right guys I could really do with some help here, I'm new to CNC but I have been practising quite a bit over the past two weeks. I'm working with a full 800x770 work area of 18mm mdf, cutting out some basic 200mm letters, I'm using Aspire 9 for all my CAD work and universal g code sender for the CAM side of things, but here's the problem, the gcode for the letters and tool path all seem fine (it cuts them correctly), I'm set to a depth of 19mm just to make sure, but the Z axis is bottoming out on my material before I can even make it through the work piece, I have a good 33mm of travel below Z and the material I just cant get my head round it? the Gcode is also set to make 6 ramped passes, starting at 3mm and ending at 18/19. any help would be appreciated.
Can your bit be jogged to reach the spoilboard without the material being there? Edit: Is it the Z travel bottoming out or is your router bit collet nut hitting the material? A picture of your setup would be most helpful too.
Its the z travel that is bottoming, everything is working fine, its just on the last few passes it cant ramp down any further because the bottom of z is maxed.
Then your bit won't reach the spoilboard either. You need to use a longer bit or drop your bit lower in the collet or raise your spoilboard. I'd suggest measuring the distance from the collet to the spoilboard when your machine is at Zmin (lowest point). Then you can see how much it needs to protrude, but be careful! You have to have enough bit in the collet for it to clamp correctly. To be honest I'm not sure what the safe rule of thumb is, but I make would make sure at least half my overall bit length is inserted. I personally push them all the way in then bring it back a couple mm, but I have lots of Z-travel on my Ox.
I think I may have gotten to the bottom of it SugarJ, after sitting down and going through my aspire settings I believe my Z zero settings are way off, I believe if I lower the router itself or the bit thus bringing it closer to the material surface I'm currently at 11mm above the surface when the gcode starts. The Z axis then slowly lowers itself from 11mm to the material before cutting starts, I think if I drop the router or bit to say around 3/4mm I could already be saving around 8mm of z axis travel, so my new aspire settings would be X0 Y0 Z4. Z1 (Clearance) = 2mm, Z2 (Plunge) = 2mm, So Gcode Starts Z axis plunges from 4mm to 2mm So id have a extra 9mm of travel.
I am confused. Maybe this is the case, but shouldn't your z0 be the top of your work surface, or if you choose, the top of your spoilboard? Then set a safe travel distance of 2 mm, or more if you have to cross above clamps. I may be totally misunderstanding the issue. If so, I apologize. An easy way to zero the z without a probe and touchplate is to put the bit/endmill in, lower the z to just a bit above the work surface, loosen the collet so the bit drops down to the work surface, hit the z0, and raise the z axis back up.
