Rotorbone & RCExplorer Tricopter - Scratch Build

March 25, 2014|ikem

I had 3 extra motors... 3 esc's, and a multiwii board. Another Tricopter?? Why not!

After building a Fortis TITAN found here, I wanted to try out Flitetest's RotorBones pieces. I have always wanted to see how they go together and how they hold up.

Here is the parts list.

DJI 2212 920KV Motors
Hobby Wing 40A ESC
Turnigy 4s 2200mah
XT60 to 3 pairs of 3.5 bullet.
Multiwii 2.1 Board with 6050
1/2 Square Dowel
1/16 inch Aluminum
10 x M3x25mm Bolts with Locknuts (Flitetest)
RotorBones Stright 13-370 x2 (Flitetest)
RotorBones Tilt 13-370 (Flitetest)
Gemfan 10x4.5 Prop
Tons of black zipties

Tools List

Dremel (EZLock Fiber cutoff and High speed cutter)
Coping Saw
Allen Wrenches
Screwdrivers
Sandpaper
Drill

For the center plates, I really wanted something sturdy that would not break. I really debated getting an Anycopter, but I really liked the foldable design of David's Tri plates. So since I can cut with a dremel pretty well, I decided to make the plates out of aluminum instead of glass fiber. After 2 1/2 cutting wheels, I got them cut. The design was printed on paper, sprayed with some 3M adhesive, and layed on the aluminum and left to dry for the night. You can see an old design that was just to complex.

After getting both pieces cut out, you simply soak the parts in GooGone for about an hour, and they peel right off leaving a very protected surface. Do not try this with glass fiber, wood, or foam. The GooGone will ruin anything but metal.

I made a cutout to place the Multiwii board on the bottom plate, but had to lengthen it to get the CG correct.

I tried making a electronics cover kind of like my TITAN, but I ended up ditching the idea.

Here is how the Multiwii board and reciever are setup. It uses 3M strong tape on the underside of both boards, which gives a little vibration reduction and secures it well. I got the cables tucked very tight.

With 10 inch front booms and an 11 inch rear boom, this it a midsize tricopter. But with the power of 4s and 10 inch props, I think it should be fine.

Installed the ESCs and did all the wireing. At this point I was waiting for the Flitetest package to arrive.

The colors actually are predone, and are matched to the colors on the motors. So I do not have to test for the correct rotation.

All folded up! It is very compact and lighter than I thought.

And here it is! It took me about 30 min to assemble all the RotorBones parts, and get them on the copter. I am very pleased. The Delrin is alot thinner that what Fortis uses, but everything is designed differently. The Tilt is very solid, and I love the linkage. The landing gear is remarkably stiff when landing somewhat hard, and I can see how they will pop off when struck at an angle.

I am going to have alot of fun with this copter. I think the proportions are perfect, and everything looks great.

The G10 board is perfect for the motor mounts.

Having the Multiwii board on the bottom plate makes for a very clean plate area. If you were using fiber board or some other material, you may loose some strength in the plate, but with the thick aluminum I wont see it much.

I used HK-15178B for the tilt servo. It was a cheaper digital metal gear servo that would fit the hole in the mount.

Size compared to my TITAN. The TITAN is way heavier, longer, but has more on it.

The RC Explorer plates are very well designed. Since they are designed for 10mm booms, and I am using 13mm booms, I increased the scale of the plates to 125%. This should be enough to compensate for the larger booms, but I did add an extra inch to the tail, just to be sure. The foldable nature of this is perfect for my needs. I did have a large aluminum tri that did not fold, and it was a pain to carry around, this not so much. Thank you David for designing a great Tricopter plate system.

TLDL: If you are debating on the RotorBones motor mounts, or David's tricopter plates, do not hesitate. They are quality products that will last a long time, and they have replacement parts avaliable.