Anybody able to help Mark?

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Anybody able to help Mark?

Postby acl » Sun Jul 02, 2017 9:37 pm

Please pass this on to a member that you think can help me.

I have constructed a 3D printable Nipkow disc and I'd like to get it to
agree to the NBTVA standard - which it currently doesn't quite. (I used
to be a member, on and off, 30 years ago- still got my newsletters :)).

I'd like someone to help me close the gap and finish the design off so
it matches the NBTVA standard at the least.

Currently it is implemented in OpenSCAD which is a procedural language
for generating 3D objects. The Thingiverse site has a customiser option
which enables users to change parameters and generate objects for
printing directly.

You can see (and adjust) my current approximation here:
- https://www.thingiverse.com/thing:2414716

Its not right for Syncs, its also calculating the hole size based on
non-overlapping scanlines but it is not preserving the aspect ratio.
There are several ways to do this and I'd like to use the one most
compliant with using the NBTVA standard.

Naturally users can deviate from this and make all kinds of variations.

I'm also intending to write an Inkscape extension (based on the same
code) so laser cutters can cut Aluminium disks directly and even get
square holes for better S/N than round ones. I seem to recall a
discussion many years ago about the shape being a parallelogram (or
diamond ?) of some kind but can no longer find the reference (something
to do with relative brightness, equal exposure and swept angles).

Hope things are going well for you all.

Cheers, Mark Schafer
acl
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Posts: 111
Joined: Thu Mar 08, 2007 7:38 am

Re: Anybody able to help Mark?

Postby Andrew Davie » Sun Jul 02, 2017 10:43 pm

acl wrote:Please pass this on to a member that you think can help me.

I have constructed a 3D printable Nipkow disc and I'd like to get it to
agree to the NBTVA standard - which it currently doesn't quite. (I used
to be a member, on and off, 30 years ago- still got my newsletters :)).

I'd like someone to help me close the gap and finish the design off so
it matches the NBTVA standard at the least.

Currently it is implemented in OpenSCAD which is a procedural language
for generating 3D objects. The Thingiverse site has a customiser option
which enables users to change parameters and generate objects for
printing directly.

You can see (and adjust) my current approximation here:
- https://www.thingiverse.com/thing:2414716

Its not right for Syncs, its also calculating the hole size based on
non-overlapping scanlines but it is not preserving the aspect ratio.
There are several ways to do this and I'd like to use the one most
compliant with using the NBTVA standard.

Naturally users can deviate from this and make all kinds of variations.

I'm also intending to write an Inkscape extension (based on the same
code) so laser cutters can cut Aluminium disks directly and even get
square holes for better S/N than round ones. I seem to recall a
discussion many years ago about the shape being a parallelogram (or
diamond ?) of some kind but can no longer find the reference (something
to do with relative brightness, equal exposure and swept angles).

Hope things are going well for you all.

Cheers, Mark Schafer



Well since I've been openly promoting OpenSCAD for some time, I'm quite familiar with it. I would be happy to have a chat to Mark about his needs.
The forum is a far better place than private correspondence, though!
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Andrew Davie
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