Taking the CNC Plunge

Can you post a better picture of the cut finish?

Have you tried a 2 flute end mill? With a 2f carbide end mill I would run that at 6000 rpm (my max) 22 ipm with a 40% step over for the roughing and a finishing pass at 10 ipm and .015 cut, both run as a climb cut.

The only 4 flute end mills I use on aluminum are the corn cob roughers. I prefer single flute chamfer end mills for chamfering.
 
TomS said:
No. I roughed out a 1.240" through pocket in a piece of 1/2" thick aluminum. The gcode I sent you is the pocket finishing pass.
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Ok so the second pass

Finishing pass with a spring pass?? Ok going to back up a bit. have you checked the backlash of your X Y ball screws and what are your drivers set too? Micro stepping? What file format is the cad model in?
 
jbolt said:
Can you post a better picture of the cut finish?

Have you tried a 2 flute end mill? With a 2f carbide end mill I would run that at 6000 rpm (my max) 22 ipm with a 40% step over for the roughing and a finishing pass at 10 ipm and .015 cut, both run as a climb cut.

The only 4 flute end mills I use on aluminum are the corn cob roughers. I prefer single flute chamfer end mills for chamfering.
Click to expand...

I'll try to get a better picture. Haven't tried a 2 flute because the finish is so bad with the 4 flute.

I normally would run this job at 8000 rpm and 60 IPM with .1 stepdown and stepover for roughing. Finishing is done at full depth (.5) and stepover at .01 and 30 IPM. I've played with speeds and feeds to see if the surface finish get better but no change. I ran some mild steel parts before I changed out my electronics and the surface finish was superb. I'll try and get a picture of that part as well.
 
Davd Flowers said:
Ok so the second pass

Finishing pass with a spring pass?? Ok going to back up a bit. have you checked the backlash of your X Y ball screws and what are your drivers set too? Micro stepping? What file format is the cad model in?
Click to expand...

Yes, finishing pass with a spring pass. My drivers are set for microstepping. I'll have to look at the specific setting. Can't remember because it's been so long since I set them up.

I have some backlash. About .002" in X and Y but as I said in my previous post the mild steel parts I made before the electronics upgrade had a very good surface finish.

The CAD model is Fusion 360 format. I've attached it below. Change the file type from .txt to .f3d and it should open.
 

Attachments

Dont know if you feel safe about running some one else's g code but if you do... Stock is 3"x 3"x .5" and X Y zero is center of stock and z zero is top of stock. I used a .250" engraver for the chamfer, but any size would work as long as it comes to a point.
 

Attachments

I would be curious to see what the finish looks like if you set your drivers back to half step...
 
Are you running the ESS on a dedicated 5v power supply?

For your finishes to degrade after changing the electronics suggests a problem with the settings or possibly electrical interference. I will see if I can get screen captures of my ESS configuration for comparison.
 
Davd Flowers said:
I would be curious to see what the finish looks like if you set your drivers back to half step...
Click to expand...

Toms setup is very similar to mine and I'm running my drivers in micro-stepping with no issues.
 
jbolt said:
Toms setup is very similar to mine and I'm running my drivers in micro-stepping with no issues.
Click to expand...
Same amount of backlash? IIRC a half step on a 5mm pitch screw yields about .0005" Dont really see the point in micro stepping. What am I missing ??
 
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