[paulsanders]

Hi All,

I recently acquired a 6040 cnc router. Unit is set up and cutting G10 glass very well but runs into 'issues' milling aluminium.

Example..

Cutting 6061 alloy, carbide tian 4mm end mill cutting out some shapes on 8mm stock.

Symptom - say a square part 2 90 degree edges are vertical and the apposed are slightly tapered with visible steps for the first
couple of passes. A bearing pocket starts out pretty well but gets more oval as the depth increases. Left side of hole vertical, right is tapered.
Seems that the error is multiplied as the depth of slot increases. Most apparent on Y axis...

Have trammed z axis to within a couple of thou (had to make adjuster). no missing steps or binding (that did take some work)
Using correct feeds and speeds (calculator)
looks like Y axis backlash but also see it on the X
Using a dial indicator I can move the spindle +/- 10mm in X or Y and get no more the 2 to 3 thou backlash?

There is something simple wrong here but I can see it??? (other than it is what it is..)

Thanks,
Paul.

[KH0UJ]

can you post the actual cutting output of the product? what CAM software did you use? can you post the exact dimensions of the model? Im gonna try coding it my way then try it out on your machine, by the way im also cutting aluminum materials on custom products on a 6040, I cut 200 pcs. on it with no errors.



I even cut triple clamps on a 6040

[paulsanders]

Thanks for the quick response KH0UJ

I am using Autodesk Fusion 360 to create an STL (was using solid works but cant afford to purchase it). The cam processor is MeshCam that generates the gcode. I am machining small parts for a model helicopter.
I'll take some photos tomorrow of the parts that display the symptoms well.

Thanks
Paul.

[louieatienza]

Thanks for the quick response KH0UJ

I am using Autodesk Fusion 360 to create an STL (was using solid works but cant afford to purchase it). The cam processor is MeshCam that generates the gcode. I am machining small parts for a model helicopter.
I'll take some photos tomorrow of the parts that display the symptoms well.

Thanks
Paul.

If you have Fusion360 why are you using MeshCAM for g-code?! Use Fusion360!

[paulsanders]

If you have Fusion360 why are you using MeshCAM for g-code?! Use Fusion360!

Really? I initially bought Meshcam when using Solidworks.. had a fit of conscience and paid for autodesk, given it does everything I needed... perhaps it does more than I thought!
Will have to have a play tonight.

Thanks,
Paul.

[paulsanders]

The CAM in Fusion360 has made all the difference.. cutting parts in 1/4 of the time, getting a better finish because I can tune each step of the job.
I did not think I could get this capability for under 400 bucks! I can see I have some backlash tuning to do but nothing major.
Thanks all

[paulsanders]

Well, Fusion 360 cam is good but at the end of the day it appears the machine still has an issue.
See the stepping in the Y axis.. most obvious with the adaptive clearing. Lower cuts are profile based.
Where does one start????

[paulsanders]

I replaced the stepper cables with shielded 4 core. Terminated the shielding to the metal plug that goes into the controller.
Sanded the paint from around the fittings on the case to get a good earth and then ran a star common ground to the vfd, controller, PC,
router bed and my custom casing for the machine.

FIXED!!

I think the shielded cabling is what did the trick. Others have made this same mod to solve various problems. I found one thread
that had the same symptom as mine by replacing the cables with shielded type.