Picnic Quads: Experimenting with new micro and mini carbon/birch and Poly frames - RC Groups
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Mar 31, 2014, 05:51 PM
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Picnic Quads: Experimenting with new micro and mini carbon/birch and Poly frames


Carbon Fiber Birch Core:
Recently I started prototyping some micro and mini quadcopter frames and have been experimenting with a carbon fiber sandwich blend from a local supplier that may be even better suited for this application than solid carbon fiber. Apparently even higher stiffness to weight and strength to weight ratios can be achieved by using a construction of 2 thinner layers of carbon fiber separated by a lighter core material instead of using solid carbon fiber.

Before proceeding too far, I wanted to first verify this material performed as well as expected in a controlled test environment. A simple stress test fixture was constructed and identical profiles of 3mm solid carbon fiber and 3/16 carbon fiber / birch core sandwich were tested to failure and compared to one another. As the video below shows, the sandwich blend sample demonstrated significantly higher stiffness and required approximately 30% more force to fracture than a solid carbon fiber sample of the same weight.

Carbon fiber deflection to failure testing (3 min 9 sec)


For any unable to view the video:
3mm solid Carbon fiber sample: Sample weight - 8.32g fractured at 16.16Kg
3/16 Carbon / Birch Sandwich sample: Sample weight - 8.35g fractured at 21.5Kg

With the encouraging results from the material testing, I made a small test run of a few micro and mini frames for myself and offered some of them to any interested members of the community. Based on the excellent feedback received, unexpected popularity and my own positive experience with these frames I have decided to start making them available regularly. Details on the frames and available accessories are included below.


Other material notes of interest:
As shown, this material has a gloss finish on 1 side and a slightly textured matte surface on the other side. I personally find the look of flat black appealing and the option of having either a gloss or matte surface as the top side to a quad as a benefit. This may not appeal to everyone and should be mentioned up front.
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Since the core of this material is birch plywood the edges of the profiles are of a wood color. This can be easily painted or blacked to blend with the frame or colored as desired.

Since the core of this material is a birch plywood wood screws should be usable, however some compression of the material is expected around tensioned fastener holes. This is mostly an aesthetic note as proper tension should still be able to be achieved. CA glue around the edges of these holes and or washers can be used to minimize the compression in these areas.


G10:

Polycarbonate:
Last edited by woodsturning; Oct 09, 2015 at 08:05 PM.
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Mar 31, 2014, 05:52 PM
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Micro frames:


With positive feedback from the initial test offering, a selection of micro frames will be made available on a regular basis.
Additional designs are also being considered/prototyped. Suggested modifications to these frames or alternative designs are also welcome and will be accommodated if possible.

All micro frames are constructed from a 1/8 thick carbon fiber / birch core sandwich blend allowing for tight but direct installation of motor mounts designed to fit onto 3x3mm square carbon tubing.

Below are the micro frames that will be regularly available:
The Flying Person / Smiling Flier:
This was the first frame I prototyped and flew. The initial flying person was constructed without the cutout in the main body. The weight of the Flying person was reduced slightly by adding the cutout and smiling face and the Smiling flier was born. For these frames a rather insignificant compromise in performance was made to make this novelty design possible. I personally find the slight compromise in performance practically negligible and love seeing what appears like a micro flying person cruising through the air. Its also worth noting that the width of the main body is narrow enough to allow use of the stock bottom motor connectors on the nQX FC board.
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The micro flying person (2 min 14 sec)

Efficiency 80, Efficiency 100, Efficiency 120:
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Here is a great video provided by Benedikt of the Efficiency frame in action when coupled with the awesome performance of the Chaoli motors he offers.
The Motor Guy after work - birch quad meets birch didgeridoo (1 min 54 sec)

Platform X
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Platform X+
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Platform X^3
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Platform H:
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Convertible camera/accessory plate for Platform frames:
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Assembling a Picnic Quads platform frame and accessory plate (3 min 43 sec)

Variable
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Videos of the variable in action are provided below.
The Variable Quadcopter frame meets AlienQuads Flight Controller and Chaoli 8.5mm motors (4 min 19 sec)

Pitching the motors forward on the variable quadcopter (5 min 5 sec)

Convertible Accessory plate for the Variable frame

Motor Mounts:
6mm: Some 6mm motor mounts were initially prototyped and worked well, however demand for these was low enough that these won't be regularly stocked. It's really no surprise since most using these frames are likely going to want the added thrust of the larger 7 and 8.5mm motors anyway.

7mm motors: motor mounts from the Hisky HMX 120 will work on these frames, however I currently do not have any available. A 3d printed 7mm motor mount is available in

8.5mm motors: These motor mounts are 3d printed and 3 versions will be available for purchase in the $0.75-$0.90 range.

