Locating 0,0

[jay_mack1@hotmail.com]

How does a shopbot line up the 0,0 of the x and Y coordinates?

[gerald_d]

It doesn't normally do it by itself. Normally you move the SB to any point that you want to, and then you tell it that it is at 0,0. This point can be anywhere on the table.

There is a optional system by which you can add sensor switches to let the SB sense when it is at a particular point

[jay_mack1@hotmail.com]

Gerald,

is this optional system the (proximity switch) system offered in the accessories...

Jay

[gerald_d]

Yes, for the x,y axes and the z-zero plate for the z axis.

[jay_mack1@hotmail.com]

Gerald,

Do you use the proximity switches?

[gerald_d]

No

[jay_mack1@hotmail.com]

Does anyone use the proximity switches and doesn't feel they need them or the opposite, they have them and use them heavily

[paul]

Hi Stickman

The principle of CNC is automation, why try and guess the 0,0 position when with 2 taps of the keyboard the proximity switches will give you 0,0 with 100% accuracy every time.

Best wishes

Paul

[kfitzgerald@graphicmetalsinc.com]

Paul is spot-on. I don't know how I could work accurately without the proximity switches.

Regards,

Kevin Fitz-Gerald

Project Manager
Graphic Metals, Inc.
P.O. Box 31
715 E. Perry Street
Bryan, OH 43506
USA

V 419-636-5757
F 419-636-6404
kfitzgerald@graphicmetalsinc.com (mailto:kfitzgerald@graphicmetalsinc.com)

CNC laser cutting up to 11 ga. steel
CNC routing wood and plastic

[waynelocke]

I use them all the time. After bumping into a clamp or something and loosing your settings, it's good to know that, after the obscenity, releif is just a couple of keystrokes away. I work mostly in the middle of the table and also with an indexer. After zeroing, I can always move to the same point and rezero.
Wayne Locke

[ron_cleaver]

I lived without the proximity switches for sometime while I got used to the ShopBot. After that experience, wild horses couldn't drag them from my cold, dead hands!

[gerald_d]

If I wanted the ShopBot to tell me where to place the workpiece on the table, I would use the prox. switches. In my shop, I am the boss, and I tell my ShopBot where I have placed the workpiece. Simple matter of asserting authority.

[bjwat@comcast.net]

LOL!

That's right.

"You're not losing steps on my watch buddy! Know your ROLE!"

:D

[jschuman@hvc.rr.com]

As a ShopBot newbie, allow me to relate that the only SopBot keyboard command that has come to me in a dream is "C3"! I can't imagine having built the 'Bot without prox switches.

[bruce_clark]

Gerald,

I use to agree with your position until I had things like loose pieces of wood pop up and jam the machine during the middle of a cut. By having a known reference (0,0) point on the machine, you can restart the cutting after "homing" the machine and have confidence that the finished parts will be cut in the correct position on the work blank.

Bruce

[gerald_d]

I prefer to make sure that loose pieces of wood don't pop up.

[graphicmetals]

You just like livin' on the edge Gerald ;-)

[gerald_d]

Yeah, on the bottom edge of the African continent


Seriously though, we have an open mind to using a fixed refence point and could easily wire in a proxy if required. (We use proxy switches in the mechanical equipment that I build, and they are always in stock here - albeit 3/4" 24V models). However, we use the whole table area, even for small jobs (bread-slicers, remember?) and it would be a pain to jog all the way back to to a fixed 0,0 corner. Movable proxies would be more interesting than a fixed point, but, if we did pick a fixed point, I would like that to be in the center of the table, and fixed proxies won't give the center position.

Tape-measures glued to the rails, with a good cursor line and magnifying glass, will probably happen long before proxies in our shop. After that we might go to digital readout scales, but, by that time, ShopBot would be using the feedback DRO scales as standard equipment.

[jay_mack1@hotmail.com]

The more that I learn about this, the more excited I get learning about all this. I think the proxies would be great to have... can't you program it to use the proxies to find your center. That would be simple geometry. How many switches come with the kit. Two?

[rgbrown@itexas.net]

StickMan,

I consider Proximity switches a necessity. The kits I have seen have two.

One can inagine and use a lot of things with the "ShopBot". I think one could use small magnets to trip proximity switches anywhere they wanted them "tripped". An automatic "middle zero" routine could be written where one could get the register point near where they wanted it and the the Bot would save the numbers. It would be great for working details in a small area that had multiple bit changes.

[srwtlc]

I thought about getting the prox switches after I bought my Bot, but to get started I made my own corner block that I place wherever I want and run a modified x,y zero file of the zzero file that comes with the software. It's just an aluminum angle screwed to a block of wood. I hook it up just the same as the z zero plate. I place the block where I want x,y zero to be, put in a broken off 1/4'" bit, position the tool close and run the file. It touches off the x first then the y and it's set. I realize that it may take a little more effort, but it works anywhere on the table.

