[dminnery]

I had a problem today when carving line work with a vbit.

A little background, I imported some .dwf line work I created in AutoCad. Brought into VCarve and created a single toolpath for all my linework(I was creating animal shapes on a wood board). The depth would change randomly from line to line, some lines are at the proper depth and others were at about half the depth.

This also happened randomly when I did some lettering. I created a word in VCarve, created a single toolpath and the word would start shallow and progressively get deeper. Really strange.

I'm using Mach3 and a Romaxx CNC.

I'm thinking about reinstalling Mach3 tomorrow, unless someone has some thoughts. I have a ton of work this weekend and need to solve this.
thanks!

[rgammage]

Hello

I would track the problem .... I guess you mean you exported in DXF ... well that is all text and it can be imported into other products or just read! From memory each line starts with the word LINE and then several parameters 30 rings a bell (forgive me if I am not precise, I have not done this for a decade) followed by X, Y, Z then another parameter for the other end of the line. So draw a triangle with odd sized sides, export it in DXF ... are all the Z parameters constant? Then use Vcarve to produce G-code ... again this is text .... are all the Z values common?

If there is an error anywhere it will be clear where it came from. in 2D it is very easy to draw lines with different Z!

Good luck

Richard

You may send me small files via PM if you wish and I will look too.

[LeeWay]

There could actually be a number of things that could cause that. For starters, that is what VCarve does and does well. I don't use it that often, so not as familiar with it as I'd like to be. Make sure there isn't some check box in it that varies the depth on purpose.
Next, if it is wood, has it been planed? Wood thickness can vary quite a bit been on planed material that has sat for awhile. Depends on humidity and type of wood as well.
Next, how much work have you done on the machine? Just trying to verify that the Z axis it up to the task of maintaining a constant expected Z height when machining. Flex, backlash and rigidity will all play a role.
Lastly would be to suspect missing steps.

[FieldKnot]

I had exactly that difficulty using VCarve and some wooden disks.
Note this is nothing to do with VCarve - as the wood dried it warped a little - enough to make the height vary.
You need either to monitor the height as you cut (I've not sorted that yet) or flatten the surface you're going to engrave just before cutting.
You should be able to see easily just by manually moving the cutter and see the different height - I couldn't see the differences without measuring, but 0.5mm would make a big difference in the vcarved letter.

[dminnery]

Thanks for all the thoughts, I appreciate it.

I have owned this machine for a year and put about 30 hours on it each week. I only use it for wood and I plane all the wood before it goes on the machine.
I have put a warped piece of wood on before and noticed depth variations from one end of the board to the other. But that is not what's happening here.
For example, I have two lines, .5" long that the machine should trace at .02" depth. The lines are .25" apart and the depths are totally different. That seems to be a software not hardware problem.
I have not noticed this problem when cutting out material, just when specify to trace/write on the line.
Maybe that's what I should look at, some preferences or checked box somewhere.
I might run the tool path again just to see if the results are duplicated.

Richard, in regards to the Z height. only my drawing is exported via dxf and the Z is 0. My lettering is all done directly in VCarve, so it shouldn't be an issue.
Thanks for the thoughts though, I hadn't thought of that.

Lee, the machine is pretty stout. I'm only engraving at a .02" depth so it should have no problem. It's cutting hard maple with no issues, so I'm thinking this is a software issue.

Thanks

[LeeWay]

That is what it sounds like.

You can also load the file twice or run it twice. That would eliminate any machine error.
The only other thing I can think of is are the lines the same width in the CAD program. I know some of my older files have a varied line width. I don't do that anymore.

[jknoflicek]

I have never used a Romaxx CNC and I could be way off base here. However, if the Z axis is controlled by a stepper motor, any resistance will change the depth. It is imperative that the Z axis slide and all mechanisms operate freely. I had a similar problem on an older New Hermes machine and found buildup inhibiting the free motion of the Z axis mechanism causing the steppers to "lose steps." Cleaned it up and have never seen the problem again.
Best of luck
Jim

[bevins]

Check and see if it is doing it in the simulation. When you preview your toolpath, you can place the cursor in the v-groove and check the depth and see if it is varying in the simulation. If it is, then that's a software problem. If it is not, then you can start looking at your machine. You need to find a starting point, otherwise its a shot in the dark. Aspire or v-carve is really adamant about what is on the preview should be what is portrayed in the actual carving.

Just my 2 cents,

Bob