We Have Movement

P

papermaker

Active User
Registered
Joined
Mar 12, 2013
Messages
302
Well after mailing breakout boards back and forth from Bucksport to Peoria finally went to Plan B. I gave up on the PBX-USB breakout board and got my original parallel port breakout board back. I swapped two "dead" PC's for a good PC that is dedicated to just the CNC mill.
I got everything connected and working although there were a couple issues that have to be resolved. The biggest issue right now is that the X and Z axis are working backwards from what the buttons are pushed. Oh yeah I'm using Mach 3 demo software. If you push the left arrow key the X travels to the right and vice versa. The Z is the same...Push page up the spindle lowers . There are about 4 chances on each axis to get wires crossed. The drivers are all wired the same so I'm guessing that the plugs may be wire wrong .
So looking for ideas!
 
Seems to me I tried to reverse steppers by swapping wires. It worked for a couple of seconds, then the board 'corrected' for me and the motors went back to the original directions. It takes changing a setting in Mach3 to set your desired direction for each axis. I just don't remember off the top of my head where to find the settings.
 
EXCELLENT!!!!

Swapping the the direction should be easy, I know how to do it in LinuxCNC. Not familiar with Mach, but there has got to be a similar setting.

You can also do it via wiring. Swap any single pair of wires on the motor. If you swap both pairs, you are back where you started ;).

Once you get that sorted, you can start tuning things, you'll be slicing through aluminum in no time now ;)
 
I think you're both right. Somewhere in the settings you can invert ( I think that's what they call it ) the direction. I too am not sure where!
 
I got that figured out. Under configuration, homing and limits you can set the motors to reverse. That did the trick. We're getting closer. Now I waiting for some new fans to cool the drivers. I have a heat shrink connected to the drivers but they sure do get quite warm. I'm still trying to figure out how I'm going to power these. I had two fans installed and powered from a 12v power supply. I wanted to clean thing up a bit and bought a stepper board to reduce 40v down to 12v dc. That didn't work out so well as it burned out both fans within about 30 seconds.
Now I'm going with 4 fans and would just as soon not burn up for more so any suggestions would be appreciated.
 
Ummm-well, I am glad you figured out how to reverse the motors.

But assuming your mill is a regular moving-table vertical mill, pushing the Left Arrow key SHOULD move the X-axis table to the Right.

Movement on a CNC mill is from the point of view of the cutting tool-so moving the table to the Right "moves" the tool to the Left.

Now that you know how to reverse axes, I suspect you will need to re-reverse your X axis to get it working correctly. And you will also need to reverse your Y axis so that pushing the Up Arrow moves the table toward you.

Hope this helps,

Andy Wander
 
I think your right in what you're saying. I'm posting this graphic just so I can compare the graphic of the Mach 3 MPG

xyz_axes.gif
 
papermaker said:
I think your right in what you're saying. I'm posting this graphic just so I can compare the graphic of the Mach 3 MPG
Click to expand...

So if you are standing in front of the mill, with the X axis parallel to your shoulders, and the Y- arrow poking you in the belly, then pressing the UP arrow should move the table toward you. Pressing the LEFT arrow should move the table to the right.

Takes a while to get used to at first-just visualize all movement from the point of view of the tool.
 
I had some "mental" issues along the same lines Andy is describing. X and Y seem backwards at first. It helps if you tape a piece of cardboard to the table, and chuck a magic marker in the spindle. Then, draw a line from left to right on the cardboard. This should be done by pressing the "right" arrow. The spindle is stationary, the bed moves under it, and that means the bed is always going the opposite direction.

Took me a while, but it finally clicked, I rarely even think about it anymore. I will tell you though, with the feed speed turned up high, forgetting which direction you're going is a great way to break endmills ;)
 
You must log in or register to reply here.
Back
Top