MY NEW TROMMEL PROJECT FOR A FRIEND

[jog]

I HAVE BEEN BUILDING THIS NEW TROMMEL FOR MY 74 YEAR OLD MINING PARTNER. I'M ABOUT HALF WAY THERE....

 

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[AzViper]

Go easy on me now, I'm not a craftsman like Jog. Like I said before I may put the spray bar inside and it will be metal. I agree it needs to wash good first before it hits the screen. It's got at least a 1' 1/2 before it hits the screen. If you have it tilted too much then no it won't wash enough. Its more in the angle then the length. Below are some pics of commercial built trommels. They obliviously thought it doesn't need much before it hits the screen.

Remember the hopper is only recieving the rock and dirt. Not a lot of action until tthe material transfers into the trommel. Yes water is spraying on the rocks and dirt in the hopper but the real washing happens in the trommel. You really cannot count on a good washing in the hopper. Just my two cents...

 

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[russau]

fine design on the trommel! it even has a place to hold my drinks!

 

[JeromeAz]

Remember the hopper is only recieving the rock and dirt. Not a lot of action until tthe material transfers into the trommel. Yes water is spraying on the rocks and dirt in the hopper but the real washing happens in the trommel. You really can count on a good washing in the hopper. Just my two cents...

Right. The water does start to soak in the material loosing it up and pushes it in to the trommel and then the trommel does it's work by spinning the material around so it pounds the rocks and clumps together to break it down. The water helps to break it down, wash the rocks clean then push it out the screen.

Does a trommel need water? In my opinion, No. Now remember that's just my opinion. I'm sure other people would say different or call me a nut. A trommel works better with water then without. Its all the rolling around in the drum that does the work loosening the gold from the material. The water helps to wash it off and wash it out. Now obviously if you have a sluice attached your going to need the water unless you have a couple vibrators on your sluice and you want to try dry washing.

I've come across a couple of pictures of people's trommels that had no water system. They just turned the material and it dumped into buckets to be panned or sluiced later.

Jog's trommel has enough drum there to clean the rocks thoroughly. Like he said he could hold the rocks in there all day if he wanted.

It all depends on the angle.

 

[jog]

I have been going to add two spray nozzles that would spray water backwards into the hopper to help brake up and hold the material in the hopper for just a little longer.
jcazgoldchaser, I believe in your previous post you stated that I dislike the spraybar on the outside of the drum, If you are refering to my video that I made of my friends trommel I was saying I wasn't happy with the sray nozzles in the hopper not the drum. I like the spray bar on the outside of the drum, I wouldn't build it any other way unless I had a larger drum and a grizzly on the hopper.

jog

 

[AzViper]

I have been going to add two spray nozzles that would spray water backwards into the hopper to help brake up and hold the material in the hopper for just a little longer.
jcazgoldchaser, I believe in your previous post you stated that I dislike the spraybar on the outside of the drum, If you are refering to my video that I made of my friends trommel I was saying I wasn't happy with the sray nozzles in the hopper not the drum. I like the spray bar on the outside of the drum, I wouldn't build it any other way unless I had a larger drum and a grizzly on the hopper. jog

As an Engineer I just can't believe you get the same results with the spray bar on the outside over having the spray bar on the inside. Your spray nozzles mounted on the outside of the cylinder are competing with the rotation of the cylinder and the spray of water being interrupted by this rotation. The spraying water will not get a clean clear shot at the rocks. This would be like trying to run across three lanes of traffic at rush hour, you may get to the other side if your lucky. You have the same amount of water entering the cylinder but not with the force of water spraying directly onto the rocks with the spray bar mounted on the inside. I can understand if you used PVC and it broke by rocks getting caught on it but there are ways to solve that issue.

 

[jog]

If I had dirty rocks coming out of the end then I would think about changing my setup but since I don't have that problem I will stick to the way it is. Have you watched the video of my trommel working? no dirty rocks. I am no expert but if everything is washed clean and all the gold is between the ribbed matting and the first two riffles then thats ok with me.

 

[AzViper]

If I had dirty rocks coming out of the end then I would think about changing my setup but since I don't have that problem I will stick to the way it is. Have you watched the video of my trommel working? no dirty rocks. I am no expert but if everything is washed clean and all the gold is between the ribbed matting and the first two riffles then thats ok with me.

Jog, never said it did not work, I said, "I just can't believe you get the same results" Furthermore its more expense and more work to build that design. Most people in these forums do not have an open wallet and most are on a budget. Again it all comes down the amount of time the rocks stay within the cylinder. As I said, the spraying of water however you look at it is being interrupted by the rotation of the cylinder with the spray bars on the outside.

 

[AzViper]

Go easy on me now, I'm not a craftsman like Jog. Like I said before I may put the spray bar inside and it will be metal. I agree it needs to wash good first before it hits the screen. It's got at least a 1' 1/2 before it hits the screen. If you have it tilted too much then no it won't wash enough. Its more in the angle then the length. Below are some pics of commercial built trommels. They obliviously thought it doesn't need much before it hits the screen.

