collapse


* User Info

 
 
Welcome, Guest. Please login or register.
Did you miss your activation email?

* Who's Online


Dot Guests: 110 | Dot Users
Dot Hidden: 0

* Board Stats

  • stats Total Members: 12977
  • stats Total Posts: 130236
  • stats Total Topics: 18221
  • stats Total Categories: 5
  • stats Total Boards: 48
  • stats Most Online: 814

* Advertisers

Gear Pan
The lil Gold Spinner
BC GOLD
The lil Gold Spinner
The Pocket Sluice

Author Topic: Shaker Table Building  (Read 92601 times)

0 Members and 1 Guest are viewing this topic.

Offline Bill_Carson

  • Sr. Member
  • *****
  • Posts: 489
  • Country: 00
  • Kudos: 3
    • The Good, The Bad, and the Ugly
Re: Shaker Table Building
« Reply #40 on: January 30, 2010, 11:13:44 AM »
Hi Gary ... thanks for your incredible tech articles.

I came across this video on youtube video the other day ... it shows an abandoned Shaker Table out in the field (the table shows up at the 45 second mark) ... note that instead of using bushings/links, it seems to use tapered wooden leaf-springs of some type...


      YouTube
            - Shaker Table
   
There are 2 types of people in this world my friend; those with loaded guns, and those who dig.

Offline johanssonsan

  • PPT Invited
  • *****
  • Posts: 404
  • Province/State: Marsta Sweden
  • Kudos: 8
Re: Shaker Table Building
« Reply #41 on: January 30, 2010, 11:50:32 AM »
Guide is talking about wooden leaf-springs made of laminated birch.

Offline GollyMrScience

  • PPT Invited
  • *****
  • Posts: 2951
  • Province/State: Near Edmonton Alberta
  • Kudos: 160
Re: Shaker Table Building
« Reply #42 on: January 30, 2010, 12:36:59 PM »
I have seen a couple of older tables using plywood "springs". I wish they had shown the drive mechanism as that would have told us pretty quick what make it was.
The speaker talked about a rubber riffled top that was no longer there. That can be a hint too though it is possible that this unit was built from scratch as a copy of a commercial unit or it could have been a limited number of tables made by a small company copying other designs ot trying some ideas of their own.
What the heck - lets just keep mixin' stuff together till it blows up or smells REALLY bad!

Offline thrashmetalhead

  • Member
  • **
  • Posts: 8
  • Kudos: 1
Re: Shaker Table Building
« Reply #43 on: February 01, 2010, 08:59:58 AM »
Good job Mr.Gary.Keep do it.

Offline j9nish

  • Member
  • **
  • Posts: 2
  • Kudos: 0
Re: Shaker Table Building
« Reply #44 on: March 01, 2010, 02:48:47 AM »
 Thank you for the link <-yahoo_>

Offline Thulefoth

  • Member
  • **
  • Posts: 10
  • Kudos: 1
Re: Shaker Table Building
« Reply #45 on: March 04, 2010, 07:28:04 AM »
Hi Gary & all;

I registered with GPEX for this project.

I've downloaded the 3 PDF files, the 3 videos and the plans PDFs, and am studying them repeatedly.  Is there other material for this project & thread, that I should get?

I want to make a table that is adapted for/to screened pit-run.  Gary mentions in the docs that the type of table he's presenting here is not good for lean feed.  I am willing to get essential just mixed concentrate and some lights, instead of clean gold, or clean fractionation of the concentrate.  Then run the concentrate on another table adapted for 'fine' work.

In Washington State, we are allowed battery-electric spiral wheels, under the most-restrictive 'hand-mining' rules (i.e., no "engine driven" gear).  We are also allowed a battery-powered water pump, and it is allowed to water a mini high-banker.  Under these rules, we can have a maximum of 3 square feet of riffle area.  A grizzly & classier screen would count separate from the riffle-allowance.

Under these rules, it sounds consistent to me, that we could use a battery to power a shaker table ... although tables are not described in our rules.

The power requirement would be much easier to meet, and the battery would last a lot longer, if the table is fully spring mounted and operates at resonance.  This leads to an oscillating, rather than bump or jerk action.

I am aware of a 'flip' suspension that might let us 'walk' heavies without a separate bump or jerk mechanism.

This suspension is a version of the link-suspension Gary uses on his table design.  Instead of the table mounted at the top of the link-arms, a rigid link-support frame extends above the table, and then link-arms hang from the top end of the support frame.

Then, instead of the oscillating motion being symmetrical on each side of the link-arm, the table is (or may be) driven only to one side of the neutral, free-hanging position.

In the link-arm suspension Gary describes the table moves through a falling arc, as the link arms move away from the centered, vertical position.  If the link-arms are instead hanging from higher support-framing, then the arc rises, and when it reaches the end of its travel-range, immediately drops.  My assumption is that this could give materials a little 'flip'.  I also assume that there might be a benefit in only moving the link to one side of its neutral, vertical position.  I do sometimes get in trouble, assuming things... 

I have seen an example of what I'm describing, in an old article in Lapidary Journal.  A custom machine was made for a man by the people at his technical company, so that he could better-pursue his hobby of prospecting for gem stones.  I scanned the article.

This machine is an open frame, holding a basic gas engine which drives a reduction sheave on a jack shaft that drives a pitman arm that pushes a box-frame back & forth (~ 1/2").  The box-frame hangs from 4 short (3-4"?) swing-links that themselves hang from the top ends of 4 vertical supports. 

The bottom of the box on this machine is an open screen, loosely attached (this could be the source of undocumented but important 'action').  The box slopes uphill.  Feed is shovelled into the lower end of the box, lights & bigs spill out continuously from the low end, and anything heavy is 'pulled out' from the bottom and jiggles & hops its way up-slope on the screen bottom.  The author describes glancing at the upper end of the screen while shovelling in feed, and then reaching in and picking out goodies with the fingers.

