Need advice about RC options for ultralight paper airframe project

Discussion in 'RC Aircraft & Watercraft' started by liftline, Sep 29, 2010.

  1. liftline

    liftline Member

    Still waiting for post (there is no smilie for drumming fingers and I am not hitting my head against the wall yet). Remind me what FMS is (I have this short term memory problem).

    Thinking of upscaling my F4F Wildcat for RC while I wait. Give some competition to ParkZone

    Flyzone has scooped my ALB DIII WWI! A bit bigger than mine, but weighs in at a mere 28-31 g. 3 channel.
  2. schorhr

    schorhr Member

  3. liftline

    liftline Member

    Love that new smilie!

    Will try that freeware fms with my t6b. I'm a marginally worse remote pilot with the sims than the real models - I get disoriented easily when I'm not in the cockpit frame of reference, and the problem is even worse when I'm standing in a virtual field with my heading rotating with a small field of view. Lot less damage when I make virtual mistakes!

    Weather is really closing in fast this year. First snow already and the winds are picking up too.
  4. schorhr

    schorhr Member

    Yeah, Simulators do not really come anywhere close to reality, but at least for helicopters and such it's a good and cheap training (though I keep recomending the cb100 nowdays :) )
    At least it's fun to test some of the free model planes, and you can also choose follow-camera.

    Yep, bad weather here too. But no snow... yet.
  5. liftline

    liftline Member

    First Hobby King Shipment has cleared customs and is in Chicago USA!!! Should get it Wed. Second order is right behind it, possibly in a blimp :rolleyes: Once I figured out the Hobby King website (directions can be a bit obscure) I find it works quite well. That said, Hobby King's tracking window doesn't seem to update once the package is shipped from their warehouse. Not a big problem, since the US post office website:patriot1: picks up where HK signs off.
  6. liftline

    liftline Member

    I have saved a number of ac power adapters from numerous cell phones, modems etc. 12 volt DC output, 200 mA is typical Any reason not to just use these as my 12 volt source? Save a few bucks!

    Just found some jpegs of my old Albatros DIII design. Would scale up nicely for RC don't you think?

    Attached Files:

  7. schorhr

    schorhr Member

    Sure would :)

    Yes, Hobbyking can get a bit confusing. Big store, many things to look at, and lots of check out options.

    Yeah, tracking only works to the harbor or something ;-)

    What ever happened with the Hobbypartz express shipping bill btw?

    200mA is a bit low.
    Even though a 12v200mA has more Watts (2.4) then what you need to charge the Lipo with, most chargers need quite some power themselves (electronic, converting the voltage, etc. etc.).
    You can try, but 200mA is on the verrry low side. Getting a $5 Wii ac-dc and cutting the plug off is a cheap solution.
  8. liftline

    liftline Member

    Have been looking for a local purveyor of cheap Wii chargers; haven't found one yet. I have a ton of old chargers just sitting about in shoe box, some with much higher amp ratings. One things for sure - the power supply problem will get solved about one hour after the lipo charger arrives!!!:drag1: Off to the mall and spare no expense!!!!

  9. schorhr

    schorhr Member

    Hehe, good.

    Well, you'll find something with 12-16v that'll work I am sure. And sometimes we need to support the local economy :cool:
  10. liftline

    liftline Member

    First hobby king batch is here!

    The outrunner motor, the BS-6D ESC, 2 Turnigy lipo batt. and 3 micro servers. The ESC came with documentation, the rest - none. Hobbyking's specs will have to do for these.

    The outrunner motor just has 3 bare connector leads (pre-tinned) so I'll want to find a quick connector to mate with the ESC. Holding the motor in my hands is a real revelation! Case rotates around the armature! I did not know this! :-o Perfect for authentic WWI rotary engines! :driver1: Just attach a ring around the case to get that nasty gyroscopic coupling and slow throttle response! Put in a bucket full of rudder with that stick Biggles! Can't wait to try it on my Camel model (once I get the abundant spare time to upscale that bird by 40% - plus the pilot skill to cope with the additional challenge).

