Uncut question?

[Westside]

Our office is processing an order for a frame with dimensions:

A: 65
B: 54
ED: 67
DBL: 21
PD: 69/65
Bifocal: ST-28

What is the calculation for an uncut blank size?

:cheers:

Oops Seg Ht: 20

[QDO1]

cant do it without the height

here is a method:

• Draw a neat line on the display lens to repersent the segtop height
• Mark up the mono NOC on the line
• Mark a dot on the display lens 4 up and 2 out from that NOC point - thoretically thats the DOC for a standardly set up D28
• Measure from the DOC point outwards to the furthest point away from the DOC on the display lens extremity
• Multiply your measurement by 2 and add 2mm (for the bevel)

Thats the blank size I would order if I didnt want to optimise the job, when you get the hang of it you can do it in real time on the phone as yopu are ordering the lenses up

By the way in this instance the DOC happens to fall at the geometrical centre of the lens, and thats all you need to know to calculate a blank size on the fly - works for PPL's and S/V too, you just need to know where the GC is and you are sorted

[Darryl Meister]

Keep in mind that if you're ordering an uncut bifocal, the actual semi-finished blank diameter required for your job will also depend upon the manufacturer's segment inset and drop for those lens blanks (often around 5 to 7 mm in, and 5 to 7 mm down for hard resin blanks). This inset and drop generally reduces the total blank size you need for the job. While you could calculate the actual blank diameter to order if you know these parameters, it's faster and more accurate to use an actual cut-out chart, if you can get one.

[spartus]

That is one big frame! You must live in the land of giants.