Hi I have tried a few different post processors in Fusion 360 to work properly with mach3. But I have one issue that I think shouldn't be. When the job is finished and it goes back to xyz 0 it starts with z0 and then xsnd y 0. Fusion 360 can write G code (NC code) but you will need to tell the software how to cut your part by creating toolpaths in the CAM Workspace before Fusion 360 can write an NC code file. Once you have finished creating toolpaths, select the operations or the setups that you want to create NC code for. In the previous blog I talked about Fusion 360 software. I said that before you buy any machine you can use Fusion 360 to design and then create G-Code. Well after you have created the G-Code you can use Mach3 to simulate running an actual project. Mach 3 CNC control software is free to use up until you want to connect it to an actual machine. Mach3 is general-use software developed by Artsoft for CNC Machines. Post Processing for Mach3 Be sure that your G-Code is Post Processed in AutoDesk Fusion 360 for Mach3. Find the Mach3 Post Processor for Autodesk Fusion 360 on the Downloads page. To help you decide between the Mach 3 vs. Fusion, I’ve broken it down to different categories. The Mach 3 ranges between $5 and $10 depending on the variant you choose. Edwin Jagger also sells a handle compatible with Mach 3 cartridges in case you prefer a thicker and heavier handle. Cartridge prices will vary depending on the quality.
Mach3 goodies
The downloads on this page are designed to provide the same probing and ETS functions as the PathPilot versions. They provide support for all the programmable probing options in Fusion360 and also the added ability to use an electronic tool setter (ETS) to set tool lengths during program runs and also to check for tool breakage after each operation.
There are 3 separate files required. The download links are as follows and the functions provided by each file are described below.
File | Description |
M200.mcc | Implements a set of functions 'M200 P1'. 'M200 P19'. These are the support functions required to perform the Fusion 360 WCS probing operations |
M201.mcc | To support the ETS extensions for Fusion 360, this macro file adds 'M201 P1' . 'M201 P4' |
mach3mill.cps | The modified Fusion 360 post processor. |
Setup
Warning
There's a general problem with Mach 3 in that values entered into DROs don't have their units converted between mm and inches when the machine changes from G21 to G22 and back. If you use an ethernet smoothstepper, then you'll be familiar with the problem. Homing speeds and accelerations don't get converted, so if you set up speeds in mm/min and then execute G20 before referencing the axes, you'll see your axes attempt to find home at 25.4 times the intended speed.
There are a number of parameters required to configure the operation of the probing routines and they have the same problem. For this reason, it's best to decide what units you're going to use, configure the machine like that and then stick to it. Fusion 360 can output in either mm or inch no matter what the drawing units are, so this shouldn't be a problem. I've always used mm on my mill, so that's what I'd recommend.
The following table lists values that must be entered by the user and the DRO numbers. If you can edit your screen set, then you may add these values. If not, then the DRO numbers are the same as are used by the excellent 'ProbeIt' wizard, so you can use that wizard to enter the value. Equally, if you already use ProbeIt, then you'll already have configured these values, so no additional configuration is required. You can find ProbeIt on the Wizards menu in any standard Mach3 installation.
DRO number | ProbeIt parameter name | Function | Suggested value |
1821 | Init feed | Fast probe speed. The feed rate used for the first, rough probe | 750 mm/min |
1822 | Slow Feed | Slow probe speed. Feed rate used for the final, max resolution probe | 25 mm/min |
1823 | Max probe distance | Max probe distance. Max distance to probe whilst looking for the initial contact. This affects the M201 ETS functions only. The Fusion360 operations all provide their own values for this via the Approach and Over-travel parameters of the probing operations. | 30mm |
1824 | Slow clear | This is the distance the probe retracts after making the initial, rough probe before starting the final, slow probe operation. | 1mm |
1829 | Avg probe diameter | Probe diameter. This is not the nominal diameter of the probe tip that you would measure with a micrometer. The value here is corrected for the inevitable flex in the probe stylus and will therefore typically be smaller than nominal. The best way to measure it is with a gauge ring and use the calibrate function in ProbeIt. You can alternatively use ProbeIt to measure the thickness of a known block of material - a gauge block would be best - and then alter the nominal diameter until you measure the correct block width. Be sure to check this at different probe orientations as the effective diameter will change as the spindle is rotated and it's important to get a good average value. Ableton push 2 stores. For the Tormach passive probe with a 50mm long stylus with a 3mm diameter tip, I generally measure this value to be around 2.85mm |
Fusion 360 ETS operations
To use the Fusion 360 integrated ETS funcitons, you must set WCS 6 (G59) to have its xy origin located at centre of the ETS and the z origin located at the ETS trigger point. The xy origin can be set by eye, but to set the z accurately, position a tool of known length above the ETS and type M201 P2 into the DRO. The machine will probe downward until it finds the contact and adjusts the WCS z-offset to define that location as z = 0.
