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Unit convertion issues and g-code questions
« on: August 05, 2009, 02:46:52 AM »
Hi Guys,
I wrote along message and then it did not load and now I have to do it again!!!!

I finally got all my axis to move and home in the correct direction.
Questions:
1. I have a rockcliff router, according to their literature; the "Step Per" setting should be 4000.  Is this correct, I was using 32000 before. See attachment.

2. My units are all incorrect.  I have my Mach3 configure for inches.  I have my home limits to be 18x24x5 inches, the working envelope of my router.  When I try to run some programs, the units on the DRO are sometimes in the thousands, like the unit conversion factor is very wrong.  The machine runs out of room and cannot do the job on the table size.

3. I am using Solidworks for my CAD, which I know fairly well and SolidCAM for my CAM, which I am learning on my own (unfortunately I cannot find a SolidCAM book). I created a small part profile 4" long and .051" deep, I did this intentionally so that I know that it will fit on my router table size.  This is how I set up my machine.
 a. I reference all axis and the machine finds all the home switches.
 b. I then jog all the table axis away from the home switches to about the center of each axis.
 c.  I then zero the axis DRO to set this position as my working home. Follow me so far.
 d. Then I load my program and hit go.

So this is what happens.  From the screen shot attached, the z-axis will move down to the home switch zero position and stop. Why does it do this, if I have my router in place, the bit would have crashed into the work piece? When I hit start again, the z-axis will move up and away from the zero home switch position and stop. When I his start again, all the axis move but I have to hit the emergency stop because if I did not, the x-axis would crash into the home switch.  Some how, the work piece units are very off from the machine units.  Like I mentioned before the part is only 4" long so it should fit on my table.  What is not configured correctly.  Am I setting up the part right in steps a-d above??

Is this pretty clear?  I am so close to putting everything together but some things are not jiving.

Thanks,
skipper


Re: Unit convertion issues and g-code questions
« Reply #1 on: August 05, 2009, 02:47:32 AM »
here is the attachment
Re: Unit convertion issues and g-code questions
« Reply #2 on: August 05, 2009, 03:10:10 AM »
I'm not sure if my reply will help you but this sometime happen to me.

If I load the program I want to work with after all the homing routine and zeroing the part on the table, those weird things happen to me too.

So now, I load the program before doing all the homing routing, this solve some problems, for me at least.

Jeff
Re: Unit convertion issues and g-code questions
« Reply #3 on: August 24, 2009, 02:17:55 AM »
Hi All,

Well my Rockcliffe router was under repair but I have it working again.  I am still having issues with the unit conversions.  I thought either on this forum or CNCZone someone had added a program that converted gcode from mm to imperial and back. I searched both sites but could not find it.

So tonight I loaded this file I created.  I am attaching it in hopes that someone can run it.  I got it to run on my machine, it is how my SolidCAM generated it.  I noticed that some of the values were large like 100 units so I assumed it was in metric so I added line G21.  It seemed to work OK.

Can someone run it and let me know what they think.  What it does is after I zero my axis "Reference All Home"and put the tool where I want it to start, I then zero the software zero.

Isn't this were my tool should start cutting?  When I run the program the tool will alway go down and find z-axis home.  This will crash into my work piece.  I assume I just need to remove that line of code or should that normally happen?  Does everyone use a generic few couple of lines to get their machine to start in the same location all the time and to go back to the same location after the job is done.
I guess tweaking the gcode program is neccessary or configuring the CAM program to created programs with specific outputs. Thanks skipper
Re: Unit convertion issues and g-code questions
« Reply #4 on: August 24, 2009, 01:59:25 PM »
z axis home should be spindle up to home , not down,

Ed
Ed VanEss
Re: Unit convertion issues and g-code questions
« Reply #5 on: August 24, 2009, 03:25:28 PM »
skipper,

  Don't you have the Solidcam users guide? Its 242 pages of pdf files?
It should be on the cd with solid cam. If not , and you need it , I could send you a copy.
Let me know.

Ed
Ed VanEss
Re: Unit convertion issues and g-code questions
« Reply #6 on: August 25, 2009, 12:46:14 AM »
Edvaness,

I do not have the SolidCAM usder guide if you can send me a copy I would appreciate it.

So, tonight I reverse the homing direction of my z (homing up) and it works better :) I got confused because everything I read said that to set up Mach3, z should be the opposite of x and y.
Now there is something I am just not getting.  I don't have a router set up in my machine but I have a pencil to trace my parts, temperarily until I get everthing sorted.  My g-code created by my SolidCAM is untampered with.  I am attaching a file I downloaded from turbosquid, it is a horse and it is suppose to be a little over two and a half inches tall.  When I run this on my machine, I can see the x and y axis turning, albeit slowly but they are turning making the part.  What I see is that the part is miniture, that is the scale is such that It is tiny and the pencil trace the pattern very minute (cannot even make it out).  Some how my scales are really off.  I've tried to edit the file by adding a G20 or a G21 and the machine barleyl moves?  What is wrong with my scales, conversions?

Thanks,
skipper
Re: Unit convertion issues and g-code questions
« Reply #7 on: August 25, 2009, 02:00:06 AM »
skipper,
 I've sent you a pm (personal message)
Ed
Ed VanEss
Re: Unit convertion issues and g-code questions
« Reply #8 on: September 01, 2009, 01:23:01 AM »
Hi All,

Well Ed suggested that I try to calibrate my axises in the "Settings tab" using the "Set Steps per unit" command.  When I tell Mach3 to move x-axis 1 inch, the DRO show that it move 1 but the actually value that it move was just a little.  Trying to measure it was tough, I had my wife hold a digital caliper but it was not consistant.  When I told Mach to move 3 inches, it really moved only .233 - .261 inch. So my calibration is way off.  I am suppose to then add this value in the diplay box and do the move again but because I could not get an acurate reading I did not do this. Is it the motor step per revolution that is off then? 
skipper
Re: Unit convertion issues and g-code questions
« Reply #9 on: September 01, 2009, 02:09:39 AM »
Ok, so I changed my motor tuning "steps per" number.  It had 4000 I changed it to 32000 (20*200*8=32000).  I have a better way of measuring the axis movement, now when I request 1 inch it moved .7980 in.  Closer but still not on.  I am using Kelings motors which I believe are 1.8 deg at 200 steps per degree. Does this sound correct?

Skipper