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Trommel for screening dirt

Posted: Sat Oct 20, 2012 9:11 pm
by RonSII
Hi All, I have noticed the projects board is kinda slow lately so I thought I would take some pics of one of my projects and post it up here. I usually am so busy I don't have extra time to remember to take pictures but work has slowed to a crawl and I only have a few things going on so here is my next project a garden trommel, I call it that because it is too small to be used for any kind of regular work we do in the dirt business :) I got the idea for this when we were looking at some screens for a job with 50K yds of material and everything we looked at was either too small to do it efficiently or just way outside of out price range(cheap!!!) Of course this project is not for that job as this trommel will only do about 1-2 yds/hr for topsoil. I started the design with an old farm trailer frame for the base it is 10' X 4' with 5" X 1.75" channel on the long sides and 3" X 1.5" channel on the ends.
trommel frame 10 x 4
trommel frame 10 x 4
frame.jpg (154.89 KiB) Viewed 4754 times
Next step was the drum for the screen, now I had a couple of prospects laying around which included an old butane tank and an old worn out water well pressure tank. I will be using the butane tank first as it is longer it is also smaller diameter ~16" versus the well tank at 20" the butane tank I figured will be the test to see how well something this small OD will work to screen dirt and it is about 3/16th's" thick.
drums
drums
drums.JPG (200.17 KiB) Viewed 4754 times
Then for the trommel end supports I welded on some channel made of 3 X 1.5" from the trailer tongue and put a couple of pieces of angle on that to mount the pillow blocks the shaft will turn on.
end supports
end supports
endweld.JPG (189.92 KiB) Viewed 4754 times
Unfortunately, I forgot to take pictures of the shaft construction it is made from a length of schedule 40 1-1/2" pipe with some collar pieces welded in the ends to accept some 1" drill rod that will go into the pillow block bearings I also drilled and tapped for adjustment bolts at the inside end of the drill rod so I can true up the shaft ends axially to prevent bearing binding.

Re: Trommel for screening dirt

Posted: Sat Oct 20, 2012 9:11 pm
by RonSII
shaft alignment
shaft alignment
shaftalign.JPG (191.9 KiB) Viewed 4752 times
Once I had everything lined up and fitted I was ready to weld the drum to the shaft.... but as luck would have it the rain started and there were some very dark clouds heading this way, so not liking to get soaked holding onto the welder I decided to call it a day.
drum ready to weld to shaft
drum ready to weld to shaft
drumrain.JPG (160.86 KiB) Viewed 4752 times
But my luck changed about an hour later and the sun came out briefly just enough to lure me out to tack the drum on to the shaft.
drum temp welded to shaft
drum temp welded to shaft
drumweld.jpg (185.5 KiB) Viewed 4752 times
So the next step will be to weld permanent supports between the shaft and drum then cut openings in the drum for the screen to cover after that I will have to come up with a drive mechanism to turn the drum.

As most of my project go there could be a long delay in getting back to this one, just depends on work....and money :)

Re: Trommel for screening dirt

Posted: Sat Oct 20, 2012 9:11 pm
by RonSII
reserved 2

Re: Trommel for screening dirt

Posted: Sat Oct 20, 2012 10:11 pm
by delraydella
Looks nice!
How fast does the drive motor need to go? If it doesn't need to go that fast, but you still need good torque, you might want to try retrofitting a portable electric pipe threader like this one from Harbor Freight....http://www.harborfreight.com/portable-e ... 95955.html


I've seen them used as drive motors for pipe and tube rollers, so I know there is plenty of torque, at least for that. The price seems reasonable, too.

