Narrow-Bandwidth Television Association

by **Viewmaster** » Fri Apr 19, 2013 11:38 pm

Not that you need reminding but.......
Don't forget, Graham, that when you are positioning the 32 locations in both the position across the drum and the 11.25 degree around it that your biggest enemy is backlash in any method you may use, so take steps to nul it right out.

by **AncientBrit** » Mon Apr 22, 2013 5:37 pm

Harry,
I've spun the drum up much faster than 750rpm but I had no strobe to indicate the true speed.
Lots of windage!
With Albert's recently posted multi stobe gif I'll try it again and report back.

Albert,
I've gone to some trouble to minimise backlash in the strip 'cutter'
I've built the 3ft lead screw and sledge.
Repeatability seems good.

Actually ran the lead screw from a power drill and had the sledge motoring at a fair speed across the base board!

Now to actually drill some holes and try the strip out in anger.
If I get reasonable results I'll start a new thread here detailing the project.

I'm a cautious guy.
Don't have the confidence of other constructors who publish as they go along!!

Kind regards,

Graham

by **gary** » Mon Apr 22, 2013 5:46 pm

AncientBrit wrote:
Actually ran the lead screw from a power drill and had the sledge motoring at a fair speed across the base board!

Graham

Replace the power drill with a stepper and some simple electronics and you have a one axis CNC! :-)

by **AncientBrit** » Mon Apr 22, 2013 6:01 pm

Gary,

That's a possiblity for the future!!

I don't claim any durabilty for the device.
It's largely wood/chipboard construction so I think humidity might compromise the results.
It's essentially a one off to create the strips.

Regards,

Graham

by **gary** » Mon Apr 22, 2013 6:16 pm

a couple of coats of sealer fixes that problem

by **AncientBrit** » Mon Apr 22, 2013 6:22 pm

Good idea,

Graham

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