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Old Jan 14, 2013, 07:19 PM
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I have been using 17x23x4 Heli swashplate bearings in my build as you can see, mainly because i had a few lying around from an old 450 and they seemed to be about the right size.

As you can see from the photo's the two new parts from Shapeways have arrived the two part hub and the rotating part (which i slightly re-designed to have a bit more 'meat' in stress areas... despite that it is almost a third of the weight of the aluminium part.Only time will tell if it's strong enough..
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Old Jan 14, 2013, 09:35 PM
Obsessed with all things CNC.
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Second not working version :-)

So obviously I'm playing catch up here. This is my second not working version. This is meant to be driven by a belt attached to the cam pulley. The cam is certainly not the right shape, I just wanted to put the idea out there for creating asymmetric stroke times. Also the stroke adjuster can be placed on the other side of the swash plates in order to bring the oscillating part closer to the gear/pulley to reduce flexing.
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Old Jan 14, 2013, 09:42 PM
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My next step is to put a radial bearing between the wing and the gimble but I'm concerned about supporting the bearing through the alternating axial loads. This will be really rough on the bearings... I certainly don't want to test this out with a $130 ceramic bearing, yikes.
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Old Jan 14, 2013, 10:02 PM
Mad on everything Swash
Joined Jan 2012
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I like it Mike, yep suppose time & testing will tell
Great if it does....Big weight loss !
Im tryn to think ahead here, what if the hub had axial ball races on either side of a central like thrust washer. Make the outer wing clevis in 2 piece with axial race ways in each side, like a sandwich assembly.
Kind of like the way my fin clasp is sandwiched and Mike & Kjells refinements, using the glass bearings with their cages
This method would be light could allow for preloading if required and possibly more unlikley to burst apart, the forces are less the further away from origin of swash !
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Old Jan 14, 2013, 11:08 PM
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Link to the miniature plastic-glass bearings site :
http://www.qbcbearings.com/BuyRFQ/Ba...tic_Metric.htm
they have even double row bearings which will bare much better axial loads:
http://www.qbcbearings.com/BuyRFQ/BallB_Plastic_DR.htm
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Old Jan 14, 2013, 11:28 PM
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I think this is the solution to the bearing problem. Check it out. Imagine a clamshell case around this piece holding the bearings in place. this will withstand the axial loads of the reciprocating drive a lot better than anything else we've seen on here so far.
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Old Jan 14, 2013, 11:30 PM
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haha. It looks like Craig and I were on exactly the same wavelength. I was making this in cad and after I posted it I read lil aus post describing exactly what I just made. It's great to be working together on this stuff.
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Old Jan 14, 2013, 11:59 PM
Mad on everything Swash
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Hi Matt
That part you modelled is exactly the how i describe it and Kjell is prob dreaming it right now in his sleep if he hasn't already thought of it... i can't help but get the feeling he is holding out on us
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Old Jan 15, 2013, 12:01 AM
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Here it is in the assembly.
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Old Jan 15, 2013, 12:40 AM
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Looks like you are almost back to where i was with the single ended version except you have a through shaft...

Your missing peice is the wing spar take off points, where for me i planned a pair of 4mm Carbon Fibre rods to make a LH size bird. When you factor in the need for these two rods in a central axis position you can see why i opted (and still do) the twin caged bearings.. (oh my two spars are about 25mm apart.)

Note - although CF is light a pair of 1m lemgths each side put tremendus load on the hub, and thats without wing material and air resistance to flapping... Today i bent an 5mm aluminium shaft trying my test assembly - back to steel.!!
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Old Jan 15, 2013, 01:16 AM
Mad on everything Swash
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Mike,
Have you tried using the CF rod as spindle material
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Old Jan 15, 2013, 01:33 AM
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Hey mike, there is another difference, that piece there is a very different type of bearing from what you are using. It's hard to see in that picture, that's only an inner solid disc. Balls will go on both sides so that the bearing will be strong axially but weak radially.
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Old Jan 15, 2013, 02:36 AM
Mad on everything Swash
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Matt
To me it is exactly what Kjell has recently shown thanks !
the only difference is having a 2 piece outer Clasp / Spar holder, which would make for easier assembly and higher rigidity, the overall factor being much less weight !
Im a little busy right now, but soon as i can i will be building a prototype of recently discussed, the plastic/ glass bearings have been ordered
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Old Jan 15, 2013, 04:24 AM
Kjell Dahlberg
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Mallorca Spain
Joined Nov 2005
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I am glad to see all of you experimenting with Wiggle/Swash mecanisms.
The VWD is very good to find out what is the best flap-angle. When you know this angle, you can lock the VWD to this angle and save weight by eleminate non nesesary parts.
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Old Jan 15, 2013, 04:37 AM
Mad on everything Swash
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Quote:
Originally Posted by KJELL View Post
I am glad to see all of you experimenting with Wiggle/Swash mecanisms.
The VWD is very good to find out what is the best flap-angle. When you know this angle, you can lock the VWD to this angle and save weight by eleminate non nesesary parts.
Kjell
Any idea what you would consider a good flap angle !
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