System looks nice. I would shut down due to a few items, for one, you will be draining battery power, and two, could possible loose gold if the unit was left running.

It may not be easy access to transport the unit into the work area, save all the power you can.

I prefer my top angle a little steeper to ensure the rocks roll/slide off when feeding. As for the surge load and lossing some material, load some feed on first before starting to slow down the run or start one pump at a time.  You can add some inline vlavs near the feeder end also for flow control.

Keep up the good efforts.

Thanks for the reply.  I was going to add valves, but did not because the total flow is about 3600 GPH.  So, I did not add them because I could not think of a situation where I would want less water.  The shut down issue was something that I did not think about till later.  Frankly, if I put one more dime into this I will be in big trouble, if you know what I mean.  Any future improvements will have to be from the gold haha.  I will go with the shut down approach.  Even without valves, I can rotate the spray bars up slowly so they shoot water out of the top box, then kill the pumps.  The low angle on the hopper is intentional.  You cannot see it clearly in the video, but I have carpet with expanded metal in the top box.  I consider it a "rock message" box rather than a gold hog "destruction box".  There is a dam in the top box to slow the movement of material even more.  I watch a lot of videos and it looks like a lot of material falls out the back when the angle is extreme, especially clay.  Finally, I really like looking at and pushing the rocks.  Less material goes through, but it sure is faster than panning.

Thanks Ron:

Good advice.  I plan on a full day of testing soon and will post the recovery.  It really was a test run and I still have some finishing touches.  I was actually shocked that I did not forget anything.  I was up until 1:00 AM the night before getting the legs finished and mounting the spray bars.  Still need the expanded metal on the bottom and I am going to make a second set of spray bars with slightly larger holes, then do some water volume tests.  The last thing I realized before bed was that I did not have any punch plate at the top of the bottom box.  I got the drill and a piece of scrape aluminum and drilled holes until the battery was dead.  It was really nasty looking, but had to do.  

One thing I can say is that there is a lot more to building one of these than meets the eye.  I plan on making a video at the house going over the whole build including some credits for the local metal shop that did the bending.  It was hard just to find a shop that I felt comfortable working with.  I bought the sheet aluminum and marked all the bend and cutting locations.  The most important advice that I can give is to make a full scale cardboard mock-up.  It helped me spot issues and make adjustments.  I also left the cardboard model at the metal shop with the flat sheet.  I thought it might be silly, but they said it made their work much easier and faster.  They had estimated $45-$60 for bending and cutting both boxes and the charge was $45, which I thought was a pretty good deal for a commercial shop.