Editing the Z-Zero command

[phil_o]

I am running the SB control software ver. 3.5.1 I would like to edit the C2 command. In particular I want to change the final Z setting. After the zeroing routine is complete the Z goes to 1.000 inch above the zero for the material. When I am cutting thick material there often is not an inch left for the router to rise up and the carriage hits the frame.
How do I edit the C2 command?

Phil

[jerry_stanek]

open your shopbot software and under tools go to set up and you can input a different z safe pull up

[dana_swift]

Phil, most likely you have a parameter set wrong somewhere, as this should run bulletproof "as delivered".

However you can edit the C2 command itself by going to the sbparts\Custom folder and look at the contents of custom2.sbc. That is a text file so it can be edited with any text editor such as NotePad. (Do not edit these with a word processor!)

That file can either contain the logic for doing the zeroing, or point at another file that does. If it points to another file.. you can edit that one and change any part of how zeroing is done on your bot.

At first this seems daunting, but its not too bad. Read and study before changing anything. The haze clears pretty quickly. Be sure to save the original files so you can remove your "improvements" when things are not what you expected.

Test any changes you make completely before using your new code in production. Also save a copy of your new file in another directory, if you reload SB3 it may over-write your customized routine.

The documentation for SB3 control language is found in the folder:
C:\Program Files\ShopBot\Developer Tools (on my computer)
The specific file is:
ProgHand.pdf

Read that file, it explains all this.

Customizing the zeroing routines makes a world of sense when you understand how to change the generic routines with ones setup for what you want the machine to do. You can get rid of unnecessary question/answer sessions etc.

Hope that helps-

D

[bleeth]

The machine safe z height can also be adjusted in the "cutter" tab at the bottom left of the control panel.

[phil_o]

Thank you gentlemen.

Phil

[knight_toolworks]

I have had to do this many time when I don't have 1" left of room to raise the bit.

[phil_o]

Dave, if I use the Cutter tab to set the Safe Z is that the Z value that the Bot will wind up at upon completion of the Z-Zero routine?

Thanks,

Phil

[bleeth]

Should do.

[srwtlc]

Phil,

It depends on what version of SB3 you have installed and or if you are using a previously modified zzero file.

Up until recently, the zzero file utilized a safe z setting in the "my_variables.sbc" file that is set by running "Setup" under the Tools menu or changing it manually. Now, the zzero file reads the system variable %28 which is set with the cutter tab.

[phil_o]

I'm trying to figure out how to make the change in the final Z setting in the Zzero.sbp file. I've pasted in the portion of the file that refers to "Pull-up to safe height" I can't figure out where I need to set that variable. Is it in the My-variables file?

Phil

CONTACT2:
'This is our subroutine for action on hitting the plate the second time
'We hit the plate !
ON INP(&my_ZzeroInput,1) 'First set switch to nothing to prevent secondary trigger
VA,,,&zbot,,,,,0 'Set final Z location and Zero Table Base Coordinate
PAUSE 1
VS, ,&start_Zmove_Speed
MZ, &zup 'Pull-up to safe height
PAUSE 1
END

TEST_CLEAR:
&cleared = &my_ZzeroInput + 50
IF %(&cleared) = 1 THEN PAUSE 3
IF %(&cleared) = 1 THEN GOTO NO_CLEAR

[t_vandemark]

Phil, I ran into the same problem not that long ago. What you are looking for is in the "My Variables" file. I ended up setting my safe Z height to .25" and it worked perfect.

[phil_o]

Thanks Tyler - that helps.

Phil

[phil_o]

I found a better way. In the Shopbot Console, under Tools I went to Shopbot Setup and entered the values I wanted. This is where the My_ Variables is created.

Phil

[CNCDave]

Ok all you Z-Experts, here's one for ya:

Great thread -- thank you kindly. I followed the directions and figured I had it made in the shade.

Context:
ShopBot Desktop with Porter Cable Model 890 Router with magnetic dust shield, zeroing Z-axis with Z-Zeroing plate.

Problem:
When I use my Z-Zeroing plate, I take off the dust shield (the little magnetic one that attaches to the bottom of the router, not the big honker that surrounds the entire router) so I can see the bit to easily connect/disconnect the jumper cable (it's a bit large for me to call it an "alligator clip").

When I go to put the magnetic dust shield back on with the default of 1" of "safe z-height", I can barely squeeze the brushes enough to get the dust shield between the bottom of the bit and the work piece, usually scraping the top of the shield across the bit and wondering aloud why the default doesn't take the dust shield into account.

I followed the above instructions and changed it to 2" using the [T]ools [S]hopbot setup utility. Dang if that didn't solve it like a champ. Thank you to all who contributed -- you are Gentlepersons and Scholars.


But.

Then I put a thicker work piece under the router for zeroing. Yes, it was thick enough that when zeroed, it was closer than 2" to the top of the Z-axis upper limit. When I ran that, I got that lovely sound of gears grinding and me practicing my cursing in the specific direction of the ShopBot.


Question:
Is there a command that I can run after zeroing that will raise the router up as high as it can go without grinding it past the stops -- kinda like when I do the C3 command to zero X and Y using the proximity switches? (Am I being naive to ass-u-me that there is a proximity switch for Z?)

Thanks,
Dave

[Joe Porter]

Check your final Z clearance when you set up your toolpath for that particular job. I am talking about in PartWorks of V-Carve. The final Z clearance will be from the top of your material. The thicker the material, the higher your Z. You must adjust for each job. joe

[dana_swift]

Re-computing the maximum z height for each cutting operation is an inefficient way to do things. Much better idea: add a maximum Z prox switch. Let the machine figure it out. Then if you change the thickness of the stock you are working with, you dont have to recompute the toolpath. Just run the file. Change nothing.

Here is a series of posts where I show what I did. Works wonderfully.. Problem GONE.

http://www.talkshopbot.com/forum/showpost.php?p=131007&postcount=7

Read the series of posts I did, as each one adds more info, like the command to seek the prox switch, and where to get the parts.

Adding a max Z prox switch is easy to do, use the shopbot to make a mounting plate that works for your machine. Cost is very nominal, benefit is huge.

Each time the machine seeks max-z, the Z readout on the SB3 program is showing me how much air there is below the bit, and how much is available in any given setup. Its automatic. It corrects itself for whatever bit is installed at the moment, how deeply its nested in the collet, and the material thickness.

D

[CNCDave]

Thank you Dana. What was your source for a prox switch?

[myxpykalix]

Dave,
If you ever get down to Charlottesville look me up.:D

[CNCDave]

@Jack: I do get down that way periodically, I'll ping you next time I head out.
- Dave