Video link to my new device.....

[Jim in Idaho]

Here's a link to a video I did last fall at Bonanza Bar on the Snake. The prototype was built using a cutoff 55 gallon drum. Diameter is about 22". The units I'm selling are 18". They weigh about 11lbs. Made of painted mild steel, with some moving parts made of stainless. Time to let this cat out of the bag...LOL. Looking forward to comments, good or bad. It doesn't look like much, does it? Hard to believe how well it recovers the ultra-fine gold, even fed nearly bank-run material. And very little water for it's size. The bed is 254 sq.inches.
Jim

 

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[Reed Lukens]

Come on, let some more cats out let's see what's under the rocks...

 

[IMAUDIGGER]

How many hours of continuous use do
you have on that unit?
What did the concentrates look like prior to panning?

 

[N-Lionberger]

Like a mini derocker over a fluid bed?

 

[Jim in Idaho]

On the cons...assuming you know the largest gold size in the spot you're working, you just screen the cons to that size, and then pan what goes through the screen. When you're done with a run, you let the unit run until nothing more comes off the edge. At that point, with an 18" unit, you have about a gallon, or a bit more of material left on the diaphragm. Just screen that to the largest gold size you expect, and pan the remainder. On the Snake I screened to 30 mesh, as there isn't anything larger in the river.
Reed, under the diaphragm is nothing more than a rotating arm assembly, that contacts the bottom surface of the diaphragm and causes it to go up and down in waves.
There are some beneficial aspects to the makeup of those arms...orientation, angle, offset, etc. I'm not yet releasing all that, as testing is ongoing.

Audigger....I haven't run it more than 3 hours, continuously, but have done that several times. The weak spot in the unit is wear on the diaphragm. My overall aim was to make a rig that is really easy to maintain, and requires few special parts. The diaphragm material was a stumbling block in that desire. I tried different materials, and they all worked, but some had to be ordered online, and were costly. I finally tried plain old 6mil visqueen, and it worked better that I expected. It lasts about 2 hours, or a little more, and is available everywhere, and dirt cheap. I usually run it with 2 layers, though I've run the unit, dry, with a single layer, for over 3 hours before the first holes appeared. The rubbing underneath is where the wear shows up. Also visqueen is available in larger rolls in 10 mil, which would last even longer.
The diaphragms are easy to change out, of course.
Another point is noise. The prototype in the video required a larger gearmotor. I had to add an extra outside gearset to slow that motor down. That gearset is kinda crude, and that's what you hear clattering in the video. The finished units are extremely quiet, as they run through a simple enclosed worm gear. The motors, however, are not waterproof.
Here's a pic of the frame of one of the later versions.
Jim

Reed, this pic is for you....LOL....whats under the old lady's skirt!

 

[arizau]

On the cons...assuming you know the largest gold size in the spot you're working, you just screen the cons to that size, and then pan what goes through the screen. When you're done with a run, you let the unit run until nothing more comes off the edge. At that point, with an 18" unit, you have about a gallon, or a bit more of material left on the diaphragm. Just screen that to the largest gold size you expect, and pan the remainder. On the Snake I screened to 30 mesh, as there isn't anything larger in the river.
Reed, under the diaphragm is nothing more than a rotating arm assembly, that contacts the bottom surface of the diaphragm and causes it to go up and down in waves.
There are some beneficial aspects to the makeup of those arms...orientation, angle, offset, etc. I'm not yet releasing all that, as testing is ongoing.

Audigger....I haven't run it more than 3 hours, continuously, but have done that several times. The weak spot in the unit is wear on the diaphragm. My overall aim was to make a rig that is really easy to maintain, and requires few special parts. The diaphragm material was a stumbling block in that desire. I tried different materials, and they all worked, but some had to be ordered online, and were costly. I finally tried plain old 6mil visqueen, and it worked better that I expected. It lasts about 2 hours, or a little more, and is available everywhere, and dirt cheap. I usually run it with 2 layers, though I've run the unit, dry, with a single layer, for over 3 hours before the first holes appeared. The rubbing underneath is where the wear shows up. Also visqueen is available in larger rolls in 10 mil, which would last even longer.
The diaphragms are easy to change out, of course.
Another point is noise. The prototype in the video required a larger gearmotor. I had to add an extra outside gearset to slow that motor down. That gearset is kinda crude, and that's what you hear clattering in the video. The finished units are extremely quiet, as they run through a simple enclosed worm gear. The motors, however, are not waterproof.
Here's a pic of the frame of one of the later versions.
JimView attachment 1559460

Reed, this pic is for you....LOL....whats under the old lady's skirt!
View attachment 1559460

Maybe try some kevlar fabric for the diaphragm(?). Not sure if it is waterproof though.

