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Viewmaster wrote:You haven't mentioned on BHTV that you plan to scan at 24FPS although you have mentioned 1500RPM.
If at 1500RPM then the centrigugal forces acting on any imbalance will be high.
For example just 1 gram rotating on a radius of about 5 inches (your outermost tip of 240mm picture width) will be nearly 1 lbs. and pro rata.
SO........
Will the centre bearing shaft hole in stainless steel also be lazer cut
and if so, how well will it fit the shaft to prevent inbalaces ?
Also, how central to the slit length will each hole be?
When I made my but 750RPM mirror screw I had rumble on that due to the shaft holes not being EXACTLY in the middle of each slat.
Also as the tips of the slats will be travelling at around 60 ft/sec if rotating at 1500RPM so you may need a soundproof housing with say, a polycarbonate sheet for the viewing window.
Silver steel may be the way to go for the shaft as it is ground to a tolerance of +- .00025 inches.and it has a fine surface finish. But it's difficult to machine and die a thread on it if required. (3/4 or 1 inch dia perhaps ) A 13 inch length of 3/4 dia is about £9 plus postage.
To reduce noise further a simple ball bearing, housed in a centre drilled cone in the bottom of the shaft as a thrush bearing would be quieter (and cheaper!) than a ball race thrust bearing.
Oilite plummer blocks as bearings for the shaft will be quieter again than ball race bearings.
(I used them for my Mirror screw shaft)
Hope none of the above has put you off but just given you some food for thought.
Here endeth my 2p's worth.
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