The original images in the article were taken from b&w snapshot photos, and then in a often-seen old magazine technique, the key features in the image were outlined so they could be seen better.  I took high resolution scans, and while not great, and not as complete as I would have liked, they do cover the essentials.  All the text of the article scanned fine.

Gary, does this suspension adaptation sound like something we could use to benefit, with a shaker table?  If it is, it looks like it could be resonant-mounted, and this could reduce drive-power requirements a lot.

Thanks for the great project!

Ted Clayton


Offline GollyMrScience

  • PPT Invited
  • *****
  • Posts: 2951
  • Province/State: Near Edmonton Alberta
  • Kudos: 160
Re: Shaker Table Building
« Reply #46 on: March 04, 2010, 11:51:44 AM »
Throughput is going to be your issue. Tables are not used for primary concentration because they are best at handling high con feed rather than bank run. The volumes they can process are too small for primary unless the feed is very high value per yard.
Is there a limit on the amount of feed per hour you can do under the regulations? If not you would be better served to look at a pimary concentrator that can handle as fast as you can legally feed it with the intention of using the table to get the cons down to clean or at least smeltable gold.
What the heck - lets just keep mixin' stuff together till it blows up or smells REALLY bad!

Offline Thulefoth

  • Member
  • **
  • Posts: 10
  • Kudos: 1
Re: Shaker Table Building
« Reply #47 on: March 04, 2010, 05:02:54 PM »
Thanks GollyMrScience!

No, we aren't restricted to a certain amount of feed per hour.

Washington State regulates prospecting along streams in a special Gold & Fish Pamphlet.  The revised edition just came out last year, after many years staying the same.  As part of the review for the update, Fish & Game commissioned an Environmental Consultant group to analyse and reference all the issues at stake, from their viewpoint.  The consultant wrote a big paper, emphasizing their recommendations ... and the State is now publishing their report as a White Paper, alongside the prospecting rules.

It is interesting, to read what the Environmental Consultant thought, and compare that with the specifics that Fish & Game actually put in the rules.  Though F&G declined many suggestions that would limit prospecting by volume, rate, number of individuals, area affected, and other factors, they nonetheless put together a set of rules that consistently reinforce an integrated set of themes:
  • Try to screen pit run where it lies, and only transport fines for processing.
  • Minimize water use, bring water to the screened feed, and avoid letting mud get to the stream.
  • Batteries get a 'free pass', and gas engines bring more & tighter rules.


If we put a sluice in the stream, and bring our screened feed to it, the tailings pile that accumulates cannot be flattened, shoved into the current, etc:  tailings put in the stream have to stay where they land, and when the sluice etc is repositioned, it must be at least 50 feet away from the last location.  So really ... they'd rather you not put feed material in the stream, at all.

Conversely, if we keep the activity away from the stream, process material in place, pump a small amount of water to the work-situation and dig a little settling pond so mud doesn't make its way back to the crick ... the rules go easier on us.
====

It is common in the areas I have available, for fine black sand to build up quickly in the riffles.  Every half hour is a good round figure for clean-up.  There's little chance or point of going an hour, even if a good part of the time is spent in not-feeding activities.  If conditions allow for fast feeding, the black sand has compacted the whole bottom of whatever is being used, within a matter of minutes.

I need something that will move the concentrate out of the machine so it doesn't get packed in.  There is a little bit of very fine gold in the fine black sand.  I have not been able to run any of several types of primary concentrators so that they wash out the black sand, without gold going with it.  However, I can do this with the concentrate at home, where time, space, equipment, power, water, etc, aren't issues.

I see on the U.S. Patent Office that Wilfley tables have been adapted to cleaning & sizing coal, at the same time, and there are general-purpose table patents that claim to be high-throughput.  It's fascinating reading (and saving) all these nifty patents, but I don't have the experience with table to really know hooey from phooey.    :-\

I'll take you guys' word over someone keeping patent lawyers out of the unemployment line.
====

The other way I've thought to go on the black sand problem, is to change the design of my shaking, low-water sluice in order to make it fast & painless to dump the concentrate out, and get back to feeding.  But I sure do like the idea of concentrate creeping over to one side of the box and falling into a bucket.

Ted



Offline nuggetsucker

  • Jr. Member
  • ***
  • Posts: 16
  • Kudos: 0
Re: Shaker Table Building
« Reply #48 on: April 04, 2010, 10:14:07 PM »
Gary
I'd like to thank you for the plans on shakers .
I inherited a table an old timer was trying to build before he passed on. the problem was hardly anything worked properly
except the deck itself and that was rough .I refinished that last fall . thanks to your post on eccentrics you cleared up a lot of
brain strain over the bump and stroke adjustment spring . I've now got a table that works ,I have to plumb in the water and then run
some Fraser River cons. Fine gold [minus 60 mesh] and 30% black sand and hematite. If the table works on that stuff it'll work on anything.
Thanks again
Nuggetsucker

Offline garyww

  • PPT Invited
  • *****
  • Posts: 370
  • Province/State: Napa, California
  • Kudos: 14
    • Gold Country Outfitters
Re: Shaker Table Building
« Reply #49 on: April 12, 2010, 12:33:11 PM »
"Hanging' links works just fine but the table structure has to be larger which is why I didn't spend more time on this particular subject. Most of the old tables did use 'hangers' but I've found that the difference between a positive arc and a negative arc in the deck motion doesn't make much difference as the vertical displacement is almost impossible to measure if the hanger rods or links are much longer than 10 inches. It is a good avenue to explore however.

 


Gear Pan
Gold Rat