Angle grinder crushers

[MASSEY]

Hi All,

Looking at buying a portable crusher as I'm pretty sick of dolly potting my ore down to 30m, Looking at a Cobbers crusher so if anyone has any feedback or have any recommendations I would be keen to hear
Looking at this version with the bucket attachment

I am aware of the o ring issue with these

 

[davsgold]

make your own, I made this one and it works very well

40x40mm RHS feed tube and 200x10mm pipe for barrel






drill a series of 1/8" holes for a screen


one pass through and it's like flour


and yes wear a dust mask ay

 

[Moneybox]

I've been working on a little crusher a little bit bigger.



The truck brake drum is 420mm diameter and the shaft is 50mm.



I got the shaft from the rear end of a Lister diesel engine. I thought I could cut a V-pulley into the flange but even the tungsten tipped tools wouldn't touch it.



Then I knocked up this wooden pattern so that I could cast the pulley from aluminium but my first attempt at casting was a failure. My aluminium boiled like a volcano, perhaps it was the moisture content in my sand.



Anyway it's pretty much assembled now with grader blade hammers and half inch chain below. It will have no classifier on the output side. Whatever makes it through might need another run but we'll wait and see. It'll need a solid collection drum incase something heavy comes out but I don't think that will happen because centrifugal force will keep it out there until crushed.

The intake is 65mm ID. I still haven't got a pulley and it's too big for direct drive from the 9" grinder. I have to keep the tip speed down to something reasonable so it's a work in progress....

 

[davsgold]

hey Phill be good to see this one up and running and crushing some gold ore, it's a heavy extra heavy duty model that's for sure

 

[MASSEY]

Jeez I wish I had the skills (and tools) that you guys do!

 

[Geehi]

Hi All,

Looking at buying a portable crusher as I'm pretty sick of dolly potting my ore down to 30m, Looking at a Cobbers crusher so if anyone has any feedback or have any recommendations I would be keen to hear
Looking at this version with the bucket attachment

I am aware of the o ring issue with these

I have both the Cobbers (single feed) and the Muzzas Muncher (continuous feed).
Both units are well made - the Muzzas is powered by the Makita grinder that came with it, and the Cobbers by a battery grinder I bought on eBay.
The battery grinder is quite good, but the batteries it came with will make wonderful paper weights unfortunately.
I'm probably biased, as I've used the Muzzas quite a bit and have had good results from it.
I have found that I don't get the same degree of total crush from the Cobbers, but hasten to add that this could be a function of the capabilities of the battery grinder.
I also find that it takes quite a bit of effort to get the finished crush out of the Cobbers, having to stand the thing on its head and belt it with soft-head hammer - but that would not be a consideration for a continuous feed unit, I imagine.
Incidentally, the O-ring issue appears to have been addressed - my Cobbers unit came with a flat gasket between lid and body, no O-ring. Seems to have done the trick.
I notice that the continuous feed Cobbers you referred to is no longer in his listings on eBay - only the single feed unit at the moment.
Anyhow, they are both well made units, and both from Australian companies - but we all have our biases, and mine is to the Muzzas.
Here's the link to the Muzzas if you are not familiar with it.

https://www.ebay.com.au/itm/2046169...enxDYiZkK1k2LeqM+z1jTdSxZG|tkp:Bk9SR-CW9569Yw

PS: whichever way you go, make sure you use a mask when crushing - the dust is dynamite.

 

[grubstake]

Here's the link to the Muzzas if you are not familiar with it.
PS: whichever way you go, make sure you use a mask when crushing - the dust is dynamite.

I love his warning label!

 

[MASSEY]

I have both the Cobbers (single feed) and the Muzzas Muncher (continuous feed).
Both units are well made - the Muzzas is powered by the Makita grinder that came with it, and the Cobbers by a battery grinder I bought on eBay.
The battery grinder is quite good, but the batteries it came with will make wonderful paper weights unfortunately.
I'm probably biased, as I've used the Muzzas quite a bit and have had good results from it.
I have found that I don't get the same degree of total crush from the Cobbers, but hasten to add that this could be a function of the capabilities of the battery grinder.
I also find that it takes quite a bit of effort to get the finished crush out of the Cobbers, having to stand the thing on its head and belt it with soft-head hammer - but that would not be a consideration for a continuous feed unit, I imagine.
Incidentally, the O-ring issue appears to have been addressed - my Cobbers unit came with a flat gasket between lid and body, no O-ring. Seems to have done the trick.
I notice that the continuous feed Cobbers you referred to is no longer in his listings on eBay - only the single feed unit at the moment.
Anyhow, they are both well made units, and both from Australian companies - but we all have our biases, and mine is to the Muzzas.
Here's the link to the Muzzas if you are not familiar with it.

https://www.ebay.com.au/itm/204616915474?itmmeta=01HQMYXSDA29HF595EFX2GYQAA&hash=item2fa41e5a12:gy0AAOSwRThjcB3X&itmprp=enc:AQAIAAAA4KI7sDjLN0ATRmAXdPOoGi0NUa4AGNqqRBpnQQ5UpO10ZKcQM7/Ns4x5cIFWIimS893k5h8+P8pFHjJWqulqLLefZq92E4LUUG8AKwrw13zpOMJDAbZqpBtcyp2CetIH2KP9Zbau0qSQRL3J+UQ1jmFt0Ep2zqjAQAz+NVCuiLwaidAHXvHceWxx9fAPQkAbCt+Xrf90oHGkhomR1P4SBbfFmpOlQcWcr6p/dVi6B7KUf+ZudCt65elhgfp97Kt6zUpe5IKwufhZCGYGu0enxDYiZkK1k2LeqM+z1jTdSxZG|tkp:Bk9SR-CW9569Yw

PS: whichever way you go, make sure you use a mask when crushing - the dust is dynamite.

