Easy question.

[allesg]

I'm learning g code.
I'm capable of a few simple things like cutting out a square or circle in absolute or incremental mode. I can transfer to a subroutine and back. I can drill holes etc.

I want to hog out the center of a box and leave the wall at the thickness I want.
Actually, I can already do this, but I only know how to do it using a plunge
in the z axis to the depth needed. What I want to know is how to do a ramp cut.
Let's say I've already moved to 1,1 and I've got the spindle 0.100 above the
surface area I want to hog out. I've already got cutter comp on and coolant on. I want to do my ramp CUT from
X 1.0 Y 1.0 TO X5.0 Y 1.0 WHILE RAMPING IN THE Z AXIS DOWN 0.15.

What is the correct syntax please?

Thanks in advance,
Gary

[allesg]

WILL THIS WORK?

N45 G41
N50 G01 X1.0 Y 1.0 Z2.0
N55 G01 Z0.0
N50 G01 X5.0 Y 1.0 Z-0.15

[sinha_nsit]

Plunge entry is not possible with an endmill because it does not have cutting edges at the center of the bottom. Ramp entry with, say, 10 degree angle, or helical entry (provided you have helical interpolation available on your machine) would need to be done. Or, use a slotdrill.

[allesg]

Thanks for the reply.
If one were to assume I used the correct tool, is the code correct?

Thanks!

[sinha_nsit]

G41 has no role to play in entry.
After entry to desired depth, G41/G42 would need to be invoked for lateral machining.
If you are using a slotdrill, just a single move G01 Z_ F_ to the desired depth would do.

[allesg]

Part of my confusion was about wanting to keep X and Y absolute while
making z incremental at the same time. I've got that sorted out now.

We tested my program last night and it worked great!

I agree that cutter comp is not required to make it work.

We wanted to use a ramp cut for the tool we selected.

It seems some end mills are designed with cutting sides so they can be used
as slot drills too. The shop I used deliberately buys their end mills with cutting sides for their applications. The terminology gets a little muddled as a result, but thanks for helping to make sure we used the appropriate tool.

Thanks for the reply and your help!.

[BobWarfield]

Originally Posted by allesg It seems some end mills are designed with cutting sides so they can be used as slot drills too. The shop I used deliberately buys their end mills with cutting sides for their applications. The terminology gets a little muddled as a result, but thanks for helping to make sure we used the appropriate tool. Thanks for the reply and your help!.

Center cutting endmill = slot drill. I don't see the slot drill term used very often on this side of the pond, seems more popular in other parts of the world.

Cheers,

BW

[sinha_nsit]

Slotdrill: slot + drill
You can machine a slot as well as drill a hole.
Typically, a slotdrill has 3 flutes whereas an endmill has 4 (perhaps because the chips during drilling would come out more easily if the helix angle is large).
A slotdrill has less rigidity. Moreover, it has to run at a higher RPM.

[BobWarfield]

Originally Posted by sinha_nsit Slotdrill: slot + drill You can machine a slot as well as drill a hole. Typically, a slotdrill has 3 flutes whereas an endmill has 4 (perhaps because the chips during drilling would come out more easily if the helix angle is large). A slotdrill has less rigidity. Moreover, it has to run at a higher RPM.

No.

Traditionally, a slot drill will have 2 flutes. It's become moot though, because at this stage any endmill that has cutting edges such that it can plunge may be referred to either as a slot drill or a center cutting endmill.

As I said, it is more common to use the term center cutting endmill in the US and slot drill overseas.

See for example John Stevenson's excellent account of how this came to be:

http://groups.yahoo.com/group/CAD_CA.../message/37726

Cheers,

BW

[sinha_nsit]

Originally Posted by BobWarfield No. Traditionally, a slot drill will have 2 flutes. .... See for example John Stevenson's excellent account of how this came to be: .....

Thanks for the correction.

Thanks also for the link which has a nice discussion.

[allesg]

I've been working with NCPlot V1.2 and another simulator called CNCsimulator by Microtech. CNCsimulator is more robust, but doesn't know what to do with subprogram calls or subroutine calls. I've also tried to work with a simulator that is available to when you buy training modules at immerse2learn.com
but it seems to be in the middle of some kind of development problem at the moment. It looks great, but after lots of attempts, I just can't get it to install.

Is there a well known and reliable CNC software simulator out there that
knows most of the drilling variants and can do subroutines at least?