Motorized Dirt Soil Screening Machine

[akpilot]

akpiliot,

Thanks for the kind words. I wanted to be able to interchange screens which is causing a lot of noise! I can see how your screen welds might crack, there is a lot fo vibration going on between the frame and actual screen.

I have the screen bolted on, but am losing bolts fast! This then makes the screen very loose and it chatters something fierce, it makes a lot of racket!

I'm going to run to Lowe's tonight and get some more bolts and use Nylok nuts to see if they will hold up better to the vibration.

Yes....Nyloks are a must

I figured the welds would break on my screen and they did!!! Man...it's loud now. I plan on making my screen replaceable, that will be a winter project

 

[SkunkWerX]

This looks really nice. You did a good job.

I was curious about the flywheel. Would it not have been safer to use a solid disk instead of the lawnmower type flywheel? Also what is the offset from center for the flywheel?

Thanks Minotbob.

I didn't have a source for solid disks.

Once the guard is welded on, there is no chance of someone sticking their hand in there.

It's only a 1 inch difference in length from the center bored hole.

I will be fine tuning, and taking length off of the flywheel, until I can achieve a nice resonant harmonic vibration at higher RPMs.

It's an experiment in progress to find the sweet spot.

 

[SkunkWerX]

Akpilot,

I got the Nyloks and bolts for installation tomorrow a.m.
LOUD is right! ...when the screens aren't fastened down.

Looks like I am going to need 8 to 10 fasteners to hold it well in place, which makes interchanging screens a little less "plug n play".

I suppose with more metal we could weld the screen to a subframe, then use some big bolts ( 1/2" ??) to bolt the screen-welded-subframe to the main vibratory frame?

There has got to be an easier way.

 

[trrjohn]

Why not use an additional piece of angle iron to "sandwich" the expanded metal, with bolts through both angle irons. You might get by with three bolts each per side and top. Bottom should be OK as is.
John

 

[PILOON]

Why not use an additional piece of angle iron to "sandwich" the expanded metal, with bolts through both angle irons. You might get by with three bolts each per side and top. Bottom should be OK as is.
John

Or perhaps even flat stock (mind angle stock would be stiffer=less bolts) with bolts welded to the flats plus nylock nuts.

The flats (or angle) would then serve for any size of mesh screen.
ie sandwich the mesh in place.
Also you could sandwich rubber strips between the mesh and angles, for sure that would cut down the chattering.

Notice you left the shocks inside of the ATV coil springs.
Is that not self defeating as would they not dampen the shaking action?

 

[RedDirt]

Very nice job skunk, thanks for posting. I'd like to build one but I'm afraid next building season's list is already filled up!

Expanding on the trrjohn/PILOON screen keeper:
If angle iron screen keepers were run up the length of the screen they would not interfere with the screening action. I'm thinking of three, one at each side and one up the middle. Do you think they could be hinged at the lower end and just have a single bolt at the upper end? Or is the difference in screen thickness too great to allow this? Maybe the hinged keeper angle could have a gasket material on the screen side that would make up the screen thickness difference and you could be back to a three bolt change out set up. A strip of gasket material (stiff rubber, neoprene?) top and bottom of the screen may eliminate most of the rattling.

I am also interested in your use of the shocks on the springs. Without the shocks would the motion be too wild? Uncontrollable?

 

[SkunkWerX]

trrjohn, Piloon and RedDirt,

Thanks for the ideas on screen keepers!

As trrjohn started with, I do think angle up each side would be the way to go.
One at the top wouldn't hurt , either.

Down at the waterfall end, there is a lot of vibration, as a lot of noise comes from there.
Maybe a piece of flat stock? I think most "spoil" would hop over a piece of 3/16" once it's that far down the process.

Down the center would certainly need one.

RedDirt, I like the hinge idea, but I was thinking of side hinges, so the entire length of the keeper would hinge against the side rail, (like a piano hinge) and then have some sort of screw clamp (like a C-clamp) that would clamp it down tight. This is probably just a dream in the pursuit of a truly "quick change" and "no tools" method to change a screen.

All good ideas from you gents. Thanks again.
I'm gonig to mull it all over, and, for now, just deal with the noise.

I'm finding the 3/4 Expanded metal is a good all-round size.
It allows stuff the size of a 3/8 nut to fall through, but everything larger gets separated.

Maybe changing screens isn't one of those things that is gonig to happen all the time?? not sure.

 

[SkunkWerX]

Here is a pic outdoors with transport wheels and side spill gaurds. I need to get some inflatable wheels, these were on the shelf, so i used them.

Dirt Screener with wheels and side spill guards


.

 

[akpilot]

That looks good!! I have been carring mine, but I think, I will eventually put some wheels on it.


Notice you left the shocks inside of the ATV coil springs.
Is that not self defeating as would they not dampen the shaking action?[/QUOTE Red Dirt]

I'm not speaking for "skunkWerx" but from my experience the springs only deflect when a load is dropped on the screen, other than that they (springs) don't move in a way that the shock would affect it, also the shock will stabilize the springs movement i.e. (not allowing as much side to side motion) and I think that could be important on longer and smaller dia. springs. I used a much larger overall dia. springs that was short to counter act the side way motion and it works fine. I think "SkunkWerks" system should provide him with better adjustable control than my system allows!

 

[GuglioLS]

Hey Skunk,

I just checked out your motorized screening machine, what a very cool and clever design using the engine with off balance flywheel for vibration. How about a video of it in action?

On the flywheel adjustment to achieve harmonic balance (if there is such a thing with off balance flywheels), instead of cutting off chunks to see where the happy medium is, perhaps mill a slot or drill several holes close together so that it can be bolted on in various positions? Maybe worth a try instead of cutting off metal at random then seeing what the results are, just a thought.
A "safer" off balance flywheel idea is to use a round disk with a large hole punched out near the outer edge.

Nice build SkunkWerX


Larry