This was exactly the kind of info I was after, Never herd of the muzza's unit before, Interesting that it comes with a makita grinder! Thanks for your post!

 

[MASSEY]

So I ended up ordering the Muzz's Unit, Will report back when it arrives, Emailed the seller through ebay and he was very good to deal with so plus 1 there so far!

 

[Geehi]

You will not regret your decision.
I buckled and bought a 700W Makita for the Cobbers unit recently because I had a number of small volume samples I wanted to check out. Using the Cobbers saved me having to set up the Muzzas.
Buying a Makita for the Cobbers was way cheaper than buying decent batteries/charger for the cordless grinder – but defeated the purpose of using it out in the scrub.
Anyhow, had a crushing day today, using both units – had used the Muzzas several times before, but not so much the Cobbers.
The most interesting comparison was the amount of greater-than-30# left behind by each unit.
After crushing about 5-6kg of quartz in the Cobbers, I got about 70% sub-30#, and about 30% +30# sand. I even ended up with some pebble sized stuff that hadn’t been touched.
After crushing around 12-15kg through the Muzzas, I ended up with about 98% sub-30#, and barely enough +30# sand to see on the screen of the 30# sieve.
Had me a bit stumped till I took a closer look at both units inside.

Here is the inside of the Muzzas:



I’ve placed a 3/8” locknut on the chamber floor – it’s sitting up against the shackle, and won’t go under it.



Here’s the Cobbers:



Same 3/8” locknut sitting comfortably under the shackle with room to spare (apologies for focus).

I’m guessing this additional clearance between shackle and housing explains the greater quantity of material not fully crushed.

Another shot of the Muzzas showing what I deem to be two advantages over the Cobbers:




1. The cover is secured with three wing bolts – this means you can remove two of the wing bolts, and swing the cover up (as shown) and lock it in place with its wing bolt intact, and,
2. the residual left inside the unit after every crush can be easily swept out into a container, as there is no flange around the cover end of the crusher housing.



In contrast, the Cobbers cover is secured with three wing nuts – with studs set into the body of the crusher. Consequently you have to remove all three wing nuts, and fully remove the cover in order to access the innards. Just a little thing, but saves time.
The Cobbers also has a flange all around the cover face of the unit, making it a bit awkward to remove the residual crush.

As I said before, both Australian products, and good to see it so.
But for mine, one stands out above the other.
Good luck with it.

 

[MASSEY]

Well it has arrived! Will report back after I get a chance to try it out...

 

[Geehi]

Good one, Massey - hours of fun guaranteed

Did some crushing today - noticed something you might want to watch out for.
After crushing about 5kg, I opened up the crusher to remove the last of the dregs, and noticed that a small piece of quartz was jammed in one of the outlet slots. Obviously due to the hammering of the shackles, it had been driven into the slot and had widened it, and closed up the adjoining slot. The quartz was easily removed, and a small screwdriver blade tapped with a small hammer reopened the closed slot and reset the slot that had been widened. Hadn't had that happen before. As I usually blue-bowl the output from the crusher, it's important to maintain the integrity of the outlet slots in order to keep the output in the sub-30 mesh region.

Brought back three lots of samples from different reefs in some old workings the other day. First sample went through the crusher today and the output from the blue bowl looked like this:

This confetti was scattered throughout the output, but not enough to get excited about. This particular quartz was the clean, almost translucent type, with no significant signs of mineralisation, so I wasn't expecting anything drastic. But at least it shows that there's still some life up in them thar hills.
The second sample is a little dirtier, so perhaps a bit more promising.
And the third sample, taken from underneath a rock fall at the mouth of an open stope, is the one I've got highest hopes for:

It looks promisingly dirty

Be aware that you will get significant metal contamination in the crusher output as the shackles slowly disintegrate - this may not be an issue for you, depending on how you intend to process the output. For blue-bowling, it's a pain in the butt. I've set up some small rare-earth magnets around the outside of the blue bowl, that eliminate a lot of this contamination in the final output.
If you're going to be doing a fair bit of crushing, you'll need a good supply of 8mm bow shackles - I haven't kept a close track of it, but I reckon I'm probably getting about 20-25kg of quartz crushed for one pair of shackles. Bunnings have got the "Gorilla" for $2.40 each - that's the best price I've found.

Enjoy!

 

[MASSEY]

Geehi,

Thanks for all the info, I have referred this thread to Muzz himself as he was asking if I had any feedback to pass it on, I can't wait until the weekend to give it a good first run, I think I'll even stop by Bunnings tonight and grab some spare shackles and loctite so I'm good to go!

 

[MASSEY]

Ready for action