square main shaft anyone?

[pgkevet]

Doubtless i'm being dense but it strikes me that for fbl if we had a square (or triangular or even a star or hex) section mainshaft then you wouldn't need a swash driver. Easy enough to mount collars for bearings and swash could still ride up/down and angle..would potentially make is easier check/to align all components and test for straightness. Triangle is best for straighness checks, Hex would probably be most appropriate for general strength and is a standard type bar item.

Also if the bearing block mounts attach to the main frame from outside..as in pem type nuts in the frame.. then the frame spacing can be narrowed to the inner race of the bearing width...

Combine that with a modular dsign approach then it should be possible to build the main frame with a foam core skinned with carbon...a few inserts for wire channels and foam protectors...I'm just flying this keyboard...

(s'all right the painkillers will finish kicking in soon and I'll hobble round with the dogs)

[pgkevet]

Oh, oh, oh,,just had some more ideas...must take these analgesics more often....

[scallybert]

It's good to think outside the box... Bear in mind, though, that on current swashes, the part that would be running on your square/keyed shaft is a ball in the centre of the swash - that isn't keyed to the upper swash.

[KevDavies]

it would be easy eough to drive the swash tho. I like your thinking Paul. HOWEVER. Unless you isolate the torque of the shaft from the sliding element of the swash youll get it binding up under load. This is why the centre of the swash is a ball at the minute.

Something else for me to try and draw in a cad programme me thinks! (list is growing btw)

[Planehazza]

How would bearings work on a none round shaft?

[milly0812]

square main shaft anyone?

How would bearings work on a none round shaft?

Durrrr.......... Non round bearings ;-)

[pgkevet]

as soon as my head cleared in the frsh air while I hobbled the dogs round i saw the flaw in the hex shaft theory..wahtever bypass for the ball bit one could successfully come up with the simple fact is that as soon as the inner swah ring angles then any flat surface becomes 'wider'.
Next time I'll wait until he drugs even out a bit.
Harry: I wasn't too stupified to forget collars with round outsides on the shafts.

Only parts that still makes sense might be the idea of a solid core frame with bearings and even the majority of the front boom block mounted from outside; side pod batt holders or fuel tanks....

[Planehazza]

Durrrr.......... Non round bearings ;-)

PMSL. D'Oh, just realised how blonde my question was.

Move along now...

[ModelGuard.Com]

Re: square main shaft anyone?

I think you lot need to get down to the hairdressers pronto

[RcRotaryMadness]

How about servos that are small and powerful enough to replace the main grips, connected directly to the blades, removing the need for linkages and a swash altogether, it would need some sort of electronic virtual swash plate though, a lot like a virtual flybar with FBL... It could be doable I think.

[pgkevet]

How about servos that are small and powerful enough to replace the main grips, connected directly to the blades, removing the need for linkages and a swash altogether, it would need some sort of electronic virtual swash plate though, a lot like a virtual flybar with FBL... It could be doable I think.

Gonna be some really fast servos to constantly change the blade angles at 2500rpm!
You hair appt is 2.30

[Rotorhead]

It's good to think outside the box...

Yes but I think pgkevet has gone outside the box, doused it in petrol, burned it and buried it.

[Planehazza]

Now that I'm not being blonde and understand what he means, it's a good idea but I think it's simply cheaper to just manufacture cylindrical shafts, and have the swash drivers mounted directly to the hub. The design on the Rush 750 is a winner.

[Rotorhead]

Mechanically it's going to be better aswell to use a round main shaft rather than one with faces and corners, when you introduce corners into a system you make it mechanically weaker, think about where that goes through the swash, and into the rotor hub, it will be loading a large force onto a small area when the helicopter is manuvouring, especially when it's 3D flying.

[KevDavies]

Harry I like that idea youve got about direct servos. You could use hydraulics like F1 cars have on the valves. Thats a nice simple solution to it aswell, as all youd need is something to tell the electronics where abouts in the rotation the blades are and a controller to operate the blades. Its beyond me like, but the technology is available to do it!