Installing the Z-Zero plate

[waynec]

OK, I'm almost there. I have the plate wired and it works when I run the S_zzero.sbp file. That part is really cool.

But when I try to run the C2 program, I get a path not found error. I edit the CusCut2.sbc file on line 8, which is where the path statement is, and no matter what I put there it responds with a path not found error when I try to run it. I've double and triple checked the file path for errors, but no luck.

Am I supposed to put some path statement in the autoexec.bat or config.sys? Its been a long time since I've even looked at a .bat or .sys file.

Anyway, I'm almost there. The Z routine worked first time, dead on. I'm stoked!

Wayne from White Salmon

[waynec]

I should have mentioned that I'm on a PR, running Shopbot control software ver 2.38.

[bill.young]

Hi Wayne,

Where is your S_zzero.sbp file...somewhere other than in your "C:\sbparts" folder?

Bill

[waynec]

Its in the sbparts folder. I also tried moving it to the sbot folder, no change.

The sbparts folder is not in the root because I put it on the desktop. But I carefully copied the file path and changed the cuscut2.sbc file with the actual sbparts path.

Thanks for your help.
W

[paco]

Wayne,

can you post your cuscut2 code here?

Mine look like this...

---

FP, c:\SbParts\Paco_routines\Zzerofast.sbp

---

This is the only line of code needed. The rest is only comments... Notice the 'FP,' (along with the full file path) which is the command that call the file.

[bill.young]

Wayne,

I think having your SBparts folder on your desktop is the problem. I'd bet the trouble is that the ShopBot software can't find the custom cuts, not that the custom cut can't find the z-zero program.

I don't know of a way to set that path so that the DOS software knows where to find moved custom cuts. Does everything work correctly if you move your sbparts folder back to the C drive, so that it's path is back to "C:\sbparts"? If so, what about moving it back and then creating a shortcut to it on your desktop to make it easier to work with those files?

Bill

[marshawk]

FYI...

Coated bits don't seem to work with the Z Zero plate.

The results of that test were..."interesting".

Chip

[dhunt]

Wiring up a new PRT-96 here, (NOT an Alpha)
to be used with SB v.3.4.25 controller software/XP
but can't quite figure out where to introduce the single-wire from our DIY Z.zero-plate(brass)
onto the board inside the SB Controller box.

Manual isn't real clear about it
(gives instructions for the Alpha, involving two wires,somehow)
I helped rig up another PRT96, but that was 5 yrs ago!
Would someone please give some indication:
(we're guessing the 'other half' of the circuit is carried by a ground wire running from machine to box, is that right?)

Installed the green and black wires from the Emergency Stop panic-button into the lower(Input) block of the two light-blue input/output blocks on the board,
and reckon the Z-plate wire goes in there,too...somewhere.

[scott_smith]

Z-zero is typically input 1. (2nd terminal up on the input block)
Yes the grounded machine is the return path.

[dhunt]

Thanks v.much.

[richards]

Here's some documentation from the zzero.sbp file:

'Wire up a plate (e.g. copper pc board, aluminum plate, etc., to an input
' line) to sense depth of a Z plunge and calibrate to zero or known depth
' **Test plate by tapping it to metal on the tool ... The correct Input Switch display indicator should show

Assuming that your router/spindle is connected to circuit ground (not really a good idea since computer ground should float and be separate from chassis ground, but tying the two grounds together is commonly done), the single wire should be connected to input #1. Then, tapping the z-zero plate to any grounded portion of the machine will cause the input LED to light up.

[mikejohn]

Mike
You have confused me about the grounding. (Confusing me about anything technical isn't difficult
)
I understood that if you have more than one earthing (grounding) point, that is two separate rods in the ground, you could get something called a ground loop.
I can run an earth wire from the control box to the earthing strip, and another from the frame to the earthing strip, but as these may be as little as half an inch or less apart, what is the difference between doing that, rather than connecting the two earthing wires directly together? Or connecting the control box to the frame, as I do now?

Have I missed something here?

............Mike

[gerald_d]

Three ways of connecting 3 items to ground - first two are good, the last has a ground loop:


3221

A ground loop is a closed ring in which current can circulate. (The sketches above should have shown only one connection point on each component)

Here is a down-to-earth article:

http://sound.westhost.com/earthing.htm

[richards]

Circuit ground vs Chassis ground is usually completely different from ground loops. The ground loop problem is usually defined as the voltage potential caused when two 'grounds' have a resistance between them, which would cause a voltage higher than ground potential to exist, which could cause someone to be shocked if he/she touched the metal frame of a machine. (As a side story, ground loops were common in the dairy industry when I was a boy. Our area was just being electrified and the farmers were finally getting electrical milking machines. It was common for the cows to get a 'tingle' on their legs or belly when the metal of the milking machine was slid onto the harness. The cow would normally be standing on a wet cement floor and the 'tingle' was severe enough to cause the cow to not be able to give milk. I remember well the instructions to use rubberised harnesses and the warning to not let metal touch the cow. The farmers usually wore rubber boots, so they weren't shocked. Those early machines were quickly replaced with machines that worked on a vacuum so that no electricity was used in the milking area.)

Chassis ground is typically used to connect all touchable metal to a common ground point to protect the operator in case of electrical malfunction. Chassis ground is also typcially associated with line voltage coming directly from the breaker panel.

Circuit ground is the ground reference point for control circuits within the process control computer. The control circuits are usually isolated from line voltages with transformers and opto-isolators. Using a common ground defeats the opto-isolators. In addition, any 'problem' with the high voltage/high current supply lines would be transferred into the control circuits if the grounds are connected. It's also important to NOT connect the various circuit grounds together if one circuit is on one side of an opto-isolator and another circuit is on the other side of the opto-isolator. It's been common practice in the process control industry to use modules such as the Opto-22 G4 series of opto-isolators to conect the outside world to a computer circuit. One side of the G4 had it's own 5 -12vdc voltage supply. The other side of the G4 used the computer's 5vdc supply. The grounds on both supplies were isolated from each other and neither was connected to the chassis ground.