Sunday, February 22, 2015

Flip Sport Build - for acro flying

This build is of a Hoverthings Flip Sport with some custom 3D printed parts. As with all my builds I try and make it as thin as possible.

First up why the Flip Sport?
The main driver was price. I didn't want to spend a fortune as I was not sure what the performance I would be getting out of it, its under 200grams, but I was not sure with my motor / prop combo what the actual performance would be.

The other driver was that I already have a Hoverthings quad, a Flip Pro that was the basis for my camera ship (Build here) So if it all turned to custard the frame / arms can be used if there is a breakage on either. I also had spare ESCs and Motors are used on my other builds that also drove what was used.

I would love to get a Warpquad or a Freebird, but I would need to get a complete setup of electronics / motors / ESCs plus the frame. At this point my flying skills are not quite there yet.

So here is the parts list

Flight Controller : Naze32 Acro
Frame : Hoverthings Flip Sport
ESCs : Afro 30 amp
Motors : Turnigy D2830 1000kv (Great budget 1000Kv motor)

Prop : 8x4.5 & 10x4.5

3D parts (My own design)
Dihedral  Flip Sport motor mounts
Landing feet

Other parts
13 mm Alloy stand offs
3mm bolts
LEDs strips
Bullet connectors
All the usual other build bits and bobs

After watching the Flitetest article about the rotorhub and the dihedral arms that they made I thought why not give that ago on the new acro quad build. Using the arm from that camera ship as the template I designed and printed a motor mount that added 5degrees of prop angle that the motor bolts to using the standard motor mounts. Then used the holes that are on the Hoverthings Flip arms to bolt that assembly to the arms.

Not sure on the durability yet ... no big crashes, but they were printed at a lower setting. If it works out well I can print with more material ratio which will make them more "solid".

Here is the Turnigy D2830 test fitted to the mount.

The base is recessed to allow the motor bolts to be at the right angle and out of the way so the mounts will sit flush on the arms.

The arrival of the new frame the Hoverthings Flip sport 360mm Prop to prop.

It will be joining this collection ... the big Bertha Camera ship is not shown below.  3 ZMRs, Fortis Tricopter

The first major step is to get the ESCs sorted. I needed to shorten the motor leads and solder on the 3.5 bullet connectors

First one done.

Test fitting with the motor

More soldering and heat shrinking.

The next step was to mock up the frame and decide the layout. I was hoping that I could fit the ESC,s inboard. But there was just no way that they were going to fit. So they are going to have to go on the arms. The Hoverthings frame is American and as such had imperial fittings. 

I had to use a 3mm drill and re-size all the holes for my 3mm fittings.

I first did the build using 10mm standoffs to replace the one that came with the kit, However during the numerous  mock fitting together I become apparent that 10mm was not going to be enough to clear the Flight controller once it was stacked on top of the power distribution board. I later swapped these out for 13mm standoffs.

The kit suggested 3 bolts per arm, I chose to go with 4 for added strength and easier cable routing.

I used a 35mm power distribution centered in the frame. I find these much easier to wire quads compared to wire harnesses.  Once I got the ESC layed out and power leads cut to size and soldered it was time to sort out the motors.

I chose to go with the cheap but still great little motors the Turnigy D2830 1000kv motors. They run smooth and for $10US each very reasonable. Once I decide on the final prop size I will invest in higher quality motors. But these will be great for the first couple of moths of testing and bashing. 

The likely replacements will be the SunnySky x2212 1400kv, if I stay with 8in props

The D2830 motors from Hobbyking do not have prop adapters, But RCTimer do. These motors are almost identical to the RCTimer 2830 motors. I ordered another set of adapters. (I run these motors and adapters on my tricopter)

Link to adapter here

The D2830 only comes with a long shaft version. So I tapped the motors up and then got the trusty hack saw out and cut the shaft off. I then carefully filed the shape bits off.

Result after filing.

Once all the shafts were cut and filed the adapters were fitted.

Now the motors are ready to be mounted to the 3D printed motor mounts 

First motor full fitted to a arm, you can see the 5 degrees dihedral. 

Next I re-purposed a NAZE32 flight controller. I am waiting on some more but couldn't wait. The board was stacked above the power distribution board.

I am using a DR4II using PPM, I was running telemetry and Bluetooth, both were removed for this build.

The PDB is mounted to the frame plate using nylon bolts. I also put some silicon tube spacers to raise the FC 2mm more to make sure there was no way the two could touch, even in a crash. 

Additional power leads were soldered to the PDB, for front rear LEDs and one going to the NAZE32 for vBat. Oh and of course the battery leads.

Closeup of the PDB and silicon spacers.

After alot of mucking about I got the transmitter and buzzer all mounted inboard of the frame plates. I did not shorten the ESC signal wires yet, and with a build of this size its not going to have any impact.

Its a tight fit, It could be tidier. But once I finalize on the motors and everything else its good enough to get in the air.

First mock up with the frame complete. Everything is nicely hidden and the profile is still very thin.

The side profile of the build.

Final wiring complete, battery XT60 on and zip tied in place.

Now its time to start bolting everything on and securing the ESCs

The ESC's were zip tied and double sided taped to the frame.

Very sticky double sided tape used, on the frame to hold the esc.

All ESCs mounted securely to the frame.

Motors all bolted to the frame.

The Zippy 3700mah on the frame. I now like having the battery in the top of my acro builds as if I land or hit the ground its 90% of the time the bottom, so want to make sure the battery is well out of the way.

Test fit with 10inch props.

The next thing I needed was some little feet as I didn't want to use the Hoverthings legs on the arms. These were simple squares to use the frame arm mounting spaces. This also give the ESC a little more protection. 

I then added some simple LED to the front.

That was the build complete.

Next I configured the NAZE32 and got the motors direction/ESC calibration done and then put in some rough PIDs and receiver settings based on what I have learnt over the last 12 months.

I swapped the props for 8x4.5 and took it for a test flight. 

The below video is the first flight of the quad, Also my first time using a head mounted camera to capture my flight, sorry about the lighting, I will try and get some footage in better light. 

Next steps will be PID fine tuning and trying different prop combinations to find my sweet spot for this frame. I will update this post once I settle on PIDs that I like for this frame.


Here is a video the next day, daylight even. I crashed in the first 20seconds, My own fault not paying attention. The props are not balanced and still have the prop adapter cones which are badly balanced.

RAW video, this time with props balanced.. until I crashed again, and lock nuts replacing the adapter cones.