Timing Diagram Tool?

[xray]

Eraser shield: 0.0038" SS (0.1mm?)
3.5" floppy window: 0.014" plastic or 0.0073" SS

Sounded thin. You made me check. My eraser shield, probably from the
'60s, seems to be .0051" . (I have no way to measure just the areas
close to my most frequent mistakes -- maybe a bit thinner.) Another case
of the cheapening of modern products?

Hmm. Just noticed there is a very slight cylindrical curve to the
device. I was never instructed about that, or forgot, seems the proper
application would be convex down?

 

[Spehro Pefhany]

Sounded thin. You made me check. My eraser shield, probably from the
'60s, seems to be .0051" . (I have no way to measure just the areas
close to my most frequent mistakes -- maybe a bit thinner.) Another case
of the cheapening of modern products?

Maybe they didn't have the technology to make it that thin back then?
;-)

Hmm. Just noticed there is a very slight cylindrical curve to the
device. I was never instructed about that, or forgot, seems the proper
application would be convex down?

Dunno, I don't recall any formal training in using a shield. I barely
remember using a drafting table with the arm etc. in high school.

 

[Chuck Harris]

Sounded thin. You made me check. My eraser shield, probably from the
'60s, seems to be .0051" . (I have no way to measure just the areas
close to my most frequent mistakes -- maybe a bit thinner.) Another case
of the cheapening of modern products?

Hmm. Just noticed there is a very slight cylindrical curve to the
device. I was never instructed about that, or forgot, seems the proper
application would be convex down?

I don't think the curve was intentional. I think it was a result of
punching all of those fancy shaped holes. My recollection is the concave
side has all sorts of sharp burrs that will eat your eraser PDQ. I always
used mine with the concave side down.

-Chuck (Can 1970 really be that long ago? Damn!)

 

[Spehro Pefhany]

I don't think the curve was intentional. I think it was a result of
punching all of those fancy shaped holes. My recollection is the concave
side has all sorts of sharp burrs that will eat your eraser PDQ. I always
used mine with the concave side down.

Oh, that's what he meant. Yes, one side is rounded a tiny bit and the
other has a sharp edge.

-Chuck (Can 1970 really be that long ago? Damn!)

http://en.wikipedia.org/wiki/Image:Brady_Bunch_2.jpg

 

[Winfield]

Nah, that was Teledeltos paper. It was electrically conductive, with a
sheet resistance of something like 10k ohms per square. You cut it with
an X-Acto knife, put a voltage across it, and it solved the 2D Laplace
equation for voltage drop vs position pretty well. I went looking for
some a few years ago--it had been picked up by a British outfit,
allegedly, but they didn't seem to have any for sale any more.

Bob pease talked about the sources for Teledeltos paper:
http://www.elecdesign.com/Articles/Index.cfm?AD=1&ArticleID=2323
His links didn't work for me, but the modern equivalents weren't
hard to find. Sensitised Coatings, http://www.senco.co.uk and
Pasco, http://www.pasco.com/products/groups/70-482-1.html

 

[qrk]

[snippage]

Hmm. Just noticed there is a very slight cylindrical curve to the
device. I was never instructed about that, or forgot, seems the proper
application would be convex down?

I always bent mine concave side down. Makes it easier to pick up.

 

[Joerg]

Oh, that's what he meant. Yes, one side is rounded a tiny bit and the
other has a sharp edge.




http://en.wikipedia.org/wiki/Image:Brady_Bunch_2.jpg

When we moved out here we briefly had an apartment and thus cable TV.
Then I discovered that there was one Episode of Gilligan's Island every
morning at 6:30am or so. My wife said that I've got to be kidding...

 

[Joerg]

Bob pease talked about the sources for Teledeltos paper:
http://www.elecdesign.com/Articles/Index.cfm?AD=1&ArticleID=2323
His links didn't work for me, but the modern equivalents weren't
hard to find. Sensitised Coatings, http://www.senco.co.uk and
Pasco, http://www.pasco.com/products/groups/70-482-1.html

Thanks! But it looks like Pasco has that weird habit of not disclosing a
price until you key in your personal info, including school. So I guess
it's academia only?

 

[Spehro Pefhany]

When we moved out here we briefly had an apartment and thus cable TV.
Then I discovered that there was one Episode of Gilligan's Island every
morning at 6:30am or so. My wife said that I've got to be kidding...

Great show. Powering the radio from coconuts. Shame I was outbid on
eBay for lunch with Mary Anne (benefiting charity, of course, she's
such a goody-goody).



Best regards,
Spehro Pefhany