Something for the small operator

[Red_desert]

If you are talking about South Africa uranium... it's a very interesting geology. Where gold ore formed deep in the ground from ancient alluvial deposits, same is true of nearby uranium deposits.

 

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[Red_desert]

a few things going on with the resurgence of uranium. Last visit underground was about a couple months ago checking out a uranium mine with this fella from South Africa.

Oh, I see it was only a guy from South Africa checking out a uranium mine.

 

[arizau]

doing a crash course in centrifuges and pretty much settled on on getting a Neffco Bowl but Larry Neff passed away and Global has taken over the manufacturing of the bowl. They want $8000 usd for a new one and I cant find a used one atm. I actually can but then its just the same bunch of guys that like to mine the crap out of the miners

im in Canada and $8000 usd is about $15,000 cad. I dont want to spend $15,000 on a bowl just to see if it works, Global went radio silent when i asked if they would send me one for a week or knew of anyone local to me that could rent me one for a week and if it worked id buy it.

these things arent exactly brain science, its a bowl that spins at 120 rpm using a 120v, 1/2 hp, 1800 rpm motor going to a 15 to 1 gear box. the bowl you could copy cat the angles of a frontier bowl and then just glue in the extruded rubber riffle. from staring at pictures and paused videos i pretty much know the profile but does anyone have a profile pic of the extruded rubber riffle with dimensions? so i can just get it extruded locally or know where to buy 100 feet of it?

Maybe the manufacturer sells replacement parts(?).....might be worth the investment.

 

[Assembler]

Maybe the manufacturer sells replacement parts(?).....might be worth the investment.

Not seeing much in the way of parts. If one wants a number of units may be out of reach for many.

 

[gautman]

i printed a profile, going to play with the shape a little but its close

 

[gautman]

want to make it a little beefier to hold up to the 5g's. the rubber riffles in the original bowl this thread started on were thin and flapping in the wind

 

[Assembler]

i printed a profile, going to play with the shape a little but its close

View attachment 2183495View attachment 2183495

Will the shape of the rubber support much weight spinning?

 

[gautman]

Will the shape of the rubber support much weight spinning?

you saw the neffco bowl bottom riffle open right up from the weight of the sand, showing the inside "slit". at the "toe" of my design instead of a chamfer ill just make it round so it will match what ever angle the "heel is at. then ill fatten the "ankle" a little bit. i dont think the 5-G's play too big of a factor because inside the riffle it will have water and sands in there mixing around and exchanging but it wont hurt to beef it up afaic

 

[gautman]

Maybe the manufacturer sells replacement parts(?).....might be worth the investment.

global, the new manufacturer of the bowl, wouldnt give me the time of day once i started asking for the cost per hour, maintenance schedule, life of the riffles, life of the gear box. just "Poof!" that was it, no more emails. i think its bevause they dont know but i was told by someone they can go 24/7 for 3 years before the riffles wear out but........ i dont know about that.

 

[gautman]

 

[Assembler]

you saw the neffco bowl bottom riffle open right up from the weight of the sand, showing the inside "slit". at the "toe" of my design instead of a chamfer ill just make it round so it will match what ever angle the "heel is at. then ill fatten the "ankle" a little bit. i dont think the 5-G's play too big of a factor because inside the riffle it will have water and sands in there mixing around and exchanging but it wont hurt to beef it up afaic

The super flexing of the rubber cup shape will make for easy and faster cleanups is the upside.

There will be some flexing or shape change going on as that part of the cup channel fills up under 5 g's of force.
This may be a good trade off and some material will just spill over to the next higher rubber channel ring area. The stated holding capacity is around 1 gallon of materials.

 

[Assembler]

global, the new manufacturer of the bowl, wouldnt give me the time of day once i started asking for the cost per hour, maintenance schedule, life of the riffles, life of the gear box. just "Poof!" that was it, no more emails. i think its bevause they dont know but i was told by someone they can go 24/7 for 3 years before the riffles wear out but........ i dont know about that.

The 5 g's of force will eat up likely the front or leading part of the rubber the fastest and will effect the material holding capacity of the over all rubber cup channel over time. Maybe a new front or leading channel could be added after a year or two??

 

[gautman]

if you read earlier in this thread someone mentioned that they start losing more gold as they wear down. the reverse spiral forces the heavies down which naturally causes the lights to go up. i think you have no choice but to rip out the rubber riffle and put in a new one.

 

[tamrock]

That country / rock out crop looks uniform in color and minerals looking at the photo.
I take it that there is a speck here and there going through the rock?

Not your first rodeo if you have been at it since 1977 my hat is off to you.

Me and the cat are just a and it shows.

It was a great way to make a living. So much has changed from the way things were done 46 years ago.

 

[Assembler]

if you read earlier in this thread someone mentioned that they start losing more gold as they wear down. the reverse spiral forces the heavies down which naturally causes the lights to go up. i think you have no choice but to rip out the rubber riffle and put in a new one.

The manufacture appears to give no guidelines on wear rate time or use. Should one just measure the rubber every few months or so?

 

[gautman]

i think you have to measure the amount of float gold coming out of the bowl. then you would have an idea of the lifespan. if the bowl catches 90% and the float is at 10 % and then after awhile the bowl only catches 80% and 20% is in float youll know the riffles need replacing. i really dont know. im a placer miner with about 500,000 yards of sand to wash to get the -100 mesh gold out of it. for me its easy. if after 6 months or a year i notice that gold totals are steadily decreasing, id just replace the bowl to see if that fixes the numbers.

 

[Assembler]

i think you have to measure the amount of float gold coming out of the bowl. then you would have an idea of the lifespan. if the bowl catches 90% and the float is at 10 % and then after awhile the bowl only catches 80% and 20% is in float youll know the riffles need replacing. i really dont know. im a placer miner with about 500,000 yards of sand to wash to get the -100 mesh gold out of it. for me its easy. if after 6 months or a year i notice that gold totals are steadily decreasing, id just replace the bowl to see if that fixes the numbers.

I'm thinking of measuring the depth especially the first 25 percent of the front or lead of the channel / ring. If the depth and edges go down say 20 -35 percent just replace that first part. Maybe for some it will be every season just depends. With 500,000 yards the rubber will wear quickly. Maybe have some spare bowls to replace when needed?

I can see why you are concerned about the start up costs now. You don't know how much values there may be in the yards of sand and I'm sure it will change as you proceed through the materials. Some of the sand may contain more or less values then other sands.