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Aluminum chip management

GiroDyno

Cast Iron
Joined
Apr 19, 2021
Location
PNW
Good morning everyone,
This is a two part question but I'm hoping there will be some good input even if everything isn't magically resolved.

Working at a business that has been growing year over year and essentially needs to double production capacity overnight. Looking into adding a robot and/or dual spindle lathe to reduce ops and run afterhours. This means double the amount of chips in an ever shrinking facility.
I've been researching briquetting machines and have found some that look promising. Unfortunately they all appear to struggle with stringy chips and we end up with one softball sized birds nest from the finish of each cycle. So I looked into shredding machines and they cost as much as the briquetter (or more!).
Now it appears to me that the problem really starts in the lathe and the shredder shouldn't be necessary if we can fix the birds nest, which I'm assuming could also cause problems with robots or part exchanges in a DS lathe...

So here are my questions:
Has anyone made a cheap shredder or have any ideas on how to put something together? And then we have to figure out how to transport the shreddings into the briquetter...
How can we eliminate the stringy chips altogether? Heavier feed? Switch up the insert? Different rough/finish tools?

Haas lathes, 6061, parts are 7-11" diameter and slightly convex, CNGG 431-ML K10 insert, 1950 SFM, .005" per rev, .005" deep finishing pass

I don't exactly have a ton of experience running production so hopefully I didn't forget any vital information!
 
General consensus is scrap yards won't take briquettes. I did have good luck with getting the scrapyard to drop off gaylords and pallets.

When I got them full I'd call and they would come out, pick up the full ones and drop new empties and give me a check for the last batch.
 
CNGG 431-ML K10 insert, 1950 SFM, .005" per rev, .005" deep finishing pass

I don't know if that chip breaker is doing anything at that depth of cut.
Maybe try the PCD as mentioned above. One insert corner should last damn near forever.
 
I think briquetting is a distant priority that you probably don't need to worry about anytime soon.

For now, I think it's figuring out how to break the chip, and making sure your material is consistent enough such that you're not chasing a moving target.

PCD sounds like a good solution. A tool rep should be able to provide you with tooling on guaranteed test.

As for material, thick sections are hit-or-miss when it comes to heat treating. If you start seeing inconsistency in material properties (gumminess), you might have to figure out an alternative to off-the-shelf, large diameter rounds. For example, you can try waterjet plate, or send in sawcut discs for heat treating. This all costs money, so you have to weigh the costs vs the benefits.
 
Definitely try some PCD tools. With diameters that big you can really get you SFM up to where they excel and the chips will be a lot more manageable. Plus they will last forever in 6061. We get over 30 hours of cut time on some DCMW 32.52 inserts at about 7000 SFM with an interrupted cut in A380.

Walter is our current choice for standard ISO PCD inserts. We originally used Sandvik, but their prices only kept going up. Kyocera offers some with a chip breaker, but we had issues with them failing early. Kennametal also makes them, but I've never thrown the single test tool in a machine to see if it would last.

For custom stuff look at STF or VR Wesson. We get a lot of PCD grooving inserts through them.
 
Thanks for the input I will definitely look into the PCD inserts! Will check out the above mentioned brands and try to get a rep in. We have a few hundred unique part #'s but luckily they're all XS-XL sizes of the same thing so the right tool should take care of everything.

We fill chips in drums with holes to drain but it takes an operator or two to dump bins every hour and by the time they've also had a cup of coffee and a trip to the bathroom it really begins to add up. A full size hopper at each machine emptied would make for fewer trips, but then what do you drain coolant into? A kiddie pool?
We don't have room to store chips inside, and when it rains here (always) we can't have coolant runoff so briquetters help with reduced volume of chips, and lost coolant. We also have a couple recyclers locally who quoted us a substantial return for briquettes vs. loose chips so that pays for the equipment pretty quick.
 
A full size hopper at each machine emptied would make for fewer trips, but then what do you drain coolant into? A kiddie pool?

One of our machines makes a ton of alum chips, and coolant gets into the hopper from the conveyor.What we do is we have one of those Little Giant submersible pumps with a garden hose attached to it. We drop it into the empty hopper, fill it up and when we're ready to swap out hoppers, we just plug in the pump and the hose spits it back into the tank.
 
We dump those 1 yard tilt bins on wheels into larger 4 or 5 yard bins. Those have a tapered bottom that drains into a welded up tank below. It works great, but takes up a lot of floor space.

One thing to be ready for on the PCD is the price. If you aren't buying in bulk the inserts will likely be $80-$120 each. It hurts up front, but they are absolutely worth it.
 
J Gilles looks like you are local(ish) what distributor do you get your PCD from?

We go through MSC since we have a huge corporate account. I don't think their pricing is great if you are a smaller shop. Not really sure about local vendors. We used to use Stellar, but they didn't live up to their name.

