Delta rod length versus build diameter

Now designing my own delta, has become sort of a right of passage into the rep-rap community, I am fighting with my self to make a decision for length of the end effector rod versus build area. The question (at last) is there a sweet spot equation for best operation for build area and the length of the link rod to the end effector, we all know deltas are at there most inaccurate with the rods most vertical, how far do you go with build diameter? Rods horizontal at the furthest reach of the build area or ??????
Any advice would be very much appreciated.
Thank you all for being there.

... I was thinking around the same question when designing my first tripod/delta in 2007 and now again with a much bigger frame - I've posted some images in the German forum:
[forums.reprap.org]

The dimensions are highly depending on the available parts, but essentially it's gut feeling combined with testing.

My columns are 750mm high, the traveling range around 350mm, so I've selected 300mm for the arm-rods and 400mm diameter between the columns -- this will result in a building area of min 280mm diameter and around 350mm building height in the center ...

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Viktor
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A rule of thumb used by a few people around here is that the rod length should be about 80% of the distance between two towers. If your X and Y towers are 300mm apart, you should use 240mm rods.....

Thanks for the advice, I had them a little bit long based on the 80% rule, going to chew it for a few more days and do some simulations before I cut the carbon tubes.

Out of curiosity, are you running the simulations in Jay's Mini Kossel Visual Calculator OpenSCAD package?

https://github.com/Jaydmdigital/Kossel_2020/tree/master/mk_visual_calc2020

I have never used it, and was curious if you were using it for your simulations.....

No never heard of it, I am going to set up some motion simulations in Solidworks, basic line following of the end effector along a path sketch, just to see that all the mates stay good and nothing gets close to an interference.