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Old Dec 21, 2012, 02:27 PM
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Originally Posted by Zangetsu57 View Post
Hey folks,

I maidened my Bixler a few weeks ago but noticed that it was quite difficult to control compared to my Axn. It just wouldn't glide that well due to instability along the roll axis. Initially, I used a 2200mAh battery in the nose front with washers removed, but the unstable flight characteristics sound symptomatic of a tail-heavy configuration. When I put the washers back above the battery, however, it seemed to fly a bit better. Perhaps I need the washers to offset the weight of the smallpartscnc motor mount I'm using? Eventually I'll have a GoPro on the front so it won't be an issue, but I'd like to get used to flying the Bixler before loading it up with FPV equipment.

On another topic, I'm using a 7" prop, which means I need to use the middle position for the cnc motor mount. While the thrust angle remains the same, the thrust line moves up, which from what I understand, should pass through the plane's CG. I adjusted the thrust line to pass through the wing spar by using a couple small washers on the motor mount. See the below picture. Does this look correct before I fly again? Or should I remove the washers?

Thanks for any guidance!
For CG, I would be guided completely by at what point on the wing the plane balances at. Did you balance the plane according to the recommended CG location at the start of this thread? Can't remember it offhand, but it's just slightly in front of the spar.

Also with thrust line, probably best just to fly and see! Trim the plane for powered off flight, apply throttle and see what the nose does. Print off and take with you one of the thrust line calibration checklists that are available on the web and work through the steps by adding washers until you've got it dialled in. Edit: when I say adding washers, I mean to the motor mount to correct thrust lines.
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Old Dec 21, 2012, 02:28 PM
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I maidened mine knowing it would be uber tail heavy, as I put the servo's in the tail, still flew great and stable, needed alot of down trim for level flight, but excited for the weather to let me enjoy this plane a little more, currently snowing like mad!
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Old Dec 21, 2012, 02:41 PM
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New Zealand, Canterbury, Rolleston
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Originally Posted by Sandancer View Post
You have to remember, the fuse was already glued together. I had to use an extended phillips just to reach those (2) 30mm motor screws from inside the cockpit area, that wasn't the hard part.
I had a screw fall out and had to replace it. What I had done from new and because mine came in two pieces (not glued) was to glue it all except around the motor area. I've cut around that area so I now have a removable cowling on one side of the motor. The motor mount is glued (as it came) to the other side. Yes, I note not an original option for you.

Quote:
When I got the chance to run up the 2620-1900Kv brushless motor I found the rotor was slightly hitting several of the magnets and would not rotate easily.
Arh, that explains it.


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No disrespect here, but I disagree with your analogy of fiberglass vs. Carbon Fiber spars. I assume HK's Bixler probably does come with fiberglass spars as most Chinese manufactures do,
No the Bixler came with a thin walled carbon spar. The problem was us making the wings removable and putting point stress at the wing joint, something the tube wasn't built to deal with. The thick walled tubes I've used sort that out. Glass because I had some from kites. So our fault not HobbyKing's.


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As far as hinging I'll be using the HK Super hinges on all the control surfaces as I've done on all my [U][URL="http://www.rcgroups.com/forums/showthread.php?t=1323708"]warbirds.
Proper hinges make such a difference. Sounds like you have found the same as me.
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Old Dec 21, 2012, 06:24 PM
"Auntie Samantha"
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Originally Posted by Heliosphere View Post
Have you seen/considered cutting an access door in one side of the fuselage below where the wings fit? Makes all that space in the back of the plane easily accessible, so you can put all of your electronics back there and just have a battery up front.
Yes, I've thought about it. That's why I'm considering mounting the gyro under that cable support and cutting a access hatch below it. The RX goes behind the canopy on one side and the BEC on the other. The ESC isn't going to be in the forward fuse at all, so I should have room for future FPV hardware.

Gary
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Old Dec 21, 2012, 10:23 PM
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The new V2 OrangeRX 3-Axis gyro came in this afternoon. It's much smaller then its predecessor which translates to a much easier install.

Gary
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Old Dec 21, 2012, 10:53 PM
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Originally Posted by Heliosphere View Post
For CG, I would be guided completely by at what point on the wing the plane balances at. Did you balance the plane according to the recommended CG location at the start of this thread? Can't remember it offhand, but it's just slightly in front of the spar.

Also with thrust line, probably best just to fly and see! Trim the plane for powered off flight, apply throttle and see what the nose does. Print off and take with you one of the thrust line calibration checklists that are available on the web and work through the steps by adding washers until you've got it dialled in.
I did try balancing the plane, although I admit to being a novice at plane building compared to many folks here. This is my 2nd build. Without the washers, the CG was a bit behind the spar center - maybe 5mm or so. With the washers, the CG was about 1cm in front f the spar. I'll take your advice though and just fly it, adjusting through trial and error.
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Old Dec 22, 2012, 01:33 AM
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Lynden, WA
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Originally Posted by Sandancer View Post
Yes, I've thought about it. That's why I'm considering mounting the gyro under that cable support and cutting a access hatch below it. The RX goes behind the canopy on one side and the BEC on the other. The ESC isn't going to be in the forward fuse at all, so I should have room for future FPV hardware.

