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First cuts
« on: December 27, 2017, 01:39:51 AM »
I've generated my first GCode file out of Fusion 360 and ran my first "air" cut.  All things considered it worked great.  I do have some questions:

1.  How do I put a delay in the gcode output from Fusion 360 to give the spindle time to get up to speed?  Is this a change in the Fusion 360 post processor config, or is this a custom script in MACH4?

2.  I presume if I don't have a touch block (ordered), I can't manually jog the Z-axis to reset the starting height based on a new tool?  I guess I have to create the tool gcode outputs separately to be able to make this adjustment?

3.  When I get the touch block, I have to modify my M6 script to deal with re-checking the tool length, correct?

4.  On the Offsets tab, the Set Z under Z Offset is where I set my starting Z height based on my Fusion 360 setup starting position, what is the Tool Offset option for?

Think that is it for now.

Thanx,

Rob
- Robert Beaubien
- Drone Plastics
-
“Dear Algebra, Please stop asking us to find your X.  She's never coming back and don't ask Y.”
Re: First cuts
« Reply #1 on: December 27, 2017, 02:28:42 AM »
Hi Rob,
good to hear that you are getting some results.

The simplest way to put a delay into a Gcode program is a G04 statement just after the spindle turn on command. I don't use Fusion and don't know exactly what
is in the post processor that you have but it is common to be able to set the post to insert a G04 line.

Another possibility is to use Machs built in facility. This would require that Mach has some way of measuring the actual spindle speed ie an index pulse.

Craig
My wife left with my best friend...
     and I miss him!
Re: First cuts
« Reply #2 on: December 27, 2017, 02:47:59 AM »
Hi,
you don't really need to buy much, you can make a probe and Mach4 has some good probing scripts.

To touch off jog your tool down slowly until it pinches a piece of paper between the tip of the tool and the surface of the workpiece. If the paper is thin
just <zero> the Z axis and your ready to go. If instead of a piece of paper you used a 6mm shim, as before drive down until the tool drags on the shim
and <zero> the Z axis but with the gage block height set to 6mm, look on Machs Offsets tab.

You can set up a probe, it requires the tool, which is earthed to the frame of machine 'pull down' a isolated resistively supplied metallic target atop your material.
The target is hooked to a dedicated Probe input on your controller. Thereafter you use a G31 command and the machine will drive down until the tool contacts the target
and then Mach will stop and allow you to zero axes with or without gage block heights.

There are a number of scripts that automate this process, but it still worth experimenting with a simple probe and G31 MDI commands.

Craig
My wife left with my best friend...
     and I miss him!
Re: First cuts
« Reply #3 on: December 27, 2017, 02:53:55 AM »
Hey Joe.  You were close on the spindle.   The Accel and Decel time in the grid is the wait period when you don't have a speed signal from the VFD.

And I understand the use of the probe and have one on order.  It just doesn't look like I can manually do it with a tool change without a probe.  Not a big deal.  Thanks for explaining the Tool offset.
- Robert Beaubien
- Drone Plastics
-
“Dear Algebra, Please stop asking us to find your X.  She's never coming back and don't ask Y.”
Re: First cuts
« Reply #4 on: December 27, 2017, 12:07:31 PM »
Rob,
To answer your first question; you can input a Dwell in Fusion 360, but it won't act like you want it too.  It will put an operation in your CAM Tree like any other operation, so it won't be placed inside the new operation tool change.  

For Example:  Adaptive Clearing --> 2D Contour   A Simple Rough and Finish Tool path.

I can put the dwell in there and it will look like this:  Manual NC (Dwell) -->  Adaptive Clearing --> Manual NC (Dwell) -->2D Contour

Unfortunately, the dwell will be put before the tool change in each case.

You may be able to modify the Post Processor, you would just have to figure out where to put the G04 P#.

However, having a Dwell after the tool change would be a good idea to put in the Fusion360 Ideastation.  I know there is a large number of hobbyist who use Fusion 360 who don't have ATCs on there machines.  Having an option to wait on the spindle to speed up would be a nice feature.  

Even though this will not work, in my opinion it is always good to learn something new.  So have a look at the options you have in this Manual NC.  Under the Setup Tab in CAM there is the option, Manual NC.  Most of these don't do anything with Mach4 but some do, and they have come in handy before.  

I also recomend checking out John Saunders Youtube channel, he has some great Fusion 360 videos.  This particular video shows how he uses Manual NC and how to enable it. https://www.youtube.com/watch?v=RqfZFBxvr-s
« Last Edit: December 27, 2017, 12:12:08 PM by Cbyrdtopper »
Chad Byrd