Full Function Tests

Spontaneous Projects is a chronicle of all of my projects, a reference for me, and a way to prevent others from making the same mistakes. 

 Using the same setup as yesterday, I've changed the motor layout to Tricopter - three motors, and the servo on channel 4.

I also removed the rubber tubing to increase the strength of the joints. A few more crashes, and took the drill out to fix it up after each crash. I've now reinforced the joints with more cable ties.

Servo - Rudder control

I've increased the functionality, adding a servo to the rear motor, using an adapted method based off this one. I used the same steering mounts he recommends, but have a DS-339MG servo. I used a small piece of 5mm dowel I had lying around, and the screws from the servo. I had to place a spacer under the hinge, and found that the perfect fit was using a piece of an old sim card - but any plastic card will work.

Full Servo set up

Credit card plastic was the perfect thickness

The wiring on Tricopter is

1            2

   \        / 

      |   |

        |

        |

        3          with servo on 4. 

KK2.1 wiring, outputs on left, 1 at top

The test flights with this setup went ok: The servo popping out is now a weak point in a crash, and one of the prop nuts came loose - only indication was that one corner just would not lift properly. Testing was cut short due to low battery - looks like it runs for 20 minutes or more.

Channel Set-up

While it was charging I've modified the Rx - Flight board cabling to get my main controls (strafe) on one stick, and the ones that will mostly be set and forget on the other. 

New setup 

Left side 

Switch       - doesn't seem to transmit - kills Throttle

Dial           - Aux turn clockwise to turn on self leveling

Vertical      - Fore aft

Horizontal  - left right strafe

Right Side

Switch       - shrinks range of everything except throttle - more precision

Dial           - no purpose

Vertical     - Throttle

Horizontal  - Rudder, should be able to be trimmed and left alone ideally. 

HK-T6A layout and mods

Spontaneous Projects is a chronicle of all of my projects, a reference for me, and a way to prevent others from making the same mistakes. 

Manufacturers Layout diagram. I chose to switch the Aileron and Rudder outputs at the Rx end to better suit my application. 

This is for a Hobby King, HK-T6A transmitter, others may or may not be different

Channels

First up, I've changed the wiring around on the Rx end so that my throttle and rudder can be on the right stick, and pretty much set and forget, while the left controls the position of the craft.

USB Programmer

The elevator channel needs to be inverted though, so I'm going to try using this method to reprogram it, as the USB programming cables are fairly hard, and expensive to get. I'll even see if Jaycar has the plug for it to make a slightly more upmarket one for repeated use.

LiPo Battery 
I then had some issues with power, it turned out to be due to flicking switch A. But I'd already decided that it was dead batteries. While I was looking for confirmation that the charging port is +12V I stumbled on a page by NejC which suggested using a 11.1v LiPo battery. Given that I bought two for the 'copter, and had one spare, they're free to reuse, and last longer, it seemed like a good idea.
I followed his directions for a bit, but I wanted to keep the AA option, so rather than replacing the lead from the main board I just soldered extensions from the battery wires to an XT60 socket, and drilled out a larger hole in the back of the battery box. The batteries I have don't fit inside the battery case, so I've modded the door to hold a velcro strap and the battery just gets attached to the back of the transmitter.
When I do another order I'll get a smaller 12v battery to use as a dedicated battery, but for the moment this works well.

Test Flights

Spontaneous Projects is a chronicle of all of my projects, a reference for me, and a way to prevent others from making the same mistakes. 

The new props came in on Thursday, and the beast had a few trial runs today.

First - the Frame. I built this a few weeks back, but never got around to posting it. The prototype is a three limbed copter with no rudder servo. It's main purpose is to test the lifting capacity, and ensure that all of the electronics are working properly.

Tricopter top view, with bonus lens cap

I initially connected the limbs to the main plate using some rubber tubing to reduce the vibrations, both to improve the readings of the Gyros and to improve video quality when I get to that point. However they caused a weak point in the design, so I'll likely use a method similar to David's from RC Explorer for version 2.

Anti-vibration joints

Despite the huge and heavy nature of version 1, when I started it up it had enough power to lift itself, although it didn't like to do so evenly originally. A lot of the issues had to do with rotor directions, and the channels on my transmitter. Purists will probably hate me, but I intend to put the rudder and throttle on one stick, and the strafe controls on the other, which will simplify flying it as a camera platform.
At this point however a few of the channels are reversed, and apparently need to be programmed by USB, so in order to make sense, the craft needs to be flown backwards.

Anyway, tests:

And the damage so far, due to a spontaneous decision to test inside. Note to self, probably not an inside toy.

Had an argument with a laundry basket...

What I've learnt
- It seems to self level ok once it gets up, so don't try to hover down low
- I really need to fix the channels and orientation (Needs a USB programmer for the transmitter)
- Don't turn on CCPM in the board settings - I'm not sure what it does, but it stops things from working
- It needs some skids or something to land on
- Tighten the mounting bolts on the motors, otherwise they jump off and tangle the wires in a crash

Progress, or not

Spontaneous Projects is a chronicle of all of my projects, a reference for me, and a way to prevent others from making the same mistakes. 

Well, as far as progress over the past few weeks goes, there hasn't been a lot. A combination of 40 degree weather in Canberra and a distinct lack of funds has put a damper on things. That said, things should get more active now, as I have a lot more time, the weather has cooled off a bit, and I should be getting a few more shifts at work in the coming months.

I have ordered some left hand (CCW) propellers for the tricopter, which should come in before the weekend. Unfortunately the maiden flight underground for the beast was meant to be this weekend, but I am unable to attend, so it will be postponed for another trip.