A few on here have asked for high seat plans so i've rattled up a set. I teach technology and engineering so creating a design/CAD lesson for the students that just happens to cover a simple lean'to ladder frame structure is pretty easy.
Now i'll warn you right at the start that the design is no beauty - there's no lovely mitred welds with compound joints. Rather, i have designed a seat that is very easily to manufacture with the minimum of tools:
Drill & 12mm bit
emm.....that's about it.
Building materials have been kept to a minimum so no hard to get items and the largest part is 6ft in length- therefore should be easily transported in or on a family car. Your materials list will include:
A handful of 12mm nuts & bolts
25mm box section
30mm box section
30mm angle section
I freely admit that the design is overly 'strong.' I was tempted to design it lighter but murphy's law dictates that i'll get a complaint from some 300lb armchair warrior who'll fall off after dragging his lardy arse up one.
Please feel free to forget the height adjustment mechanism if you wish but do not decrease the size of the rail. A seat with too small a rail is a bloody nuisance and uncomfortable to shoot from.
The parts may be broken down for moving and the height can be increased by simply adding another ladder frame section.
I'll post the plans here in jpg format or can send electronic copies to anyone who pm's me. I suppose i could send paper copies to those willing to cover the cost of envelope, postage, etc but perhaps admin would prefer to 'sell' them as a means of raising site funds?
I'll add a timber version, free standing and perhaps swivel types if there's a demand.