Messages

21

General Mach Discussion / Re: Need help with basic understanding

« on: February 20, 2011, 09:08:57 AM »

Yeah, I do see the tiny little offsets on it in the images.

I just reduced the acceleration from 500 all the way down to 50, and it didn't make any difference.

Cheers,
Dan

22

General Mach Discussion / Re: Need help with basic understanding

« on: February 20, 2011, 08:51:41 AM »

Hmm, OK.

This is why I am doubting it's a mechanical problem.

This is the image drawn normally:



And this is the image flipped 90 degrees in lazycam:



How, notice how the outer square is perfect? Parts of that outer square are drawn after the glitches.

You'll also notice that the diagonal lines meet up in the corners of the outer square perfectly. 3 of these 4 diagonal lines are drawn AFTER the glitch in the corner of the box, yet they are still where they should be.

My theory is, if the steppers were skipping steps, or the belt was slipping, wouldn't the outer square also be effected, and the diagonal lines wouldn't match up either?

Does anyone have some different software they know works with their machine, that they could do up a simple DXF like this for me? Just so I can eliminate some things?

Cheers,
Dan

23

General Mach Discussion / Re: Need help with basic understanding

« on: February 20, 2011, 07:40:19 AM »

Hi, would it be possible for you to post the gcode you created? That way I can try it on my machine and see if it's just the code, or my actual machine. I'm having a hard time thinking it would be my machine, as I can create some text in lazycam and it'll come out perfectly on the machine, jut seems that anything I bring in from a DXF doesn't work properly.

I did this using all the exact same settings:


What makes me thing it's not skipping steps or slipping the belt, is it can draw a misaligned line, but then it can go right to the corner of the square and draw the diagonal line. If it was skipping steps, the diagonal line wouldn't line up with the corner perfectly.

Cheers,
Dan

24

General Mach Discussion / Re: Need help with basic understanding

« on: February 20, 2011, 07:26:31 AM »

Just thought of something. The DXF export plugin for Sketchup has multiple export options. They are polyface mesh, polylines, triangular mesh, lines, and stl.

Are any of these better than others? I've been using polylines.

25

General Mach Discussion / Re: Need help with basic understanding

« on: February 20, 2011, 07:08:34 AM »

Hi Rich, thanks for the info.

I tried the text feature in Lazycam, and that comes out flawlessly, so I've come to the decision something is going wrong between the DXF and gcode conversion.

Here is the DXF: http://dl.dropbox.com/u/203420/moreshap.dxf

Cheers,
Dan

26

General Mach Discussion / Re: Need help with basic understanding

« on: February 20, 2011, 05:44:11 AM »

I tried rotating the image 90 degrees, and that causes the triangle at the bottom to be on the left side of the vertical line and not partly thru it, though I still have the problem with the little box and the diagonal lines not meeting up.

27

General Mach Discussion / Re: Need help with basic understanding

« on: February 20, 2011, 04:06:12 AM »

Hi, this is how it looks in LazyCam straight from the DXF (No optimizations)



Cheers,
Dan

28

General Mach Discussion / Re: Need help with basic understanding

« on: February 20, 2011, 12:34:26 AM »

OK, that makes sense

Just one more question, which is probably more mechanical related.

I drew this up in Sketchup:



Then ran it on the laser, and ended up with:



I have circled 2 points, where I'm not quite sure what happened. It seems almost like the machine has lost track of where it was and kept going, before realizing it was off track.

I don't think it's my machine skipping steps, because other stuff drawn after those points lined up OK, so seems more like a glitch.

EDIT: I just ran the exact same program again, and it glitched in exactly the same spots. To me, that doesn't seem like a machine problem (skipped steps etc)

Cheers
Dan

29

General Mach Discussion / Re: Need help with basic understanding

« on: February 19, 2011, 11:58:00 PM »

OK well, I drew up a 10x10mm box in google sketchup, exported it as a DXF using a free plugin, loaded it into LazyCam, then into Mach 3, and I got a 10x10mm square

One more question I have, what determines where the engraving/cutting actually starts? All the g code I have seems to have an offset from home it starts at, and I have to test it a few times on scrap before I know its in the right position.

Cheers,
Dan

30

General Mach Discussion / Re: Need help with basic understanding

« on: February 19, 2011, 11:40:09 PM »

Hi, thanks for the reply.

Right after the modify button expired, I found the set steps per feature on the settings page. Seems my guess of 20 steps per mm was accurate.

I'll try a few softwares and see what results I get.

Do you happen to have an answer for my +/- coordinate problem?

Cheers,
Dan