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Precision screen printing

barbter

Diamond
Joined
Oct 27, 2007
Location
On Tour...
When I worked at the black box company, we used to screen print a lot of panels where some info was finer than this.
Screen mesh size is important (finer = more detail/"crisper"), orientation of mesh is also important as it's 90degree/crisscross.
So you wouldn't want to orientate it with the "vertical" side of the mesh running vertical with what you are printing (hopefully makes sense?)
Basically think along the lines that mesh that is positioned vertical (so a square with vertical sides and horizontal top and bottom) will leech more, if you are printing a vertical or horizontal line. It's to do with mesh contact area.
When the mesh is then rotated 45degrees, the edge of the line being printed, is produced by the mesh "corner".
Hopefully the ramblings make sense - If not I'll sketch and upload a piccy.
 

Scottl

Diamond
Joined
Nov 3, 2013
Location
Eastern Massachusetts, USA
Makes sense when they were building a ton, I have a feeling that now they would silkscreen

But it does bring to mind the do it in house idea.

Making it negative as you mention would make it a lot easier I would think to make your own 'stamp' as it were. Let a little end mill go to work on a chunk of aluminum

Roller some black paint and try it on a white painted chunk of aluminum...

No, the offset printing method used was practical for short runs. A great deal of the orders were custom or semi-custom and the way the factory did it was to have special fixtures to mount the stamped dial blanks that were easy to change. The high volume stuff was done in another section of the plant using different presses.

This was in the days before CAD was widely available and the dial calibrations for non-linear scales such as thermocouples were done using a Fortran program using dial-up access to a mainframe that generated a text printout. The printout was then forwarded to the layout department where a couple of women hand-inked the master patterns using standard drafting equipment. The master patterns were then photo reduced to generate the actual size artwork to burn the plates.

The same Fortran program also calculated windings and springs for jeweled instruments or band size and tension for taut band instruments. Many of the gauges were high end and used for everything from industrial processes to military applications and even nuclear power plants.

PS: If the OP is looking for a one-off the cheapest method would be to create the art on a PC and use either direct toner transfer or toner or inkjet decals. The aluminum we used for dial scales was the same as the white aluminum trim stock used by siding contractors.
 

kustomizer

Titanium
Joined
Aug 17, 2007
Location
North Fork Idaho
Cost is not of real concern, getting them to be as correct to original as possible is the main goal. These will end up on a 1930's toy worth 50-100k. I found a stash of NOS gauges with everything correct except the face markings and fonts. It will be worth my time to learn to do them correct as there are several styles that I can do. I found out yesterday I have a friend who does this, he says he can do them for $53. each for 12 pcs and $2.50 if I get close to 100 pcs. He will do 1 and send it to me so I can check and adjust the location of the printing if required. I think I will try this and see how it goes.
Thanks for your input, it really did help me decide.
 








 
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