Anyone know why it does this?

Have you checked your G-Code? How are you setting your Z zero?

I think never mind. Looks like my t but might be loose.

Man, what a pain. T nut worked loose and of course not where I could fit my hand in. Dismantled z and x, rebuilt z . because it never ends,my lead connection kept letting go.(rubber tube) couldn't get the clamp tight enough for some reason. Then for same unknown reason it worked.
NOW, I noticed that the bit drags about an 1/8 maybe even 1/16 inch before z lifts .WTF? I run $h, move to project zero, reset zero,run file. Bit heads for first point and a moment later the z goes up. What / where should I start to look? Am I too close to top? Thinner paper for a spacer?
Table is level now. I was off .008 across x axis.

Is this a Bob’s CNC ? In the Bob’s Facebook Group there are lots of Z-axis issues discussed. You might find suggestions there.

If it is a different machine, please post some pictures.

No, its homebuilt. Don't think it will show up in pic.

Ever have one of those days you just know its not a good day to sharpen knives or clean weapons? Been that kinda week. Surprisingly , I just switched to writing paper as a gauge instead of the paper from 2 sided tape. Seemed to fix scratch at start up

Actually that first move is probably a rapid move so if it is not lifting up before the move it might have something to do with your safe Z setting.

Mike safe z is .25

I know you'll ask for pics but I didn't take any. How do I check or know if this is emf or something else? Backlash?(seems backlash would give me sloppy cuts,corners??
Design is ava ' s
Fairy garden
The cut did ava ' s then started at n of garden,got to the g ,cut over ava, then went back to correct line and did fairy.

I rebuilt z axis, bad coupling(slipping down), it still seems to cut deeper at each letter and letters gets closer . I air cut the same file 3 times.x y returned to work 0, z gained .001 (6.026 to 6.027).
I moved motor wires and put some vinyl tubing over them where they still crossed.
I also did a cut with a square,star,circle in the corners ,they cut perfect shapes ,close to even depth

You are right, without pictures we don't know what the carving looks like.

I asked you before what design software you are using now and you never answered. The problems you are having might be with the post processor you are using. It might also have to do with how you are toolpathing your cuts for the text and this is probably the trouble you are having.

You say when you air cut 3 times then returned to work 0, z gained .001. As loose as you CNC would be I think this is really good. Did you expect it to be perfect? Do you know what 0.001 is? It is about the thickness of a human hair or at least the hair on my arm!

I know its tight. The table was off about 08 got that to .02, I checked it with the calipers.
I went with aspire(didn't think of looking at eBay).
What do you mean toolpathing ? Vbit 60 at .02 flat depth.
I do have a question tho. When I wrote text I just centered then reduced to size (about .5 )with handles. Does that water as opposed to setting font size?

jeffp60 said:

I know its tight. The table was off about 08 got that to .02, I checked it with the calipers.
I went with aspire(didn't think of looking at eBay).
What do you mean toolpathing ? Vbit 60 at .02 flat depth.
I do have a question tho. When I wrote text I just centered then reduced to size (about .5 )with handles. Does that water as opposed to setting font size?

Click to expand...

So you bought a pirated copy of Aspire off Ebay?

Toolpathing = running a toolpath on vectors. Vbit 60 at .02 flat depth does not tell me what kind of toolpath you are running on the text, what kind of toolpath are you running on the text?

You can use handles or settings in the text tool to adjust the font size.

Not pirated I guess. EBay doesn't sell illegals. Guess it is "technically" legal .something about first sale copyright s.
What else is there? V carve Raster x.

I know 2 sided tape is throwing it of a little bit but doesn't explain amount. Or jumping line. Gonna try it with gcode and grbl posts with insulated wires.I'm leaning towards rf interference.

jeffp60 said:

Not pirated I guess. EBay doesn't sell illegals. Guess it is "technically" legal .something about first sale copyright s.

Click to expand...

That's BS.

Sure seems you want a lot for nothing.

I don't even understand why these guys still try to help you get your cobbled up "system" going. I know they try to help most anyone, but this just continues to go downhill with your "frugal" ways.

Sorry about that "frugal ways" and my "cobbled system" offends you. I am retired on fixed income and am not doing this to sell anything.this was about building a machine,much like the arduino.
I appreciate all of the help I have received.
Moderators can feel free to delete my account.