Messages

41

G-Code, CAD, and CAM discussions / Re: Gcode pause

« on: July 20, 2010, 05:30:05 AM »

Your laptop is probably set to CV mode and the mill is probably Exact Stop mode. Or, if both are in CV mode, it may be some of the CV settings.

Thanks for that Gerry
I will read up on it and see what  can find

Brian

42

G-Code, CAD, and CAM discussions / Re: Gcode pause

« on: July 20, 2010, 05:28:40 AM »

Brian
i tried to modify my post but could not.

it dont work like that.

example:
the next time you drive your car to the store at 60 miles an hour just turn in so that you back into the parking space without slowing or stoping.
this would not be a good thing.so some preperations for the moves will have to be done and this prep will consume some time.same thing with milling
when you notice some pauses.it is doing some prep work.

bill

Hi Bill

Thanks for the response but I cant see that as the feed rate equates to a very slow MPH about (0.00 mph to 2 decimal places) and the speed at which the CPU is able to number crunch, I can't really see that this is what is happening.

I am not seeing the motor decelerating and then accelerating again, it is actually stopping but not on my laptop.

Brian

When I am in my X wing fighter, however I use the force.

43

Show"N"Tell ( Your Machines) / Re: The Laser Project.

« on: July 20, 2010, 04:42:48 AM »

Hi Tweakie

You do realsie that suger is a dust explosive
http://www.youtube.com/watch?v=LQZGWjVwN58

Have fun

Brian

44

General Mach Discussion / Re: True 4 axis milling

« on: July 19, 2010, 03:15:10 PM »

G03 and G02 are circular interpolation so they are not straight line:) these moves can only be taken into Plane.. so for a true 3D the interpolation is very difficult... and the softwares are very costly..

Cheers for the response.

As refinement to my original post what software can do this?

Brian

45

General Mach Discussion / Re: True 4 axis milling

« on: July 19, 2010, 03:04:25 PM »

if you move X & Y at the same time you are moving in a plane not linear.


bill

Hi Bill

My interpretation is that the axis are moving in such a way that they generate a straight line between 2 point (linear), that straight line may be at an angle to all three axis but it is still the machines attempt at moving in a straight line.

For example this code from previous post
g1 x-.655 y.165 z-.060 a15 f5.0

Is still generating a linear interpolation it is only the fact that the A axis is a rotary axis that you get a non linear path and that IMHO is not the code doing this but the mechanical attribute of the rotary table; the same way a lathe generates a cylinder from a single point cutting tool and a linear movement.

Where as the code below does seem to be generating a non linear path that is non reliant on the mechanical generation of the path. The only caveat is that it is not using the 4th axis and the axis of rotation must be in a normal relationship to either the X, Y, or Z axis.
==============
G0 G49 G40  G17 G80 G50 G90
M6 T0 (TOOL DIA. 10)
G21 (mm)
M03 S0
G64
G00 G43 H0  Z1
X14.5 Y-5.75
G00 Z-2
G01 G42 P5 X8.75 F30
G02 X3 Y0 R5.75
G03 X-3 Y0 R3 Z-1.5
G03 X3 Y0 R3 Z-1
G03 X-3 Y0 R3 Z-0.5
G03 X3 Y0 R3 Z0
G03 X-3 Y0 R3 Z0.5
G02 X-8.75 Y-5.75 R5.75
G01 G40 X-14.5
G00 Z1
M5 M9
M30
=============

Are my conclusions correct?

Brian

46

General Mach Discussion / Re: True 4 axis milling

« on: July 19, 2010, 01:45:39 PM »

He showed you simple 4th axis code... The complex true 4th axis code can be generated Via true 4th axis software only;)

Yes but my original question was for non linear code not linear code which i am aware of. Sorry if I am using the wrong terminology.

Brian

47

G-Code, CAD, and CAM discussions / Re: Gcode pause

« on: July 19, 2010, 01:36:28 PM »

the mill has to use the steps and count them off.so you will see the actual axis change.the laptop just runs right through it.

I would of thought that steps could be counted off very quickly. Sorry to sound daft but I don't really understand this.

Why pause at particular points but not at others.

Brian

48

General Mach Discussion / Re: True 4 axis milling

« on: July 19, 2010, 01:07:40 PM »

just type out a line of code.

g1 x-.655 y.165 z-.060 a15 f5.0

that is all 4 going at once,pretty simple.

Yes but not non linear. What would the code looke like to get the cutter, for example, to move in a simple arc at an angle that is not normal to any axis?

Brian

49

G-Code, CAD, and CAM discussions / Gcode pause

« on: July 19, 2010, 12:16:58 PM »

Hi

I am using the Gcode below to face a block on my mill. When I test it on my laptop it runs continuous whilst it does the spiral but when I run the same code on my mill, with the same xml file it keeps pausing at each quadrant of the spiral. It doesn't pause for long, about a second, but i was wondering why it does it?

Thanks in advance for any suggestions.

Brian

=========================

G0 G49 G40  G17 G80 G50 G90
M6 T0(TOOL DIA.10)
G64
G21 (mm)
M03 S0
G00 G43 H0  Z1
X0 Y25
G00 Z-0.95
G00 Y20
G01 Y0 F20
G01 Z-1 F5
G2 Y0 X2 R1 F30
Y0 X-2 R2
Y0 X4 R3
Y0 X-4 R4
G2 Y0 X6 R5 F50
Y0 X-6 R6
Y0 X8 R7
G2 Y0 X-8 R8 F70
Y0 X10 R9
Y0 X-10 R10
X10 Y0 R10
Y-1 X9 R1
G00 Z1
M5 M9
G00 X0 Y25
M30
========================

50

General Mach Discussion / Re: True 4 axis milling

« on: July 19, 2010, 11:36:56 AM »

ArtCAM, Deskproto, VisualCAM are not true 4th axis programs.. They always generated gcode for 3-axes...

Meshcam generates code for the 4th axis, the point is it will not generate code so that all 4 axis can be moving at the same time. Or is this not what you are saying?

The main reason for my question is so I can be a bit ahead with my planning. I have a possible requirement to reproduce small complex casting by milling from solid. As it stands at the moment it would seem Meshcam can cope with this but will I need a more sophisticated Cam package in the future, perhaps for speed or smother finished.
I will probably look at bit closer at 'DeskProto Full'

As I am new to Gcode programming what would a simple piece of Gcode look like that would have all 4 axis moving together in a non linear way; for that matter I don’t think I could do it in 3 axis.

Brian