[webgeek]

Ok, so I have Mach 3 set up with the tool length measurements for all my common tools in repeatable Tormach holders. These have all been measured from the face of the spindle. I have the g-code post processor set up to look like this "TXXX M2 G43 H2" where XXX is the tool number every time a tool change is exported.

Now the stupid question - how do I properly tell mach 3 what the surface of the part is?

I don't have a dedicated set up tool currently. I broke it by driving it into the table about 30 minutes ago and am still kicking myself over that stupidity. I assume I can make one of my drill bits that. If I do pick a dedicated tool, do all the lengths in the tool table become an offset from the length of that tool? IE: shorter tools are a positive distance and longer tools are a negative?

Also, assuming I do all that, how do I properly orient Mach 3? There is a touch off tab but that doesn't seem quite right to me.

Thanks for all the help, it seems this is obvious but I'm just not quite getting it!

-Mike

[hoss2006]

You should find a new dedicated tool for tool one as all the offsets are relative to tool one.
A regular tool can be used but will have to be recalibrated again if the length changes if you have to replace it.
You have to zero tool one on the part to set the origin even if you don't need it to make the part.
Hoss

[cyclestart]

Just in case you haven't seen them,

Tormach has videos on this topic on their YouTube channel
YouTube - tormachllc's Channel

The dial indicator in a TTS holder makes a nice reference tool but anything in a holder should work in a pinch ?

Warning: I haven't tried the method in the video using Mach.

[webgeek]

Their video doesn't do any offsets - they just set the length of every tool into the tool table. They also use a customized version of Mach 3 so even after watching their video I was a little confused.

-Mike

[SCzEngrgGroup]

Make yourself a reference tool, which is simply a fixed holder (I use a spare endmill holder) with a length of steel rod in it, that is longer than your longest tool, and zero its offset in the tool table. ANY tool number can serve as the reference tool, depending on how your macros are setup. I use tool #253 for mine. Mount the reference tool, leave tool length comp off (G49), then touch it off on your workpiece, and zero the Z DRO. Now you can mount, and touch-off your next tool, and the DRO reading will give you the correct tool table offset.

When it comes time to start your job, you can set the Z offset using ANY tool in the tool table. Mount the tool (M6), ensuring it is well above the work. Then turn on tool length comp (G43), then touch off to the workpiece and zero the DRO.

BTW - You're going to get 20 different answers to your questions. There are MANY ways of doing this, and which is best depends on how you work, and what macros you're using.

Regards,
Ray L.

[cyclestart]

BTW - You're going to get 20 different answers to your questions. There are MANY ways of doing this, and which is best depends on how you work, and what macros you're using.

So true ! The Tormach method is slick and encourages the purchase of dedicated TTS holders. These 2 things are not likely to be a coincidence

webgeek
OOPS, I'm not a Mach3 user so wasn't aware Tormach's version is not standard. The work offsets are set in part 3 of the video at around the 6 minute mark. Not much use if your software has different features.

Cnc Cookbook has an entry on this topic. Maybe it helps in some way ?
CNC Cookbook: Tool Length Offsets and Tool Data Management Part 1