New Shopbot owner

[hhk]

I just picked up a used PRT Alpha 96x48 with router. I've been lucking this site for a while but now I'm going to have a ton of questions.

I make carbon fibre sporting goods. I need the CNC router to cut foam cores and trim carbon fibre parts. I might also use it to make aluminum moulds.

I set up the table and I'm able to move the router around. I also ran the Z-axis zeroing routine. Some initial questions:

1) Occasionally, I'm the inp4 indicator will go red and the machine stops responding. What causes this?

2) What exactly triggers the 4 inputs and outputs? I know input 1 is the z-zero plate.

3) After moving the machine, is it a good idea to re-surface the machine top?

4) Is there a test cut that will tell me the table is square and level?

Thanks everyone.

[zeykr]

1) Occasionally, I'm the inp4 indicator will go red and the machine stops responding. What causes this?

2) What exactly triggers the 4 inputs and outputs? I know input 1 is the z-zero plate.

Input 4 is the emergency stop button. It's a normally closed circuit, so any loose connection or break in the wire could cause it to trigger. Check your connections in the control box, at the emergency switch, and the wire between.


3) After moving the machine, is it a good idea to re-surface the machine top?

Yes. Surfacing the top will level the surface to the machine and it will tell you if your z axis if plumb. Should not be large ridges.

4) Is there a test cut that will tell me the table is square and level?

You can just cut a large square and measure diagonals in a scrap piece of material. There are also some articles in the web columns section of the shopbot website on squaring and plumbing your table.

[hhk]

Thanks Ken.

How about input 2 and 3? And the 4 outputs? No explanation in the manual as to what these indicate.

[Gary Campbell]

Henry...
THE OEM configuration of a PRT has nothing on input 2, and uses input 3 for the X & Y prox switches.

Output 4 will be on anytime the machine is active.

[hhk]

Wiring on the estop seems okay. I trigger inp4 when I move any of the axis too far. For instance. I hit MZ 80 and the z axis will move then a message will pop up that !!!TOOL STOP BUTTON ON!!!

Does this sound right?

Also I tested moving the tool with the keyboard and it seems odd to me

Pageup moves z up
Pagedown moves z down
Up arrow moves y in positive (right) direction
Down moves y in negative (left)
Left moves x in negative (to back of table)
Right moves x in positive (front)

Up/down and left/right seem counter intuitive to me. Is there a wiring problem here? I didn't set up the control box so not sure what supposed to plug in where.

[gc3]

wow...80" Z let's see a photo of that!

[Gary Campbell]

"Wiring on the estop seems okay. I trigger inp4 when I move any of the axis too far. For instance. I hit MZ 80 and the z axis will move then a message will pop up that !!!TOOL STOP BUTTON ON!!!"

IF, by too far, you mean until it hits a prox switch or hard limit at the end of its travel, then yes that is correct action. IF the machine doesnt reach the end of its travel limits, then you may have a problem. At this time one (or more) of the inputs lights should be lit indicating a prox (limit) switch actuivation. Check the eStop wiring and all of its connectors for a loose or open condition, especially under motion.

"Up/down and left/right seem counter intuitive to me. Is there a wiring problem here?"

IF you look at the table in design view, that is with the X rail closest to the Y zero at your belly, negative x to your left, positive to right, positive Y away and negative towards you, you are now at the FRONT of the machine. Orient the keyboard with its front towards you and now the arrow keys should be oriented correctly with the machine movements. IF not, then there could possibly be some unconventional (but not neccessarily wrong) wiring.

[hhk]

Sometimes the answers are right there in front of your face. The only other Cnc Router I've used was oriented in the "portrait" direction.

The reason I tried to move z 80" was to hit the limit.

Thanks for your patient explanations.

[br928]

It sounds like your limit switches are wired to input #4. E-stop should be input #4 and limit switches should be input #3 for factory defaults. They can be configured to different inputs however.

Do you have a limit switch on your Z? I only have limits on my X & Y axis.

[adrianm]

It's an Alpha and they will fire the eStop on input #4 if you move the axis' until they stop such as going to far on the Z.

[hhk]

Stan, yes, I have a limit switch on my Z. Without one, wouldn't the motors just keep going?

I was able to write my first tool path. I had to take 2mm (.06 in) off the surface of a small foam part. I zeroed the XY at the approximate middle of the part, Z zeroed to the part surface. Used a 1/2 inch bit and just moved the bit across with repetitive commands.

eg.

MZ -.06
MY -5
MY 10
MX .5
MY -5
MY 10
MX 1
....

Try not to snicker veteran Shopbotters! You gotta start somewhere.

Relative movements would have been more efficient but I could not figure out where to set this mode. The Command Reference manual talks about it in many places but doesn't tell me where to set it. Would be great to have more hyperlinks in the PDF version of the manual.

[GlenP]

Here is a link to shopbot docs. PRT Alpha manual.
http://www.shopbottools.com/files/docs/AssemblyBinder060828.pdf