Indexable Carbide Tips and Tricks

[faavs730222]

Hi, I made the mistake that I am sure a lot of beginners make when they get their first lathe. They buy an assortment of Carbide tipped tools.
I bought mine in a nice set. (Chinese no doubt!) I also bought a nice SDJCR 1616 tool holder(cost more than the whole set of my other carbide tools).
After a number of broken tips and disappointing finishes I switched to HSS.
But I have the Carbide tips and would like to use them.
Are their any advice you can give on their use. Like cutting speed etc. Some things I must look out for? Any general advice would be appreciated.

Thank you,

Anton

 

[chuckorlando]

You did not mention the size of the machine but carbide likes to eat. It likes more rpm, more feed and more DOC. I can pull off .025 doc on my 9x20 with carbide and she runs nice. That seems like a healthy cut for a tiny machine. Really my biggest problem with carbide is I can take more meat then the insert is able to cut and it starts to plow into the work like a V. Make sure your using a feed and speed calculator as carbide wants to be in it's happy place or it breaks. Make sure all your gibs are adjusted and the lathe has min flex as that becomes chatter and that kills carbide.

I dont use the brazed carbide as I just cant get it to work well. Might just need to stone them a bit. But I love my indexables.

 

[Tozguy]

Sounds familiar
Talking brazed carbide tips, I was able to grind my chipped and broken tools into something useable and durable.
It was a worthwhile experience because I learned how to grind and hone a good edge on carbide. Also realized that the edges on budget brazed carbide tools are not ready to go when new. Look at them under magnification and you will see what I mean. They need to be touched up and honed before using or they don't last.
I waited before trying indexable carbide inserts, I would say that you should learn and practice some basics about speeds, feeds and cuts with HSS and brazed carbide before using inserts. Carbide inserts can be an awful expensive alternative to learning how to grind tools.
How is it going with the HSS tools?

 

[Bill C.]

I agree, I always touch up brazed carbide bits. I usually needed to grind a little more clearance on the front and nose. I usually wore them down to where there was hardly any carbide left before replacing tools.

 

[Ebel440]

Never stop the spindle when the carbide is touching the work it can chip the tool.

 

[Ebel440]

And the most important thing I've found with inserts is to always grease the screw that holds it with the proper grease and don't over tighten the screws.

 

[faavs730222]

My Lathe is a 1.1kw 9x20. I get varied results with the HSS but I think it is in part the different grades of metal I use. I am using the angles that they recommend in the South Bend book. I would like one tool that I can do all my basic turning, facing and do it all with a reasonable finish. I would like to see pictures of the HSS tools you use the most.

Thank you for all the comments,

 

[Tozguy]

The HSS tool that I use the most is this one. Very versatile.
http://www.eccentricengineering.com.au/index.php?option=com_content&view=article&id=2&Itemid

This is a 'road test' of the tangential tool holder in the above link.
http://modelengineeringwebsite.com/Diamond_tool.html

 

[mattthemuppet2]

here are some different ones I've used (most of which I've made)
http://www.hobby-machinist.com/show...-HSS-grinds?highlight=HSS+grinding+shear+tool

I've since ground a RH knife tool that's really useful for facing and a trepanning tool, which was rather fun. On my small lathe these all work waaay better than the generic indexable tools I have. Also worth getting an arkansas stone or diamond hone for final touching up after grinding, it makes a big difference.

 

[kevin]

Sounds familiar
Talking brazed carbide tips, I was able to grind my chipped and broken tools into something useable and durable.
It was a worthwhile experience because I learned how to grind and hone a good edge on carbide. Also realized that the edges on budget brazed carbide tools are not ready to go when new. Look at them under magnification and you will see what I mean. They need to be touched up and honed before using or they don't last.
I waited before trying indexable carbide inserts, I would say that you should learn and practice some basics about speeds, feeds and cuts with HSS and brazed carbide before using inserts. Carbide inserts can be an awful expensive alternative to learning how to grind tools.
How is it going with the HSS tools?

I'll second that. When I was starting out, I bought a set of cheap brazed carbide tools and could never get them to work. Recently, I bought a silicon carbide wheel for my bench grinder and reground some of the tools, finishing up by hand with a diamond "file." Made a world of difference! Now they actually cut properly, whereas before they just rubbed and chattered.