Sorry no pics of Kayak Cart but i made it out of 1 1/2 sch 40 pvc, 6 tees and 2 caps, 1 36" piece of all thread 1/2" , and 2 Power Wheels that a really nice Guy from BWE sold me ( They WORKED Perfect BTW )
It is very lite, about 21" wide at top that kayak sits on which fit into the like tri hull areas of the bottom. 1 strap and i'm rollin....
Also the wheel spread is about 26" on the inside and if you add the tire width which is 7 3/4 that is how wide it is , Very stable
OH YES for the axel i Glued 2 tees apart about 20" then glued on the 2 caps , then i drilled the holes in the caps to 1/2 " slid in axel 2 Nylock nuts and axel is solid put on Power Wheels then 2 Nylock nuts DONE
Rolls Great Painted it, strapped it to Kayak and Proceded to Baja around my property works great and with wide tires i think it will go through deep sand easily
Hope this helps i'm not that computer literate to post pics mabee some day Bob..............................