Building the CrossFire II quadcopter

It 's cold and damp weather and summer is done, at least in Belgium.
So time for a new project !

I’m interested for some time in the CrossFire II quadcopter from MikeyB.
Let’s try to make one on the Velleman K8200 printer.

For files & instructions please see

I started printing the legs, and that was not that easy as it should be. The legs are really long so I had to put them at an angle from absolute corner to opposite corner. Further I had to take into account the mounting screws from the heated bed.

Anyhow 10 attempts later I experimentally found the correct position.

The story in some pictures:

Printed straight on the bed, no Kapton, hairspray, gluestick, …
And after some time:

Leg 1 finished !

[ul]Printing time : 8 hours
Weight : 75 grams
Slicer : Simplify3D
Layer height : 0,10 mm
Nozzle size : 0,25 mm
Infill : 50 %
PLA : ultimate white 1,75 mm

Not that bad. :slight_smile:

The legs are finished:

And here is the top plate, hot from the 3D press:

Not sure if I’m 100% happy with the plate. Thickness is just 3 mm and it does not seem sufficient.

Really nice!
Especially for printing on the naked stock heater PCB.

Indeed the stock PCB works perfect. The only thing I do before starting a new print is cleaning the surface with a soft sanding pad slightly soaked in isopropyl alcohol.

Since I was not 100% satisfied with the thin design of the plates, I adapted the original drawings from 3 mm to 5 mm. SketchUp did do the job:

New prinjob for the top plate just released, if all goes well new photos will be published tomorrow.

The customised plates are noticeable stiffer the the original design.

[ul]Printing time : 3 hours
Weight : 30 grams
Slicer : Simplify3D
Layer height : 0,10 mm
Nozzle size : 0,25 mm
Infill : 50 %
PLA : ultimate white 1,75 mm[/ul]

See respectively the top & bottom view:

Time to order the brushless motors & ESC’s.

After some research and based on MikeyB’s advice, I decided to purchase:

[ul]4 x DYS D4215 650KV brushless motors
4 x DYS 30A SimonK ESC’s
4 x carbon fiber 11" propellors make the setup complete[/ul]

Some specs:

[ul]Expected lift per motor/propellor : 1720 grams @ 7100 rpm
Max power : 865 W @ 10660 rpm[/ul]

Got all the required stuff on Ebay, now waiting for delivery…

Really nice job!

What electronics do you plan to use for the flight controller?
What Radio do you want to use?

I’ll go for the KK2.1.5 (Hobbyking).
This is a convenient module with mini display and four buttons to tweak.
Costs less than 20 euros.

I already use a Devo7 (Walkera) 2,4 GHZ transmitter and have some matching receivers available.

Thanks for the info dude!

Today the brushless motors, propellors & ESC’s arrived. So I took some time to assemble the legs:

Next step is to print the battery holder.

I’d recommend the NAZE32 board over the KK2.1. It’s usually pretty good straight out of the box (use cleanflight firmare) and much more up to date tech.

After some doubt, I decided to go for the KK2.1.5 because of the built-in screen and programming buttons. Tweaking on the field should be possible without laptop or external controller. Anyhow, I can easily change to controller in a later stage.

Battery tray completed and assembled with rubber damping balls:

KK2.1.5 controller in place:

Also the legs are already mounted:

After some unsuccessful drawings, I managed to create a protection cover (just in case of a future crash) for the KK2.1.5 controller.
Slices with Siplify3D, and printed with the following settings:

[ul]Layer height : 0,10 mm
Nozzle size : 0,25 mm
Infill : 50 %
PLA : ultimate white 1,75 mm[/ul]

Here you are:

During the build, I changed my mind. It is rather difficult to recognize the front and back side when the quadcopter is in the air.
For that reason I started reprinting some parts in a dark PLA.

A few pictures:

Vibration damping plate for the KK2.1.5 finished:

And here is a pair of legs in dark grey PLA:

Printing completed:

Assembling started:

Very nice fitchie

Because I already have printed all the parts in double (once in white, once in dark gray), I decided to assemble both quadcopters. :slight_smile:

In the meantime the white quadcopter is completely finished except the props. The black one is waiting for some missing electronic components I ordered today at Hobbyking.