How to build a mini trommel

Canuck

Jr. Member
Aug 2, 2012
73
53
Alberta
Detector(s) used
Fisher gold bug pro
Primary Interest:
Prospecting
I have built 2 now. If you have questions I can probably save you a lot of headaches
 

Could the engine be off to the side where it might be in a dryer location?
 

I was planning on building one also but use a 12 volt dc motor with a battery and solar panel.
I am a solar tech and electrician also.
Maybe change the size of the barrel a little bit.
 

Our motor is right underneath the hopper and honestly it doesn't get that wet. It has definitely not been a problem for us.
 

I am in the planning stage for a small trommel that I can fit into a ridged frame backpack to get into those harder areas. I was thinking of using a power wheels battery and possibly a windshield wiper motor and possibly a small solar panel to be able to keep the battery running strong. Any suggestions on what I would need for the solar panel to run the wiper motor and possibly a bilge pump.
 

I have a Gold magic wheel. It has a 12 volt, 5.0 AH battery from Amazon for $13.
5 ah means it can draw 5 amps in 1 hour, or 1 amp an hour and run for 5 hours. So a 2.5 amp bilge pump from ebay, I have one on my mini highbanker, will run for 2.5 hours.
Now, my magic wheel I use a 10 watt panel. It draws only small watts,dont remember what but this battery will run it for 6 hours no problem,no charging.
I use a charge controller,5 amp,just to protect my battery and for other batterys as well.
So it all depends on what you draw.

Now, a 240 to 260 watt panel,that is 40 inches by 65 inches weighs 44 pounds.
Puts out 5 amps. This is why you need a battery. A small panel will not put out enough juice by itself.
This panel will put out about 31 volts also.

The window wiper is a small watt output.
I know promack here in aj uses a wiper motor on there bellows drywasher. It is from a mercedes I think. I will have to ask, or go to promack prospecting and see if it lists it.

I was thinking about a small trommel also for back packing. Use wet or dry.
8 inch barrel. Plastic with some cutouts and 3/8 or 1/4 inch raised expanded, on a pvc frame.

but with my gold magic wheel all I nedd is a a round classifier, and the wheel.
The gold magic works wet or dry.
 

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I'm not sure a wiper motor will give you fast enough rotation . I guess with a pully system it might . I would look for a motor that you could , use as a direct drive for weight reduction if your going to pack it in .
 

Wiper motors or window motors work great!

Window motor........



Wiper motor..........


I like the window motor because it can reverse.
 

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Remember battery is always less than the ratings and gets worse as the batteries age.

So a 2.5 amp bilge pump from ebay, I have one on my mini highbanker, will run for 2.5 hours.

That is only true if your battery is charged to 100% (almost impossible with home chargers or standard solar controllers) and if there is no resistance loss in your wiring connectors.

It is much better to assume a 20%-30% loss off the top! So that would be closer to 2ah in reality for a 2.5ah rated battery or 3.5ah for a 5ah battery - so not trying to nit pick but people should keep this in mind when doing there calculations. Not to mention batteries lose their capacity and efficiency over time.

One more after thought: sealed gel batteries can not take a charge higher than 14.1v without damage...

I use a few UB12350 35ah batteries and they are a great solution for my needs. I can put one in the bottom of a 5gal bucket and a bunch of other gear on top. Two buckets with a battery in each is easy to cary down the path (balanced buckets are important lol)

http://www.amazon.com/s/ref=nb_sb_s...&field-keywords=ub12350&sprefix=ub123,aps,217

Hope this helps some people out there!
 

I use a few UB12350 35ah batteries and they are a great solution for my needs. I can put one in the bottom of a 5gal bucket and a bunch of other gear on top. Two buckets with a battery in each is easy to carry down the path (balanced buckets are important lol)
Hope this helps some people out there!



Sounds like you know a great deal about batteries......:icon_thumleft:

Do you use both batteries at the same time wired in parallel or do you use them one at a time?
I'm wondering if you would get a little more than double the combined amp hours when running in parallel by conserving some energy due to the increased mass of the combination of the two batteries or would the combined amp hours (35ah+35ah=70) still remain the same :icon_scratch:

Lets say the motor draws 3 amps, will it run longer with two batteries wired in parallel or longer using two batteries one at a time or will it be the same either way. :dontknow:

I'm thinking one battery would not run the motor up to speed once it dropped below 3 amps but two batteries with 2 amps each connected together would equal 4 amps thus allowing the motor to operate at full speed a little longer. Does that sound right?

What are your thoughts?
I am aware that it needs to be two identical batteries equally charged when running in parallel.


GG~
 

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Batteries can not compare to a gas pump - except quiet and clean ;)

Yeah I usually run them in parallel because the pump slows down after the batteries start to drain and you almost always want max flow for as long as possible. [current/amps/I] *

But I have another neat trick for when the batteries start to slow down; I use Johnson pumps that are RATED for 12v OR 24v... so when things slow down I then put the batteries in series for another hour or two of work!
The higher voltage is able to spin the pump faster even with the reduced power supply of the draining batteries ;) [voltage/potential/E] *

Now I must say do not use 24v on a cheap 12v pump - the pump will melt down even under water!!! Been there done that lol

My 2 bits...

* That is the simple way to think about it - in reality OHMS law says the load draws the current based on the potential. So it is the voltage/potential that goes down but the voltage is directly proportional to the current going down across the load due to E = IR. So if the load / R is more or less constant and the voltage goes down, then the load draws less current
 

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Cool :icon_thumleft:

Makes sense to me. Great answer!

Thanks ebuyc
GG~
 

I was planning on building one also but use a 12 volt dc motor with a battery and solar panel.
I am a solar tech and electrician also.
Maybe change the size of the barrel a little bit.

We use an 800CCA 12 volt truck battery and hook a 20 watt solar panel to it while we work our little 12 volt pump powered high banker. I leave it hooked up till we pack up for the day. We do two or three clean outs a day usually for coffee and lunch and the solar panel does a good job topping the battery off during these breaks.

Then I hook the battery to the quad to help recharge the battery on the way back to camp. Usually the battery is fully charged by the quad traveling to and from the river. If not I hook it up to a battery charger at camp (usually a small generator).

We are only using a small 1200 gph pump at this time. It does not draw a lot of current.

One thing I really like about our setup is that it runs very quiet. If I build a mini trommel it will be powered by a 12 volt motor for sure.
 

We use an 800CCA 12 volt truck battery and hook a 20 watt solar panel to it while we work our little 12 volt pump powered high banker. I leave it hooked up till we pack up for the day. We do two or three clean outs a day usually for coffee and lunch and the solar panel does a good job topping the battery off during these breaks.

Then I hook the battery to the quad to help recharge the battery on the way back to camp. Usually the battery is fully charged by the quad traveling to and from the river. If not I hook it up to a battery charger at camp (usually a small generator).

We are only using a small 1200 gph pump at this time. It does not draw a lot of current.

One thing I really like about our setup is that it runs very quiet. If I build a mini trommel it will be powered by a 12 volt motor for sure.

Me too :icon_thumleft:
My next trommel will definately be run by a 12v motor.

I've been using a 110v gear motor on my 15" trommel and powering it by using two 12v power chair batteries and an inverter.

Recently though, I've been using a small 900w generator from Harbor Freight to supply the 110v current to the gear motor and it works out great, no battery drain to worry about plus I can use the generator to power a fan while also powering the trommel, comes in handy on a hot day with no breeze stirring. Plus the generator comes in handy for lots of other uses. And it was only $89

GG~
 

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