Motorized Dirt Soil Screening Machine

[SkunkWerX]

First,
I would like to give credit to AKPILOT for the inspiration and answering all of my dumb questions.
AK's screening plant thread can be found here:
Akpilot's Screening Plant Thread


I used Ak's basic design, which I think is the basic design for most of these rigs. My BX's bucket is just under 48" wide, so, I made the screening bed 4 feet wide x 6 feet long. Was originally going to use a full 8 feet, but it was just too long. Hopefully the 6 foot length will allow most of the screening to take place before "waterfalling" off the end. I was looking for the most vibration at the shallowest angle for the most efficient (full) screening of the material.

Features:
-The Back (loading end) and Front (waterfall end) height are both adjustable.
-Used ATV coil springs.
-Interchangeable expanded metal screens, with abilty to overlay hardware cloth for finer screening of compost, potting soil and such.
-Sliding/adjustable motor mount for maintaining proper belt tension.
-Honda 5hp G200 motor with quiet muffler.
-Flywheel is 3/8" thick x 2" wide-orange (Yes, it will get a guard)
-Side Unloading of screened material
-Waterfall end will get a plywood divider.
-Will use small wheels and hitch for towing behind tractor. (soon, soon)

It has been test-run in the workshop a few times, needs wheels installed before it can be taken out for it's first real screening. (next day or two hopefully). It really scoots across the concrete floor in the shop!!

Dirt Screener Side View.jpg

Dirt Screener Flywheel.jpg

 

[atgreene]

Nice. Does the vibration cause an issue with the belt, or are they somehow isolated?

Keep posting pics.

 

[SkunkWerX]

Nice. Does the vibration cause an issue with the belt, or are they somehow isolated?

Keep posting pics.

Great Question! I thought about this a lot.

In my design I was going for a lot of high speed small vibrations, rather than large loping actions. Using varying RPMs and different sized pulleys I hope to find the "freuqncy" of the unit and establish a harmonic resonance, if that makes any sense.
Anyway the small vibrations don't seem to affect the belt function.

Here is my seat-o-pants theory as to why:
The belt is not experiencing a lot of rotational resistance. Not like a belt would if it were a fan belt running pumps or like a belt driving a rotating implement, therefor in this application slippage is not much of an issue.

I had originally planned on an idler pulley, as discussed in AK's thread, but, figured that could be an add-on if belt slippage became a problem.

I do have some small springs at the back end keeping a measured amount of back tension, so it's always pulling the screening deck (and attached pulley) into tension.

 

[MrJimi]

Looks great, do you have a way to get rid of the larger material off the screen?

 

[atgreene]

Does it rotate so it moves material up the screen until it breaks down into heavies and rolls off the screen or so it shakes it down the screen? Most large screens (hydro) you can run in either direction, shaking up the screen gives it more time on the screen, but doesn't work well with wet material.

How do you like the expanded metal for a screen? I would think that it would hold small roots easily. I always had better luck with the piano wire screens, but expanded would be slick if it works for you I'll have to work that into my plans.

I've always wated to build one that I can feed with my Takeuchi and take away with my Kubota. Hiring in a big trommel with a large loader to do 1000 yards per day just has made better economical sence for now.

Here's one desin that is kind of unique. I'd love to try it. Snake Mountain Rattler

Thanks for the info.

 

[SkunkWerX]

Mr. Jimi, The larger material ends up going over the waterfall at the downhill end. FEL to take it away. I have plenty of gullies and eroded areas to get rid of the spoils, then top coat with good topsoil. Best method if accessible would be let the spoils cascade directly into a fill "zone".

Atgreene, It shakes/vibrates and the material gravity feeds as th bed is vibrating.

Just came in from running an outdoor screening test using the FEL.
I screened about 3 yards of clay based fill dirt with rocks and clumps in it.
We had rain a day or two ago so it was moist, as well. The screener did a good job considering clay. I "worked" the pile for a few minutes to get everything loose, so it wasn't stuck together in big clods, then starting dumping onto the Screener.

Used about a 25 degree angle, not real steep. Ended up with about 1/3rd spoils and 2/3rds screened material by volume. The good news is that it fully screened each load, letting only screened spoils spill off the end. That was the goal.

The flat expanded metal worked well. Almost all of the roots and sticks rolled down and off the edge. 1 or 2 got stuck, no biggie, no show-stoppers.

A couple small bugs to work through, biggest is the set screw on the weight keeps loosening.

Then it will be dirt guard for the motor, shield for the flywheel, and some sort of hitch for towing and moving.

 

[akpilot]

Wow That looks great!! Looks like you did a real nice job. Yes they do "walk" around the shop You will want a gaurd on your flywheel they act like a baseball bat with small rocks I think your on the right track about the belt and the frequency. because there is very little load on the belt they can run amazingly loose, with no problems.
I have run about 100-150 yard of topsoil and about 50 yards pit run across mine and it seems to be doing very well. the only problem I have had is some viberation cracks in the welded on screen and the screen frame, nothing my welder and I can't fix. I figure mine has paid for it self couple times already.

 

[SkunkWerX]

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.

 

[Minotbob]

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?

 

[bob_wood]

Great lookin machine ya got there SkunkWerX ... you did a very good job. Impressive !
I have been following the threads on dirt screeners and want to build one of my own someday, when I can find the time. With steel prices being what they are, I was thinking of building the base unit out of pressure treated and adding hardware and the screen, motor, flywheel, etc. Also, I was thinking of setting my screen up on skids and having a hitch on one end so I could pull the unit around with my tractor. Do you think my ideas would work ? Did you go with all new material ? Costs ?

Thanks for sharing your info, ideas and pictures.

Bob

 

[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