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Thread: Surgery on a fixed-pitch flybar...

  1. #31
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    Quote Originally Posted by norty303 View Post
    OMG Adam, what have you done!!!!????!!
    The stuff they sell on that Banggood site!!!!!
    I posted about the temp controllers and some of the other electronics in another post. But yeah, they have a little bit of everything. The temp controllers are pretty cool looking. They are about 2 inches square and about 4 inches long. I haven't hooked one up yet, but given how cheap they were, I bought 4 of them.

    The missus is looking at clothes and strangely, a rubber unicorn head mask thing. :-/
    Zoinks! I had nothing to do with the rubber unicorn head mask, I promise!

    I'd just never really thought about how the swash plate actually moves the pitch of the blade.
    To be fair, both Randy and I are simplifying the interaction of the servos, the swash plate, the rotor head, and the flybar (if present). There's a lot of physics going on in that rotor head, including things like gyroscopic offset, lead-lag effect, flapping, and plenty of other details that we haven't mentioned at all. But none of that is really relevant to the discussion about the differences between fixed-pitch vs collective pitch. (And you don't need to understand these extra things to be able to fly a helicopter either.)

    I thought long and hard about how I might just go straight for the CP bird but ultimately my budget wouldn't stretch to a large enough one for my liking.
    To be honest, I would never suggest that anyone go straight to CP, unless they at least had a chance to fly someone else's Fixed-Pitch bird first, to be sure it's something they both 1) want to do, and 2) have an aptitude for.

    Besides, I know you'll have a blast with the V912, especially with the camera add-on. Just remember: it flies like a truck and turns like a brick. And if you hit something with it, you will probably break the "something" that you hit. (Surprisingly though, the bird will probably survive OK. It's remarkably durable.)

    Adam

  2. #32
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    swamidog is online now Jr. Woodchuckington Janitor III, Esq.
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    Quote Originally Posted by norty303 View Post
    The missus is looking at clothes and strangely, a rubber unicorn head mask thing. :-/
    please turn off the webcam...

    suppose you're thinkin' about a plate o' shrimp. Suddenly someone'll say, like, plate, or shrimp, or plate o' shrimp out of the blue, no explanation. No point in lookin' for one, either. It's all part of a cosmic unconciousness.

  3. #33
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    I just ordered a load of tecs and controllers and PSUs and DC-DC converters and tools and STUFF!!
    I wasn't going to go down the tec route, but I think I'm going to stick 120W of cooling under the baseplate as I've got big heat sinks and fans to go on there anyway. My 2W green module is small and if anything like the OEM-V-S heads will run hot. And I might be able to push the new Oclaro reds a little harder too
    Frikkin Lasers
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    You are using Bonetti's defense against me, ah?

    I thought it fitting, considering the rocky terrain.

  4. #34
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    Oh yeah, I haven't mentioned really that flying comes easy to me and I have flown coaxial birds briefly before and thought them a little dull after the first 5 mins. And I do like to test/push myself, hence the spares.
    Frikkin Lasers
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    You are using Bonetti's defense against me, ah?

    I thought it fitting, considering the rocky terrain.

  5. #35
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    @Norty (and whoever else might be interested)

    I'll offer this last round, then bow out -
    A lot of point / counterpoint going on in this thread, which probably isn't helping clarify things a lot, and all the cross-referencing multi-quotes doesn't help.
    Hell, now I'm confused, and I flew the real ones for 20+ years, LOL!!

    So, sorry if we managed to confuse you, as well!!
    I'll use this post to consolidate all those scattered thoughts, then move on...

    Anyway, I'll offer this advice as retired "real pilot" that also flew 30-class nitro copters for several years, then after stepping away from the hobby for a while, spent WAY too much frustrating time - and money - trying to find decent indoor electrics that handled even remotely like the bigger aircraft I was used to. Similar to lasers - and one you probably already know from flying your sailplanes - cheaper is not necessarily better when it comes to RC helicopters.

    I'll caveat everything I'm about to discuss by saying this up front -
    The lightweight micro/mini sized indoor helicopters tend to "change the rules" a bit when it comes to helicopter rigging, handling and performance, in a lot of different ways. They can be fun (AND very frustrating!), but their capabilities & shortfalls don't necessarily reflect all that happens with the larger CP (collective pitch)copters.

    Unless you just specifically WANT to concentrate on the inexpensive indoor lightweight copters, maybe think about moving up to one of the larger (300-class or larger) CP copters that is a bit more "standardized", then work with someone that knows about the bigger helicopters and get it setup properly. "Training gear" may look a bit stupid on the bigger copters, but they can sure save a lot of frustration and $$ when trying to learn!! Plus, the skills and handling you learn from flying - and maintaining - that size copter can easily translate into the bigger, extreme models, if you decide to go that route.

    Bigger copters generally fly better, and seem to act more like a "real" helicopter, if that happens to be something important to you.
    (Which is why I have zero interest in flying 3D, but think some hammerhead turns and high-speed low-level passes are awesome!)

