Bellows puffer style drywasher plans

[BrisJoe]

I was thinking of what motor to use to power the bellows.
A couple of options include
Windscreen washer motor, 12v trolling motor off a tinny, electric gate motor.

All can be fitted with a variable speed controller to get the best motion going.

What do you guys think will give the least current draw on say a deep cycle battery? While also being budget conscious.

 

[thedigger]

Variable speed is a good move,and a second hand car battery,will run it a long time.

The digger

 

[G0lddigg@]

seen these variable speed device's on ebay mate for $35 http://www.ebay.com.au/itm/12-volt-...=AU_product_Trailer_Parts&hash=item56625d6c40

Now here's a thought what about using a cordless drill? has variable speed control you can purchase/charge as many mobile batteries as you like and shouldn't have any issue turning a crank with a bit of air resistance.
Certainly would be lighter than a car battery and it never hurts to have an extra drill in the car.

 

[BrisJoe]

Very interesting there digga will have to think about that would save mounting issues as well

 

[thedigger]

I have keene puffer and the speed control is just in the line,so it just lays on the ground.

The Digger

 

[BrisJoe]

Might just go a gen set and an electric drill, easy speed control there and a small genny isn't as loud as a leaf blower, plus can charge the mobile while working lol and also eliminate a pulley system and use direct drive. Just got to make a dust shield so the dust can stay away from the rotor and stator inside the drill as long as possible

 

[gcause]

Ok my only problem getting started with my build right now is the lack of a shed and tools. I think I will approach the local men's shed in Cairns with a project. I'm sure they have nothing better to do than to help me out....lol

 

[gcause]

This fellow has a good setup:

http://s859.photobucket.com/albums/ab154/flyingbrass45/prospecting/drywasher/?start=all

 

[BrisJoe]

Does it really matter about the riffles compared to a sluice?
As the popular mechanic has straight square pine and the above has skirting board and others has the alloy/steel reversed riffles.

 

[gcause]

I'm making mine out of wood using a half round dowel like you get for cornicing. It's flat on two sides and round on the other. I would face the round side to the top end of the sluice.

 

[MJB]

My understanding of the Dry washer principles is that the riffles have to be opposite than that of the water sluice riffles. The reason being the dry washer has no water and so no areas of lower water current for the gold to drop out behind the riffles. Your picture Gcause shows the right idea and the flow or top of the sluice would be to the left. In a dry washer yo want to catch the heavies in front of the riffles, not behind.

Hope that helps out or makes sense.

Cheers,
Matt

 

[G0lddigg@]

The one things i learned from trying different riffles was that the higher they are the further apart they need to be and vice versa, they need some angle to allow material to jostle around just like that of a sluice on the underside.
I know i draw like a 3 year old but i hope this makes sense, the first three riffles here are evenly spaces and of the right height to restrict the airflow and cause a constant exchange, the material is also pushed upwards and back into the flow which makes for a waterflow effect and moves lights out of the box, number 2 is 90 degrees and has the right space but needs high feed to maintain exchange if you stop feedimng for too long with this setup your material will built up like a shelf once a clearway for the air-pressure has been established. number 3 the riffles are too low and again needs high feed rates to bloack and even out air to get thiongs jostling.

all this theory goes out the window when you introduce bellows thought because they use a puffing action to lift material,

 

[BrisJoe]

Any recommendations for the bellows design them?
WOuldit change much from a constant flow and the puff flow of air?

 

[G0lddigg@]

I still think the high reverse riffle is vital especially if your in ironstone country but you need to remember that once your setup and running material you can adjust the angle of the drywasher itself so you can compensate for different materials.

 

[MJB]

If you have a look at the different Keene dry washers, bellows and constant air, you can see a slight difference in riffles in the trays. I am not sure if this is to compensate for the differing air flows or just a slight change over the years. Either way, they are definitely both of the reverse type aiming to catch heavies in front of the riffle.

Cheers,
Matt

 

[gcause]

Thanks for that MJB and Golddigg I was wrong in my thinking that the riffles were like a river sluices. :8

I was also thinking I would make a riffle box with just the membrane material on the base of it and the riffles themselves be an independent unit that would slot in like in this picture, note the wedge shape above the riffles. That way I could swap them out until I get the right ones sorted for the type of material and feed rate. I would make it a tight fit so they are hard up against the membrane.

What are your thoughts on that or do they have to be attached to the membrane?

 

[G0lddigg@]

I cant see an issue with that so long at the riffles are clamped/supported underneath the cloth to make sure heavies dont slide under tge riffles.

 

[gcause]

I was also wondering if a fly screen mesh could be used as the membrane?

 

[G0lddigg@]

I jad the same thought when I first started looking for cloth that and shade cloth. I found it really hard to get it tight enough. Tge main issue especially with a ouffer style is fines falling into the box then cloggong from underneath. The puffers suffer from vaccume on the down stroke causing fine gold to work its way I to the puffer.

I reckon a well worn cotton shirt would be more effective provided it could breathe. Like an old polo shirt

 

[gcause]

Thought you might like this.

[video=480,360]http://youtu.be/CfxCPkDjwQ8[/video]