For more info on the motor mounts is provided in this video:
Picnic Quads micro motor mount info (9 min 10 sec)


Mounts integrated into the frame are also being prototyped. Details to follow.

The image below shows the prototype motor mounts as they were received along with an image showing the weight of a set or prototype 6mm, 7mm and Hisky HMX-120 motor mounts. As shown the weight of the Hisky motor mounts can be significantly be reduced and still remain functional although probably slightly less durable.
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Frames will available at www.picnicquads.com
Last edited by woodsturning; Sep 18, 2014 at 09:46 PM.
Mar 31, 2014, 05:52 PM
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Mini Frames:


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It seems a 195mm acro oriented quad designed for 5 props is a reasonable size to start with, as there are little to no options currently available of this size & type. Also a smaller 195mm size frame will allow further confirmation of the durability of the planned 3/16 thick carbon fiber / birch sandwich material before larger designs are constructed. There are currently 4 versions of this frame available. Each version is available in both a solid 1 piece design and a modular design with independently replaceable parts. Flight controller mounting holes are currently set on a 30mm square hole pattern, however any interested parties will have the option to specify mounting holes/slots for the flight controller and motors of their choice. If necessary, slight modifications (specifically the motor mounting area) will be made to accommodate this. Available models are as follows:

195-C1404 designed for:HiModel C1404 3000Kv 9.6g brushless outrunner
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195-1612 designed for:Hobby King S-Line 1612 3200Kv
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And a video showing the 195-1612 in action
Picnic Quads 195-1612 Crazy Flipping action with Alien Quads Flight Controller (4 min 33 sec)


195-1811 designed for: Turnigy 1811 2900 Kv Brushless Outrunner
Below the motor mounts designed to accept Turnigy 1811-2900Kv motors are shown inserted into the 195-1811 frame. Small holes are drilled through the side of each motor mount to allow access to the set screws contained in the base designed for these motors.
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195+ a frame with a bit more area added designed for the following more powerful, larger/heavier motors:
Turnigy Aerodrive SK3 - 2118-2750 Brushless Outrunner,
RCX 1804 2400KV Micro Outrunner Brushless (CCW Here) or
Tiger Motor MT1306-10 - KV 3100
The modular version of this frame also features standard 30/60mm square hole patterns allowing interchangeability with frames using the same mounting configuration.

These frames are not expected to be indestructible, however they do seem to be take a beating pretty well. A video including a couple crashes (at the end) is included for reference. A full crash test video is eventually planned.
Fast action and crashes with Picnic quads 195mm quadcopter (4 min 18 sec)


Frames will available at www.picnicquads.com
Last edited by woodsturning; Sep 18, 2014 at 09:47 PM.
Mar 31, 2014, 05:53 PM
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Brushless motor testing


Planned for the future
Last edited by woodsturning; Sep 18, 2014 at 09:50 PM.
Mar 31, 2014, 11:24 PM
GOT WINGS
siriusflier's Avatar
Great looking frames woodsturning. Some of those frames are very tempting. You know I like to build.
Apr 01, 2014, 12:35 AM
Team Warpsquad!!!
Btnewman's Avatar
A frame cut out by the op! Frame is made the 1/8" birch/cf ply, and surprisingly ridgid! I am still working out some bugs in the electronics. But the little bit I have flown it, it is a smooth and sturdy frame!

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Apr 01, 2014, 01:53 AM
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deleted's Avatar
Very interested in your micro frames Woodsturning...
Apr 01, 2014, 02:24 AM
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It looks amazing!!

I'm very interested in your frames too
Apr 01, 2014, 11:26 AM
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Glad to see there is interest this quick.

Quote:
Originally Posted by Btnewman
A frame cut out by the op! Frame is made the 1/8" birch/cf ply, and surprisingly ridgid! I am still working out some bugs in the electronics. But the little bit I have flown it, it is a smooth and sturdy frame!
Nice Ben!
I figured you would have that together in short order but man that was quick.
Inspiring me to get going on mine. Setting a goal to have it in the air by the weekend. Today I am also trying to finalize the design of the second optional plate for carrying an 808 cam with the H frames.
Apr 01, 2014, 11:41 AM
Team Warpsquad!!!
Btnewman's Avatar
I cheated, everything was already soldered together, all it needed was a new frame.