    PC-based simulators - invaluable! Combine one of these with a properly-setup larger copter, training gear, and a slow methodical approach to learning (that's my inner Instructor Pilot speaking...), and a CP helicopter can actually be a very good way to learn, especially for someone who already has a lot of RC experience. My guess is your radio already has a lot of the same helicopter programmability that you would find on helicopter radios from Futaba, Spektrum, JR, etc., so from that standpoint it wouldn't be too difficult for experienced RC copter pilots to help with the initial programming.

    Throttle & pitch curves, head speeds, etc., etc. -
    Visit an active RC helicopter flying site, and I think you'll find that most of the guys that are running "wide open" are only doing so if they are going to be flying the extreme 3D maneuvers that some of the modern RC copters are capable of performing. One of the nice things about programmable radios is that the Idle up / Flight Mode switch lets you program in 2,3 or more completely separate sets of control parameters, with each switch position completely changing the way the aircraft handles, and possibly even what some of the other switches do. SO, in one flight, you could feasibly start out with some fairly docile hover settings, flip the switch and be in full-blown extreme 3D crazy mode, then flip back to more docile handling for autos, precision hovering practice, or just to take a bit of a breather.

    You've probably figured out by now that airplane control functions don't necessarily translate directly into helicopter control functions.
    "Elevator" control - in quotes, referring to the function, not necessarily the movable plank at the end of the tail on an airplane - is definitely one of those!
    While we all know that just about every control movement in any powered aircraft requires some change in power as well, I think most would agree that for airplanes, the primary way to climb & dive is using the elevator.

    The "elevator"- fore/aft cyclic of a helicopter - is not just an up/down pitch/altitude control; this is what makes a helicopter move forward and backwards.
    Forward cyclic with power increase (either increase in RPM for fixed pitch copters, or increase in collective for CP) will make the helicopter move forward, either faster or with a climb. Forward cyclic without a power increase will put the copter in a dive, similar to an airplane.

    Now where it really gets interesting - an AFT application of cyclic, combined with a power increase, can make a helicopter either slow down / stop at hover if already in forward flight, climb while continuing forward with reduced airspeed, or fly backwards, with or without a climb. Aft cyclic without a power increase might initially slow down with a slight climb, but as the copter slows down it will start to lose altitude. Continued aft cyclic without any application of power will eventually lead to an accelerated decrease in altitude, going backwards. Fun (NOT!!).

    I'll repeat a comment I made earlier about collective / increased RPM on fixed pitch copters -
    True vertical flight - "elevator" control without the elevator, if you will - can be accomplished using nothing but collective pitch or fixed pitch RPM increase.
    When climbing straight up to hover, be it at a few feet or several hundred, properly-applied cyclic is doing little more than just stabilizing the aircraft's horizontal position. (Which, granted, is till no small feat when learning to hover, be it RC model or learning to fly a real one!)

    So, all this considered, there isn't really a single "elevator" equivalent on a conventionally-rigged helicopter, but the one control that can actually make a helicopter climb & descend without any other control input (other then that required to stabilize the horizontal position & heading) is the collective, or RPM increase for a fixed-pitch helicopter.

    Lesson 2 if I'm invited back -
    What the tail rotor control REALLY does ...
    Last edited by Stuka; 04-10-2014 at 04:21.
    RR

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  6. #36
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    I just ordered a 450 class nitro collective pitch bird. nearly 3 foot blades. should be a blast. Had the 911 out today and the wind creamed it. The 912 drove like the truck it is.

  7. #37
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    Quote Originally Posted by kecked View Post
    I just ordered a 450 class nitro collective pitch bird. nearly 3 foot blades. should be a blast. Had the 911 out today and the wind creamed it. The 912 drove like the truck it is.
    Cool!
    Which 450-class did you wind up getting?

    No more nitro anything for me - although I do miss it at times!
    Currently resurrecting a Blade 400 3D that's been hiding in a box for several years, and keeping a 500X FBL in the box until I get some of the rust scrapped off me...
    RR

    Metrologic HeNe 3.3mw Modulated laser, 2 Radio Shack motors, and a broken mirror.
    1979.
    Sweet.....

  8. #38
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    Holy crap.... wasn't aware that there were so many RC flyers on PL...
    Got a few planes... helies... and multirotors myself..

    I started way back with Nitro power when the electrics were not up
    to snuff. Now I only run Electrics..


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  9. #39
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    Yeah, this group definitely seems to be drawn to high-maintenance expensive hobbies!!
    RR

    Metrologic HeNe 3.3mw Modulated laser, 2 Radio Shack motors, and a broken mirror.
    1979.
    Sweet.....

  10. #40
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    I think it's probably because they share a control/dexterity/skill element and an engineering element. As do motorbikes which also seem popular in the same group.
    Frikkin Lasers
    http://www.frikkinlasers.co.uk

    You are using Bonetti's defense against me, ah?

    I thought it fitting, considering the rocky terrain.

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