Grizzly has been put to work.

[kg7il]

I tackled #4 above and created an add on screen to reduce the pass size.
Material is running low, so I tried Rebar attached to the 1" square tube.
I welded to vertical pins to the main frame that holds the tube from sliding down the tube.
It is also constrained from moving sideways.
At the bottom, I have a small pin that sets into the center angle bar to keep the bottom edge from sliding sideways.

Still working well, But I sure have a lot more rocks. (and smaller ones at that) to move out of the area.

Since the angle iron takes about 1/2 the force, rebar seems to work 'ok'. The slight flex of the rebar does make clearing stuck rocks easier than when he bigger rocks got jammed between the rigid angles.

 

[kg7il]

I will continue to share my experience with my Grizzly.

2. Better lips to retain the OSB side boards. Right now they slide in and are held in place by friction. I have to re-install the same boards after they vibrate loose.

3. No need for angled feet to slide the unit, I just pick it up.

On the main foot rail, just left of the angled feet, you can see the small angle iron used to retain the osb.
You can also see that the separator doesn't like it's pounding and needs a brace. Still works for now

New Item 5. Frame needs add'l support if I want this thing to last a long time. The frame side (now horizontal for maintenance) is a single angle and is carrying more of a load that I thought (my pounding mostly). Need to build a simple truss of rebar.

 

[kg7il]

Here are the pins to hold the rebar grill that reduces the pass size.
Two 1" square tube on the frame top. only one corner is shown


One 6" piece of rebar on the bottom center. slides into the angle on the main screen frame


rebar grill slides up, locking the bottom with the pin, then drops over the square pins on top.

Last photo shows the rocks out a couple of previously run material.

 

[Whitnel]

Nice and simple. I should have made one of these when I bought my property a few years back. I probably could have gotten more done than using the rock bucket method and saved some ware and tear on my tractor.

 

[kg7il]

Nice and simple. I should have made one of these

I just couldn't come close to justifying $3,000 for one. I'm trying to keep it simple and easy to reproduce.
As far as wear and tear on the tractor, I have spend a couple of days jockeying the tractor back and forth for load after load.

 

[Renze]

yesterday while using a spare bale fork tine as a prybar, it occurred to me that these are the ideal material for a vibrating grizzly. They are hardened, cheap (if bought from the right wholesale supplier) the slot between them is tapered so rocks dont jam between them, and they can vibrate individually so rocks dont jam between them.

 

[kg7il]

bale fork tine . . are the ideal material for a vibrating grizzly.

I'd be interested in seeing a picture of what you have. An internet search showed quite a few types.

Are you thinking of the ones with a thread end and nut, possibly attached to the upper cross-member

 

[2458n]

I thought your taters were mighty big till I saw that piece of firewood by your tractor. very nice build and it is doing what you want.

 

[Renze]

I'd be interested in seeing a picture of what you have. An internet search showed quite a few types.

I mean the tapered forged I beam type. Very strong, light, and tapered so any material that jams, will be tickled loose by other material rolling downhill. Tapered off course means tapered both on the tine end, as well as on the end thats put through a heavy walled tube.

Are you thinking of the ones with a thread end and nut, possibly attached to the upper cross-member

yes indeed, like these, except for no crossbolt but a threaded end on the tine, with a tapered washer so that it spans tight from both ends, otherwise it will cave out the hole in a matter of days.
http://www.hayspear.com/media/img/panrack/-/hay_spears/hay_bale_spear_tine_fork_square_1785.jpg

What i'm actually wanting to make a grizzly for, is because i fantasize about building a jaw rock crusher for some years now, i'm saving up heavy H and C beams as its the cheapest way to get big steel, and the company i work for is going poor so most likely i will be unemployed next month, which gives me time to invest some savings in a hobby project which will, if succesfull, result in some revenue by renting it to local farmers. I watched allmost all Youtube videos on rock crushers, seen no home made jaw crusher other than a single brick model, and read university thesis of students from germany, sweden, India and the USA on the subject, however there is no definate clue on how to calculate the max force excerted on the crusher before the rock gives way. only indicational clues, so it will come down to educated guessing, as i dont have hard data to base any strength calculation on...

Anyways, for this application i only need a grizzly as wide as the crusher will be so the number of tines i need to sieve out undersized material wont be so big, i'm still deciding between 500 or 600mm (20 or 24") width (depending on the size of flywheels and other freebies or scrap value materials i can put my hands on) , for a vibrating grizzly as a feed hopper bottom which i will fill with the front loader.

 

[kg7il]

What i'm actually wanting to make a grizzly for, is because i fantasize about building a jaw rock crusher
.

Sounds like a great project. 48" (or less) bars should be great for your process. You will need to keep us uptodate if you start this project.