New Moulding Question -what is it doing now?

[coopcnc]

I am trying to make a simple taper across a 15" wide by 30" long blank tapering from a slight cut at one end of the length to 1" deep the far end.
I am using VCarve Desktop with tiling. The simulation looks perfect using a clearing toolpath and then the final. Both tiles are properly being saved. However, when it comes time to cut, the Z axis hits the top limit a few times, then moves what seems to be an appropriate amount but then cuts .5" deep on the first clearing cut, should be .25" at most (clearance tool pass depth) and much less given the profile. Using a .75" end mill.

When at the upper limit, the bit is .75" above the surface with .2" set as the clearance gap.

Pictures attached of the first tile toolpath and the result.

Nothing like ruining a huge blank of Walnut for the client

Thanks in advance,
Marcus

[Adrian]

If the Z has hit the top limit then everything after that will be moot as it will have lost positional awareness.

Do the clearance/material gap settings on the material setup make sense for the thickness of the material and length of bit?

[coopcnc]

I had the same thought about it confusing itself. However the zero position for the Z axis stays good after I stop the process.

There is about .75" of space above the surface for the Z axis to move, and the clearance gap is only .2" I even tried starting the router off to the side of the material and lowering the bit to below the surface to give it more room to travel. No change.

[Rcnewcomb]

If the simulation is perfect then you are dealing with a machine issue: loss of position, something binding or loose.

[wbrock]

In the first pic at the bottom it shows your home position for the Z axis is set to 1.5", you need change that. I set mine at .3". I keep having the same problem when I was carving thicker pieces. once I changed that it stopped.

[martin54]

Not sure why your z position is returning to the original z position when you stop the machine because it probably shouldn't
The home Z position for the Vectric software is set to 1.5" above material surface as wbrock has pointed out. Unless you have edited the post processor to remove this home position the first thing that happens is the bit will try to lift 1.5" which it physically can't do if you only have about 3/4" clearance above the material

I never walk away from the machine until I know it has started to cut properly, soon as the z axis had moved up & hit the upper limit I would have hit the e stop button

[coopcnc]

wbrock, thanks for the great attention to detail! That was it. No clue why 1.5" was in there but removing solved everything.

Unfortunately, being a rookie the fact it hit the Z stop was not a great cause for alarm for me. Now I know better and will certainly hit pause a whole lot quicker.

Thanks for all the inputs folks!

Marcus

[LittleGreyMan]

Marcus, wbrock,

Please read again carefully Martin's answer.

Depending on your postprocessor and the behavior of your machine controller, setting the Z home position at a very low value may be dangerous.

If the machine goes back to the home position after machining, depending on this position, on the tool length, on your Z0 setting and on the geometry of your part, it may cut through the part (in the best case).

[wmgeorge]

I am trying to make a simple taper across a 15" wide by 30" long blank tapering from a slight cut at one end of the length to 1" deep the far end.
I am using VCarve Desktop with tiling. The simulation looks perfect using a clearing toolpath and then the final. Both tiles are properly being saved. However, when it comes time to cut, the Z axis hits the top limit a few times, then moves what seems to be an appropriate amount but then cuts .5" deep on the first clearing cut, should be .25" at most (clearance tool pass depth) and much less given the profile. Using a .75" end mill.

When at the upper limit, the bit is .75" above the surface with .2" set as the clearance gap.

Pictures attached of the first tile toolpath and the result.

Nothing like ruining a huge blank of Walnut for the client

Thanks in advance,
Marcus
]

Practicing on expensive wood is not what I do. Find scrap pieces to use until your a 100% sure of your machine and skills.