Re: Horrible Surface Finish
Can you post your .cb file. Add a .txt extension to be able to attach it to a post.
Re: Horrible Surface Finish
From the info you provided it seems that you have identified he two most probable sources, machine loosesness or software.
I would look into the software setting for how small the linear segments are to interpolate an arc. If the linear segments are too large you might get arcs that are not smooth. That would mean your software that generates the g code, does the g code have line segments that correspond to the surface finish?
You mention arcs have bad surface finish, what about straight segments that are not parallel to the axis of the machine?
And on circles, is the surface finish uniformly bad around the circumference or is there a correlation between changes in finish and the axis of the machine? ( ie possibly good when movement parralel to X and Y )
Re: Horrible Surface Finish
It could be a Mach3 motion setting. Maybe post a screen shot of those settings.
Re: Horrible Surface Finish
The 3rd one with all the lines all over it looks like what my little X2 machine now produces.
I've rebuilt the whole thing to no avail.
I've narrowed mine down (I think) to the head gib slideways. Been like it since I badly crashed it and it looks like my head spread thus resulting in massive head vibrations. Looks, set and feels tight with no vibrations from table or column, just the head.
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Re: Horrible Surface Finish
Quote:
Originally Posted by
Jim Dawson
Can you post your .cb file. Add a .txt extension to be able to attach it to a post.
Jim - here is my CamBam file.
Re: Horrible Surface Finish
Quote:
Originally Posted by
cncuser1
From the info you provided it seems that you have identified he two most probable sources, machine loosesness or software.
I would look into the software setting for how small the linear segments are to interpolate an arc. If the linear segments are too large you might get arcs that are not smooth. That would mean your software that generates the g code, does the g code have line segments that correspond to the surface finish?
You mention arcs have bad surface finish, what about straight segments that are not parallel to the axis of the machine?
And on circles, is the surface finish uniformly bad around the circumference or is there a correlation between changes in finish and the axis of the machine? ( ie possibly good when movement parralel to X and Y )
Thanks for responding. I looked through the CamBam configuration settings and found Arc Fit Tolerance which is set to .001" and Auto Arc Fitting which is active. In the Mach3 post processor Arc Center Mode is set to Incremental CP-1 (options are Default, Absolute, Incremental P1-C, C-P2, and P2-C), Arc Output is set to Normal (options are Convert to Lines and Helix Convert to Lines), and Arc to Lines Tolerance is .01". I have listed all of the settings related to arcs.
Straight segment cuts not parallel with X or Y are represented in picture 3. The surface finish is uniformly bad on circles and arcs.
The gibs are a tight as I can get them without losing steps. I use the "Bridgeport" method where for X you center the table on the saddle and mount an indicator on the saddle and place the DI on one end of the table. Pushing and pulling on the table the goal is to get no more than .001" of movement after letting go of the table. The same method is used for Y except the DI is mounted on the mill base. I've done this and the best I got was about .0015". Not too bad for a Asian machine.
Re: Horrible Surface Finish
Quote:
Originally Posted by
CL_MotoTech
It could be a Mach3 motion setting. Maybe post a screen shot of those settings.
I will do that in the morning when I get in the shop. Specifically what settings are you interested in seeing. I'd like to get you everything in one shot.
Thanks
Re: Horrible Surface Finish
Quote:
Originally Posted by
dazp1976
The 3rd one with all the lines all over it looks like what my little X2 machine now produces.
I've rebuilt the whole thing to no avail.
I've narrowed mine down (I think) to the head gib slideways. Been like it since I badly crashed it and it looks like my head spread thus resulting in massive head vibrations. Looks, set and feels tight with no vibrations from table or column, just the head.
I'd like to say I never crashed my machine but that wouldn't be the truth. The mill is quiet and doesn't vibrate and straight line cuts are absolutely smooth. I'm thinking it's software related.
Re: Horrible Surface Finish
I don't see a problem with the CB file, all the settings and tool paths look normal. What you might try is edit the post processor, set Arc Output to Convert to Lines, and set Arc to Lines Tolerance to 0.001. I creates a huge G code file, but it might smooth things out. If that fails, then it is either a mechanical problem or a setting in Mach3. I can't help much with Mach3, I don't know much about the settings. With that much scollop, you should be able to feel the machine jerking as it cuts.
Re: Horrible Surface Finish
Quote:
Originally Posted by
Jim Dawson
I don't see a problem with the CB file, all the settings and tool paths look normal. What you might try is edit the post processor, set Arc Output to Convert to Lines, and set Arc to Lines Tolerance to 0.001. I creates a huge G code file, but it might smooth things out. If that fails, then it is either a mechanical problem or a setting in Mach3. I can't help much with Mach3, I don't know much about the settings. With that much scollop, you should be able to feel the machine jerking as it cuts.
Thanks Jim. I'll try your suggestions tomorrow.
Re: Horrible Surface Finish
"The surface finish is uniformly bad on circles and arcs." if this means that the phenomena is the same around the whole 360 degrees of a circle then to my mind this is a software issue.
I suggest three things
1- use a simple example, to simplify debugging: A circle.
2-Machine a simple circle and post the gcode and picture in this thread.
3- Try a whole new software to generate the gcode, see if that recreates the problem, this will eliminate or focus the source of the error.