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aussie_bloke wrote:G'day all.
I found a sheet of plywood that is roughly 4mm thick which I am going to try to make a Nipkow disc out.
aussie_bloke wrote:...it weighs probably something over 500g so I need a bigger badder motor,
aussie_bloke wrote:...a tool that looks like a screwdriver but has a nail like pointy end (what is it called???)
aussie_bloke wrote:drilling
gary wrote:Yeah at 2mm that would mean you would be getting more than 50% overlap of the scan lines - you'd get a picture but it would be very blurry I would think.
I should have mentioned, if you didn't already realise it, that you can prevent a lot of chip-out by having a backer board against the plywood whenever you drill or cut.
Not sure how you will control the speed of the fan motor - but a mechanical braking system may be the go.
Good luck.
Viewmaster wrote:Nice to see someone else making their own Disk. If the plywood doesn't make out you might consider MDF, if you can get it in your area.
MDF will not split and is very machinable.
Re Gary's mention of the tunnel effect, you might carefully countersink the holes on one side to reduce the tunnel length.....there is always light at the end of the tunnel (!)
If you finish up with plywoood, don't forget to have a fire extinguisher nearby just in case it catches fire.
harry dalek wrote:Good luck troy with this one ,never tried a wooden disk ,i tend to use records when i need some thing round.
Also never tried an AC motor to drive the disk so yours is a bit different in that way to me .
How are you going to control the AC motor ? i have a circuit and parts can be got from jaycar if you need it ,think you could pulse width control this with the circuit just need a 555 timer clock at worst a little amp ...i can see that the PLL could be hooked up to this as well.
You may just want to use a light dimmer and try that ?
i don't like the idea of manual braking a AC motor with brushes brush less ones might be safer but think both have a bit of a kick to them if you tried to slow them down by force ,recall in one of my book posts they use to do this with a paddle with rubber i suppose like a big bike brake / i wonder how many motors went up in smoke trying this back then.
aussie_bloke wrote:There is another strange issue I'm having with the pictures, they seem to be back to front which is noticeable when viewing letters and numbers, I wonder what might be causing that to occur???
gary wrote:aussie_bloke wrote:There is another strange issue I'm having with the pictures, they seem to be back to front which is noticeable when viewing letters and numbers, I wonder what might be causing that to occur???
Your disk is on backwards - as the apertures are moving upwards across the gate the outermost aperture should be first, in your case it will be the innermost.
I look forward to seeing some video of the pictures. Well done.
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