    The micro servos are little marvels. I hope they work out, 'cause I really like the push-pull action of this particular design. Makes slaving the ailerons easy in a small space.

    The charger and some props should arrive sometime tomorrow or the next day. Can't test anything until then. They caught up with the first order even though ordered a week later. I'm off to the hobby shop for a connector.
  11. schorhr

    schorhr Member

    Fresh out of the factory :)
    Well, most stuff does not need a manual anyway (Motor running the wrong way? change two random wires...)

    Sorry about the motor info- Outrunners have a spinning can, I totaly forgot this. They have lower rpm but more force, while inrunners have high rpm...

    Connectors: Solder :D Except for the battery. Something simple will do though wih the low amps running to the tiny motor.

    Post some pics as soon as you get building! :)

    Perhaps someone at the us customs scanning for bombs had a week off, so it all piled up. Yey for customs!
  12. liftline

    liftline Member

    outrunners no problem

    Outrunners really simplify motor mount design. The high torque is good too - avoids the need for gearing.

    I'm kind of freakish about snap electrical connections between components-snap it in-snap it out. This could be an American cultural trait. On the other hand, old VW beetle engines were pretty modular too.

    Threw everything on the scale and it looks like takeoff weight for a 3 axis + throttle Se5a will be very close to 40 g. Can lower that a bit by eliminating the transmitter case - but I'll wait until spares are on back order.
  13. schorhr

    schorhr Member

    Well, some hate outrunners if they want to hide the motor in the canopee :)
    The little 2g motor has a rather high kV rating, probably due to it's size.
    7000kV it is i think? Usualy the cheap big outrunners have 800-2500 or such, even the 5g BL has 2000kV. But for such a small plane I bet it is not as critical as with quadrocopters.

    Sure, plugs are convinient, but also cause extra weight :) Some micro builders just use thin insulation-paint coated wire to save every microgram...

    For such a light plane you could strip everything; Shorten cables/use other cables, shrinkwrap the reciever or just padd it with something else... lots of ways to save a few grams.
  14. liftline

    liftline Member

    I hear you... a disciple of Ed Heinemann, the weight shaving designer of the A4 Skyhawk? His philosophy can be summarized as simplicate and add lightness. Works for bicycles too (another Eddy comes to mind - Eddy Mercks.)

    The single best weight reduction for my model would be for Hobby King to get that nifty .7 g boosted ESC back in stock ;-)...a sweet 4 g savings over my present configuration! Shaving weight is likely to be an evolving process for me. The nominal thrust for the 2 g motor is 30g. That's a 67% thrust to weight ratio, which in theory ought to make the Se5 pretty hot. Even if the thrust is only 20g, that's still 44% -fairly close to the t/w the blogs recommend for advanced flying. As I get to be a better pilot I'm sure I'll demand more of my designs. Right now, if I can just get the thing maneuvering in the air I'll be a happy camper! Something around 33% should be enough for the later. Or so I'm told.

    I'm lucky the original Se5 was configured for a big powerful & fairly heavy motor. My CG calculations show it wants a lot of weight up near the nose - leaving lots of space for servos and push rods towards the cockpit area.
  15. schorhr

    schorhr Member

    Oh Im sure it'll fly... my first plane was hopeless underpowered untill changing the prop to a bigger three-blade which burned out the motor in the long run :) But it flew... 1,2KG, 300g thrust.... Poor thing. Lead duck.
  16. liftline

    liftline Member

    The second package arrived today with props and a Lipo charger.
    The charger instructions are tough to decipher but the schematics and assorted accessory plugs should be enough to sort things a flower pot, in the fire place! The charger case is the heat sink, so it can get hot according to the blogs. Since I won't be running many amps I doubt this will be a problem.

    Looks like one of my vast collection of 12 V power supplies should work. Radio Shack is close if not.

    Do they make shaft extenders for the out runners? Might be helpful in some applications.

    Once I get all the batteries charged up I'll start trying to make all this RC stuff work. Looks pretty daunting with everything laid out on the table!
  17. schorhr

    schorhr Member

    I do not know about shaft extendors, but it might cause wobble. Also- at least with the bigger motors, you can replace the shaft with a longer one.