Scott

[gerald_d]

Scott's method beats fixed proximity switches.

[rgbrown@itexas.net]

I think some of this is determined by how each of us uses his/her/its machine. I have some production Jigs with register plates on them. These plates are made to contact the shaft of the router-bit above the cutting edge. On some I have a "Z" plate also. These register plates allow me to reset the X, Y, and Z azis near the part.

On reflection, I think I have spent more time building register plates than I have saved by not registering my machine "2-Axis" near "0,0".

One of the nice things about America is we can do things our own way. We are all allowed to make our own mistakes and if we care to, repeat others mistakes. In fact our government requires us to participate in some mistakes.

Ron

[gerald_d]

Yeah, your government even requires us to participate in some mistakes.

(Moderators can delete this post if they think I have been serious at all)

[beacon14]

I use a somewhat similar approach to Scott. My Z-zero plate is a length of 1/8" x 3/4" aluminum bar stock with a wire bolted to one end, so I can use it anywhere on the table. I also use it vertically against a jig or fence to set the x and y locations, whether they be 0 or 62.25 or whatever.
A slight modification to the z-zero routine gives me x-zero, y-zero (or any other location), adjusted for the diameter of the bit I'm using.
It also makes it easy to put a jig down on the table, since I can put it anywhere and let the ?-zero routine tell the 'Bot where the fence is, and go from there

[kerrazy]

The machine has a nice built in measuring system, that I use all the time, especially if i do 2D offsets.

Once you have your material placed where you want it just zero it to your origin of the material, and than you can use J2 or M2 to move the machine to the co-ordinates you desire and run your file using the 2d offset. It works like a charm and you have not lost your orignal home position.

I too have prox switches and am sure you can add a routine to the program to move to the middle of your table rather than the lower left corner.

I am constantly using the 2D offset feature when i run several pieces with multiple bit changes of the same item. I just load up my table with blanks. Home to the first blank, run the part file. I then move to the next origin point on the next blank, and rezero my z then reeun the part file selecting the 2d offset feature and Bob's your uncle. I do make sure I wright the co-ordinates of each piece right on the blank so there is no confusion. This way if I miss a step for some reason I caneasily reset and carry on.
Dale

[garbob]

I just can't restrain myself from putting in my low tech opinion, specifically for a zero z axis plate. I went through a bin of square electrical junction box covers and found a perfectly flat one for $0.22 CDN. Big bucks! I'm a terrible solderer but I finally managed to solder the lead from the controller to the plate and then siliconed the leading edge to the top of the plate. Now when I zero the axis there is really no aiming of the bit involved, I just throw the plate near the head on the table and guess the coords. or use the K command to zoom over the plate and run the z zero command which uses the plate thickness of exactly 1/16" (0.0625). Tada, I'm done. I just can't imagine having to line up the bit up over these skinny bars you guys use!

[beacon14]

Gary;

It's the other way around - wherever the bit happens to be, I slide the "skinny" bar under it (usually the dust skirt gives me a nice bit of tension to hold the bar in place) and hit "C3", which is my shortcut for the z-zero program.
The wire which is attached to the bar runs along with the other wires to the z axis, and there is a holster for the bar on the vertical strut of the z axis, so wherever the tool is, so is the bar.
It's that easy.

[gerald_d]

The size of the plate is not as big an issue as the weight of it being able to resist the strain of the wire trying to move it around. A telephone handset "curly" cable works great.

[jay_mack1@hotmail.com]

THANK YOU

I started this string, so I thought I would add this message to the end of it. After sic months of looking, talking and discussing with all of you. My shopbot is on the floor at ShopBot Tools.

Gerald D... ...Thank You
Dale Kerr... ...Thank You
Ron Brown... ...Thank You
Kevin Fitz... ...Thank You
Brady Watson... ...Thank You

All the others... ...Thank You.

I am looking forward to the deliver, set-up and my first few projects. I hope with my AutoCAD programming experience and my drafting talent as well as my artistic feel, I'll be able to give a little back to you. You have given me so much information, advice and help with my decisions. Thank You.

I hope to make some more great relationships with this venture as well as help the next little guy up the steps.

When I get up and running, I am sure I'll have a few things to ask and a few to add back into the group.

If anyone is interested in starting a yahoo group, in order to place pictures. Or if the "Let's Talk ShopBot" forum wants to add a file storage place we can upload pictures to. So that everyone has a place to look. I feel and still like getting pictures from everyone. It helps to see how things are put together or how things work. Just a side note.

THANKS!