View attachment 822570


View attachment 822571


View attachment 822569

OK so the one's a little big but you get the idea.

I do have some other ideas in mind.

Jerome, of the four images you provide (only 3 showed up) all four have the spray bar inside of the cylinder and only one has it done correctly using a steel pipe and mounted far enough below the top of the rotating cylinder. This is the same image I posted earlier in this thread. You will arrive with what's best for you. Don't let me or anyone else sway your thoughts. I am only pointing out what I see. Your geared for the trommel being light weight so think of ways to shed the weight not add weight.

 

[jcazgoldchaser]

I have been going to add two spray nozzles that would spray water backwards into the hopper to help brake up and hold the material in the hopper for just a little longer.
jcazgoldchaser, I believe in your previous post you stated that I dislike the spraybar on the outside of the drum, If you are refering to my video that I made of my friends trommel I was saying I wasn't happy with the sray nozzles in the hopper not the drum. I like the spray bar on the outside of the drum, I wouldn't build it any other way unless I had a larger drum and a grizzly on the hopper.

jog

Nope, I'm the 'less screen, more water slush area' guy.

Spray bar inside reduces max material size.
Spray bar outside reduces efficiency because screen occasionally blocks stream.

I was thinking all the plants I've seen only seem to go larger with a pipe inside the drum. Instead,... multiple smaller diameter pipes. A rectangular tube or, build a semi-circular chunk of tube to conform to the drum.

Large wash plant/hopper. At least big enough to drop a load and let water wash it into the barrel. Area of drum to wash rocks just like river tumbles them in the water during a storm. Then screen.

 

[JeromeAz]

Jerome, of the four images you provide (only 3 showed up) all four have the spray bar inside of the cylinder and only one has it done correctly using a steel pipe and mounted far enough below the top of the rotating cylinder. This is the same image I posted earlier in this thread. You will arrive with what's best for you. Don't let me or anyone else sway your thoughts. I am only pointing out what I see. Your geared for the trommel being light weight so think of ways to shed the weight not add weight.

OK? Now if only 3 pics showed up then how do know that all 4 have a spray bar? Actually only 3 of the 4 have a spray bar. Who's to say it's built right just because it has a metal spray bar. Does it really matter? It could be pvc, metal, hose or a guy standing there with a hose spraying water in the drum because it doesn't have a spray bar. It doesn't matter. What matters is that it works. Just about every trommel you see is pvc. When they start getting bigger then of course its metal. Mine will be metal because I don't want it getting broke.

 

[JeromeAz]

Nope, I'm the 'less screen, more water slush area' guy.

Spray bar inside reduces max material size.
Spray bar outside reduces efficiency because screen occasionally blocks stream.

I was thinking all the plants I've seen only seem to go larger with a pipe inside the drum. Instead,... multiple smaller diameter pipes. A rectangular tube or, build a semi-circular chunk of tube to conform to the drum.

Large wash plant/hopper. At least big enough to drop a load and let water wash it into the barrel. Area of drum to wash rocks just like river tumbles them in the water during a storm. Then screen.

Ok barrel then screen but don't forget the rock is going to tumble and wash in the screen too. Remember its on the wash cycle all the way through.

Maybe instead of welding 4 or 5 bars inside the trommel to help tumble the material I'll weld 4 or 5 pipes to it and that will be my spray bars. That way there's no spray bar on the outside, there's no spray bar going down the center taking up space and the material will get washed from all directions. Only thing is I'm sure there'll be somebody out there telling me what's wrong with it and to do it some other way.

 

[AzViper]

OK? Now if only 3 pics showed up then how do know that all 4 have a spray bar?

Go back and look at your post on this page. You posted the four trommels. One was embedded somehow that I could not capture it. I believe most trommel builders use PVC because they are not using bars, tubes, etc. welded to the inside of the cylinder and they have no issues with rocks climbing the walls of the cylinder to get stuck up against the PVC. As I said in an earlier post use small pipe with rounded edges and you will eliminate rocks from traveling up the walls of the cylinder while spacing the spray bar away from the rotating cylinder at the top. This trommel the builder below left plenty of room between the spray bar and the cylinder. The other three images you posted it appears the spray bars are near the top of the rotation cylinder.

 

[JeromeAz]

I do this post on my phone which is new but come to find out It Sucks! When I first put the pics on I could see them. Now I can't. All I see is 5 blank squares. I'm just going by what you tell me. I don't think they're using the pvc because they don't have bars in the trommel, I would say they use it because its cheap and its lightweight.

 

[jcazgoldchaser]

Ok barrel then screen but don't forget the rock is going to tumble and wash in the screen too. Remember its on the wash cycle all the way through.

At what point along a screen is the rock finally washed? I went to bed having rewatched Joe's videos and thinking about his "my rocks are clean" comment. Where along that screen/trommel did that happen.

It would be interesting to know, during say a 1/2 hour run, where the material in the drum no longer has fines associated with it. Sample every 6" or so. Does that screen, and structure to support it, really need to be that long?

