I had this topics up before and has been try get a solution.
It's no real need to has a equal sided triangle as Plop do the math, but its more easy do them equal ( even in CAD/CNC machine ) and centre is correct located so balance is perfect.
If I take my cell for a example.
457 mm in diameter. ( 18" )
1829 mm FL ( f/4 )
33 mm edge thickness.
18 pt cell.
Automatic cell get's me a nm RMS at 9.2e07.
That gets me the 2 radius at ;
Now I did a even radius to 0.8 and 0.4 and run the program.
The side # 2-3 got me a number.
The #1 side got me a shorter number.
To get this equal one has to add +15.47% on that shorter number, and then the triangles is equal.
In program I let the radius 0.8 be there but I must adjust the radius 0.4 some.
The number was instead 0.414111, so one add 3.525 %.
The readings in Plop now show a hair more at 1.15e06 now, so it's a 'price' to pay.
A note here.
One could try adjust the 0.8 radius to get it more equal, so then the nm RMS readings might be little better, or clooser to the automatic number.
Edited by hakann, 11 May 2019 - 01:28 PM.