If I could make a request on the 195mm frame, I would like to have smaller holes out on the tips of the arms. Also, the ability to fit a 4x 14mm motor mount, maybe even slot them a little.
I would love to be in one of the test or of that frame! Especially after receiving the 155mm from you.
Apr 01, 2014, 11:58 AM
Registered User
UltimateMicroQuads's Avatar
Count me in!! I want to try your H frame. Maybe you could try to fill out a little more surface in order to be able to add the fpv gear?
Apr 01, 2014, 12:10 PM
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Exelent!


Being a woodworker by trade i have been playing around some myself. I know everyone likes the look of CF and all but it is suspect to critical failure from light damage (Knicks and scratches) i have been thinking of laminates reversed with wood veneers and thin carbon cores. have a frame now with a foamboard core and wood veneer with glass tape between layers. really light but " squishy" under compression.
awesome frames. love breaking the mold!
Apr 01, 2014, 12:30 PM
Registered User
Quote:
Originally Posted by Btnewman
I cheated, everything was already soldered together, all it needed was a new frame.

If I could make a request on the 195mm frame, I would like to have smaller holes out on the tips of the arms. Also, the ability to fit a 4x 14mm motor mount, maybe even slot them a little.
I would love to be in one of the test or of that frame! Especially after receiving the 155mm from you.
I kind of figured that was the case, but still seemed fast to me.
I'll count you in for a 195mm, making the holes smaller is easy. I plan to redesign the ends of the arms for the 4x14 motor mount anyway. Since they are for a much heavier motor I'll make sure there is plenty of material, but you will have the ability to make the call in the end if it's not what your looking for. For the C1404 motors I think the current holes will be fine but time will tell. Believe it or not the one I have cut seems significantly more rigid than the frame I sent you. I'm hoping it's a bit overkill for the lighter motors.

Although it's not the most popular motor and probably not relevant to you, here is a prototype for the Turnigy 1811-2900Kv. Need to poke some small holes through the sides to get to those set screws but am hoping it will end up looking more refined than putting the mounts on top.
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Apr 01, 2014, 12:44 PM
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Quote:
Originally Posted by ogrope1
Count me in!! I want to try your H frame. Maybe you could try to fill out a little more surface in order to be able to add the fpv gear?
Sounds good, I'll count you in, I am working on the second optional plate for the H designs and will also look into adding some more material to the main plate for a third frame option. Hoping to have a prototype cut within a day, and will appreciate any feedback you can provide.


Quote:
Originally Posted by mokermeister
Being a woodworker by trade i have been playing around some myself. I know everyone likes the look of CF and all but it is suspect to critical failure from light damage (Knicks and scratches) i have been thinking of laminates reversed with wood veneers and thin carbon cores. have a frame now with a foamboard core and wood veneer with glass tape between layers. really light but " squishy" under compression.
awesome frames. love breaking the mold!
I understand your concerns and am sure knicks and scratches add up but am hoping they won't be significant. I don't think there is any frame designed to crash many times into hard abrasive surfaces anyway. Most crashes are hopefully over grass or something that gives a bit.

Your idea is likely sound from a standpoint of protecting the CF, however the added strength I demonstrated in the video is coming from having the layers of carbon separated from the neutral bending axis. This makes more efficient use of the carbon's strength. If abrasion to the carbon surface becomes an issue perhaps a thin veneer of wood could offer some protection. Interested to see your frame.
Apr 01, 2014, 01:25 PM
Tri-Quad-Hexa-Octo-copters!!
@W
Nice work
@m
I wanted to do similar experiments with the blue foam that the carpet cleaners use as small squares under furniture to protect the carpet when cleaning. That stuff is some of the lightest and toughest foam I have ever seen!... So far I have not been able to get anyone to let me find out where I can get suitable sizes other than the 2x2 inch squares they use...still working on that

Back a few years ago we would use Gorilla glue and balsa (wetted) inserted into carbon fiber square tubes for our homebuilt frames which works very well almost doubling torsional strength: From the Arm Materials for Multicopters section of the Quadrocopter and Tricopter Info Mega Link Index

--Rusty's TRex CF and aluminum tube strength tests: https://www.rcgroups.com/forums/showp...postcount=2293 and https://www.rcgroups.com/forums/showt...f#post10242432

BTW the first Ascending Technologies aka as Astech X-BL frames were sandwiched balsa and CF: https://www.rcgroups.com/forums/show...&postcount=228
Cheers,
Jim
Quadrocopter and Tricopter Info Mega Link Index
Quote:
Originally Posted by mokermeister
Being a woodworker by trade i have been playing around some myself. I know everyone likes the look of CF and all but it is suspect to critical failure from light damage (Knicks and scratches) i have been thinking of laminates reversed with wood veneers and thin carbon cores. have a frame now with a foamboard core and wood veneer with glass tape between layers. really light but " squishy" under compression.
awesome frames. love breaking the mold!


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