For most of the Fanuc Series Controllers (FS) OT,16/18T,10/11T you can have
a condition where upon every time you attempt a Zrn (Zero Return), a Soft Limit
Over Travel occurs. This is especially troublesome with the Z axis of vertical
machining centers and the X axis of turning centers. These axes tend to drift
during the night. When this happens, here's what you do...(Article)
Do You Document Your CNC Programs Well Enough?
I have been programming for about 2 years, and before that I had been a
manual machinist for 15 years. I have found that by making a program easy to
read and consistent every time you make one makes it easier for operators and
new personnel to read. I have seen many old programs made by previous
programmers and even I even have to look hard at it to see what's going on. If
you start it the same and don't try to put everything on one line the operator
knows what to look for and doesn't get confused. For example MO3 on one line,
and the rpm on another. They both go together and should be on the same line.
Its just like a sentence. Here is an example of how I write a simple program.
Safe Index Position For CNC Machining Centers
The question: On a horizontal milling center, how far away from the work
piece must the Z axis be positioned to allow a ≥safe≤ pallet index? The safest Z
axis position prior to a pallet index is Z home. This can result in tool being a
long way from the work after the pallet index. To save time the least amount of
retract must be determined. The following code allows the machine to calculate
the safe index position based on predetermined values stored in the #500
variables and the tool length variable. This runs on a Fanuc 16MB driving a Mori
SH-50 Horizontal. It should work on most Macro B systems where access to system
variables are allowed. The following system conditions and variables must be
How fast can you rapid?
CNC Programmers have the tendency to ignore the effects of rapid motions on
cycle time because of the very fast rate of motion. While today's CNC machines
do rapid at amazing rates (some over 1,500 inches per minute), no rapid motion
can be made instantaneously. In order to minimize cycle time, you must minimize
rapid motions. To stress this point, we offer a simple rule of thumb called the
one second rule. One second of saved cycle time will total 16.6 minutes
of saved production time in one thousand cycles. While this may not sound like a
lot, it can add up fast. If but four seconds can be saved per cycle in a one
thousand piece order, over one hour of production time can be saved. And if this
four seconds can be saved without spending money (by simply formatting your
programs efficiently), all the better...(Article)
Getting parentheses on 16 and 18 series Fanuc controls
Some series 16 and (especially) 18 series controls come with a "limited
keyboard", meaning only essential keys are available. If you do not have a full
keyboard on your 16 or 18 series control, you will find that there are no
parentheses keys [()]. If this is the case, you cannot type or edit messages at
the control. (Article)
G code help screen on 15 series Fanuc controls
Here is something you can use with Fanuc series 15 controls that is quite
helpful. If you cannot remember the format for the various G codes, the 15
series will give you some help. In the EDIT mode, type G and press INPUT (not
insert). The display screen will show you a list of all G codes and their proper
format and meanings. You can use the left/right double arrow keys to move up and
down the list.
Which mode is better, inch or metric?
If you are one of the many companies that still work exclusively in the inch
mode, you probably don't know about the accuracy advantage of the metric mode.
This advantage has to do with the least input increment of the input mode. The
least input increment in the inch mode for the vast majority of CNC machines is
0.0001 in. In the metric mode, the least input increment for these machines is
0.001 mm. 0.001 mm is less than half of 0.0001 in (0.001 mm is equivalent to
0.000039 in), meaning your CNC machine will have a much finer resolution when
the metric mode is selected.