dingebre wrote on Sat, 15 May 2010 14:06
Hi James,
Coming from an education in mechanical engineering and physics, the
terms "mil" and "thou" are completely unambigous and equivalent. That
said, I think in the world of PCB layout, "mil", "thou", and "mm" do get
confusing, especially to one with little or no machining background or
mechancial engineering studies.
Form my experience, "thou" is more arcane and "mil" is more commonly
used. Either works.
Maybe there is a cultural thing here too. First, I am not a mechanical
engineer so I don't have any background in using this term in that context.
Second, I grew up in Canada as the first generation that only learned
metric and not imperial units. Thirdly I grew up on a farm so we weren't
often concerned with things that were so small--if you couldn't fix it with
a hammer, some binder twine, and a role of duct tape it wouldn't last very
long 
In any case, I have heard mil used as a short form for both "millimeter"
and "mm" within about 15 minutes in a high end PCB design class by an
American (who has been educated in imperial units)! This person is very
well known and well respected in the PCB design world.
The reason I like "thou" is because it is arcane and no one uses it any
more for anything. So I can define that in my organisation as 1/1000 of an
inch. I realise it could be confusing but for us it is not. I have yet to
hear a better alternative that isn't confusing. I'm open to it though
since I like unambiguous.
Quote:
A curse on whoever set up English units!
Agreed. I suspect most of those units were devised in the late evening
inside English pubs.
--
James Morrison ~~~ Stratford Digital
email: james@eaglecentral.ca
web: http://www.eaglecentral.ca
Specializing in CadSoft EAGLE
Online Sales to North America
Electronic Design Services
EAGLE Enterprise Toolkit
--
Web access to CadSoft support forums at www.eaglecentral.ca. Where the CadSoft EAGLE community meets.
dingebre wrote on Sat, 15 May 2010 14:06
Hi James,
Coming from an education in mechanical engineering and physics, the
terms "mil" and "thou" are completely unambigous and equivalent. That
said, I think in the world of PCB layout, "mil", "thou", and "mm" do get
confusing, especially to one with little or no machining background or
mechancial engineering studies.
Form my experience, "thou" is more arcane and "mil" is more commonly
used. Either works.
Maybe there is a cultural thing here too. First, I am not a mechanical
engineer so I don't have any background in using this term in that context.
Second, I grew up in Canada as the first generation that only learned
metric and not imperial units. Thirdly I grew up on a farm so we weren't
often concerned with things that were so small--if you couldn't fix it with
a hammer, some binder twine, and a role of duct tape it wouldn't last very
long
In any case, I have heard mil used as a short form for both "millimeter"
and "mm" within about 15 minutes in a high end PCB design class by an
American (who has been educated in imperial units)! This person is very
well known and well respected in the PCB design world.
The reason I like "thou" is because it is arcane and no one uses it any
more for anything. So I can define that in my organisation as 1/1000 of an
inch. I realise it could be confusing but for us it is not. I have yet to
hear a better alternative that isn't confusing. I'm open to it though
since I like unambiguous.
Quote:
A curse on whoever set up English units!
Agreed. I suspect most of those units were devised in the late evening
inside English pubs.
--
James Morrison ~~~ Stratford Digital
email: james@eaglecentral.ca
web: http://www.eaglecentral.ca
Specializing in CadSoft EAGLE
Online Sales to North America
Electronic Design Services
EAGLE Enterprise Toolkit
--
Web access to CadSoft support forums at www.eaglecentral.ca. Where the CadSoft EAGLE community meets.
