JCDammeyer's 42 projects

[Dan Dubeau]

FWIW - the tool table in PathPilot is the tool length referenced from the spindle nose (positive #). So a small endmill and holder is say 50mm tool length and a large drill chuck and 12mm drill is 180mm tool length. And Pathpilot recommends you to reference the spindle nose before doing any tool length measurements. If there's any files or other stuff that you want I can have a look at them in Pathpilot and make a copy for you to have a look.

That's always been my gripe with how pathpilot works. I don't, and have never set tools that way out in the wild. The only shops that have ever set tools that way have had huge tool storage carousels and automatic setters with probing. I prefer to touch off on the bed of the vise, and adjust my g54 Z to wherever my z0 is for the part i'm machining. In path pilot, you have to make sure that the z value in the tool table is 0, otherwise it will ADD that # to your tool length when you touch off. Such a PITA. In Haas controls you can turn that feature off, but so far I have not found that option in pathpilot. I always have to make sure to zero out my work coordinate Z before bringing new tools to the party. Otherwise, I really like the path pilot control.

 

[David]

This is not germane to LinucCNC but Masso has very specific instructions for calibrating 3D probe length when using a tool setter. Maybe something in here is a clue to the issue?

Measure Touch probe length

docs.masso.com.au

 

[jcdammeyer]

This is of course expensive and most of us sneak up to this cost and in my case I use Chinese TTS holders that do not have the groove for automatic tool changers. Some of my brand name TTS don't have that either.

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But the key here is the granite surface plate with the TTS hole and the height measurement gauge. When you install a new cutter into a TTS holder you slip it into the hole, measure the value, enter that length into the tool table, save and reload the tool table.

I think depending on the job and maybe the tool rack beside the mill has a spot for 8 tools you'd number #1 to #8. Starting a project that may require the 8 tools and 20 pieces then requires a tool table that has all the parts. And the CAM software ahead of time needs to also know what tool number and diameter is required for the operation. So there's planning and forethought for all of this.

There can be some standard tool numbers of course. I have #1 to be a spotting drill held in a collet holder. TTS #5 is the 1/4" drill bit in this case for the pilot hole and then there's the new 3/8" holder from Little Machine Shop which does have the groove and the taper for the ATC. The #5 holder has a zero length in the tool table so it uses the tool setter to determine tool height.

And there's the rub. Nowadays with CNC why bother with the surface plate to measure. Especially if you have to swap 3 different drill bits to get up to 7/8" for example. Again the tool setter is pretty handy even if it's in the way all the time.

And that becomes the real decision. Maybe you have a tool setter but what is clamped onto the table precludes the use of the tool setter. So you have to measure tools and fill in the table.

 

[jcdammeyer]

This is not germane to LinucCNC but Masso has very specific instructions for calibrating 3D probe length when using a tool setter. Maybe something in here is a clue to the issue?

Measure Touch probe length

docs.masso.com.au

If your tool setter requires 200gms of pressure and moves 2mm to make the contact switch while your touch probe requires 100gms and moves 0.5mm it's really hard to measure the length of the touch probe with the tool setter.

 

[David]

If your tool setter requires 200gms of pressure and moves 2mm to make the contact switch while your touch probe requires 100gms and moves 0.5mm it's really hard to measure the length of the touch probe with the tool setter.

Totally agree. I'm going to use a touch off plate to measure mine.

 

[jcdammeyer]

Totally agree. I'm going to use a touch off plate to measure mine.

Careful. Your touch plate will make an electrical contact to let you know it's seeing the probe and your Z axis will tell you the probe is x.xx mm long. Doesn't help if the head has to move down another .2mm before it trips unless you record both values and subtract the additional motion from the first reading. And even then how do you know your probe didn't move 0.1mm when it made contact with the touch plate?

 

[whydontu]

Forgive my ignorance of all things formal-CNC. My CNC engravers run on GRBL controllers, and a CAM/CNC program called Estlcam. When I place a metallic workpiece on the platen, I then install my chosen cutter and run a surface scan. (Quick-n-dirty, the workpiece is grounded, the cutter is electrically isolated from ground and is connected to one input pin on the GRBL controller). Surface scan sequentially contacts the workpiece and develops a surface map, Estlcam cutter position is automatically adjusted to compensate for any taper or irregularities in the workplace or platen. Is this type of control not available in more sophisticated systems?

I've thought about using a tool setter, but it just seems counter-intuitive that the tool setter isn't a fixed known height.

 

[jcdammeyer]

Forgive my ignorance of all things formal-CNC. My CNC engravers run on GRBL controllers, and a CAM/CNC program called Estlcam. When I place a metallic workpiece on the platen, I then install my chosen cutter and run a surface scan. (Quick-n-dirty, the workpiece is grounded, the cutter is electrically isolated from ground and is connected to one input pin on the GRBL controller). Surface scan sequentially contacts the workpiece and develops a surface map, Estlcam cutter position is automatically adjusted to compensate for any taper or irregularities in the workplace or platen. Is this type of control not available in more sophisticated systems?

