This will not work as is for a cylinder but for a conical scale it might work.
Instead of projecting a line and then indexing the dial you could look at some of the long wave UV photo cure polymers that are used for 3D stereo lithography. You would dip the scale in the resin, pull it out and project an image with a UV modified DLP video projector, no need to dry the resist as you would be hardening it in-situ with the UV image. Have to keep the projector as far as convenient to maximise the focus depth if you have a conical scale (long focus lens) but you could have arbitrary complexity of the artwork that could be changed on every scale.
You would rinse and post cure the resin and then try out various etching methods to get a good bite. You could paint fill and then strip the resin off with a suitable solvent.
This method might have some value in making DIY PCBs as well, I know there are very (very) expensive industrial machines that do just this and have many of these projectors and expose a 50mmx50mm square (or whatever) and scan across the material and have the image track the material motion to get a continuous scan while having a largish projection area (instead of a single laser spot or scan line that is too slow). Imagine a video projector and a simple jig to position a pcb in 50mm grid, you could manually project, move, project and expose arbitrary image. Using the 3D printing resins might be a way to do a wet photo resist at home but I have not tried it. The materials are still a bit expensive but the layer required for etch resist should be fairly affordable.
A Google search found these two interesting hits, the second is just an abstract unless you pay or are a member of some secret cabal.
http://maskless.com/High_Speed_MLI_TechPaper.pdfhttp://www.researchgate.net/publication/24261077_Direct_projection_on_dry-film_photoresist_%28DP%282%29%29_do-it-yourself_three-dimensional_polymer_microfluidicsRegards
Kalle
--
Johannesburg, South Africa
--- In Homebrew_PCBs@yahoogroups.com, "Rick Sparber" <rgsparber@...> wrote:
>
> Bertho,
>
> I have a full machine shop including a Gingery shaper which can cut these
> tick marks. But my goal is to invent a new way to make a graduated dial.
> Being able to etch a dial would be an advancement.
>
> Rick
>
> -----Original Message-----
> From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
> On Behalf Of Boman33
> Sent: Sunday, March 24, 2013 4:03 AM
> To: Homebrew_PCBs@yahoogroups.com
> Subject: RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
> graduated dial
>
> If you do not have a rotary table it is simple to make one since there is
> zero force on the subject. A 100 tooth gear will give you accurate
> indexing.
>
> No art work is needed for the critical lines, either optical projection or a
> laser line source.
>
> Bertho
>