450 size collective pitch tricopter build

Ok, started on a new build today. It is going to be a collective pitch tricopter that uses three sets of 450 helicopter main blades. Main rotors driven from the center via bevel gears and drive shafts. I will start with a KK2 board, but would like to have an Ardupilot function with RTH at some point. The attached is the first two machined parts, lot's more to go. Will be doing a bit of waiting on parts from China.

Cool.  So we're talking about 325 mm main blades or thereabouts?  With the right motor(s) you should be able to do some heavy lifting.  Do you have a target weight lift ability?

Yep, 325mm, I would think 8Lbs payload could be done, but only with good motors and blades. I am using economy stuff to get it going and then see from there. SpinBlades are design for heavy lift, but kinda spendy.

So you must be looking at around 1300-1400 mm diameter!

McMaster Carr order came in today. I interpolated the bearing bores -.0015" under and the new bearings were a perfect press. So far so good.

Cool!  More, More!

Got some more stuff done. This is not a final design, far from it. More of a "live" drawing since I have not worked with gears much before so I did everything piece by piece, the next style will be one solid machined part and will have thrust bearings installed. But it is a start anyway.

Coming along nicely.  What attaches to the other end of the main shaft from the head?

Nothing, it needs to be pushed up more and maybe only a 1/2" or so will stick out of the bottom, might even cut it off in the lathe once I figure out the right length for everything. The 450 rotorhead from HK was a lot nicer than I thought it would be. very tight and clean machining on it.

Wow!  That looks great Tyson!

...Tiger

Good stuff.
Can't wait to see how this comes together. 

More stuff, this is how the gear box was intended to be. A monolithic machined part. Everything is very smooth and easy to make/assemble. Not sure if it is Delrin or ABS, but machined well anyway. Bearings are a stiff finger press fit, then retainers will be added to them.

http://www.youtube.com/watch?v=beRN6sVIt5Y

Very cool.  Much nicer than the "U" shaped test version.
If this is a tricopter I guess you will still have to tilt one of the assemblies even though you have variable pitch won't you?

Nope  ;D Well at least that's the plan, I am going to use the swashplate tilt left and right on the tail to provide side thrust as well as collective pitch. Just like the heli, but without CCPM, just two servos working with each other.

So are you going to have a 90 degree swash then?

...Tiger

Sort of, but through a mechnical setup since I can't work out how to just have CCPM on one rotor and not all of them. But the tail swash will move straight up and down, and also tilt side to side using two servos.