Folding Quadcopter for the holidays

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Not much space if you're going on holiday with the family in a Renault Clio. This design fits into a 52cm toolbox with transmitter and all accessories.

Just thought I'll share my crash resistant design that has evolved through many drops and repairs. On impact it is now usually just a matter of replacing a rivet or a prop. The electronics and battery can quickly be removed for installation on another airframe.

The props are 15" RC timers and as shown I get about 23min flight time with a slightly damaged 5000mAh 4cell Lipo at 1500m above sea level, 25 deg C.

The difference in spacing between front and rear props doesn't have a noticable effect on stability and it flies waypoints very well.

I'll post basic plans if anyone is interested or if you want an airframe let me know.

Update: Plans for the airframe

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Comments

  • The Black Mantra does look good, but the camera isn't protected and it also lacks landing gear. Today I added a front support just to let the quad stand better on the ground. I've decided the area around the battery is unbreakable. It is the same landing gear I've had for over a year on various configurations and through many, many crashes. My idea is just to have a practical device that I can quickly fix when I need to.

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  • I'm hoping to add a gimbal one day. Probably upside down on top if they work that way. A top mounting plate like Jeff uses should enable you to move the battery right back.

    Otherwise add landing gear, hang it below nearer the CG and change the GoPro lens?

    A lightweight gimbal that I like for front top is this one

    http://www.rcgroups.com/forums/showthread.php?t=1793759

  • Today I upgraded to Arducopter 3.0.1 and took the 10" quad pictured earlier for some tests. Wow - rock solid! Big improvement over 2.9.1, especially with altitude control. An interesting thing was the compassmot procedure. According to the tutorial 30% interference is on the limit - mine sits at 53% and 51% for the retest. The quad has no metal between ESC's and APM, so probably needs it. Still it flew waypoints better than ever with the quad pointing exactly where it should.

  • I think it looks great! For the main plates I would still consider keeping the arm attachment sections separate so they can be replaced individually if they break. The carbon will probably break where the aluminium could be bent straight again. A shaped foam block should work fine as landing gear. I'm going for upper fuselage plates without holes as I hope the carbon will reduce electromagnetic interference. A vacuum formed or 3D printed enclosure for all equipment on the floating plate would make it look quite proffesional,  even though it will be a bit of a weight penalty.

  • Is it flying with the CG in the new position? I see you also changed the curved slots. Are you planning some kind of quick release? Interesting engine mounts - my guess is they'll help reduce vertical vibrations, but most vibrations are in the horizontal plane and you lose efficiency if your props are too close to the motor arms.

  • Developer

    no, you need to draw lines between the front two motors and back two motors and look at the half way point between the two lines.

  • Thanks Jonathan, I'm considering replacing the sliding bolt and wingnuts with 3D printed bumps. My idea is to let the round tube be held in position by the bumps on each side, top and bottom. The plates should give spring action for it to click into position and be held firm. I bought some tiny spring plenums once, but they are heavy and the very tiny ones with a pop-up ball didn't grip enough.
  • What a great design! Any thoughts on adding spring plungers and modifying the design to accept them for rapid deployment of the arms? Here's an example of what I'm thinking of using, or something similar: Spring Plunger at McMaster

    Unfortunately, I can't find a weight specified for these, but other than that, I think it should work with a little modification like replacing the slot cut in the lower plate with two holes at each end of travel, and possibly a spacer just outside the arm's swingpath to help rigidity since the clamping action from the previous locking method is lost, and I guess I have to figure out a way to secure it in the arm... to the CAD machine! This is one of the reasons I love this site: a bunch of really talented people contributing their thoughts, designs, and results. Thanks for the inspiration!

  • Developer

    I can confirm Murray's statement there. The CF needs to be on the center of lift.

  • mdrm, your CG is too far fwd. It should not be at the centroid of a circle through all the motors, but rather halfway between front and back motors. With a Gopro in front the rear of my 5Ah 4s battery is about in line with rear of back plate. I suspect the flight controller gets confused while it is trying to lift off and it ends up pivoting about the front arms.
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