Impact Mill , Chain Type .

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Oct 3, 2019
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This is what I am building at the moment . I am making it in units so that it can be dismantled and packed in the truck . I do not want to weld it all together and then have to use a trailer . It will be petrol engine driven with a belt . Also thinking of having the option to fit a 240 volt electric motor . As you can see , I am mounting it on springs . Chains get out of balance and cause a lot of vibration . The exit is on the bottom of the drum . It is small round bars that are spaced at 2 m.m. This is removable and I hope that there is less chance of it getting blocked up . I have a small flywheel that I am going to fit on the shaft . This is to smooth out some of the vibrations .

This is the discharge grill , the bars are silver steel and spaced at 2 m.m . It fits in the drum so the bars are level with the bottom . I did arc weld the bars in but that might not be a good idea , they might crack and break off at the ends . We will see . I used silver steel because it is hard and will not mark as against mild steel or stainless steel , when it is hit by flying rocks.

The bars are in line with the rotation of the chains , I will put up more photos as work progresses .

Showing how the discharge grill will fit in the bottom of the drum . I have put it in the bottom as I want the material to dis charge as quickly as possible . If it does not work out , I will move it up the side .
Went and bought some 8 m.m. chain to day . Was advised by the expert to use R70 and not R80 . R80 is used for lifting chains and has a little bit of give . R70 is used for tie down chains .

Shaft is 1 inch dia , needs to have keyway cut before welding flat bars on . Also needs to be cut to length .

I have drilled the holes "neat " that is 10 - 10.1 m.m. dia. for 10 m.m. bolts . The idea behind that is they will be less likely to come loose . I am planning to use some Locktite on the bolts but not the real strong stuff.

Flat bar is 10 x32 m.m. 300 m.m. long , mild steel .
With a straight feed tube , you have to be care full that the rocks do not fly back . That is MIG welded , I only have a stick welder . My welding is not so good as it was , but I am happy that I can still do a bit of welding at 75 . Keeps me out of mischief !

End plates for my mill . I have put 3 m.m. insertion rubber on with contact adhesive . This will seal the ends and maybe reduce the noise ... Been welding the flat bars to the round shaft to day .

The steel plates are to stop the rubber pealing off .
No I have never had rocks come back up the straight tube and also have added a lid the rubber on your end plates is a good idea all the best with your crusher cheers Muk.
Not much work done on the impact mill lately . All the construction work is more or less done . Engine needs setting up , pulley is a bit too tight on the shaft . Drum needs to be bolted to the frame and shaft fitted . Will put photos up when it is finished and running .

Bought this Nox 800 which has been taking up my time . The beaches in Sydney have been washed away . Raining at the moment but hope to get out to morrow . The Nox 800 is a good machine , I am very happy with it .
Nice design Mike. I have a few different crushers on the go at the moment. Chains are OK but I got tired of hard facing and building them up.,, So,, I got hold of some 20mm thick Bisaloy 600 and made up a rotating assembly out of that. My mill is side discharge so the screen will last along time. I hope yours works out well. What are the drum dimensions. Maybe look into buying a taperloc pulley to suit your motor shaft, as this will be easier and to adjust for alignment and have a stronger clamp on the shaft and Key.
By the way Mike, If youre still able to see a weld pool through a welders lens at 75yrs old then well done to you . I really struggle now at 55yrsold.
Mike678 said:
Not much work done on the impact mill lately . All the construction work is more or less done . Engine needs setting up , pulley is a bit too tight on the shaft . Drum needs to be bolted to the frame and shaft fitted . Will put photos up when it is finished and running .

Mike, looking forward to seeing your running photos.
My next project, for starters, have the motor. :playful:
Same here.....
Me Im only a young pup....
67 lol.....
Can still run a bead or two......
No Magnifying Lenses Required.....
The old Sparklers / Fizzle Sticks P5s were many years ago lol:....

Thought I would put up another photo or two . Not much work been done on it in the last few months .

The handle and wheels will only be used to move from one spot to another . The legs slot and bolt onto the main frame , might need some cross bracing but I want to keep it clear under the drum to get plastic buckets in .

I have put a small flywheel on , it was sitting under the bench doing nothing .
these impact chain mills look good, a bit different to the ones I built using a 5" angle grinder to drive the mill.

I have stainless Steel chain fitted to the 25mm shaft to do the smashing and for the outlet sieve I drilled 1/8" holes in a 45mm x 70mm rectangle on about a 5mm grid pattern in the 210mm dia pipe drum

The 25mm shaft has a 14mm internal thread so it screws to the angle grinder shaft

cheers dave
My understanding is that 'Riggers' chain is harder an less wearing also, other chains can stretch and break by fatigue and impact.

Most chain is mild in hardness, but I sense that you guys will already know this and have your reasons for selection.

Pointing it out for the beginners around.

Cheers. :)

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