Trex parts based V22 osprey

[BigS]

Well I have started to design my second V22.

I am thinking of using 2 x Pheonix 10 esc's on 5S lithium for around 300watts total power input. The AUW should be around 1-1.2 kg. I am looking at using 600mm+ diameter proprotors for a scale of 1/16 or bigger. Trex swashplates, blade grips, mainshafts will be used with a custom CNC three bladed head.

The wingloading isn't looking too good for scale, as at 1.2kg and 1/16 scale the wingloading works out at 47oz/sqft :eek: It would drop to 39oz/sqft if I can keep the weight below 1kg. Although at 1.2kg the osprey would have about 113watts/pound for propulsion.

What I do need to know is how fast it would have to fly at the wingloading to not fall out of the sky. Then I can design the pitch speed into the proprotors for efficient flight at that speed or faster.

I am planning to use a three bladed head on my trex to test out the proprotors in the hover.

Shannon.

[v22chap]

Shannon
I don't know how fast it will have to fly to stay wingborne ,,but I was told that because you are not rotating from the ground or slowing down to land on the ground like an airplane or doing aerobatics ,,that high wingloading doesn't matter much to the V-22 like it does a regular plane ...as you are already in the air flying when you go to airplane mode and the same landing.
Your wingloading don't sound all that bad.The real one has a hugh wingloading too.
Good luck
Larry

[BigS]

The stall speed link Rudy posted in the other thread comes out to 50khm/30mph stall for 1/16 scale at 1.2kg/2.64pounds and around 40 kmh/24mph for 1kg/2.2pounds AUW.

Should be fine with the wingloading as my Trex will do over 100kph.

EDIT: I got some nice CNC bits for my osprey, wonder what they could be for though ;) :D :D :cool:

Shannon.

[Tuner]

Nice Hubs.
I need to do the same but I dont have my motors yet so Im not rushing out to do anything.

[v22chap]

Hey looking like a good start there ... :D

[rdresch]

Shannon, I wish I would have known you were building 3 blade heads, I would have added a few to your order! I'll probably build a Trex size to get some expierance with. Crashes should be cheaper. Looks like you are on the way.
Good luck Rudy

[BigS]

Hey we can whip out more of these heads as my bro made them at his work :cool: :D

Total cost of head hubs = nada, zip, zero :cool:

Shannon.

[v22chap]

Shannon
Great ,,,put Rudy and I both down for a couple as one of these yrs I know both of us are going to do a Trex size bird.It only makes sense

[BigS]

Here's a few pics of the new three bladed head. :cool: :D



Shannon.

[rdresch]

Shannon, I know what you mean about the wing loading. Mine will be in the low 70's. Larrys white one was in the high 70's I think. We do still need to keep it down as much as possible to lower the transition speed. That and the smaller the scale the greater the effect of the wingloading. It's that reynolds thing I think. I am thinking of a way to tilt the rotors at the nacelles so I can put some dihedral in the wing. I'll let you know if I can get it small enough.
Rudy

[v22chap]

Rudy .. I had one that had the screws at the wing tip .... lots of extra weight to get it to hold solid ,,but it did work .I used a car transmission in the middle with 1/16" drive wires to the nacelles and a worm gear setup at the end.I will see if I can find the few pix I have of it. Some where I saw small screw drive retracts that might do the job for you .... I think I lost that url in the HD crash ,,but I will look for it again as I think they were small enough to do what Shannon needs.
Larry

[BigS]

Im going to use some carbon tube for the tilt mechanism with a central screw drive for the tilt. I can use some oversize carbon tube to make unversal joints so I can have the dihedral in the wing too.

Shannon.

[BigS]

Here's a tryout mounting on my Trex, still need to make an antirotation linkage and the twisted blades.

Shannon.

[rdresch]

Shanon, I was just wondering if the spindles are rigidly screwed into the hub? I hear on a multilade head some damper to allow a bit of flapping is benefical to calm the head down. It also reduce stress on the spinde at the point that it exits the head. The T-Rex SE uses the rigid design on the tail and they have been throwing alot of blades from fatique failure of the spindle screws. They break right at the transition of the head where the spindle screw exits. Complex issue. That said the plastic grips may well have enough flex to accomodate the loads.
Rudy

[v22chap]

This looks to be about the same setup that MS uses on their 3 bladed head for their seaknight ,,,but they also use very flexible and small span rotor blades .
This will be a good test to see how it controls with the larger blades ,,and slightly stiffer.

[Tuner]

The Trex Main shaft is 6mm diameter correct???

Where did you get the 3 point swash plate??? Or did you drill a standard one.

I would gladly pay your for 4 of those 3 blade hubs if I could get them with holes tapped for the blade holders and main shaft hole.

I was going to have my own hub done to test out 2 3 4 blades but I think 3 is adequate. I dont have a shop at my disposal so Im limited to out sourcing everything major.

Scott

[BigS]

Rudy,

The plastic Trex grips are really soft plastic so I dont think the dampening will be a problem. I will find out in testing though ;) :rolleyes: :D

Shannon.

[rdresch]

The T-REX mainshaft is 5mm
Rudy

[BigS]

Tuner,

I missed your question there, I drilled a standard plastic swash with the three holes.

Shannon.

[Tuner]

Wow oopps my fault for assuming. Now it looks like I will need a custom shaft after all.

Scott
Thanks

[BigS]

I could easily make the head fit a 6mm shaft if that is what you need?

Shannon.

[Tuner]

Yah I might take you up on that shortly but now Im not sure what swash I will use?

I might need to drop the whole CCPM for just variable pitch using a hollow shaft.
The shaft size of this motor has bugged me from day 1.

I might put this on hold till I get my motors and work on a KISS Parkfly VTOL Kit.
Using MS Compisite 3 blade head and plastic blade grips along with the props I got of the larger of the 2 coaxial heli toys. GWS also challenged me to build one using just thier components and it sounds like fun being that they have pico sized equiptment.

Thanks Im going to be playing with the TH-2 some to see what I can do.

Scott

[v22chap]

Scott ,,yep I have just this weekend started to play with the TH2-GP that Joe has for VTOL's and it has a ton of things that I am just starting to get my head around. I will have to wait until I call Joe to learn more as you can only find out so much just hunting and pecking. :o ;) :rolleyes:
But it really seems to do a lot of things for VTOL .... not quite all that I wanted ,,but enough that I will be using it as it is much simpler.
Larry