Homemade Jaw Crusher.

[Renze]

The Jaw plates will have weld beads along each ridge and ground into some form of a point.

Welding on the compressed side isnt much of an issue, if a crack appears, it will be pushed closed at every load cycle. Welds on the back side, the tension side, are nastier because they are pulled further open at every tension cycle.

https://www.youtube.com/watch?v=DlORya3hh04

This machine is quit a bit larger and seems to work good with rebar teeth.

I have watched virtually all home made jaw crusher videos on Youtube but hadnt seen this one yet The one my neighbours once rented had a foot wide opening, and the back plate was just a hot rolled C channel. Then cast manganese jaw plates bolted to that. With smaller crushers the stress is rapidly decreasing with size, it seems.

What i would want to make is a crusher this size, yet without the tracks, engine and belts.
https://www.youtube.com/watch?v=4vA2GaSM4AY

And when that crusher works, sitting on a simple farm wagon frame, PTO driven, i want a feeder grizzy like this slightly bigger model has:
https://www.youtube.com/watch?v=-ym6jXU15mY

 

[FarmWrench]

Very cool. Anyone have a translation transcription of the narration? Round rock is a bit more resilient than old concrete. Also on my fantasy build list.

 

[David Devuono]

This was my idea for a CAM lobe. Took an X Series Hub, used a hole saw to cut a hole the size of the shaft. Then turned the outside of the hub to the Bearing ID. Then I will weld two of these to the shaft. This will give me about 3/4 inch stroke.

 

[David Devuono]

This is one of two cam lobes pressed onto the axle. I will add some weld to the side to hold it in place.

 

[David Devuono]

Two cam lobes cut and pressed on. Mocked up the housing and bearings that the Jaw plate frame will be welded to. I am a bit concerned that the stroke will be too Small at under 1/2 inch. I will likely try it out before rethinking things as bearing size limits the cam lobe which means $$ more on bigger bearings etc.

 

[Baby Grand]

That's lookin' great, Dave. Really nice workmanship.
It's just a notion, but I'd be tempted to keep the stroke modest to amplify the crushing power.
You're very wise to leave this variable as something you can adjust.
I suspect the secret is to start a crack on the first stroke; not shatter the stone outright.
The second stroke should finish breaking the stone and let the fragments drop down for another cycle or right thru if they're small enough.

 

[Renze]

I think you'll end up lathing an eccentric shaft out of solid... But lets see how it turns out !!

 

[BHD]

dumb question ?

are the fly wheels for inertia or just for speed reduction.

if it is more for inertia would a "old steel wheel" and rebore the hub, (as most are wore, as the hub many times was the bearing). but then fill with concrete, or would vibration beat it out, or even a hub, so one could fill a old rim with concrete,

this has got me thinking and the idea of making a small trailer type unit what would be ran off pto of tractor, I have a large pile of concrete and field rock that is lime based,

the idea as much of the video posted above, https://www.youtube.com/watch?v=DlORya3hh04

 

[David Devuono]

I would have to look for a 4 jaw chuck for my chinese lathe in order to machine a cam from a single piece of steel. At least I can't figure out how to offset the the shaft on my 3 jaw. It would take me three days to cut down a 2" shaft anyway. BHD the flywheels are for inertia. The bigger the flywheel, the smaller engine required. Hoping to start welding tomorrow, though its extremely cold and I have no heater in the garage. As far as strain and everything, there is a site where a company rebuilds broken Jaw Crushers. Really big machines that eventually broke. Like 5 inch thick Steel cracking. Then there are ones still in use that are 100 years old.

 

[Renze]

dumb question ?

are the fly wheels for inertia or just for speed reduction.

I have a PTO driven log splitter/shear. It has no flywheel and sends the tractor engine barking at every chew. Result is that my 30 PTO horsepower tractor splits PTO shafts lengthwise, that are normally capable of 100hp. The entire driveline of the tractor acts now as a flywheel, putting 100hp torque peaks on the PTO gears by extracting the inertia energy from the rotating mass inside the gearbox.

A flywheel as close as possible to the end user of intermittent power peaks, saves the driveline before it.The driveline behind the flywheel has to be designed for the peak loads, the driveline before the flywheel can be designed for the average load. (thats why im afraid the cam lobe on Davids eccentric shaft gets sheared off, its a high fatigue load, and empirical studies show that welds are 6 to 8 times more prone to fatigue than the base material)

Nevermind, i'd get that crusher working first, before getting into means of lathing the shaft out of solid bar...