Topics

1

General Mach Discussion / circles are not round - need advice

« on: February 28, 2009, 10:18:05 AM »

I need your help.   I'm not sure what questions to ask or where to even begin looking to solve this issue.

I use Bobcad V21 and Mach3 2.0.  I am trying to cut a simple round circle.  The G-code looks correct in both Bobcad and in Mach3 but the circles are not round.  They are off about a 1/16” on a 2” circle.  I noticed this when I started to cut out gears and they would not line up correctly, so I thought I would try just a std circle to see if I could identify the problem.  The X dimension is correct.  The Y dimension is correct.  It is the verticals that are off and causing it to be slightly oval.   

The frustrating part is that I used to be able to cut circles perfectly on this machine with this software.  I have changed nothing (as far as I can recall).

Where should I start looking.

Here is the G code I tested with.

N1 G00 Z0.5
N2 X1.
N3 G01 Z-0.12 F50
N4 G03 I-1. J0.
N5 G01 Z-0.24
N6 G03 I-1. J0.
N7 G01 Z-0.36
N8 G03 I-1. J0.
N9 G01 Z-0.48
N10 G03 I-1. J0.
N11 G00 Z0.5

2

General Mach Discussion / Speed, Size, New and need help

« on: May 28, 2006, 05:43:48 PM »

Ok, I almost have the machine completely set up.  Still waiting on the actual spindle and some more software to be delivered, but I have enough where I could mount a marker on the router holder and try it out.  I have loaded the Mach 3 program and BobCad V20.  the Mach 3 I have found fairly easy to get started with.  The video tutorials are great.  The Bobcad is another issue, but I'll figure it out.   (Is there somewhere on the web of tips and tricks for using BobCad?)

1.  I ran the roadrunner sample and the skull and crossbones sample in mach 3.  They worked great with 1 issue.  The digital read out for the skull program limits in mach 3 indicate an X value of +25.6 units and a Y value of +16 units.  I have the scale set to 1.00 I have my units set to inches.  I was assuming that 1 inch would = 1 unit.  What I am finding is that my machine doubles the units.  The X wants to run 50 and the Y 32 units.  How do I get it to match.  Had the same issue with the roadrunner.

2.  Would also like to increase the speed of the cut.  (I think this is the same as feedrate?)  I want the router to travel faster along the coordinates.  The router is capable of cutting much faster than the current travel, but I have no idea how to do it.  This is a bigger problem when I import a g-code text file from BobCaD v20.  I did a simple 3X3 square and it took over 3 minutes.  The machine was barely moving.  I'm sure it's user error but I don't know where to begin.

Your assistance is most appreciated.  Any tips, tricks etc.. would be appreciated.
Thanks,

3

General Mach Discussion / Initial set-up Mach 2 or 3

« on: May 18, 2006, 09:36:43 AM »

I am brand new to CNC and find myself coming to the forum for basic questions once again.  I have Mach 2 downloaded and licensed.  Now that I am configuring I turned to the on-line video training.  I have noticed that all the on-line video training is for Mach 3. I assume the configurations work the same?  Please confirm. 

Also the configuration for mach 2 provided by the machine dealer shows to use pin 10 for X-, X+ and X Home.  (11 for Y and 12 for Z).  On the training video you indicate X+ as pin 10, and both X- and X home as Pin 11.  Whic is correct?  IS it dependant on the controller.  It makes more sense to me to use a different pin numbers for X+ and X- but I am not sure how this will effect the controller.  Please advise.

ANd again thanks in advance to everyone for your help.

4

General Mach Discussion / USB - Parallel laptop

« on: April 16, 2006, 09:06:04 AM »

Some of the new laptops only have a USB port.  Has anyone had success with a USB printer cable converter? 
Also concerned about getting a true 5Vdc to the controller.  Are there any power regulators out there that have had success?