    If the manual causes trouble look in the product discussion, reviews or forum of Hobbyking, some chargers also have a discussion going on rcgroups.
    Usualy they get hot when people charge their 22v 5000mAh packs ;-) I doubt it will get more then warm on such a small pack.

    Buy some marshmellows, and get a stick- just in case.

  18. liftline

    liftline Member

    Nothing like having the components on hand to see I have made a bunch of rookie mistakes. wall1wall1wall1

    wall1First, the ESC, Blue Arrow BA-BS 6D. Had I read the reviews I would have seen there are "quality control" issues with this model. Polarity of the battery leads is reversed. Burns out if hooked up as indicated. It may be fixed in later production runs, maybe not. How is one to know? Hobby King is getting a lot of consumer flames on this one! Rightly so IMHO. Not the right design for my application anyway, too heavy for what it does. Didn't even mean to order it in the first place!

    wall1 Second, the flysky receiver requires 6V (nominally). I've only got 1S. THe Turnigy 5A 1S Brushless ESC might solve this problem without adding more battery weight. The reviews indicate the boost is just to the receiver supply. It's in stock. But is 5V enough for the RX? Reviewing our old posts, I'm not sure. I'm going to try getting in touch with Hobby Partz support on this one.

    wall1The Hobby King 1.7 g micro servos are strictly 1S (4.2V max)capable according to the discussion groups. So, it Turnigy boosted ESC just juices the receiver, I think that solves the problem. If the flysky receiver can really perform on just 5V!

    I'm kind of stuck here - between micro and mini if you will. Like the transmitter/receiver package, but it doesn't really like 1S power. I require very small servos due to space and weight constraints. Don't want the bird to get much heavier. The horizontal action of the HK 1.7 servos is very helpful in a tight space.

    Then their is the problem of electrical connections. The receiver wants mini connectors. The rest of the components want micro. I'm willing to connect wire to wire if need be. If I crack the RX case can I just take out the pin connectors and solder directly to something? Are there going to be heat sink issues? I have not soldered anything small in a very long time! I have a feeling there is an adapter to mate the pins on the receiver with the micro plug on the servos, but can't seem to find it.

    The Hobby King lipo charger defaults to 2A charge for the 1S. Wow, that seems high, but lipos play by there own rules. I suppose I should not go lower than 2A. I checked out the charger using a handy compatible 12V DC supply, but unfortunately it is only rated to .75 amp. So, I guess it's off to radio shack again. My local hobby store has a $20 option which charges a singe Turnigy 1S using a bunch of rechargeable Nicads. Simple and compact, but you only get about 4 charges from a bank of 8 Nicads. Seems pretty inelegant to me.

    Well, the good news is I can move on to making journeyman mistakes soon, and expert mistakes in the more distant future.
  19. liftline

    liftline Member

    No idea how that got posted twice!
  20. schorhr

    schorhr Member

    ESC: Yikes. Odd that the problem still occurs. If it's their fault, open a claim ticket.

    Receiver: 6V? Usualy a bec delivers 5V-6v. so 5v should be fine.
    Also, if the reciever has a simple voltage direction protection, you could bypass the diode and it would be more tollerant to lower voltage as the diode causes a slight voltage drop.

    Servos: Hook them up to the battery and maybee ad a resistor to the signal line?

    Micro RC is just more difficult due to weight, size and small components wall1

    Go wire by wire.
    As for the reciever, my t6a reciever has tiny scres.
    I doubt that soldering directly to it would cause heat issues, never noticed getting mine hot (even though I have the pins on it).

    No clue about adapters, gotta read through the discussions or so.

    No! Not 2A unless you want an early new years celebration! :)
    100mAh batteries -> 0.1A charging. That lets them live long and saves you from increasing your house insurance.

    750mA ac/dc might work with the batteries (if you do not charge them with 2A...!)

    Mistakes is what makes this hobby fun. No wait, it does'nt. It's what makes the house burn down.

Share This Page