Messages

1

LazyCam (Beta) / Re: Lazy Cam breaks up curves

« on: February 07, 2008, 04:54:41 PM »

OK, well I re-drew the clamp in acad, and it was screwed up, only differently. It took the top line and separated it off. So I deleted that line in acad and re-drew it and it showed up fine in lazycam. So now the outside shape is great, and the circle is still in two parts, which is weird... but it will cut it ok I think.  So .. why did that solve the problem? Is this just an lcam quirk or is there something I can do to make my drawings actually show up correctly in the first place?

 I can see why people charge so much for setup when there are so many problems...

2

LazyCam (Beta) / Re: Lazy Cam breaks up curves

« on: February 07, 2008, 02:59:31 PM »

So what is the cad problem? How can I fix the problem? I drew circles in autocad before and saved them the same and they worked out fine. Now, they break apart. I don't know what I did different. Anyone have any tips to fix this?


I'm having a similar issue with this gear a guy wants me to cut. I'm not sure how to draw it any differently, the part is joined and all together in autocad.

I'm also using lcam 3.00.2 if that makes a difference.

Thanks!

3

LazyCam (Beta) / Lazy Cam breaks up curves

« on: February 07, 2008, 11:33:35 AM »

OK, so I take my R12 DXF drawings from autocad (because lazycam will not read anything newer than that), which are composed of curves and lines for a part. I set everything up, but lazycam reads certain sections of the drawing weird. It breaks circles in two, and then posts g-code to cut them one piece at a time, and it breaks up other parts as well. This is a weird problem, any ideas?

I've posted the gcode for one of the parts, if you take it into mach, you'll see how it tries to cut. How do I either change my drawings or setup lazycam to cut smooth lines around the entire piece all at once?

Thanks!

4

General Mach Discussion / Re: cuts are off a bit

« on: February 02, 2008, 03:19:27 AM »

Yep, I thought of that. And I think I can deal with doing that for now until I can get a cam program, or until I decide to get a license for lazycam if I end up liking it enough. I'm pretty happy with the results I've had with my homemade cnc though, and recommend it to anyone!

5

General Mach Discussion / Re: cuts are off a bit

« on: February 01, 2008, 11:21:41 PM »

OK, so I noticed something today. When I had a shop machine the pinion shafts for me to fit on the motors, they didn't do a perfect job. There was some play in the shafts where they connected to the motor, which caused some serious backlash after they worked themselves loose. I modified the x and y axis a bit and added a spring compensation to the x axis because the play was worse. But there appears to be no backlash, or at least not any play in the gears anymore.

So I went ahead and cut the mount with the code generated from lazycam. It cut exactly what it was supposed to (according to my tape measure, that is). The problem is, the circle cutout is 1/4" too big, and the outside dimensions are 1/4" too small.

I can not offset in lazycam to account for the bit because I did not get a license for it yet, but it appears the cuts being off just a bit and the circle issue is figured out.

6

General Mach Discussion / Re: cuts are off a bit

« on: January 31, 2008, 07:29:45 PM »

For that much, there would be some noticable play I would think. And I have never noticed any when assembling or adjusting the machine. It's pretty tight.

7

General Mach Discussion / Re: cuts are off a bit

« on: January 31, 2008, 11:28:59 AM »

Yeah, that's what I meant by whacked out. That is my first time using LazyCAM for anything but entertainment or frustion. Everything else I posted from it was a garbled mess.

Thanks for the help. Could my original issue be backlash? I don't have an accurate way to measure it right now, but it did run past my mind.



Edit: ... Wow. That was easy. I spent a while trying to re-organize entities, and after that didn't work I clicked "clean. This little button just put everything in order for me. New G-Code is added.

8

General Mach Discussion / Re: cuts are off a bit

« on: January 31, 2008, 03:30:44 AM »

OK, so I watched a lazycam video and it no longer looks COMPLETELY foreign to me anymore. I generated the gcode as attached here, does it look better to solve my jerking motions?

It uses G2, which is apparently this 'clockwise interpolation' to cut the arcs, which I'm trying to understand what that actually means from the limited definitions I can find on the net. The G code is a little wacked out, but I think it will work a bit better, I'll test it out tomorrow.

9

General Mach Discussion / Re: cuts are off a bit

« on: January 30, 2008, 02:29:30 PM »

Whoops, I missed that you already answered that it is made up of a lot of lines.

A friend of mine had his buddy at work generate it with ArtCAM. I put most of my funds into the machine and havn't really decided on a CAM option yet. I wouldn't mind using LazyCAM but it is a bit difficult to understand.

Is this a CAM issue, or could I be saving it wrong as a dxf? I need to save it as an R12 DXF or nothing will open it, not even lazycam.

10

General Mach Discussion / Re: cuts are off a bit

« on: January 30, 2008, 02:23:58 PM »

OK,

So, in the code, the farthest points away from each other repsective to the circle are 3.25". I thought this was the center of the bit? So If I'm using a 1/4" bit, shouldn't it be cutting 1/8" extra off all sides? Where am I wrong?

The circle comes out to 3 7/16" when its cut. The outside dimensions come out to a little over 6" on the X, almost exactly 6" on the Y. Please excuse my tape measure. I'm new to CNC and have a digital caliper on the way.

The other issue is the jerking. I have been reading other issues with cutting circles. I have found that some software exports dxf files as a bunch of little lines instead of true circles. I'm using AutoCAD to design these things, any thoughts on that? Does the G Code look any different for true circles? I'm also curious if changing the CV settings in Mach will help out at all?

Thanks!