I think that it has something to do with copper thickness, but what does the number with the copper cups mean? If it is thickness, how thick is it in comparison to millimeters? Thanks.

If you're referring to something like "made from .050" copper", then it refers to the thickness of the copper the cup was spun from.

.050" is an imperial measurement. It means that the thickness of the material is 5/100 of an inch thick.

After the decimal point, it is like units, tens, hundreds etc but the first number is tenths, the second is hundredths, the third is thousandths and so on.

I hope this has explained rather than confused.

Tom

Alright, thanks.

I asked about it in millimeters only because I read somewhere about Gary Animal making the Gazzo cups in 2 millimeter thick copper. Alright, thanks.

Actually I was also wondering what that meant. Your answer Tom was not really clear, I am not a wizard with numbers, I already have some problems with the metric systems not even to mension another system.


Do you know what these measurements are in millimeters?

Thanks.

Etienne

The Imperial system is the one that uses inches, feet, miles etc.

One inch = 2.54 mm.

.050 copper means that the copper thickness measures five onehundredths of an inch (5/100").
.075 copper means that the copper thickness measures seventy five hundredths of an inch (75/100").
.008 means that the thickness is eight one thousandths of an inch (8/1000").
.300 means that the thickness is three tenths of an inch (3/10").

From memory, the only size I know, apart from the one inch one above is that 1/16 of an inch equals 1.6mm or 1/16" = 1.6mm.

Just looked at my calculator and 0.050 inches =  0.127mm.
So a cup that is made from 050 copper ought to be 0.127mm thick.

I hope that I've made things a little clearer.

Tom

Thanks Tom,

that made I much clearer for me. So, the g2 at RnT2 are 0.068 thick. That would be then 0.172 millimeters.


That would make this set very mega,mega thick. For comparison, what is the normal thickness of a cup?

Etienne

Etienne,

I'm not sure what the normal thickness of cup material is, I'm not even sure if there is a normal thickness of the materials used.

I don't have access to accurate measuring instruments at home.
I can measure the cups at work using Vernier Calipers and micrometers to find out an average of the cups I own. It will have to wait until January 5th though, I'm on vacation until then.

Tom

Nearly right . It wirks out to be 1.27 mm approx. That is the sheet thickeness.
I spin fron 1.2  1.6 and 2mm sheet.  0 .127 mm is to thin to spin.
Happy new year

Most cups are spun from 1.27mm copper . Some like riser jumbos are heavier at about 1.6 mm or so. I use 1.27 for regular and 1.6 for thick and 2mm for mega thick. most people prefer cups spun from 1.6 or there abouts . 2mm producers a very heavy cup and its a bugger to spin. I'll be doing mostly 1.6mm from now on and 2mm now and then. I have some 1.27mm copper and when thats gone that will be it.
Another point is how good the spinner is . You could start with 2mm and end up with a cup as thin as 1.2mm . One technique keeps the disc flat and it thins as it takes shape .
The other involves getting the disc over into a cone shape real quick. It then lays down to the chuck without thinning . Also if the copper is annealed a lot you'll end up with a soft cup. It's best to let the copper work harden. I anneal the copper before I start as it comes semi hard and then do not anneal again. 

Sorry about that, I forgot move the decimal point.

My only excuse is, it was late at night when I posted.
Apologies to anyone I misled.

Tom

Thanks Gary for clearing that up.


You helped me very good Tom, mistakes can happen and what is in a decimal point.

Etienne

Thanks Gary and Tom!