Im in the process of designing a new one so ill explain what ive got going on
1 - keep my sluices so they easily fit in my boot or anyone elses car with ease. Sluice extensions slide inside one another incrementing down in size.
2 - drawing the design makes this a lot easier than ending up with random drill holes everywhere and bolting things on. Quick clamping systems which lock in place. Most attachments ( trommel ) are pre-thought and added to design. Quick leg changes in height should be simple as can be, keeping in mind that sand always fills and blocks most designs.
3 - has been a struggle to minimize the height of what to shovel into, so i want to have a sluice i could launch a shovel load at it at least 1 meter away onto a strong backplate, rather than lifting. If i have no choice i make a ramp from my tailings and rocks to walk up and out of my hole. Eventually the ramp is as tall as the sluice.
4 - cleanup im thinking the simple lock down and clamping riffle / mat design. One clamp to unlock / lock all layers. cleanup can be annoying as we struggle to unclamp, roll mats, lift sluice into a bucket..etc. a simple tray that clips onto the sluices end after mesh and riffles lifted, washed down with a spray of water from a garden hose sprayer. I tend not to mess with cleanup or even looking at my finds while digging. It all goes straight into a container with the days heavies collected.
5 - depends on the area
6 - banker should be structually build strong. I use thick alloy ( wish i could weld it ), around 3-5mm mostly and some thinner in sections of the sluice. A strong design in how the legs keep the system straight and sturdy by holding the top and bottom sluice as one. I now use a small clamp over the top of the sluice walls to hold its shape strong from water and rock forces pushing the walls outwards and making the sluice bend under matting.
7 - i try to keep it so the banker can be held one handed always, even when assembled but struggle at times with this. They are roughly the same weight as a walbanker and the option to carry it on your back is useful as well so keep that in mind. Ive thought of a transforming wheelburrow / sluice with a wheel or multiple wheels as well.
8 - always consider everyones designs. As jemba said, basically a stick in a cardboard box will catch gold, just make what suits you. Be careful of dodgy fast built sluices if you are buyingone. Check for upside down riffles.. sloppy tack welds leaving gaps everywhere and vortexing issues..too thin of material and the innability to modify freely..etc.
Be creative and try something new. Something i use that i dont see many members use, is matting and mesh in my top box. This isnt only useful for rubbing and breaking clays, but why not have an extra carpet on the top box? I catch gold up there as well as below.
Might be a bit of a mixed post ive done here but just trying to input from my perspective on things as ive dealt and seen most issues sluices have had and read most studies about designs and vortexes that others have done through the years. My first sluice was a 12" wide river sluice ( stollen now ) that had yukon style riffles on it. I needed 3 times the water to make the riffles even turn material and they just didnt happen. They would be great riffles on a steep, fast sluice for chunky gold though, but no good for gravity creek flow :lol: