Feed Rates with writing our own G code.

Discussion/questions about software used with your CNC Shark and programming issues

Moderators: al wolford, sbk, Bob, Kayvon

Post Reply
User avatar
gmm50
Posts: 46
Joined: Fri May 16, 2014 5:22 pm

Feed Rates with writing our own G code.

Post by gmm50 »

I have a program that is auto generated. Inspecting the G Code it looked wasteful and decided to write my own.

I kept the starting portion and the ending portion of the auto generated code and then entered my own.

I can't seem to control the feed rate. Here's the actual code enample

(|---------------------------------------)
(| Toolpath:- 'Pocket 1' )
(|---------------------------------------)
G90
G20
F25.0
G64 P.1
S 2000
M3
G0 Z0.8000
(New code starts here)
G00 X-0.1750 Y0.2500 Z0.2000 (Start lower channel on left)
F5.0
G00 X-0.1750 Y0.2500 Z-0.0500 (move down)
G00 X 7.6750 Y0.2500 Z-0.0500 (move to right)
F25.0
G00 X 7.6750 Y0.2500 Z0.2000 (move up)
G00 X-0.1750 Y0.2500 Z0.2000 (Start lower channel on left)
F5.0
G00 X-0.1750 Y0.2500 Z-0.1000 (move down)
G00 X 7.6750 Y0.2500 Z-0.1000 (move to right)
(.......................)

The F25.0 and F5.0 seem to have no effect. any suggestions.
George

ruhnau
Posts: 59
Joined: Wed Nov 30, 2011 1:22 pm

Re: Feed Rates with writing our own G code.

Post by ruhnau »

I'm not sure but the G00 is a rapid move that may have a set feed rate that cannot be changed in the toolpath data

ruhnau
Posts: 59
Joined: Wed Nov 30, 2011 1:22 pm

Re: Feed Rates with writing our own G code.

Post by ruhnau »

I also notice that you have G00 which are rapid moves. You should have G01 which are straight line moves which should accept your feed rates.-

User avatar
gmm50
Posts: 46
Joined: Fri May 16, 2014 5:22 pm

Re: Feed Rates with writing our own G code.

Post by gmm50 »

Very good catch. I should have realized that.

I bet that's the issue. It will take a couple of days for me to test and I'll report back here.

Thank You
George

dan1931
Posts: 11
Joined: Wed Feb 05, 2014 9:32 am

Re: Feed Rates with writing our own G code.

Post by dan1931 »

The above answer is correct. You need a good book on Gcodes.
Then you would have realized your problem is the fact that G00 is a Modal code.
That means that once entered is stays in effect on all following lines of code until changed.
The only code that will change it is G1 or more properly G01.
Dan1931

Post Reply