3D finishing
-
- Vectric Apprentice
- Posts: 53
- Joined: Mon Oct 29, 2018 12:44 am
- Model of CNC Machine: Carve King
3D finishing
After the roughing pass and the finishing bit has been put in, do you move Z back to zero or Do you jog Z down to the new surface that the roughing created.
- Adrian
- Vectric Archimage
- Posts: 14655
- Joined: Thu Nov 23, 2006 2:19 pm
- Model of CNC Machine: ShopBot PRS Alpha 96x48
- Location: Surrey, UK
Re: 3D finishing
You re-zero to the same level you zeroed the roughing bit at. You can't go back to the original zero as the bits are almost certainly not exactly the same length.
-
- Vectric Apprentice
- Posts: 53
- Joined: Mon Oct 29, 2018 12:44 am
- Model of CNC Machine: Carve King
Re: 3D finishing
so you are saying to go back to original zero which was the surface point before ruffing. but at the same time you are saying you will never get true zero because of bit length. if this is what you are saying then i understand. the finishing file will plunge down to ruffing area just done.
Re: 3D finishing
Where have you set your XYZ datum point? (hoping you haven't milled this away with the roughing pass)
C
C
-
- Vectric Apprentice
- Posts: 53
- Joined: Mon Oct 29, 2018 12:44 am
- Model of CNC Machine: Carve King
Re: 3D finishing
X0, Y0, Z0...This will be my first attempt at 3d and hope to learn before taking a run at it.
- Adrian
- Vectric Archimage
- Posts: 14655
- Joined: Thu Nov 23, 2006 2:19 pm
- Model of CNC Machine: ShopBot PRS Alpha 96x48
- Location: Surrey, UK
Re: 3D finishing
Use the original zero point but not the original zero value. When you set the initial z-zero you should use a point that won't be removed by the roughing tool pass. If you've removed all the material at the level that was the original zero point then you've got a problem.electrictermite wrote:so you are saying to go back to original zero which was the surface point before ruffing. but at the same time you are saying you will never get true zero because of bit length. if this is what you are saying then i understand. the finishing file will plunge down to ruffing area just done.
-
- Vectric Apprentice
- Posts: 53
- Joined: Mon Oct 29, 2018 12:44 am
- Model of CNC Machine: Carve King
Re: 3D finishing
I thought you could jog back and watch the X,Y,Z change until the G code sender showed x0, y0, z0 and that would put you at the original pre ruffing start point.
-
- Vectric Craftsman
- Posts: 277
- Joined: Mon Apr 29, 2013 3:37 am
- Model of CNC Machine: Tormach PCNC770
- Location: Cobourg, ON, Canada
Re: 3D finishing
If you are using CNC software (LinuxCNC or Mach3 or PathPilot or...) that uses its tool table to compensate for the length of your tools, removing the material is not an issue.If you've removed all the material at the level that was the original zero point then you've got a problem.
- TReischl
- Vectric Wizard
- Posts: 4652
- Joined: Thu Jan 18, 2007 6:04 pm
- Model of CNC Machine: 8020 48X36X7 RP 2022 UCCNC Screenset
- Location: Leland NC
Re: 3D finishing
Another way of saying this:
You must use the same plane for setting both tools.
You must use the same plane for setting both tools.
"If you see a good fight, get in it." Dr. Vernon Johns
- Xxray
- Vectric Wizard
- Posts: 2304
- Joined: Thu Feb 17, 2011 8:47 am
- Model of CNC Machine: CAMaster Stinger 1
- Location: MI USA
Re: 3D finishing
Always Z on top of original material for all passes, if you Z what has been cut you will be in for an unpleasant surprise of the finishing pass going way too deep, perhaps through the material into the spoilboard.
Doug
- martin54
- Vectric Archimage
- Posts: 7349
- Joined: Fri Nov 09, 2012 2:12 pm
- Model of CNC Machine: Gerber 48, Triac PC, Isel fixed gantry
- Location: Kirkcaldy, Scotland
Re: 3D finishing
The point people are trying to make is that you will zero your "Z" axis on the material surface with the bit you use for roughing. Once the roughing pass is complete you would then normally change to a different bit for the finish pass. The bit used for the finish pass is unlikely to finish up at exactly the same length below the collet as the roughing bit which would give you a false z zero position unless you had some way to set it. There are ways to do this but a lot of people will just re-set the zero position for the z axis on the material surface the same way they set the z zero position for the roughing bit in the first placeelectrictermite wrote:I thought you could jog back and watch the X,Y,Z change until the G code sender showed x0, y0, z0 and that would put you at the original pre ruffing start point.
-
- Vectric Apprentice
- Posts: 53
- Joined: Mon Oct 29, 2018 12:44 am
- Model of CNC Machine: Carve King
Re: 3D finishing
That was the answer I was looking for is just jog down Z to new surface and reset Z to zero before running finishing gcode.
- gkas
- Vectric Wizard
- Posts: 1451
- Joined: Sun Jan 01, 2017 3:39 am
- Model of CNC Machine: Aspire, Axiom AR8 Pro+, Axiom 4.2W Laser
- Location: Southern California
Re: 3D finishing
The key is NOT using a NEW surface. You should set your Z to the same spot for ALL of your bits. Pick a spot that won't get machined. If you use 3 different spots, you may be picking 3 different thicknesses of wood.electrictermite wrote:That was the answer I was looking for is just jog down Z to new surface and reset Z to zero before running finishing gcode.
- Adrian
- Vectric Archimage
- Posts: 14655
- Joined: Thu Nov 23, 2006 2:19 pm
- Model of CNC Machine: ShopBot PRS Alpha 96x48
- Location: Surrey, UK
Re: 3D finishing
Wrong. You use the old (uncut) surface not the new surface. Both bits are zeroed at the same level (plane).electrictermite wrote:That was the answer I was looking for is just jog down Z to new surface and reset Z to zero before running finishing gcode.
Of course we're assuming that you have set the z-zero in VCarve to be the material surface. If it's the table surface then you have to zero to that. Either way you zero to the same level (plane) for both toolpaths.
- martin54
- Vectric Archimage
- Posts: 7349
- Joined: Fri Nov 09, 2012 2:12 pm
- Model of CNC Machine: Gerber 48, Triac PC, Isel fixed gantry
- Location: Kirkcaldy, Scotland
Re: 3D finishing
pick a spot on the material surface that isn't going to be machined by any of your toolpaths & use that spot after any bit change to reset your z zero. I generally put a small pen or pencil mark on the surface so I don't have to try & remember where I first set my z zero position