wondering if any one here has made or used one of these and can give us some ideas on required turns required.

https://vk2zoi.com/articles/half-wave-flower-pot/

they look ideal for some sites used as there easy to blend in and not stand out like a sore thumb.

I've used them loads of times. They're a good quick solution. The 2m and 4m dimensions are widely available.... The 3m version is easily deduced from the other information!