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Old Dec 15, 2006, 12:58 PM
John Cock...tos...ton
Stephan8's Avatar
LaGrange, GA
Joined Oct 2006
117 Posts
amity animal- I only have a HD here. So I looked for blue fff but could only find pink. I checked each pile to find the neatest, cleanest and most thin I could find. THis pile is a 1/4 or less in thickness. I didsee stacks of the fff that were thicker. Just go through until you find a thin one

Stephan
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Old Dec 15, 2006, 01:07 PM
John Cock...tos...ton
Stephan8's Avatar
LaGrange, GA
Joined Oct 2006
117 Posts
Hey Magic,
don't know why I like it so much...maybe because of the simplicity. This is only the third different plane I have constructed with fff. I have found that a mailing tube and hot stove top will put awesome airfoil in the wing. And it never comes out. I just wave it over the hot stove top and roll it in to shape on a tube. The wing will hold airfoil without the supports.

I love working with the fff. I just hate the color.

I will maiden this one but really want to add ailerons to the top wing also. I think I will see how it flies first and then see if I want to add them.

As for a smaller version...SOund great. Or you could just fly an AIr Hog Aero ACe. Just Kidding!!!

Larger sounds great too. I just like how the body is open and easy to work with. I also like your wing design with the rubber band. This might save it from a few crashes.


Last question...Where was your cg? 1inch behind LE of bottom wing? Am I close?

Thanks, Stephan
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Old Dec 15, 2006, 01:21 PM
Bernoulli+Newton=Lift
magic612's Avatar
Somewhere south of Chicago, IL
Joined Jan 2006
1,952 Posts
I balance my CG from the top wing (easier to get it to balance on my fingers that way). CG is about 2.5" - 3" back from the LE of the upper wing. Since I haven't been able to maiden this latest version, that's my best estimate at this point based on previous version of this plane. I can give a more accurate CG location when I have had a chance to get this one in the air.

Ailerons up top would certainly make for superb aerobatics, though I've had no trouble doing aerobatics with just the lower ones on previous attempts with this design, too. Let me know which you like better!

Also - my daughter and I each have Aero Aces - this plane is an direct result of wanting a slightly more aerobatic backyard flyer than an Aero Ace.
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Old Dec 15, 2006, 02:44 PM
John Cock...tos...ton
Stephan8's Avatar
LaGrange, GA
Joined Oct 2006
117 Posts
Awesome, I have about 3 (still alive) aa and even my 4 year old love to fly them. So I know what you mean. I can't wait to have a sporty front yard go bipe.
STephan
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Old Dec 18, 2006, 12:08 AM
Bernoulli+Newton=Lift
magic612's Avatar
Somewhere south of Chicago, IL
Joined Jan 2006
1,952 Posts
Maiden Flight Report

Well, the winds around the Windy City finally died down enough today (3-6 mph) to maiden this version of this plane. It flew... okay. Nothing amazing, but it did fly. I was pleasantly surprised at how little throttle was needed to get it airborne , but a bit frustrated that it didn't want to "really get up and go". Couldn't get it to pull a loop, even from a dive.

Now, several factors could have contributed to this: One, I don't know what the wind was doing higher up (there was still some breeze, if only slight). Plus, I realize I'm using a GWS IPS "A" motor/gearbox on this. But I think what made me wonder why it wouldn't do much is that my previous version of this plane, using a 7.2V 220mAh NiMh battery that weighs almost 1.5 oz (making for an AUW of almost 6.5 oz) would pull snap loops and do rolls, even marginally fly inverted. Yet this plane, weighing 20% less wouldn't loop.

So, not quite getting the "ooomph" I was looking for, I decided to dig into the numbers a bit. AUW with a 200mAh 15 gram LiPo pack is 5.187 oz. GWS says that motor will produce 4.55 oz of thrust with a 7.2V battery, and draw only 1.67 amps. Granted, at this setup, it's only producing about 41 Watts per pound, which is nothing stellar by a LONG shot. And a strange thing was when I put a Wattmeter on it, it actually drew more like 2.2 amps to start (using a 350mAh battery) finally tapering off to 1.9 amps after 45 seconds or so. So I'm thinking that the battery may not have been able to push the amps necessary (or I might have messed up my pack? It's a 10C pack...). Anyway, I figure I should use the 350 mAh pack I've got, which only adds a quarter of an ounce, so I'll still be under 5.5 oz.

