18-03
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06-30-03 04:48 PM - Post#22227
In response to TMoore
Thanks Terry ,
I am using the HH type gyro.
Joe
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JoeK
Member
Posts: 55
Reg: 06-18-03
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07-08-03 10:29 PM - Post#22682
In response to JoeK
Just wanted to say thanks to all the good words of advice everyone offered. I got lucky and found a group here in San Diego to fly with and low and behold one of the members used to be a Robbie rep. Well after about 1 hr of this and that and fixing some of my errors we got it up and flying. Damn what a difference a decade makes.
When I was in this sport before we only had the mech gyros , the new HH's are just incredible. On my first try I picked it up and held it in a nice stable hover, had about a 15 MPH cross wind and the nose never even moved. The biggest difference I noticed was that I did not need to add any tail to the lift off as you used to do. Just got it close to hover and when she came free from the ground no tail input was reqired at all. WOW !! It felt so good to be back in the air again and to find a really nice group of guys to fly with. ( thanks Andrew )
Joe
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