Enlighten me on copper

[GunsOfNavarone]

Thanks guys for the PCD suggestion, I should have some tomorrow. This lead me down another path as well...CBN. Whatcha guys know about that? As Ti and SS are my 2 main materials I do or will be machining, is this a good thing for me to look towards? Is my sub 4000 rpm lathe going to come up short? The CBN I'm looking at isn't the big old honking crystals with a small piece brazed, rather a carbide insert with a small piece brazed. Now, find holder for them is a bit challenging as my lathe needs under 1/2" holders and cross referencing against an insert is a PIA. (Unless I can find inserts for holders I currently have, but again, I don't find TCMT, they are more like TCGT. So it's a bit more of a head scratcher.

 

[macardoso]

Thanks guys for the PCD suggestion, I should have some tomorrow. This lead me down another path as well...CBN. Whatcha guys know about that? As Ti and SS are my 2 main materials I do or will be machining, is this a good thing for me to look towards? Is my sub 4000 rpm lathe going to come up short? The CBN I'm looking at isn't the big old honking crystals with a small piece brazed, rather a carbide insert with a small piece brazed. Now, find holder for them is a bit challenging as my lathe needs under 1/2" holders and cross referencing against an insert is a PIA. (Unless I can find inserts for holders I currently have, but again, I don't find TCMT, they are more like TCGT. So it's a bit more of a head scratcher.

can’t comment about CBN for titanium and stainless. There may or may not be chemical incompatibility. I know CBN is typically used for hard machining of steels when carbide lacks the capability. It also has some use in machining super abrasive materials like nodular cast iron.

As far as the shape, TCMT and TCGT are compatible in the same holder as long as the numbers following it match. TCGT indicates a positive rake triangular insert with a ground (rather than pressed) periphery. The next numbers after the TCGT are the size (inscribed circle), thickness, and corner radius.

Using the ANSI designation, TMCT32.21 and TCGT32.21 are the exact same shape and size and can share the same insert holder.

 

[Tim9]

Copper is a pain....brass, especially leaded brass.... is an absolute joy to work with. Only problem is it’s expensive to work with. You don’t want to be working with a real big chunk of brass and mess it up. That’s an expensive blunder.

I bought a small rod of titanium to just see how it machines. It’s a tricky metal to work with. Since I have no need for it... I decided to forget about titanium.

303 and 304 Stainless steels machine nicely. But most stainless that I’ve used tends to be very stringy. Need to keep the long needle nose handy to keep from clogging the works.
When I’m planning to machine something out of my normal comfort zone, I go to YouTube and search for it. Usually there’s someone who has a decent video pointing out the “how to do it”