I do have a "C" IPS motor/gearbox (which I confess, MAY have been what I used on the prior version, but I can't remember), and GWS claims it will produce 5.19 oz of thrust with 7.2V. Wattage and amperage differences are negligible between the two, but since thrust is more than 5/8 of an ounce greater (even though I'll need to "prop up" to a 12"), maybe that's what I need to do. Or, I should build myself a thrust stand which I've been meaning to do for the past few weeks, and see if a larger prop on the "A" motor will produce more than 4.55 oz of thrust, while also determining what amperage that will draw.

Any words of wisdom from you guys who have done this longer than me? Any other things I can try? I do have a brushless motor, but before I put that on and make it race, I want to see what I can squeeze out of brushed system for those that don't have the bucks to afford the tiny brushless stuff yet. Any ideas?
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Old Dec 19, 2006, 08:50 AM
Bernoulli+Newton=Lift
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Somewhere south of Chicago, IL
Joined Jan 2006
1,952 Posts
100 views since I posted this Sunday night, and not a single idea posted on how to improve this design? Come on guys, don't hold back... it's the holiday season, a time of giving - you know, like giving your sage advice / wisdom to a newbie plane builder / flyer...

Seriously, any thoughts on how I can improve the thrust without going brushless (yet)?
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Old Dec 19, 2006, 09:59 AM
Registered User
Joined Dec 2006
53 Posts
I have no advice which I am qualified to give but I just want to say thank you for posting this and I intend to build one here soon. I am brand new, never flown anything but that AA but am really looking forward to building some new planes with the gear I just bought. I still have to learn to fly have a finish STC waiting for gear, after that I plan to build this and the Nasty. Thanks again, and I'll be looking for the Vid!
Mike
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Old Dec 19, 2006, 06:39 PM
RPV builder & operator
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Canada, QC, Gatineau
Joined Jan 2001
2,303 Posts
Move the CG back a bit, could be simply nose heavy. Also, do you have downthrust as shown on your plans?
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Old Dec 19, 2006, 06:40 PM
John Cock...tos...ton
Stephan8's Avatar
LaGrange, GA
Joined Oct 2006
117 Posts
I am no expert but am just wondering why not go ahead and go brushless?

I am 90% done with mine but I think I have fried my ESC. ANd I am leaving for Xmas for week so it will probably be next year before it's flying.

Stephan
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Old Dec 19, 2006, 07:46 PM
Bernoulli+Newton=Lift
magic612's Avatar
Somewhere south of Chicago, IL
Joined Jan 2006
1,952 Posts
Quote:
Originally Posted by micob
I just want to say thank you for posting this and I intend to build one here soon.
Thanks Mike! Let me know how it turns out.

Quote:
Originally Posted by Pierre Audette
Move the CG back a bit, could be simply nose heavy.
Aha. I didn't think of that.... I'll give that a try. Thanks for the idea!!

*smacks forehead*

Quote:
Originally Posted by Pierre Audette
Also, do you have downthrust as shown on your plans?
Yup, sure do.

I'm going to try the "C" gear drive, too - it does put out more thrust, so that may explain at least part of why it wasn't performing like I expected. But the CG might be an issue as well.

Quote:
Originally Posted by Stephan8
I am no expert but am just wondering why not go ahead and go brushless?
It was more for the benefit of those that didn't have brushless equipment to start with. I started out with brushed equipment, since I wasn't aware of some of the less expensive brushless options out there when I first got started. So I wanted to offer something that could be done less expensively to start out, as a LiPo for a brushless motor is more $$$ too, since a higher "C" rating is generally going to be required.

It's a weight issue too, since finding 20C Lipo's in the 200mAh - 350mAh range is a bit challenging, too. The brushless I have will pull 6 amps, which means a 15C 450mAh Lipo is necessary. Granted, the brushless will easily overcome the weight differential, but it was just an effort on my part to make the plane as accessible as possible to as many out there as I could by making it brushed-capable.
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Old Dec 19, 2006, 11:25 PM
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Maryland, USA
Joined Mar 2006
896 Posts
Thanks for the plans for this little bipe magic612! Since I'm kinda new to this foamie stuff all I have is FFF to work with but figured I'd give the full-fuse treatment to her. To me it was just begging for a S.E.5a styled fuselage...not to mention it would be really easy to do.

