## How to calculate Plot distortion?

Moderator: Frank Burgos

### How to calculate Plot distortion?

Hi,
I would like to know if there is a formula to calculate Plot distortion.
Friend of mine works for a company that makes liquid plates. they have a proofing machine with 66" cylinder.
They have a chart of distortion for Polymer and the cad( plot).
I found Frank Burgos' formula for polymer distortion but I was wondering to know how to calculate CAD( Plot) distortion if the actual press that job is going to be printed on has a different size cylinder than 66"?

Thank you
ajflex

Posts: 3
Joined: Sun Jun 24, 2018 9:24 am

### Re: How to calculate Plot distortion?

Don't know if you mean plate , or plot . We work in millimetres here , but will give it a bash ;( will use 330mm cylinder as an example. Using vernier the diameter is 102,04mm )

.Cyl. diameter (102.04) divide by 25,4 ( inches ) = 4,0173228 inches
.Add tape thickness twice 0,020 + 0,020 = 4,0573228 inches (example 20 thou tape )
.Add polymer thickness twice 0,045 + 0,045 = 4,1473228 inches (example 45 thou plates )
.Multiply by Pye 3.1416 = 13,029229 print-out inches
.Multiply by 25,4 = 330,94 Cyl in mm
Distorted Repeat Length ;
.Cyl . diameter as above 4,0173228
.Add tape thickness twice = 4,0573228
.Add 0,015 for discrepancy = 4,0723228
.Multiply by Pye = 12,793609
.Multiply by 25,4 = 324,95766 mm
Distortion Factor .. Divide distorted repeat length ( 324,95766 ) byCyl. 330,94241 = 98,1916%
guy de cafmeyer

Posts: 71
Joined: Tue Apr 14, 2015 3:13 am 