4 axis carving

[trampasD8MEH]

I would like to use Fusion 360 to generate machine code to carve surface on a 4 axis machine.   Is this possible? 

[daniel_lyall]

Yes, but what would you like to be making?

[trampasD8MEH]

My daughter wants a wand from harry potter, so I got the STL files but could not figure out how to get fusion360 to generate the tool paths.  

[mathew.hutton]

Hi @trampasD8MEH 

Do you have a project you can attach? The attached image shows you how to export your project.

Mat

[trampasD8MEH]

So I went to thingverse and downloaded the STL

https://www.thingiverse.com/thing:1069671

My mill is a Roland MDX-650 with 4th axis. The MDX-540 is the closest Fusion360 (same machine) has Fusion360 does not include the 4th axis option for the machine.  So I changed the machine in setup to generic 4 axis machine (Generic A axis).  

Once I did this I tried to change operation to "Turning or milling" but could not get axis set up correctly.  I tried with selecting milling 'operation type' but when I select "Turning" from the operation it says it is not compatible with machine.   

I did a search on the web and it looks like all the 4 axis operations require a cylinder to be selected for the rotation axis, which the STL did not have.    

So I assume the operation is possible but I do not know the magic settings to make it work. 

Thanks

Trampas

[trampasD8MEH]

I have enclosed the project here if you want see. 

[mathew.hutton]

Hi @trampasD8MEH 

It would need to be computed against the same stock as what you're intending to use. Generally if it's a 3 axis router with a 4th axis then i'd guess you have a chuck rotating around your X axis, something similar to the attached image. If that is the case it is still possible. I have aligned your setup with round stock and attached the project. Looking at the dimensions of the stock though, it looks like the import of the CAD went wrong. Try using the insert function in the design workspace. This should import the CAD to the correct scale. 

Mat

[mathew.hutton]

Hi @trampasD8MEH 

Attached a screenshot showing the import function. Select this and then select the CAD file, this should import it to the correct scale. 

Hope this helps

Mat

[trampasD8MEH]

Yes the rotary axis (A axis) is rotated around the X axis.   I was planning on using a square wooden stock and chucking in the rotary axis. 

I noticed the scale was off in the model, and needs to be scaled down. 

[trampasD8MEH]

I have imported the mesh with the correct scaling. Using the multi-axis rotary option I have created a tool path but it attempts to take all the material off in one pass.  There does not seem to be a way to control the step down size in the passes dialog for the rotary. 

The project file with correct scale is enclosed. 

 

[mathew.hutton]

Hi @trampasD8MEH 

The multiaxis rotary toolpath is inly a finishing strategy so you would need to use a 3 axis roughing strategy first to get the bulk of material off, you can duplicate the operation and change the tool orientation to get it from both sides. Then go in with a ballnose with the rotary toolpath. I'm away from my computer until tomorrow morning when i'm back at work so i'm happy to make an example project for you if you let me know what cutting tools you have? 

Mat

[trampasD8MEH]

Tomorrow is great! 

I did look at doing a roughing and rotating and doing again, however I could not find any option to enter the part rotation command such that I could do roughing on both sides. 

From what I have seen other CAM tools do is they use the rotary with multiple step downs to do the roughing and finishing.  If Fusion360 had the option for step downs in the rotary passes it would be able to do this as well. 

Thanks

Trampas

[trampasD8MEH]

I have a 1/4" flat end mill I was going to do roughing with.  Then a 1/8" ball nose end mill, followed by a 4.82 Deg Tapered Angle Ball Tip Radius=0.5mm  bit for final pass. 

However I can buy any tool needed. 

Trampas

[Anonymous]

You set the rotation amount by using the [Tool Orientation] option. How the z direction in the tool oriention differs from the Z direction in your main setup determines how much the part rotates. you can do 2 steps of 180 degrees or 4 of 90 degrees, etc.

[trampasD8MEH]

@jswetz,

  Will doing that cause the A axis to rotate for the correct tool orientation?  

[johnswetz1982]

Woops, used my work ID instead. Yes, that is why I just said that is what you need to do.

[mathew.hutton]

Hi @trampasD8MEH 

Okay, i'll use those tools in an example project tomorrow morning to show you how to machine this in fusion. You will possibly need an extruded body at the bottom of the wand so the toolpath does not cut the wand away from the stock before you want it to be removed. I'll make you something tomorrow and can explain what i've done so you understand what steps to take

Mat

[trampasD8MEH]

I have added a nub on the ends of the wand to hold it in place.  I think this is the correct approach, I have not set the feeds and speeds for the material yet. 

Trampas

[johnswetz1982]

That is the idea. With the Adaptive you dont need to go down past the centerline/mid plane because you are rotating the object and coming from the other side, but would work as you have it.

Also you dont need the second rotary operation. Rotatory will get to all sides of the object. And at least when I open the file the second rotary looks like you you changed the B axis angle.    

[trampasD8MEH]

The first rotary is with a 1/8" (~3mm) ball mill to do better detail than the roughing.  The last rotary is the detail with a 4.75 degree 0.5mm ball mill.   I am new to carving so I am not sure if the extra step with the 1/8" ball mill is needed but figured it would not hurt anything but time.  I also figured that if I did the 1/8" step if the homing to center of rotation is off then it would compensate.  That is I think I want to leave the first two roughing steps with more spacing than my error on homing to center of rotation.   Such that the rotary will clean up any parting line errors on the roughing.   I would like to have origin be on side of work piece, however I could not figure out how to set the rotary axis to be an offset from the origin. 

I am a bit worried bout the diameter of the tip of the wand,  specifically if I test with a pine wood it might not be strong enough for the detail rotary operations, oak should work better but might not be strong enough. I was going to do a test run with some pine just to make sure everything works.  Then do it with Oak.