After taking inventory of my flight gear (not hard to do as I have VERY LITTLE) the decision was made to scale it up just a tad. My intended motor/battery/servos are to be transplanted out of an Amos Mose 3D'r and could be considered overkill for this one. Basically light enough electrics...but gobs of power. Therefore the wingspan is now 23", fuse 19", and the tail surfaces were enlarged by about 1/4" all around. Not much, but just enough to hopefully keep it backyard worthy.

I have yet to install the electrics but did get a chance to weigh it. Looks like I will be coming out at an AUW (with 3S1P) of 6.6oz. The bare frame with paint is just a tad bit over 2.5oz. I'll provide full stats after completion and maiden (hopefully successful) tomorrow or Thursday.

Cheers,
golem
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Old Dec 20, 2006, 08:41 AM
Bernoulli+Newton=Lift
magic612's Avatar
Somewhere south of Chicago, IL
Joined Jan 2006
1,952 Posts
golem - your welcome for the plans, and thanks for sharing the pics! That looks GREAT! I'm loving the full fuselage you've added to it; really fills it out to be sure.

Couple questions: Did you glue the fuse directly to the wing? Are you planning on adding landing gear?

Let us know how the maiden goes!
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Old Dec 20, 2006, 06:15 PM
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Maryland, USA
Joined Mar 2006
896 Posts
Yup...to both questions.

It was bite-the-bullet time. I contemplated making a smooth saddle as a bottom mount and rubber band it but opted for the notched permanent route. These light frames seem to take minor ground-loops pretty well without much damage, we'll see! Also, as the pictures below show, it now has landing gear. I just slotted them in so the friction fit allows for quick removal if desired.

I'm a bit bummed as its AUW seems a bit heavy at 7.25oz. Was hoping to be sub 6.5oz but after a bit of number crunching I don't feel all bad. Being FFF and with the 23" wingspan it comes out to 307sq. in. giving it 3.4oz/sq. ft. wing loading. Sub 3 would have been nice but this should still be a bit floaty. Will also have lots of unused power on tap...2.7-to-1 P/W ratio!

Didn't get a chance to put her in the air today which is a shame as it was dead still outside but this darn winter darkness sneaks up on you so quickly. Tomorrow is supposed to be a balmy 55 degrees with 5-10mph winds so I should be able to find a flying moment in there somewhere.

Cheers,
golem
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Old Dec 20, 2006, 07:45 PM
Bernoulli+Newton=Lift
magic612's Avatar
Somewhere south of Chicago, IL
Joined Jan 2006
1,952 Posts
golem - that looks excellent, man. VERY nice. Looks like you've got the same little brushless motor I'll be trying on mine later on. I'll be very interested to know how it perform on this plane. And I think your weight will probably be okay - your weight to wing area ratio looks okay, especially considering the powerplant you'll have on it.

I noticed you put the aileron servo underneath the bottom wing. Not that doing that is bad, as the pushrod lines are definitely cleaner that way, but I found on a previous version of this plane that when I put that servo there, it was prone to getting whacked on rougher-than-normal landings. An extra bit of foam - or better yet, plywood - as a shield for that servo wouldn't hurt. Just a thought.

Looking forward to your flight report!
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Old Dec 21, 2006, 06:25 PM
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Joined Dec 2006
53 Posts
Hey guys,

I havenít had a chance to start mine yet since I am out of the country right now but I am still following the thread. United hobbies has HexTronik 460mAh 11.1v 15C Lipo Pack (37 Grams) for $14, see
https://www.unitedhobbies.com/UNITED...idProduct=2050

You can find some smaller packs at a cheaper price from http://www.bidproduct.com, They have unreal prices on everything but there shipping times vary from 12 days to 3 weeks. Much of what the have is untested from what I know, but many people have had good experiences with them.

Hereís a link to a thread talking about bidproductsí products.
http://www.rcgroups.com/forums/showthread.php?t=591584

If anyone knows any other threads talking about bidproducts let me know. I have ordered about $250 worth of stuff from them but since I wonít be home till mid January I can wait for the slow shipping. Iíll let you know when I get back how the products fair.

Golem----your bi looks great, cant wait to hear how it flies! You going to vid the maiden? What components are you running, motor type, lipo size, Rx weight ect?

Mike
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