Maybe instead of welding 4 or 5 bars inside the trommel to help tumble the material I'll weld 4 or 5 pipes to it and that will be my spray bars. That way there's no spray bar on the outside, there's no spray bar going down the center taking up space and the material will get washed from all directions. Only thing is I'm sure there'll be somebody out there telling me what's wrong with it and to do it some other way.

I've considered the spraybar lifter idea and the issue there is the inlet water will have to be at the rotation point. Not that it couldn't be done, mind you, there'd be a seal or something at the bearing. I do not believe the spray would be contained to inside the drum without a shield. At various rotation points the spray would not be pointed at material or covered by material and likely pointed at the open screen. Though nothing says that shield has to be something of any weight. Just needs no not fly off when the spray hits it. Lastly, there's the issue of holes plugging when the water pressure drops.

 

[JeromeAz]

I do this site on my phone which is new but come to find out It Sucks! When I first put the pics on I could see them. Now I can't. All I see is 5 blank squares. I'm just going by what you tell me. I don't think they're using the pvc because they don't have bars in the trommel, I would say they use it because its cheap and its lightweight.

As far as I know there's no scientific study out there saying what's the best way to build a trommel. People talk about how they're going to build their trommel and you always come back with your input on how they should do this or that. Almost like we should build ours just like yours. Don't get me wrong, you do have some good ideas and I might use a couple but people are going to build it the way they want. Instead tell them how your going to do yours because you make it sound they're doing it wrong and they should do it the way you say.

Just saying

 

[jcazgoldchaser]

I do this site on my phone which is new but come to find out It Sucks! When I first put the pics on I could see them. Now I can't. All I see is 5 blank squares. I'm just going by what you tell me. I don't think they're using the pvc because they don't have bars in the trommel, I would say they use it because its cheap and its lightweight.

As far as I know there's no scientific study out there saying what's the best way to build a trommel. People talk about how they're going to build their trommel and you always come back with your input on how they should do this or that. Almost like we should build ours just like yours. Don't get me wrong, you do have some good ideas and I might use a couple but people are going to build it the way they want. Instead tell them how your going to do yours because you make it sound they're doing it wrong and they should do it the way you say.

Just saying

I'm pretty sure we're not reading the same posts.

 

[jcazgoldchaser]

The other three images you posted it appears the spray bars are near the top of the rotation cylinder.

I had a thought when I reread this looking for "offensive" posts. If the spraybar isn't rigidly mounted, then so what if the rocks make contact? Some kind of bungee attachment was my first thought, but a lever arm with a spring would probably be simpler.

Another thought, isn't rotation speed going to have something to do with how far up the rocks get?
[edit]I see you addressed that in post #41.

Last, on drum size I believe the limit in my case is the size I can pick up with a shovel. How long can you go about scooping 8"+ rocks into the hopper?

 

[JeromeAz]

I'm pretty sure we're not reading the same posts.

Sorry jc that post wasn't for you it was for Viper. You got your post in before I finished mine.

 

[jcazgoldchaser]

Sorry jc that post wasn't for you it was for Viper. You got your post in before I finished mine.

Understandable, but itz not clear what you're taking offense to. Other than a comment(s?) about the rotation seeming too fast, the posts have been observations, suggestions or iders and not "you're doing it wrong".

 

[JeromeAz]

At what point along a screen is the rock finally washed? I went to bed having rewatched Joe's videos and thinking about his "my rocks are clean" comment. Where along that screen/trommel did that happen.

It would be interesting to know, during say a 1/2 hour run, where the material in the drum no longer has fines associated with it. Sample every 6" or so. Does that screen, and structure to support it, really need to be that long?

I've considered the spraybar lifter idea and the issue there is the inlet water will have to be at the rotation point. Not that it couldn't be done, mind you, there'd be a seal or something at the bearing. I do not believe the spray would be contained to inside the drum without a shield. At various rotation points the spray would not be pointed at material or covered by material and likely pointed at the open screen. Though nothing says that shield has to be something of any weight. Just needs no not fly off when the spray hits it. Lastly, there's the issue of holes plugging when the water pressure drops.

Good question! Who knows? I would say it depends on the angle, how hard packed the ground is and how much water pressure you have.

OK stop the trommel! Pull the rocks out. Nope! Still dirty! Load it up again. Give it 10 more revs. OK check it! Yep, right here where the screen starts. Its clean! Good job! Pay raise! Woo Hoo!

Does it matter where its clean at as long its clean before it drops out.

I get all set up and start running a test to make sure the rocks are coming out clean. If they are I'm good to go. If not I'm going to angle it up some and test it again till its right.

Does it need to be that long. I guess that's up to you how long you want it. It could be shorter. It's like the long sluices. Does it really need to be that long when your catching everything in the first 3 or 4 riffles. Some people like longer. Maybe they're compensating?

The cover doesn't have to be heavy just put latches on it to hold it down.

If the holes plug pull the cap off and wash it out.