We have been machining Copper 110 alloy for 15 years on a manual lathe. We have found that a positive rake of 25 to 30° works best, and a slight radius at the tip of the Tool bit. Also, taking a small hone stone and Dulling the very tip of the high-speed steel radius greatly improved surface finish to a near polish. But the major problem is the continuous stringy chip. If you continuously break the chip…interrupted cuts…, it affects surface finish negatively. The long stringy chips are extremely dangerous and using a collet chuck has greatly helped in safety and keeping the chips from wrapping around anything. We have experimented over the years with chip breakers, trying to get the chip to curl on all cuts with some success, heavy and light cuts. this is the only area we have yet to achieve total success, that is the chip control. It is insanely sharp and dangerous. when cleaning up the swarf, I have been cut through leather gloves, as if I was barehanded, nasty stuff

Hi Chris, Thanks for sticking with that turning of copper... it good to learn how to get good results. Take care Paul,,

Hi Chris. I remember being taught that rake angle of upwards of 30° is good for turning copper with HSS. No need for T.C. tips, although sSanvik and the other high quality tip manufacturers all offer tips designed to cut copper. That piece of copper you're playing with must be worth a fortune! I think copper is going to be the next precious metal!

@chris-the-bodge-sculptor

3 жыл бұрын

Stuart York 30 degrees thanks Stuart, very expensive I think , the next size up is a 65mm which is silly money and ships from China , so I’m looking to make one from 3mm plate doubled up to 6mm as that’s very pricey to ! One thing I have to ask .. how the devil did you get the little degree symbol next to the 30 ?

@joejoejoejoejoejoe4391

3 жыл бұрын

We often have tons ( not an exaggeration ) of copper ( but usually bronze ingots ) at work, - tin is also VERY expensive.

Oh, and thanks for sharing your findings. I keep all these little tidbits tucked away so if I ever run into a problem, I say to myself.... oh yeah, I saw a video on that! I have a terrible memory but when it comes to things I'm interested in, I'm pretty sharp. Good thing it's not the other way around! Lol Take care buddy!

@chris-the-bodge-sculptor

3 жыл бұрын

One Stop Fab Shop thank you for viewing! , one thing I’d say is hone the radius really fine with a diamond wet stone to get a polished edge

@onestopfabshop3224

3 жыл бұрын

@@chris-the-bodge-sculptor Thank you sir!

About to machine some copper myself for the first time in 15 years. Knew the high conductivity of copper could possibly pose a problem with galling and surface finish, so here I am. My gut instinct would be to increase feed dramatically, use a much wider edge radius tool/insert, and cutting oil/coolant.

@shonuff4951

Жыл бұрын

You need to dissipate the heat. That's the problem. Maybe even add a "dwell" code if need be, for CNC. Having a sharp tool with slow feed rate is only increasing the time of surface friction, and thus heat build up, rough finish, and galling.

@shonuff4951

Жыл бұрын

That's why your chips are literally about to catch fire. Don't underestimate the fire hazard from dry very fine chips by the way. I've seen a clump of titanium strings light up and explode like a flash grenade.

Never tried it mysrlf but the old timey lube was milk, the cow's variety not white soluble cutting fluid. I would try a high shear round ended high rake HSS tool at a faster feed rate for a fine finish but that is just a guess as I can't recall ever turning pure copper myself.

@chris-the-bodge-sculptor

3 жыл бұрын

Chris Stephens thanks Chris ! I’m guessing using milk could get stinky 😅 if you didn’t clean up properly, I have a look at that high shear geometry, and as you know I’m a big fan of going flat out on the Colchester lol thanks for viewing and have a nice day

I think the 1 issue was you were using a right hand tool cutting a left hand cut. The sharp edge wasn't able to shear, it was kind of ramping on the relief taper before the cutting edge got to make contact. My opinion anyway, that will contribute to a difficult material.

@chris-the-bodge-sculptor

3 жыл бұрын

One Stop Fab Shop your 100% right I just picked it up , as it was handy

@onestopfabshop3224

3 жыл бұрын

@@chris-the-bodge-sculptor Ok, we've all been there!

You seem to like using a sharp corner on your tools, when turning bronze I often use tools with a radius of about six inches ( yes, really ), the swarf comes off in big curls ( unless I use a negative rake at 500rpm 6 inch dia workpiece, the swarf goes up in a big string to the ceiling ). If you're aiming for a finish like you get on fancy hi fi volume knobs, I got good results with a very shallow angle on a brazed carbide tip, honed with a ultra fine CBN hone - but it did need cutting oil and that was on stainless and high tin bronze.

@chris-the-bodge-sculptor

3 жыл бұрын

Thank you that’s certainly very interesting I will definitely try your suggestion 😊

Have you tried alloy c14500?

That copper looks like a CD :-)

@chris-the-bodge-sculptor

3 жыл бұрын

Tool Addict that’s exactly what I’m making a Rick astley cd 💿 😅, love the engineers tool box ! Plenty of do- da’s in there!

What about trying a garden rake...🤣😂🤣😂

@chris-the-bodge-sculptor

3 жыл бұрын

Might just do that ... cut a tip off and case harden it ....🤔😅👀

Try a negative rake.

Something my friend recommended was to use some stick glue on the surface. I actually found a video on the topic after the fact as well. kzread.info/dash/bejne/mZ6rsqOgdqS3hag.html

I appreciate what you are trying to prove. But, use a sharp carbide tool and spin the piss out of it. 2000 rpm if you’ve got the gears. Carbide has been around since before WW2 , It’s cheap. I use CBN at 4500 rpm,, telescope mirror finish. Just sayin, if you are just looking for finish, there are options. Anyhow, thanks for sharing. Nice lathe too.

@chris-the-bodge-sculptor

3 жыл бұрын

Phase Converter 135 amp 208 V Hello 😄 thanks can i ask what CBN is , the max she will go is 1200rpm ! , this was a feasibly video to see what would happen on previous videos I’ve had success with CNMG polished inserts for aluminium, I was just wondering how the finish was achieved say a hundred years ago ... to to bad I’ll do some more experiments, thanks for viewing, With Those speeds I’m guessing your a professional machinist? ?🙂

@joejoejoejoejoejoe4391

3 жыл бұрын

@@chris-the-bodge-sculptor If you want to see how they got a good finish 100 years ago, try using swan necked tools. I made a swan necked parting off tool a few years ago ( out of a broken carbide tipped circular saw blade ), it worked remarkably well.

@chris-the-bodge-sculptor

3 жыл бұрын

@@joejoejoejoejoejoe4391 I’m not sure what that is I will Google that !! 🙂 You certainly know your stuff are you a machinist? Or keen model engineer etc 🙂 many thanks Chris

@joejoejoejoejoejoe4391

3 жыл бұрын

@@chris-the-bodge-sculptor When I first started using a lathe ( possibly a Southbend ), I had to stand on a stool ( HEALTH AND SAFETY ! ), to see what I was doing ( I was perhaps 6 ). I used to read Model Engineer magazine LOTS, sadly I used to look thorough the Buck and Hickman catalogue, for my 18th ( I think ) birthday I got a book on reconditioning machine tools, Fred Dibnah was like a god to me, I've been hand turning bronze as a profession for nearly 30 years. How sad am I ! PS it's nice to hear someone with a proper accent on you tube !

@chris-the-bodge-sculptor

3 жыл бұрын

@@joejoejoejoejoejoe4391 😅 only 50% of KZread viewers can understand my accent ! 🙂 thank you for taking the time to share your knowledge with me 🙂👍