Help with css,feed...

[CNCbook]

Hello!

I am using mastercam x and i dont know what constant surface speed should i use for any materials. I only know what they are for aluminium(1200 rough finish 1300). Does anybody have a table, website... so i can learn from.
Am not talking about rpm but constant surface speed, feed....

[WallyL7]

Hey CNCBOOK,

Welcome to the zone. My first (and really sarcastic) suggestion is...have you ever seen a CNC Book?...lol

Most tool manufacturers for inserts and endmills will give you surface speed for different materials based on the grade of carbide, coating, etc...so that is really where you get exact surface speed.

[foxsquirrel]

Man, that is an extremely wide question. Best thing to do is ask the machine operator what he suggests or you can crack the book and read. The internet is loaded with Feed data from various manufactures such as Niagra and Mil-Tec.

[rusty abe]

Hi CNCbook,
Last time I have came across the same problem. My suggestion is to go to Sandvik as well as Dapra website, they both have formula to download. But you still have to look for material cutting speed to plug into the formula. It really help. Hope this help.

Regard,
rusty

[camtd]

sometimes I refer to this site

Speeds and Feeds

[Superman]

Cutting speed referred to in the tooling manuals is the speed at which the material is travelling past the cutting edge

when turning,
The material is moving and the RPM is calculated at the diameter the tool point is cutting at. This can be a fixed RPM (G97 Sxxx ) if turning a known, constant diameter... or you can have the control adjust the RPM (G96 Syyy ) depending on the diameter the tool is presently cutting at.
and if using CSS always use a clamp speed ( G50 Szzz ), to stop the machine goimg to it's maximum RPM

xxx is a set RPM speed
yyy is a cutting speed ( how fast the material passes the tool )
zzz is the safe maximum RPM you want it to go to
G95 ( feed per rev ) is commonly used on lathes, alter the RPM and the actual feed is unchanged

When milling
The tool is moving, so the cutting speed is calculated to the edges of the tool.
CSS is NOT used on a milling machine as a fixed RPM is defined
G94 ( feed per minute ) is most commonly used, altering the speed over-ride does NOT alter the feed, alter the feed over-ride does NOT alter the feed
G95 can be used, most use it when tapping, where you may alter the speed to get it to run better, the tapping pitch will remain constant....just remember to set it back to G94 after tapping......it is good practice to have in any milling code to have this G94 at the end of machining, before toolchanging, just to be safe