Yes I thought of shaft couplers you can get quite fancy bellows type wich look as though they might be best although quite a price too. but ive tried to avoid them, as they must reduce the overal torsional stiffness to some degree,
Ive glued the bearings in place in situ so it should be aligned and this has helped. removing the preloading also helps a lot with the error cuased by drag but the play in radial ball races without preload is then a problem.
Colin =^.^=
Have you considered using an active magnetic bearing?
Guy Macon
It's called the "critical speed". You might try asking at sci.engr.mech-they get quite lonely over there....
See if you can find a shaft of some composite material - I heard a couple guys talking about "graphite" golf clubs, and I asked "what's the advantage?" and one guy says, "The club face doesn't 'open'..." and indicated with his hand that the club shaft resists twisting, to minimize the hook or slice, whichever.
Anyway, it's an idea.
Good Luck! Rich
a hollow shaft, better tortional stuffness to rotary innertia ratio.
move the encoder disc and use a fibre-optic link thus keeping the electronics remote?
why are you tryint to do this?
Bye. Jasen
Something you should have made clear at the beginning.
Go with a 1" diameter water pipe, or a section of automobile driveshaft at that speed it'll need to be balanced so use the yellow pages...
Also viscous drag (force proportional to square of speed), and some bearing noise (rumble), and the shaft probably has some torsion modes at 10 kHz or at harmonics of that frequency...
Your best bet might be to mount an encoder disk close-coupled, and run fiber optic light pipes to illuminate and read out its position.
A simple spoke pattern can be illuminated from afar by a laser, and read out with a photocell/telescope. A phase-locked loop might help generate a good 'digital' signal for you. Or the correction signal to the PLL can tell you about fluctuations of speed.
hi , i presume at that length 1meter, u have it supported in several places along the shaft ? are u using seperate ball bearings , or ball bearings already in a race ?
mark k
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