Problem with 3D vector carve

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Chilidawg
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Joined: Thu Nov 30, 2017 3:46 pm
Model of CNC Machine: X-Carve

Problem with 3D vector carve

Post by Chilidawg »

OK I dont think this is a newbie question as I have been carving for a while.
I bought a 3D model from Design and Make and running with V-Carve 9.517.
When I do the roughing pass all looks well..... When I run the finish pass it roams to the left as it runs.
I have tried many carves between the first and second attempt with no machine issues.
Any help here?

Chilidawg
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Model of CNC Machine: X-Carve

Re: Problem with 3D vector carve

Post by Chilidawg »

Here is a pic
Attachments
IMG_0776223.jpg

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TReischl
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Re: Problem with 3D vector carve

Post by TReischl »

Sure, first off it is not the software. You probably knew that already.

Something is moving or you are losing steps. If it is clamped firmly then it is losing steps.

Not sure what you meant when you said you tried many carves between the first and second attempt?

Finish cutting with a small stepover will show all sorts of problems that might not be very apparent when doing regular or rough cutting. Lots of moves, lots of small stepovers, a missed step here, a missed step there and pretty soon you are talking about real lost steps. Sort of the way government thinks about money, a million here, a million there and pretty soon they are talking about real money.
"If you see a good fight, get in it." Dr. Vernon Johns

Chilidawg
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Model of CNC Machine: X-Carve

Re: Problem with 3D vector carve

Post by Chilidawg »

I do a lot of precise laser engraving in between a few carves.
my laser movements on this machine have never had a problem.
What I meant by my statement was that I tried to carve this once and it went wrong.
I did 6 or 8 other projects on the same machine without incident.
Then went back to try the carve again and it did the same thing.
the final cut pushed to the left on both attempts.

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Adrian
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Re: Problem with 3D vector carve

Post by Adrian »

Chilidawg wrote:I do a lot of precise laser engraving in between a few carves.
my laser movements on this machine have never had a problem.
What I meant by my statement was that I tried to carve this once and it went wrong.
I did 6 or 8 other projects on the same machine without incident.
Then went back to try the carve again and it did the same thing.
the final cut pushed to the left on both attempts.
The difference between laser cutting and cutting with a bit is the forces on the machine. With the laser the stepper motors only have to move the laser head around. When you're cutting wood you've got all the forces of that operation feeding back through the structure of the machine. If you're pushing things too fast and/or trying to cut too much in one go it's easy to put the machine in a state where steps are being lost so the physical position of the machine no longer matches what the electronics think it is.

ezurick

Re: Problem with 3D vector carve

Post by ezurick »

I am no expert in 3D carving, and in fact I just started getting into it. But for the life of me, I can't tell what that picture is... is it s shirt with outlines of underwear at the bottem? lol. Sorry, but it is really hard to tell what is right and what is wrong. Also what spindle do you have on your xcarve machine and what speed settings? which tool are you using for the finish. As others have said, if you are losing steps, then possibly you need to re-think your speed settings on the finish.

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dwilli9013
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Re: Problem with 3D vector carve

Post by dwilli9013 »

ezurick wrote:I am no expert in 3D carving, and in fact I just started getting into it. But for the life of me, I can't tell what that picture is... is it s shirt with outlines of underwear at the bottem? lol. Sorry, but it is really hard to tell what is right and what is wrong. Also what spindle do you have on your xcarve machine and what speed settings? which tool are you using for the finish. As others have said, if you are losing steps, then possibly you need to re-think your speed settings on the finish.
It's actually a baby onesie I suspect he is carving a baby's arrival, birthweight and gender with the plaque. LOL I could see where that could be easily misinterpreted. :lol: :lol: :lol:
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scottp55
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Re: Problem with 3D vector carve

Post by scottp55 »

Just thinking here, but if it looks a little like you MAY have lost steps in the Roughing, as the Finish path doesn't appear to be centered?

Did you Re-Zero X,Y before going for the Finish toolpath?
I lost position on a Roughing Pass(actually using Offset Finishing and cheating Z down) recently because combos of speed/depth/Offset path literally SHOOK my machine at the start so much I lost a cup of coffee before I could stop cut.
AND I didn't rezero X,Y, and didn't notice I'd lost position until near the end of the first pass when it became obvious it wasn't cutting centered on the piece!

IF so then if using a Tapered Ball Nose, was there a slight squeal on the left side of every pass as the shank hit?
Did dust foot possibly hit the left side with just enough force to possibly throw you off a hair each pass?
It just looks to evenly progressive from the bottom of the shield(?) to the top getting evenly more off each pass.

I mis-measured the cutting edge of a newly entered 1mm TBN recently because the deep gullet threw me(AND I was rushing:( and didn't notice until until a faint sound keyed me in.
Sure enough, the shank was JUST beginning to rub in one spot on the outside deep edge of a Mountain Topo....and I had lost a hair of position :oops:

Like I said, just thinking,
scott
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