Other Steve

Re: Trommel for screening dirt

Posted: Sun Oct 21, 2012 2:05 am
by RonSII
Hey Steve, That's a pretty good idea :D hadn't thought of using one of those for high torque shaft driving... my only concern would be the duty cycle, this trommel would be continuous for hours on end. I was just going to look through my scrap bins for a gearbox I could fit to an electric or gas motor that would give me around 50 RPM's as I have seen homemade trommels with 4 foot drums running a bit faster and they seem to work pretty good, this being quite a bit smaller diameter I figure 50 would be the fastest I would try to start out with.
I also plan on making the water tank drum interchangeable with the one I put on it already so I can have a 'quick change' drum system maybe different screen sizes....plus I still have to find a source for woven screen with heavy gauge wire as the stuff they sell in regular hardware stores wouldn't last 5 minutes :cry:

One other thing I forgot to mention in the first post was how I am going to feed material into this contraption??? For now it will just be shovel-fed by hand, I would like to build a conveyor for it so it could be fed by wheelbarrow or even a bobcat but this is a garden trommel so for now it will be fed with a garden shovel :D

More info on the build:
All welding will be done with my lincoln 155 220v wire feed running .035 E71 wire
the only thing I have had to buy so far is the bearings 2@7.42 = $14.84
the 1" drill rod runs about $30 for 3' so I have less than $15 into that
all the rest of the steel I have had laying around waiting to go for scrap so by the time I'm done it should weight about 400 lbs or less so less than 40 bucks worth of scrap
The motor shouldn't have to be greater than a half horse(elec.) or if I can find a small rototiller they spin about the right speed, then I could just mount the whole thing right on it ready to run. ;)

I am hoping the weather will cooperate and I can get a few hours in each week, but with winter coming I guess we will see. :)

Re: Trommel for screening dirt

Posted: Sun Oct 21, 2012 1:48 pm
by Otto Nobedder
Very nice!

And a very creative use of recycled material. Somewhere between "you might be a redneck if", and an episode of MacGuyver. :D

I think you're right about the hardware cloth. I've had it hold up well as a shaker screen, but it'll get a lot more abuse in your drum. Maybe some 11 ga expanded metal? Might even find that in a scrap pile.

Steve S

Re: Trommel for screening dirt

Posted: Mon Oct 22, 2012 12:01 am
by RonSII
Otto Nobedder wrote:Very nice!

And a very creative use of recycled material. Somewhere between "you might be a redneck if", and an episode of MacGuyver. :D

I think you're right about the hardware cloth. I've had it hold up well as a shaker screen, but it'll get a lot more abuse in your drum. Maybe some 11 ga expanded metal? Might even find that in a scrap pile.

Steve S
Thanks Steve, I get called a redneck every now and then :lol: I have made small hand shaker screens with 1/4" hardware cloth before for use on separating tumbling media from castings I make and the screens usually last a month before the welds start to come apart and wires break but that is just from hand shaking use, on this I will try to keep really big(+4"-5") rocks out of it but even then I think 3" and smaller rocks tumbling around would not last long at all.
I might try expanded metal because I have a few pieces laying around but all the commercial and the home-built-sort-of-commercial ones I have seen use woven screen for some reason??? for topsoil I have seen them with what looks about to be 1/8" wire with 1/4" openings of course that's for semi-dry material now that were into rainy season I will have to go to 1/2" openings and more than likely rig a brush on top to keep it clear....well that is if I get it finished before next summer ;)

I managed to get the permanent supports welded in today between rain showers :) once I cut openings in the drum I will probably add another set of supports in the middle, it's just too long of a reach to weld them in right now ;)
end supports right
end supports right
endsupr.JPG (114.18 KiB) Viewed 4719 times
end supports left
end supports left
endsupl.JPG (116.14 KiB) Viewed 4719 times
Here is one we looked at with the brushes on for keeping the screens from clogging up.
commercial trommel
commercial trommel
ctrommel.jpg (157.67 KiB) Viewed 4719 times

Re: Trommel for screening dirt

Posted: Mon Oct 22, 2012 6:35 pm
by Otto Nobedder
I thought of the expanded metal, because it has a "grain". It can be oriented so each opening has a slight slope before it, so the rocks and gravel tumbling in it wil be lifted slightly in rotation and help it be "self-clearing". This is just theory, though, as I've never attempted it. Hell, it might work better in the reverse, with rocks banging the dirt into the low spots to force it through.