If your z-axis is referenced using simple microswitches, you will have to repeat this process every time you reference the machine in order to get accurate results from the ETS.
Fusion 360 Probing operations
Apart from filling in the values noted above for ProbeIt, there's no additional setup required for Fusion360. If you can use the basic xy probing functions in ProbeIt, then the FUsion360 ones should just work.
M200 Probing functions
The functions supported by the M200 macro file require a number of parameters to be passed via g-code variables #1000 through #1017. as a result, the M200 functions are too complicated to use via any other route.
M201 ETS functions
Unlike the M200 functions, the M201 functions that support the ETS ops are very simple and can be used from the MDI command line. Joomla dropbox.
Command | Operation |
M201 P1 | Perform 2 stage probe vertically down (max distance governed by DRO 1823 (ProbeIt parameter Max probe distance). Display the result in the status line. If you have voice output enabled in your Mach 3 settings, then the result will be read. |
M201 P2 | Similar to M201 P1 except that the current WCS z-offset will be modified so that the probe result point becomes z=0. |
M201 P3 | Again similar to M201 P1, but this time the tool length is adjusted so the point found by the probe is z=0. |
M201 P4 Qtol | Runs M201 P1 but then aborts the running program if the result was outside the range -tol <= z <= tol |
This site was last updated 07/09/20
Cutter compensation is a great way to dial in a hole to be a very precise size. I learned about cutter compensation from a John Saunders video How to Use Cutter Comp on a Tormach! WW180. In his video, he's using PathPilot on a Tormach. But I have Mach3 with a Taig, so the workflow is a little different. But not by much.First, some background. Cutter compensation is done use a set of g codes: G41 and G42. Which one to use depends on the direction of cut. Fortunately, Fusion 360 handles choosing the correct one based on what you're trying to do.
Here's the high-level overview of how it works. Normally, Fusion 360 will calculate the correct location of the tool path based on the diameter of the cutter. In the picture below, you can see that it's moved the tool path for the cutter inward by half of the tool diameter.
In other words, Fusion 360 is handling the calculations to compensate for the diameter of the cutter.
Cutter compensation in Fusion 360, at least at the time I'm writing this, is only supported for 2D operations.
Setup in Fusion 360
If you change the default In computer to In control, you're telling Fusion 360 that the controller (Mach3 in my case) will handle compensation instead. Here is how you make that change:
Fusion 360 Mach3 Mill
Once you regenerate the tool path, you'll see the following:
Fusion 360 Mach3 Turn Post Processor
This may be a little hard to see, but now the tool path (the blue line) is exactly along the profile, rather than 1/2 a diameter away.
Setup in Mach3
Mach3 has a tool table. I have never used this before, which means I've always been using tool 1. To set a tool diameter in this table:
Fusion 360 Mach3 Post Processor
- Click the Offsets tab
- Click the Save Tool Offsets button
- Edit the Diameter (D) cell for tool 1
- Click Apply (very important, because it won't keep your changes otherwise)
- Click OK
Edit G Code
Mach3 4th Axis Setup
You might think you're done, and ready to make small changes to the diameter (making it slightly smaller to make the hole larger). But that's not the case. Fusion 360's post processor for Mach3 emits g code that looks something like this:
G3 X3.26 Y-1.5 I0. J0.15
Notice the P0.125 at the end of the line that contains G41. This tells Mach3 to use this tool radius instead of the value in the tool table, so you have to remove this. Additionally, I found comments that Mach3 doesn't like having G41 on the same line as other commands. So, I edited the g code so the above appears like this:
G1 X3.11 Y-1.65
Fusion 360 To Mach3 Driver
Once I made those changes, I was able to slowly change the diameter of the cutter in the Mach3 tool table until I had the hole just the right size. I started with 0.25 and then worked my way down to .244 (I made the hole in CAD slightly smaller than my target).