Thread: speed feed and cut rates

Check the web for various cutting speed data,that will let you know SFM or MM.
For your feed rate you normally dont exceed your nose radious.
For the DOC for roughing what ever the machine will handle without stalling,for finishing maybe .005" to .010".
When Im turning 45mm DIA cast on my Hercus I run at 300/400 RPM,between .030/.060" DOC and .002 to .006" feed.I alter the DOC for finishing
You can use coolant if you want to if you feel the job might be getting overly hot,but normally on a smaller lathe it shouldnt be needed for cast.

I take it t/c means Tungsten Carbide??

If so, the appropriate feed and speed will be written on the box of inserts.

75rpm on a 43mm round is way too slow for tungsten carbide.... Also you do not use coolant on TC unless you can pour heaps onto it like they do in CNC..

thanks guys i was experimenting with the different feeds and speeds but wasnt quite game to up the doc @400rpm ......putting a new motor on in next few days with forward and reverse so ill get a bit more adventurous with the settings
and yes t/c is tungsten carbide but chines budget version with no name inserts who knows what there specs are but its fun experimenting .ok on the no need for coolant too just need to cover my arm where the hot bits land

Are the tools your using positive rake.
If you like and have the room cut your self a little bit of shim either steel strapping,brass,aluminium you could even use a piece of plastic milk bottle (although this has a tendency to melt ) to form a small guard just shy of your work piece and cutting tool.
Bend the end of it up slightly this should deflect the chips from flying up and landing on your hand or arm,will also be good for brass or bronze,experiment with placement to suit your needs.
The shim doesnt need to be overly thick .010" to .020" is usually fine.
How did you get on with your mounting plate?

sounds like a great idea making a deflector ...... as for progress had to take a bit more off the outer diameter with the 3 jaw chuck holding the centre section so it would fit better in the 4 jaw on the outer (the jaws were at maximum and wasnt holding it as well as i wanted )
spent the rest of the day trying to work out the reversing switch contacts but im almost sure its not the right kind of switch )
I finally got adventurous and tried out a a tuegatec tipped tool loaned by a forum memeber WOW what a difference a tool makes you definatly get what you pay for

Here is a nomograph that you can save and print out for the workshop...

http://img.photobucket.com/albums/v6...enomograph.jpg

thanks rc just what i was looking for