Much success in your venture!

 

[Jim in Idaho]

Yup, thought of that, but extremely hard to find in a waterproof material...and spendy.
jim

 

[Jim in Idaho]

Another thing about this unit...it works dry, too. The water, when running wet, has no impact on the recovery. All the water does is keep the material from sticking together. Recovery percentage dry is the same as wet. I'll be doing a lot more testing, dry, this summer. I have a couple of old spots that were abandoned back in the old days, due to lack of water. Should make for good testing. But, I have done real runs, dry in the shop, and have panned the tails, and come up with actual percentages. I'm not guessing on any of this.
Jim

 

[Jim in Idaho]

Here's another view of the prototype under the rocks, and some shots of it being run, dry, in a local defunct gravel pit. I did recover some flour gold that day, but not much.

 

[Johnnybravo300]

And at the end of the day you can make some ice cream!

 

[Goldwasher]

What about nylon cordura I know a guy that works with it for very heavy duty raft guide shorts

I know some of it is waterproof

I can get you samples but, the guy is in Thailand until next month.

 

[Goldwasher]

Where does the gold collect?

 

[Lookinghard]

EPDM roofing rubber for membrane

Try used EPDM roofing rubber for the membrane. They keep the pull-offs for people building ponds. 1/16" thick, tough, I use it for a lot of stuff. Small pieces like that might be free if they make it back to the pile. A $50 sheet would last a life time. You’d want the un-reinforced stuff of course, all that movement would make for internal wear on the rubber. Most of it will have no reinforcement. Comes with free gravel stains.

As an aside, does anyone here know how thick the spring steel mounts are on the RP4 shaker table? .050"? .062"?

Lookinghard

 

[Jim in Idaho]

The gold collects on the diaphragm. The diaphragm droops about 6 degrees to the center, or a little more. The collection zone is at the bottom center of the diaphragm.
This device is mainly for people recovering flour. If you're after gold in the +30 mesh range, might as well use a sluice....other than the sluice can't be used dry....LOL
Jim

 

[Jim in Idaho]

Can be found...not readily and easily available, so doesn't meet meet my criteria. Also, probably not flexible enough.
Jim

 

[Gambrinus]

Great job Jim, I really like the idea of it being able to run dry and not having to choke on dust.
Are you going to make a larger size unit?
I wonder if you could use rollers for your arms? maybe not but it would sure make your diaphragm material last longer.

 

[arizau]

Great job Jim, I really like the idea of it being able to run dry and not having to choke on dust.
Are you going to make a larger size unit?
I wonder if you could use rollers for your arms? maybe not but it would sure make your diaphragm material last longer.

Instead of a pair of long roller arms I would suggest each arm consist of a series of narrow rollers/idlers. The outside end of the sweep arm covers a greater distance than at the hub for each rpm and individual rollers would allow them to equalize and turn at it's own rpm on the axle.

 

[QNCrazy]

Does everything under the diaphragm stay dry? If so, I wonder about repurposing an old ceiling fan motor and blades using the low speed setting. Bend the arms and trim the blades to suit. Just brainstorming.

 

[Jim in Idaho]

Actually, I started out with rollers.
I even made them vertically adjustable, so I could try various settings. They have to be able to rotate them horizontally, too, as the offset arms mean the angle they're set at changes as you go toward the center. Very time consuming to machine, so I quit using them after determining what I needed to know. And, they didn't decrease wear all that much. You can't use a long roller as the rotational speed varies with the position along the arm. I've done a LOT of experimenting on this, guys.
I like the skeletonized frame for portability, but for ease of building I'm thinking of using 18" HDPE corregated culvert pipe for the bodies. The trouble with the skeletonized version is keeping the tails scraped away from the motor. You either need a canvas wrapped around the frame, or set the whole unit up on a stand or something.
Jim

 

[Jim in Idaho]

Wrong kind of motor....it requires considerable torque, and I wanted it portable, and that means 12v DC. Everything under the diaphragm does stay dry, assuming you swap out the diaphragms in a timely manner. I've got the max RPM, based on the overall diameter, all figured out. The 18" is just about right on the money. I got lucky finding a good motor to match what I needed....and no speed control needed...just connect to a 12v battery, and go. The motor only draws about 1.25 amps, so a small battery pack gives pretty decent run time.
Jim