I'm in Vancouver and if you are close by I'll give you the Kennametal test insert I've got. DPGW3251FST
 
One thing you could try that is less expensive are the DLC inserts (Diamond like Carbon) from Kyocera. I'm not sure if other mfg's make something similar but for less than $20 it's worth a shot.
They have different styles not just the one I linked.

https://www.mscdirect.com/product/details/97767818
Do you or anyone else have any experience with them? Quite curious about those but MSC UK don't have them listed so I'd probably have to buy a pack to try them.

Korloy make/made DLC coated inserts as well,

http://www.korloy.com/en/ebook/2018Technews_PD1005 PD1010(EM)/assets/contents/download.pdf
 
Good morning everyone,
This is a two part question but I'm hoping there will be some good input even if everything isn't magically resolved.

Working at a business that has been growing year over year and essentially needs to double production capacity overnight. Looking into adding a robot and/or dual spindle lathe to reduce ops and run afterhours. This means double the amount of chips in an ever shrinking facility.
I've been researching briquetting machines and have found some that look promising. Unfortunately they all appear to struggle with stringy chips and we end up with one softball sized birds nest from the finish of each cycle. So I looked into shredding machines and they cost as much as the briquetter (or more!).
Now it appears to me that the problem really starts in the lathe and the shredder shouldn't be necessary if we can fix the birds nest, which I'm assuming could also cause problems with robots or part exchanges in a DS lathe...

So here are my questions:
Has anyone made a cheap shredder or have any ideas on how to put something together? And then we have to figure out how to transport the shreddings into the briquetter...
How can we eliminate the stringy chips altogether? Heavier feed? Switch up the insert? Different rough/finish tools?

Haas lathes, 6061, parts are 7-11" diameter and slightly convex, CNGG 431-ML K10 insert, 1950 SFM, .005" per rev, .005" deep finishing pass

I don't exactly have a ton of experience running production so hopefully I didn't forget any vital information!

there is the problem, tip radius is 0.016" you need a feed larger then that to control chips.

that is definitely the wrong geometry insert. looks like it is more designed for cast iron and not a sharp cutting edge for aluminum, it is trying to shear it and not cut it. plus the feed looks really slow to me.

it is also only a medium chip breaker, need a finishing insert for a finishing chip breaker. ML is a negative insert, you would need better geometry like a MT chip breaker.
 
Spoke with a couple reps and have some DLC samples coming.
It did occur to us that we weren't engaging the chipbreaker, or even using the proper insert. The other half of our applications are cast iron so these inserts may have just been adopted from that. We are going to try a different flavor of insert that should be able to break a chip under a much lighter DOC.
We don't really want to run faster because the jaws we use are heavy enough that increased RPM might reduce the clamp pressure too much.
Thanks for the suggestions, keep 'em coming!
 
Last edited:
An update for those who might be going through similar growing pains:

We really had to find a way to deal with chips, we were emptying bins too frequently, spilling chips on the floor, and storing leaky bins was a problem.
We produce about 1000-1500 lbs of aluminum chips depending on the day. We purchased a briquetter from ARS-inc with 600lb/hour capacity and its been running for one month now, we get $0.70/lb for briquettes so more than 2.5x. At this rate the machine will pay for itself in about a year.

We still have some issues with bushy lathe turnings. There is a feed ram on the briquetter that helps force chips down the gullet which helps but sometimes it runs a couple extra cycles to reach full pressure. We have some new insert tooling coming from Sumitomo that should finally resolve this issue.

We use 1/2 yard hoppers at each machine and stagger when they get dumped (once or twice a day) so we don't overfill the briquetter hopper. After we resolve the bushy chips we should be able to dump multiple hoppers at once, but will continue the staggered approach to keep a continuous flow of briquettes out of the machine.

One last thing to note; if you have someone haul away your scrap make sure they you continue to call them on the same time interval...We waited until we had the same quantity of bins to haul, but they were full of solids not chips and it was almost too heavy for his truck!
 
To successfully apply any type of automation, chip control is essential. It cant just work 99% of the time, it has to work 100% of the time, day after day after day. Once you control your chips, you will greatly decrease the volume of space your chips take up, increasing the ease of disposal (bird nests versus 6's and 9's). 6061 can be challenging, if for no other reason than it seems to vary from batch to batch. Go with a good material supplier that will deliver consistently high quality material. Insist on the same source every time. What works great for aluminum from vendor A may not work worth a shit with material from vendor B.
I don't know if simply switching to PCD will help. It will undoubtedly increase your tool life, but it sounds like the machine you are working on will not give you the high RPM's you need to take advantage of PCD, and carbide will last a very, very long time in 6061 anyway. There is a plethora of different styles of chip breakers available, and I do not doubt there is something out there that will work for you. Don't look only at aluminum specific inserts, we have found some general purpose inserts that work great on 6061. We machine many tons of 6061 every year, and have tried numerous grades, nose radii, relief angles and chip breaker geometries. The solution is undoubtedly out there, it is just a matter of good, educated guesses along with trial and error.
 








 
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