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Haas Mini Mill Fines in coolant - Filter screen?

Micmac1

Cast Iron
Joined
Jun 9, 2017
We do alot of mixed materials in our mini mill... cast iron, bronze, stainless, alloy Steels etc. We are getting a ton of fines built up under the chip screen from running the bronze and cast iron. We obviously dont use coolant for the cast iron and we try to pick out, clean & vacuum the cast iron chips before running the next job but the small stuff always finds a way into the coolant. Has anyone come up with a filter/screen solution to prevent this from happening as much? We use a chip trapper to filer the coolant at least once a month but the amount of build up under the factory chip screen we usually have to scrap out by hand because there is so much. Should note we do not have the chip auger option on this machine. Basically we are trying to figure this out because we are switching coolant brands soon from hangstefers s-500 as it is not working well in the high pressure coolant pump (foams & seperates). Also the NexGen skimmer on the machine clogs up easily with the fines in the coolant.
 
I'll chime back in later with some pictures but I made a frame and mesh basket that gets out into the sump. Clean it out once a mk th or so for my volume, it keeps LOADS of fines out of the sump.

The mini has such a terribly designed sump.

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I keep a swimming pool cleaning net on top of our tank to catch chips that get through the chip trough. When running material with very fine cuttings, I started keeping used HVAC filters from the office that I will lay on top of the tank. It's a bit of a hack, but catches a lot of material before it goes into the coolant tank.
 
I think we are going to try a 100-200 micron filter on top of a wire cloth screen and just fixture it somehow under the chip pan inside the coolant tank. The trick is going to be keeping it accessible for cleaning off the chips.
 
I took an old t shirt and wrapped it around the coolant return chute. Clamp the arm and head holes off and clamp it to the chute. Super hack, but lasted longer and worked better than any of the filter options I tried.
 
I took an old t shirt and wrapped it around the coolant return chute. Clamp the arm and head holes off and clamp it to the chute. Super hack, but lasted longer and worked better than any of the filter options I tried.

I like that idea.
 
I also resorted to fabricating a mesh basket for the sump. I purchased my mill used and always wondered if I was missing a filter/separator of some sort. I don't understand how someone could run this mill in a production environment without cleaning massive amounts of chips from the sump every week.

Screen is 304 Stainless Steel Woven Wire 120 Mesh from Amazon and seems to be about right. The chips shown in the basket are from less than 8 hrs of machining time.

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This looks like exactly what I need for my Mini Mill 2. Does this basket fit out the hole in the side of the machine? Do you mind sharing the plans for it?

-Coby
 
Unfortunately any written dimensions are long gone but yes it was sized to fit through the side opening. If I don't catch it before it's overflowing it can be a pain to remove. Though it's a huge improvement over nothing.
As I recall the screws in the sides are threaded into some solid rod to give it some stiffness. The stainless mesh is held in place between two pieces of formed stainless sheet(lower piece is tack welded to the side and top piece removable with screws. Mesh is secured to the rod with a piece of plastic tubing split along it's length. Designed it to remove/replace the mesh but I've never needed to.

Hope that helps.
 
I have 2 minimills, I just ordered 2 of these,

MM tray filter

drilled holes around the edges and add disposable filter media, is easier to throw it all away than clean the filter.

I just dump the whole tray out, new filter media, and back in.
 
I have 2 minimills, I just ordered 2 of these,

MM tray filter

drilled holes around the edges and add disposable filter media, is easier to throw it all away than clean the filter.

I just dump the whole tray out, new filter media, and back in.
How does that big old tray work with a mini-mill which has an integrated sump?
 
How does that big old tray work with a mini-mill which has an integrated sump?
The built in sump, at the very front of the machine has a perforated plate for the auger screw.
the holes in it are HUGE, and if you've ever owned one you would know they build up tons of chips in the sump.

if you add one of these, with a filter media or even thick filter battens it gathers all the chips in the bin so they aren't all over in your sump.

Then you can pull it out dump it, new filter, and reinstall.

pain in the as, but not using one is a bigger pain in the ass, anyone who owns a minimill can tell you.

enough that someone sells them.
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When another company I know bought one, and complained about the tons of chips in the sump getting to the coolant pump because of the huge holes in the auger screen, Haas just said "make bigger chips then"
 
I do own a 2013 mini-mill and yes the chip management is retarded. What I don't understand is how that big tray actually fits into the machine. Maybe things are different on the last gen model, or you've got a machine without an auger?
 
I do own a 2013 mini-mill and yes the chip management is retarded. What I don't understand is how that big tray actually fits into the machine. Maybe things are different on the last gen model, or you've got a machine without an auger?
I don't think so my machines are 2017 2018, they have a small hole on one side and a larger hole on the other, the tray just barely fits through the large hole.
 
Ok, I think yours must be the redesigned (last gen) version which has a roof and larger openings to the sump. The Haas youtube channel has a video from Aug 21, 2015 which introduces the redesigned mini-mill so presumably they started selling them right around that time. Mine is the old model with no roof and the sump openings are tiny. I've contemplated cutting larger openings in the side of the tank with a plasma cutter.
 
Ok, I think yours must be the redesigned (last gen) version which has a roof and larger openings to the sump. The Haas youtube channel has a video from Aug 21, 2015 which introduces the redesigned mini-mill so presumably they started selling them right around that time. Mine is the old model with no roof and the sump openings are tiny. I've contemplated cutting larger openings in the side of the tank with a plasma cutter.
Ahh yeah, I didn't know there was a revision that soon ago. yeah mine are like the vijeo :D
 
Ok, I think yours must be the redesigned (last gen) version which has a roof and larger openings to the sump. The Haas youtube channel has a video from Aug 21, 2015 which introduces the redesigned mini-mill so presumably they started selling them right around that time. Mine is the old model with no roof and the sump openings are tiny. I've contemplated cutting larger openings in the side of the tank with a plasma cutter.
If you can fit a vacuum nozzle in the rear and extension to reach up front, I think thats best.
yes having the chip catch is nice because the chips stay up there, not all over in the tank, yuk.

But to clean it and keep up on it, a vacuum is the deal.

With my Freddy Ecovac, I can suck the sump dry, vacuum the chips up, spray it down and vacuum it through 2 more times,
all in less than half an hour.
because its so fast we do it 2-3 times a month.

This shape work well
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I clean with a round cobweb brush, works well.
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I'll add that the old model Mini doesn't even have a rear opening to the sump. Only two tiny square holes on the sides, and on one side it's mostly inaccessible because of the coolant pump.
 
I'll add that the old model Mini doesn't even have a rear opening to the sump. Only two tiny square holes on the sides, and on one side it's mostly inaccessible because of the coolant pump.
That's HORRIBLE! yeah I would definitely cut at the very least the hole in the back.20240226_105351.jpg
 
I don't think cutting a hole in the back is an option on the old model because the square cross beam that the frame sits on is right there in the way.

With the old model I think having the auger may be worse than not having one. The only mod that can be done is cutting the sump windows larger by a few inches.
Well, it's also possible to cut a removable window in the front of the machine, but it needs to bolt in place and seal. This front window would allow the area under the auger plate to be accessed.
 








 
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