Bad and not smooth shapes - CNC from Pronterface

Hi all,
actually I try milling with Pronterface, I use Sprinter, Nema 17 motors, M8 rods for moving, backlash 0.

This is my setup: #define _AXIS_STEP_PER_UNIT {2560, 2560, 2560, 682}.

Actually I have very smooth gcode but I am not able to mill it like that. I did many tries but always the same, even with lowerized feedrate to minimum my result
is always like in attachment, so shape with teeth.

Is there any other setup for make it better in resolution and more smooth ? Any idea what should I change ?

generally it is a good idea to clear out at least 10% larger than the tool bit size, and to clear it out with a Conventional milling approach.

[www.cnccookbook.com]


slow feed rate is a must if cutting through an object that would otherwise warp. then other things to think about are tool bit speed as to ensure the material is not overheated, but it is fast enough that the part does not become loaded. then also you need to consider run-out or the centering of the bit when it rotates.

remember the dimensions of the bit and the cut needs to take place 1/2 distance from that

Ok, so I have found the cause. It was in G-code, it has low resolution. Pronterface showed it ok, so I was confused, but I tried Repetier for preview and there g-code was with teeth. So I increased resolution and it is ok now.

Quote
Arnold
Ok, so I have found the cause. It was in G-code, it has low resolution. Pronterface showed it ok, so I was confused, but I tried Repetier for preview and there g-code was with teeth. So I increased resolution and it is ok now.

Could you show us a picture of how it came out now?

---

http://www.marinusdebeer.nl/

Sure, much better.

You also have visible backlash in your cuts where the cutter force is dragging the head around.

Yes, there is, I think its Z, I am still working on it to make this axis more solid,

Quote
Arnold
Sure, much better.

Thanks for sharing, indeed, this looks way better

---

http://www.marinusdebeer.nl/