I've thought about using a tool setter, but it just seems counter-intuitive that the tool setter isn't a fixed known height.

I use a PC board with a clip lead to the router bit. The piece is laid on top of the part I want to carve and the MACH3 code I wrote subtracts the thickness of the PCB from the Z value.

The whole point of TTS holders or the more expensive type used on HAAS etc is that you measure once, cut many times. As opposed to measure cut, measure cut, measure cut...

The tool setter height is known and in a fixed position. The registration surface of the tool holder is also known as is the Z axis position. With the correct math and parameters it doesn't matter where the work is the tool can be loaded, length measured and then a compensation parameter determined that is adjusted to work piece 0. That's usually determined with a probe of some sort like a touch plate (for my router) or a probe like what @David also has.

 

[David]

Careful. Your touch plate will make an electrical contact to let you know it's seeing the probe and your Z axis will tell you the probe is x.xx mm long. Doesn't help if the head has to move down another .2mm before it trips unless you record both values and subtract the additional motion from the first reading. And even then how do you know your probe didn't move 0.1mm when it made contact with the touch plate?

The Masso instructions have you reassign the probe input to be the touch plate so what the touch plate is doing is just being a reference surface.

 

[Arbutus]

So maybe I'm missing something, but there shouldn't be any mystery here.
I do not have a TTS type system, just collets - that means that every tool change needs to be measured against a reference.

The procedure uses an electrical touch plate, exactly 1.5mm thick connected to the probe input. That thickness is an offset which is added to head position. i.e the head position is now measured at 1.5mm above the datum. I also have a fixed position tool height setter which is also an electrical contact area mounted on the mill bed.

I start with "Tool Zero" - which is a piece of brass, 3/8 dia x 3" long - this is used to set the Z reference height when measuring the workpiece offsets. I use M6 T0 to begin the procedure.

Tool Zero is then used to touch off the work with the 1.5mm touch plate. Now I know where G54 is.

Now I mount a cutter in the collet. There is no collar to reference with, unlike the TTS system so the procedure simply compares the new tool with Tool Zero and the difference is the tool height offset. I mount the cutter or drill, then run M6 T32 . That measures Tool #32 cutter length by touching off on the tool set height gauge. The offset is the difference between Tool Zero and the current cutter length.

The tip of the tool is now at work Z=0 and the job will proceed.

"if in doubt, draw it out"

 

[David]

So maybe I'm missing something, but there shouldn't be any mystery here.
I do not have a TTS type system, just collets - that means that every tool change needs to be measured against a reference.

The procedure uses an electrical touch plate, exactly 1.5mm thick connected to the probe input. That thickness is an offset which is added to head position. i.e the head position is now measured at 1.5mm above the datum. I also have a fixed position tool height setter which is also an electrical contact area mounted on the mill bed.

I start with "Tool Zero" - which is a piece of brass, 3/8 dia x 3" long - this is used to set the Z reference height when measuring the workpiece offsets. I use M6 T0 to begin the procedure.

Tool Zero is then used to touch off the work with the 1.5mm touch plate. Now I know where G54 is.

Now I mount a cutter in the collet. There is no collar to reference with, unlike the TTS system so the procedure simply compares the new tool with Tool Zero and the difference is the tool height offset. I mount the cutter or drill, then run M6 T32 . That measures Tool #32 cutter length by touching off on the tool set height gauge. The offset is the difference between Tool Zero and the current cutter length.

The tip of the tool is now at work Z=0 and the job will proceed.

"if in doubt, draw it out"

That's basically what I do as well, no TTS holders either. The only difference is that I plan to use a 3D probe to establish X, Y and Z for my G54. The 3D probe will become my reference tool.

 

[jcdammeyer]

That's basically what I do as well, no TTS holders either. The only difference is that I plan to use a 3D probe to establish X, Y and Z for my G54. The 3D probe will become my reference tool.

The TTS just makes things faster and easier. And if you want an auto tool changer way more convenient.

 

[jcdammeyer]

The TTS just makes things faster and easier. And if you want an auto tool changer way more convenient.

I use my probe for that too. And the center of circles or squares or corners etc.

My M6 command is remapped (not with the above screen) but with a different G-Code 'm6remap.ngc' from Alkabal. The original screen used the prolog.ngc and epilog.ngc with the psng_manual_change.ngc doing the grunt of the work.
# Alkabal Version
REMAP=M6 modalgroup=6 ngc=m6remap
# Original Version
# REMAP=M6 modalgroup=6 prolog=change_prolog ngc=psng_manual_change epilog=change_epilog
# ---- PSNG end ---- #

So I can customize my tool changes. I have done something wrong and my measurements are wrong at one point and I don't know what I did.