Enlighten me on copper

[macardoso]

Give the ground and honed carbide inserts for aluminum a try. They work pretty well from the limited experience I have with them. I also found isopropyl alcohol to be a great cutting fluid for sticky non-ferrous metals. My go to mix is 91% isopropyl + a bit of synthetic coolant mix + a touch of water soluble oil. I use this in a squirt bottle and it really works well.

Try a VCGT110302-AK (VCGT220-AK) insert in an appropriate holder. The "V" is a 35 degree diamond for low cutting forces and fine finishing. the "GT" and "-AK" indicates a ground/polished insert for non-ferrous metals, and the "110302" is a small insert, good for 1/2" or 3/8" tool shanks with a very small nose radius (again, low cutting forces for fine finishing).

I buy the cheap China knockoffs of these particular inserts and have had excellent experience with them. At $0.50 per edge or so, I am not afraid to try them on just about any material. I've done a bit of copper and gotten great finishes that have the rainbow light diffraction pattern on them right off the machine.

10p VCGT110302-AK H01 CNC turning insert VCGT220.5-AK Metal Lathe for Aluminum | eBay

Find many great new & used options and get the best deals for 10p VCGT110302-AK H01 CNC turning insert VCGT220.5-AK Metal Lathe for Aluminum at the best online prices at eBay! Free shipping for many products!

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Also found a reasonably priced set of import PCD inserts in the same size.

2Pcs PCD Tipped Insert VCGT110302 Single Edge VCGT220.5 Polycrystalline Diamond | eBay

Find many great new & used options and get the best deals for 2Pcs PCD Tipped Insert VCGT110302 Single Edge VCGT220.5 Polycrystalline Diamond at the best online prices at eBay! Free shipping for many products!

www.ebay.com

Here is a RH holder, 10mm (roughly 3/8") square, at rock bottom import pricing. I've bought similar listings and have had no problems. Super cheap negative rake import tooling is a different story, but the positive rake tool geometry is pretty hard to mess up IMO.

1P SVJCR1010H11 CNC Lathe Turning Tool CuttingToolholder For VCMT1102 Inserts | eBay

Find many great new & used options and get the best deals for 1P SVJCR1010H11 CNC Lathe Turning Tool CuttingToolholder For VCMT1102 Inserts at the best online prices at eBay! Free shipping for many products!

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I'll add that I love these inserts for fine finishing in non-ferrous, but also in 4140 (at higher SFM), and all stainless, especially 316. The insert life isn't very good, but they are so cheap and the finish they leave is amazing. I keep coming back to them. Think I bought 6 boxes in my last order.

 

[GunsOfNavarone]

Give the ground and honed carbide inserts for aluminum a try. They work pretty well from the limited experience I have with them. I also found isopropyl alcohol to be a great cutting fluid for sticky non-ferrous metals. My go to mix is 91% isopropyl + a bit of synthetic coolant mix + a touch of water soluble oil. I use this in a squirt bottle and it really works well.

Try a VCGT110302-AK (VCGT220-AK) insert in an appropriate holder. The "V" is a 35 degree diamond for low cutting forces and fine finishing. the "GT" and "-AK" indicates a ground/polished insert for non-ferrous metals, and the "110302" is a small insert, good for 1/2" or 3/8" tool shanks with a very small nose radius (again, low cutting forces for fine finishing).

I buy the cheap China knockoffs of these particular inserts and have had excellent experience with them. At $0.50 per edge or so, I am not afraid to try them on just about any material. I've done a bit of copper and gotten great finishes that have the rainbow light diffraction pattern on them right off the machine.

10p VCGT110302-AK H01 CNC turning insert VCGT220.5-AK Metal Lathe for Aluminum | eBay

Find many great new & used options and get the best deals for 10p VCGT110302-AK H01 CNC turning insert VCGT220.5-AK Metal Lathe for Aluminum at the best online prices at eBay! Free shipping for many products!

www.ebay.com

Also found a reasonably priced set of import PCD inserts in the same size.

2Pcs PCD Tipped Insert VCGT110302 Single Edge VCGT220.5 Polycrystalline Diamond | eBay

Find many great new & used options and get the best deals for 2Pcs PCD Tipped Insert VCGT110302 Single Edge VCGT220.5 Polycrystalline Diamond at the best online prices at eBay! Free shipping for many products!

www.ebay.com

Here is a RH holder, 10mm (roughly 3/8") square, at rock bottom import pricing. I've bought similar listings and have had no problems. Super cheap negative rake import tooling is a different story, but the positive rake tool geometry is pretty hard to mess up IMO.