Just the redneck in me thinking out loud...

Steve S

Re: Trommel for screening dirt

Posted: Mon Oct 22, 2012 6:39 pm
by Otto Nobedder
I also suspect the woven screen has more to do with economies of scale than any particular virtue of the square opening.

Woven wire is inexpensive to install, and inexpensive to replace. If you have expanded metal in the scrap pile, it may be worth the experiment.

Steve S

Re: Trommel for screening dirt

Posted: Mon Oct 29, 2012 11:19 pm
by RonSII
Well with all the rain and wind lately I haven't had much time to get anything done for a drive mechanism but I did find a gearbox laying around that might work, it isn't exactly what I was looking for but I had it onhand so for now looks like this will be the one. It is a 180:1 ratio rated for 1800 rpm input. I was looking for a gearbox I could direct drive to the drum shaft but to get the speed I need on the drum I will have to put a bigger sprocket on the gearbox and then about a 1:2 or 3 up ratio to the drum shaft I think I will still direct drive the motor to the input of the gearbox though.

gearbox 2
gearbox 2
gearbox2.JPG (143.29 KiB) Viewed 4447 times
gearbox 1
gearbox 1
gearbox1.JPG (129.75 KiB) Viewed 4447 times

Re: Trommel for screening dirt

Posted: Sun Nov 25, 2012 10:50 am
by RonSII
Well it's been a while since I updated this project, so yesterday I managed to get a little work done on it :)
I had a scrap of 1/8th inch flat bar laying around so last week I drilled some holes in it and made a gearbox mount.
gearbox mounting plate
gearbox mounting plate
driveplate.JPG (130.82 KiB) Viewed 1625 times
After that I found some 1-1/4 tubing and welded that to the back of the mounting plate to provide for an adjustable slide, the 1-1/4 fits inside the 1-1/2 tubing that will be welded to the frame of the trommel.
Gearbox mounting plate being welded to tubing to make adjusting slide
Gearbox mounting plate being welded to tubing to make adjusting slide
driveslide.JPG (147.02 KiB) Viewed 1625 times
Needed another crossbeam on the frame to support the gearbox
Crossbeam and gearbox mounting parts
Crossbeam and gearbox mounting parts
crossmemberslideparts.JPG (245.55 KiB) Viewed 1625 times

Re: Trommel for screening dirt

Posted: Sun Nov 25, 2012 10:58 am
by RonSII
Here is a pic showing the gearbox and adjusting slide sitting in place to be welded.
Gearbox and slide waiting to be welded
Gearbox and slide waiting to be welded
slideinplace.JPG (215.18 KiB) Viewed 1625 times
Another pic with them tacked in.
slidewelded.JPG
slidewelded.JPG (221.43 KiB) Viewed 1625 times
Another pic with some supports added.
driveslidewelded.JPG
driveslidewelded.JPG (204.38 KiB) Viewed 1625 times

Re: Trommel for screening dirt

Posted: Sun Nov 25, 2012 11:13 am
by RonSII
Finally managed to round up some sprockets and chain for coupling the drive box to the drum shaft. The chain is #50 roller chain and the sprocket for the drum shaft will be a 13 tooth with a one inch ID that will just be welded to the shaft, the sprocket I'll be putting on the gearbox is an eighteen tooth this will give a little speed increase from the gearbox... not sure if it will be enough so I guess time will tell.... I have a 25 tooth if it's not fast enough but the 25 tooth has a one inch ID and the gearbox has a 7/8th shaft so will have to make a sleeve or something to use it.
sprockets.JPG
sprockets.JPG (155.88 KiB) Viewed 1625 times
And here it is all assembled, still need to add some transversal supports to the slide mount and drill for pins to prevent the gearbox from lifting under load but making some progress anyway.
chaininstalled.JPG
chaininstalled.JPG (142.58 KiB) Viewed 1625 times
Next will have to decide on the motor and how it will be mounted... would like to make it direct drive :? but then I'd have to come up with a coupler and all that.... we'll see I guess.