Gary
that looks neat and all, but you wont be able to connect the batt to that thing. Plus it looks like the wrong plug.
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Old Dec 22, 2012, 06:54 AM
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Australia, TAS, Devonport
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Quote:
Originally Posted by Zangetsu57 View Post
I did try balancing the plane, although I admit to being a novice at plane building compared to many folks here. This is my 2nd build. Without the washers, the CG was a bit behind the spar center - maybe 5mm or so. With the washers, the CG was about 1cm in front f the spar. I'll take your advice though and just fly it, adjusting through trial and error.
Steady on there! I would strongly suggest not adjusting CG through trial and error flights. Keep on adjusting it by moving things and adding weights where needed, before flying it, until it balances at the recommended CG point. I've got two Bixlers (plus one "retired") and they all fly/flew really nicely when balanced.

Keep the trial and error for the thrust line adjustments
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Old Dec 22, 2012, 09:23 AM
"Auntie Samantha"
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Originally Posted by JohnVH View Post
that looks neat and all, but you wont be able to connect the batt to that thing. Plus it looks like the wrong plug.
That wasn't the ESC I originally planned for, it was a mock-up for the pic, I'll be extending the battery lead. I use the XT60s for all my 3S & 4S systems, and the XT90s for 5S & 6S.

Gary
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Old Dec 22, 2012, 05:24 PM
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Australia, SA, Aldinga
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Maiden

Maiden this morning.

Bixler 1.0 with AXN Motor fitted on account of the OEM motor being DOA.

All I have to do now is learn to fly smoothly. I'll get there.

:-)

Bixler (4 min 29 sec)


Mike
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Old Dec 23, 2012, 09:17 AM
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Canton, Michigan USA
Joined Jul 2007
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Originally Posted by CPMBOY View Post
the other day, garfield came to the house and gave my Bixler a one two punch on the wings and canopy.......any idea on how to repair this?......a foamy filler maybe?....
Holy crapola, that's one weird cat you had visit.

Yes, AJ's method would work. There are other methods too such a Evercoat Polyflex filler used on flexible bumpers. It can bend up to 77 degrees. I used it to skim coat foam for painting. It's pricey at $30 per 30 ounces.

Here is a link to a data sheet.
http://www.evercoat.com/imgs/salesflyers/POLYFLEX.pdf
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Old Dec 23, 2012, 09:34 AM
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United States, FL, North Fort Myers
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Originally Posted by Prof100 View Post
Holy crapola, that's one weird cat you had visit.

Yes, AJ's method would work. There are other methods too such a Evercoat Polyflex filler used on flexible bumpers. It can bend up to 77 degrees. I used it to skim coat foam for painting. It's pricey at $30 per 30 ounces.

Here is a link to a data sheet.
http://www.evercoat.com/imgs/salesflyers/POLYFLEX.pdf
Aircraft attack cats! Sounds like one of those strange WWII experiments where the attack cats were to be dropped in Germany to destroy their Air Force. Then there are carrier pigeons on acid flying aerobatics for the entertainment of the troops.

I printed out the poly-flex data I'm very excited about this possibility. I'm always trying to make planes look smooth so I can get a nice finish on them. Does this work better than using light weight spackle?

DJ
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Old Dec 23, 2012, 10:51 AM
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Canton, Michigan USA
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Originally Posted by Sculptor View Post
Aircraft attack cats! Sounds like one of those strange WWII experiments where the attack cats were to be dropped in Germany to destroy their Air Force. Then there are carrier pigeons on acid flying aerobatics for the entertainment of the troops.

I printed out the poly-flex data I'm very excited about this possibility. I'm always trying to make planes look smooth so I can get a nice finish on them. Does this work better than using light weight spackle?

DJ
DJ,

Wild house cats have done a job on foam plane in my house too.

The Evercoat polyflex is pretty amazing. Lightweight spackle is brittle. I am using it for the first time on Habu 2 airframe. I tried liquid sheeting and that was the biggest waste of time and money. It requires encasing the foam in liquid sheeting. One edge left open will lift from the foam and can be peeled off like a banana. Constrast that with the evercoat and it is like a thick primer or filler but flexible. You spread it like bondo, it kicks in 6 minutes and sands in 20 minutes. Its flexibility is what makes it perfect for foam planes. You can buy it at a local collision shop paint suppy house. I paid $30 for it. It includes one small tube of catalyst. Get an extra tube because you will use too much inevitably.

Bill
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Old Dec 23, 2012, 11:39 PM
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Joined Jun 2012
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Has anyone built a Bixler 1.1 Kit ?
Are there any servos that fit with out cutting the foam servo 'mountings'

Shimmy
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Old Dec 24, 2012, 10:33 AM
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United States, TN, Taft
Joined Oct 2012
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Quote:
Originally Posted by Shimmy View Post
Has anyone built a Bixler 1.1 Kit ?
Are there any servos that fit with out cutting the foam servo 'mountings'
Shimmy
I am in the process of building a B1.1 kit. I used HS-65MG and HS-65HB servos. I had to cut just a notch out on the wings to give the servo arms a little room. The width of the servo is just right, but the height is about 1/8 inches shorter than the space provided. I put my servos in with some super-duty double sided tape on the bottom and 3M extreme packing tape covering the servo. seems to work so far. you will need to cut the servo arms for the rudder and elevator servos so they will not interfere with each other. I am not sure I like that configuration. Seems like the servo arm throw will be shorter.
good luck
farmetom
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