cutting air

[billybobron]

I have been doing some cramming in V carve over the last couple of days and created 2 files to finally test my machine, loaded them into Acorn. One file I zeroed at the top of the material for all 3 axis the 2nd file loaded fine used the puck to set z zero and the other 2 axis at the top of the material.
Both jobs ended up cutting air! Why would that occur? remember that this a learning curve and attached is the report form the machine along with the G code .
Thanks for the help!!

[cnckeith]

well thats better than cutting thru your table.

Graph shows the G cocde looks reasonable.. so i would assume you set your Z zero position incorrectly.

do you have photo album of this machine?

[ShawnM]

If you look at his report Keith the Z axis turns ratio is not setup correctly. He has 2.601249 and it's a direct drive metric ballscrew. That's an impossible number and why it's cutting air.

[Gary Campbell]

Make sure that your vcarve file Z reference (zero) is the same as you set it at the machine

[billybobron]

The z point is set the same in both, I have fought with the z turns ratio for a while and thought it was right after measuring several times, I have to recheck again tomorrow. It was 100 in the shop and had to give up the Ol Mellon was starting to hurt

[grossmsj]

Try setting the Z0 with the 'paper method'. There is no ambiguity with the puck. When you run the program, the bit should cut properly. If it is still cutting air, note how high above the material it is. If the height above the material is the thickness of the material you set up the Z zero to Machine Bed in Vectric. If it's something higher/lower than that it's likely inaccurate machine set up. Be systematic and rule of potential causes.

If something bad is going to happen, its probably related to Z height being set wrong. Air is okay. Machine bed no bueno. You can set your feed rate to something low like 25% so everything happens slow.

[cnckeith]

If you look at his report Keith the Z axis turns ratio is not setup correctly. He has 2.601249 and it's a direct drive metric ballscrew. That's an impossible number and why it's cutting air.

yeah i saw that, this is why i always ask for photos of the machine. if i had photos i could tell how the z axis motor was mounted to the axis, (direct? belt reduction? etc..etc..) without the photos we are just guessing

[ShawnM]

Yup, I understand. He started a photo album I think and shared it in one of his posts. After I helped him get the machine running correctly in all directions and homing properly I urged him to take his time and dial in the turns ratio. I told him the machine will only cut as accurately as you dial in the turns ratio. If you are off a little it only gets worse the further you travel.

His ballscrew is either a 1610 or 1605 and while 2.601249 is in the ballpark for a 1610 ballscrew it will cut air if the depth of cut is small enough. I thought at one time he had the Z axis set to 5.08 which is a 5mm pitch screw, it's now setup more closely for a 10mm pitch screw.

[billybobron]

I have photos and will post 2 new ones to this post, after spending hours upon hours yesterday and today going back and forth setting figures i am no closer today than I was yesterday not to mention my machine did not get set up the way I wanted, due to Shawn not being able to figure out why it would not save certain settings and it did that same last night as well as again today. I will sat here today meticulously setting the numbers checking adjusting, rechecking, running the machine, then to try and run one of the files that I had created for it to only fail! I have spent so much time last night and today adjusting numbers that I never got to check the file that was created to see if it was correctly done and then to fight with the machine due to it not being setup the way it was wired for and intended to be! It has begin and beyond being a real P--esr

[Ken Rychlik]

I have had g43 and g49 offset's sneak up on me and mess up the z height so double check that. Your toolpath has a .8 G43 tool offset in it. I don't know that simple machines need to use G49 and G43 offsets. You can type G43 and G49 in the mdi and watch what the z dro is doing.