Taking the CNC Plunge

[TomS]

I consider myself somewhat computer savvy and of average intelligence but I've had no luck with Mach 3 motor calibration. . This is my procedure and dilemma. My X and Y axis drives are set for 1000 micro steps, have 5 pitch ball screws and are direct drive. Went to motor tuning in the config menu and input 5000 in the Steps Per box and saved the axis setting. I set up a 123 block square to the table and zeroed my DTI to the 123 block after removing backlash. Went to the Settings tab and clicked on Set Steps Per Unit, selected Axis Section and clicked on X. Input 3 in the distance to move dialogue box and clicked OK. The table moved about 3". Using another 123 block I slipped it in between the 123 block clamped to the table and my DTI. My DTI is .030" travel and evidently the table moved less than 3" because I maxed out the DTI travel. My guess was that the table moved about 2.970" so I entered that in the dialogue box. I accepted the number in the Steps per Unit box. My logic is I could run this exercise again and get closer with each successive run. Not so. Each time I ran it I am getting further away from my 3" calibration mark.

I know there are literally thousands, if not tens of thousands, of copies of Mach 3 in use so I can't blame the software. What am I doing wrong? If you need additional information I'll gladly provide it. This can't be as hard as I'm making it.

Thanks for your help.

Tom S

 

[jbolt]

You have 5mm pitch ball screws so you initial setting should be 5080. 25.4/5 = 5.08*1000 = 5080.

 

[TomS]

You have 5mm pitch ball screws so you initial setting should be 5080. 25.4/5 = 5.08*1000 = 5080.

Thanks Jay. I had it etched into my brain that my ball screws were 5 pitch, not 5mm pitch. I will input 5080 into the Steps Per box then fine tune, if necessary, using the Set Steps Per Unit feature on the Settings page.

For info I played with the velocity and acceleration slide bars and have a feel for where I need to be.

Tom S

 

[TomS]

Thanks Jay. I had it etched into my brain that my ball screws were 5 pitch, not 5mm pitch. I will input 5080 into the Steps Per box then fine tune, if necessary, using the Set Steps Per Unit feature on the Settings page.

For info I played with the velocity and acceleration slide bars and have a feel for where I need to be.

Tom S

Your number worked great! The X axis was within .0015" of my target and the Y axis was within .0005". I fine tuned the X axis and it is now spot on. Tomorrow I'll work on the Z axis. I'm slowly moving forward but slow progress is still progress.

Tom S.

 

[jbolt]

Fantastic! You are getting close to making chip!

I was super cautions when I ran my first parts. The first thing I did was run a text program with a Sharpie held in a collet. When that went well I did a couple parts in acrylic. That really helped in gaining confidence with the machine and software.

When you get into metals I highly recommend G-Wizard for calculating speeds and feeds. CNC machining can be way different from manual machining.

Oh and be sure to post some pictures!

Jay

 

[TomS]

Fantastic! You are getting close to making chip!

I was super cautions when I ran my first parts. The first thing I did was run a text program with a Sharpie held in a collet. When that went well I did a couple parts in acrylic. That really helped in gaining confidence with the machine and software.

When you get into metals I highly recommend G-Wizard for calculating speeds and feeds. CNC machining can be way different from manual machining.

Oh and be sure to post some pictures!

Jay

Got the Z axis calibrated today and set velocity and acceleration. All three axis' are set at 180 ipm and acceleration at 18. The motors run smooth and reasonably quiet. These settings will change but I wanted to see what the motors were capable of. I checked backlash and was quite surprised to find X and Y with less than .001". I'm sure these numbers will change after I have a few hours of run time on the machine. Z is another story as I have about .018" of backlash. I wasn't expecting it to be as good as X and Y but .018" is excessive. I'll look into it but I'm certain the contributing source is between the ball nut housing and the sleeve that connects to the headstock base casting. I need to make this as one piece. If I can get less than .007" I'll be happy.

Next steps are to make guards to keep chips out of the motor couplings and an enclosure. And of course play with the machine.

Tom S

 

[TomS]

I was going to play with my mill today using a felt tip marker to test my programming but had a glitch with my D2NC software and will have to reload it. That pesky UC100 Did Not Respond message reared it's ugly head again but I think it was nothing more than a startup glitch. Restarted the computer and all is well again. I did get all of the motor, limit switch and power cables organized and up off the floor and I made a couple of chip guards for X and Y axis couplings. And fine tuned the Ultron quick change tool holder system. Now I can start on the enclosure.

 

[TomS]

After reloading the D2NC software I'm still having the same problem. What's interesting is I have a duplicate copy of D2NC loaded on my other laptop and loading the same .dxf file it works fine. This leads me to believe the process I'm using is correct.

Here's what I'm doing. I'm opening D2NC from within Mach 3 and selecting my .dxf file. I select the origin then click the Offset button. I'm doing an internal hole so I click on the circle in the drawing section, select In/Right, input the tool diameter and click Offset. So far good. Next I click on the Path button, again select the circle in the drawing section, and click Contour. The Contour screen appears and I select Local Shape and then None. I select the circle in the drawing section then press the Move Current Selection to Local Shape button. When I do this the Close, Add Only and Add and Close buttons at the bottom of the screen disappear. I've moved the cursor around to see if the function is still available. No luck. My questions are:

Is it a D2NC issue?

Is it a Mach 3 issue?

Is it me?

I'd like to get my machine running but these hardware and software problems are keeping me from doing so.

Tom S.

 

[jbolt]

Have you tried running D2NC outside of Mach3 on the same computer?

Nice work on the Ultron adapter! I never heard of that system. I will look forward to hear how it works out.

Jay

 

[TomS]

Have you tried running D2NC outside of Mach3 on the same computer?

Nice work on the Ultron adapter! I never heard of that system. I will look forward to hear how it works out.

Jay

Just solved the D2NC problem. It was a screen resolution problem. Changed the text size to medium from large and dropped the resolution one setting below max. Now I can play with Mach 3!

I picked up the Ultron system for a song from a local machinist that didn't want to spend the time and money to set it up. Parts from the manufacturer are not cheap. This system is made for a Bridgeport style mill so I had to make the plate and riser to adapt it.