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MrBean
09-26-2004, 06:04 AM
Hi. I've got to the stage now where I need to start wiring for home / limit switches. Would it be normal on the Z axis to have the home switch at the highest point of travel, and machine zero at the lowest point (the cutting table)?

How do you guys set up the Z axis?

Also, can I wire the limits and e-stop to the same input pin (10)? I'm using the demo version of Mach2 for testing, as it seems quite popular. It looks very comprehensive so far.

Will post some pics when my camera batteries have charged.

Thanks for any help.....

kong
09-26-2004, 08:00 AM
I have my Z-home at the top of travel as you suggested, but also a limit at the top and bottom of the travel (Home is hit about 1mm before the limit). I set Z=0 for each new workpiece, at the top of the workpiece. The only time I use home is to get the axis out of the way when I finnished a program. Since I don't use precision switches, using home as a reference point can be quite hit and miss!
As for Mach2, I believe there is a setting in there somewhere to use the limits as home switches, meaning you don't need the two-switch setup I have. You should double check the manual forst though:)

MrBean
09-26-2004, 08:05 AM
I'm finding the Mach2 docs pretty tough going. There's so much stuff to set up. I'm not too sure which parts are relevent to me and which are not. It's all new to me.

BTW. Wasn't it you that had your computer featured in Custom PC a while back?

MrBean
09-26-2004, 10:37 AM
The camera batteries are charged so here's a few pics. One of the overall set up as it is at the minute, and one of the Z axis.


If the top of the work piece is manually set as machine zero for each job, does that mean when you create your solid model, the top of the model has to be on Z=0 and all depth cuts will be negative values. e.g. Below the normal ground plane. Or is there some kind of off-set value to account for this.

I don't know if I explained that too good, hopefully someone will know what I mean.

kong
09-26-2004, 12:55 PM
Section 4.6 in the Mach2 docs goes over limits and home switches. Yup, it is one confusing document, so I only read the sections I need to! And yes, I won the readers drives competition in the magazine, and got a £1000 pc from pc-world as a prize :)
As for z=0, I think you have it. Although I do not use a solid model to create g-code, when converting a dxf to g-code in Mach2, you can set the Z value the router will cut at. Therefore, I will manually setup z=0 at the top of the stock, then set the "z-cut coord" in Mach2 as a negative number to get my depth of cut. Hope this helps.