X, Y, and Z zeroing routine

[Gary Campbell]

joecnc...
It is not neccessary to add an 1/8 plate to the bottom, unless you want to. You do need to enter the proper thickness for whatever material you use.

Joe J...
If you are asking about my corner jig, the aluminum block is screwed to a plexi plate, which in the video is held by vacuum. I have tried just setting loose, but have not had the best luck with that method.
Gary

[gundog]

I like using a laser edge finder a couple minutes and I am zeroed anywhere on the table. I use the factory supplied jig to set the z. I cut plastic most of the time and the material is not very square so using a small jig in a corner tends to not lay the material out very good for me. I can adjust the move commands to move slowly then in SK mode with the laser edge finder chucked into the spindle locate the edge and zero that axis I can make the edge finder travel up and down the material to get the best alignment for the material (that is not square)

I also use the laser edge finder to find zero when machining both sides of one sheet. For machining 2 sides I pick a couple spots in the waste material and drill a 1/8” hole. The holes you drill will be in the same position relative to the other parts. I save the file in a mirrored copy and record the position of those holes when the sheet is flipped. I screw in a small screw so you have an x in the middle of the hole with the laser edge finder in the spindle send the machine to the coordinates of that hole move the material to match do this for 2 or 3 holes you now have the machine setup to machine the other side.
The edge finder finds duty on other machines in my shop like my mill for tramming in the vise or finding marked holes on material in the mill or drill press. I use it for my lathe for setting the tail stock.

Mike

[sagreen83]

Thought I would post a video of my XYZ zero jig in action. I made the base on my Bridgeport and the center tube was made on my metal lathe.

http://www.youtube.com/watch?v=tXSaSZ3ZchY

Thanks to everyone for their work in making these things happen!

Scott...

[Ted D]

Very cool. I came to this forum to ask about making a zero plate (I just bought an older machine and it doesn't have one) but obviously this is even better. The only thing I'm not completely clear on is the wiring. I'm assuming the wire from the copper cup goes to the zero plate input connection in the control box, but what are the other wires I see in the pictures doing? TIA

[Ted D]

Never mind. I learned that with a router you sometimes have to ground the bit directly because you don't get a good connection through the brushes. Simple enough.

[j_richardson]

Dusting off this thread while I try to get some clarity on the topic of x, y zeroing.
Let's say I make a prototype part on the bot, and then shut down the machine. A few days later, we want to modify the prototype (maybe cut a little more material off), so if I have pinned the part, I can relocate it in the same spot on the table from the first time, but since the machine was shut down, the x and y will be off a little on restart (the z I can re-zero with the z plate routine). What is the preferred method to set up the x and y again? Use the limit stops? I think I saw that there is a routine to do that (?). Or is it better/easier to use one of the machined jigs like Scott Green's that could either be permanently mounted in the corner or pinned so that it can be remounted when needed?

After locating the xy I would have to offset to where the part is located (if for instance it was at xy 10,10 on the table) and rezero at that point to do the new machining.

[curtiss]

Is your C3 command working ? (type C3)

It should z the x/y axis in relation to the prox switches.

With that said, I do not think the xy can move much over a few days unless you bump it.

[j_richardson]

I tried the C3 command and the carriage passed the limit switches and crashed against the end stops. I think the switches work, because if I jog the carriage, it will stop at the limits, and the light on the switch goes out. Is there such a thing as a bug in the C3 program?

[beacon14]

No the C3 program is well-tested but it is looking for your prox switches to be on certain input switches and either normally open or normally closed.

Open up the SBParts/xyzero.sbp file and look for the block of code that looks like this:

[CODE]Check_PRT:
&TrgtHIT = 1
&Xtrgt = 3
&Ytrgt = 3
IF %(53) = 1 THEN GOTO Getoffprox
GOTO Start_Zeroing
Check_PRS:
&TrgtHIT = 0
&Xtrgt = 2
&Ytrgt = 3[/CODE]check the first or second paragraph depending on whether you have a PRT or PRS. The &xtrgt and &ytrgt should be equal to the input switch number for each axis. If those are correct then the switch type might be reversed from what is expected.

[backyard_cnc]

Hi All,
At the start of this thread the originator Barry posted links to his XYZ zero jig and shopbot routine. I have made a jig from a milled block of aluminium but would like to modify the routine so that the Z zero is set at another spot on the jig (1.5,1.5) other than at the 0,0 or center of the cup. I wonder can anybody either share a routine that can do this or tell me what to look for in modifying the routine that Barry has posted.

Appreciate all comments. I am a newcomer to SHOPBOT so have much to learn!

Gerald
2004 PRT96