1P SVJCR1010H11 CNC Lathe Turning Tool CuttingToolholder For VCMT1102 Inserts | eBay

Find many great new & used options and get the best deals for 1P SVJCR1010H11 CNC Lathe Turning Tool CuttingToolholder For VCMT1102 Inserts at the best online prices at eBay! Free shipping for many products!

www.ebay.com

I'll add that I love these inserts for fine finishing in non-ferrous, but also in 4140 (at higher SFM), and all stainless, especially 316. The insert life isn't very good, but they are so cheap and the finish they leave is amazing. I keep coming back to them. Think I bought 6 boxes in my last order.

So I'm on board. I am searching around to see if there are any similar product available in the states. Made in China is fine for this, But I just hate ordering from overseas. I have had things not show up, take 2 months, etc.... Also, are you saying the PCD inserts don't last for you or the carbide inserts?

 

[macardoso]

So I'm on board. I am searching around to see if there are any similar product available in the states. Made in China is fine for this, But I just hate ordering from overseas. I have had things not show up, take 2 months, etc.... Also, are you saying the PCD inserts don't last for you or the carbide inserts?

Check for different eBay listings. I can usually find what I want in US warehouses with fast shipping. Usually the same price too.

I have not personally ever used PCD. What I meant by my comment was theses inserts (very sharp for non ferrous materials) work great in steel, stainless, etc, but has less than optimal tool life. Unless I crash, chip, or weld them up them from abuse, I have never worn one out in aluminum.

I did a small production job of turning some profiled 1/2" "balls" out of 316 stainless. I'm sure I could have improved the feeds and speeds for better tool life, and I was cutting dry, but I'd get about 20 minutes per insert edge (roughly 5 parts). After that the insert still cut fine but the finish started to suffer and I would index. Changed it up later, roughed with a finishing insert for ferrous materials and took 2 finishing passes with the non ferrous insert and finished probably 200 balls before needing to change the insert. This was a CCMT insert of the same grade as the VCGT I recommended.

 

[hman]

Man! Are you worried about an infest of bugs on your machine chowing down on the lard?

My go-to cutting fluid for aluminum is a mix of lard and either kerosene or WD-40. It's in a semi-open container. My back stock of lard is in an old peanut butter jar in a cabinet. Never had a problem with bugs ... either 6-legged or microscopic.

Of course, I get the outside of the shop building sprayed (along with the house) by our monthly bug service, and it's a nice, tight building. Your situation may well be very different. All I can report on is my own experience.

 

[jbobb1]

I used dry film silicone spray before on copper and aluminum in the past, when nothing else could be used. Works good and not much of a mess, but it is very pricey.
Maybe there's something similar that's cheaper.

 

[GunsOfNavarone]

I wonder if dry graphite spray like you would use on locks would work?

 

[ACHiPo]

I machined some oxygen free full soft copper and it was a b$@#h as John said. I didn't like the idea of food products on the lathe either. I tried and got pretty good results with an HSS shear tool and no lube.

 

[jbobb1]

I'm not too sure about graphite. Not something I ever used.

 

[GunsOfNavarone]

Check for different eBay listings. I can usually find what I want in US warehouses with fast shipping. Usually the same price too.

I have not personally ever used PCD. What I meant by my comment was theses inserts (very sharp for non ferrous materials) work great in steel, stainless, etc, but has less than optimal tool life. Unless I crash, chip, or weld them up them from abuse, I have never worn one out in aluminum.

I did a small production job of turning some profiled 1/2" "balls" out of 316 stainless. I'm sure I could have improved the feeds and speeds for better tool life, and I was cutting dry, but I'd get about 20 minutes per insert edge (roughly 5 parts). After that the insert still cut fine but the finish started to suffer and I would index. Changed it up later, roughed with a finishing insert for ferrous materials and took 2 finishing passes with the non ferrous insert and finished probably 200 balls before needing to change the insert. This was a CCMT insert of the same grade as the VCGT I recommended.

Ok...I gotta ask, what are those? Also, I see you are using your mill as a lathe, but I can't figure for the life of me how your milling a sphere!

 

[macardoso]

Ok...I gotta ask, what are those? Also, I see you are using your mill as a lathe, but I can't figure for the life of me how your milling a sphere!

It was a 2 op part (actually 3, but that part isn't in the pictures). Op 1 was on the manual lathe, face, drill, tap M3.5x0.8, and use a radius form tool to set the rear radius. Then part off with stock remaining. Op 2 threaded that part into a fixture in the mill spindle, basically a M3.5x0.8 stud loctited into a steel plug in a collet. It was drilled and tapped in place for minimum runout and never removed. The part was threaded onto the stud and CNC lathed to form the larger radius (not exactly a full ball, but close). The fixture worked perfectly and the blend lines at the edges were perfect 98% of the time.

The brass part was done in a similar manner, Op1 on the lathe, then the ridges and thread on the CNC using that Thinbit grooving tool in the back.

I'm not super efficient at larger volumes yet, but it worked well enough. Hardest part was turning the long thin part of the brass bar.

EDIT: They were a customer part. Can't say what they are for, but they were OK with pictures shared.