Using a probe as a reference tool

[swissi]

My post is to clarify the required changes when going from using a master tool to probe - I am using Swissi's probe App.

I currently use T1 as my reference tool - it's a 4" 3/8 rod in a CAT40 holder. Knowing that my touch off tool is 1.451" at contact, I would change Parameter 3 to 6, set up gage blocks to 1.451 - touch off the probe to establish it's length. T1 had been set up as the longest tool, as of now my probe is considerably shorter, although I could move it to a CAT40 tool with longer offset.
- Is the the probe going to become T1? -I currently have the probe as T14
- When Probe App asks to re-establish the offset for the reference tool I assume I will still use the the gage blocks.

My goal would be to use the probe to establish the top of the stock, currently it is only used for X0 Y0
Based on the Parameter 3 change to 6, making Z home my reference, are there other changes that causes anything that I should be aware of?
I will go measure tool lengths as before - I would expect them not to change when re-measured. (EDIT)

Looking at the pictures of your machine, you do have a knee mill. Unless you lock down the machine table and never move it up or down, you should NOT use the Fix Z-Home Method. I wrote the ProbeApp to take the confusion out of Tool Height Offset setting and I tried to make it as fool-proof as possible so let's go trough the steps and you let me know which of these steps is unclear so I can improve it.

Process to Configuring Tool Height Offset with the ProbeApp:

• Open the ProbeApp and go to the Tool Library Manager

• If this is the first time the Tool Library Manager has been opened, the Guided Setup will automatically open. If a Configuration has been saved before, press the Gear Icon on the bottom left of the Tool Library screen. On the Configuration screen that will open, press the Guided Setup Button.

• Go trough the Guided Setup screens:

• After pressing the Finish button, the Configuration page will open with the Tool Height Offset Method selected that should be used based on the selections made in the Guided Setup:

• Complete the other Configuration Parameters (for a more detailed Parameter Description consult the ProbeApp User Guide):
  • 1) For a Knee Mill the Reference Tool Method should be used
  • 2) The ProbeApp always uses the configured Tool Height Offset Method so the value of the CNC12 Parameter 3 does have absolutely no impact on the ProbeApp. Note that the CNC12 Parameter 3 is a 3-Bit Parameter that configures 3 separate things at once. If you use the ProbeApp to set the Tool Height Offsets, you only need to change the Parameter 3 Value if you want to change the CNC12 behavior configured with Bit-0 and/or Bit-2 of Parameter 3. My recommendation for the Reference Tool Height Offset Method is to use a Parameter 3 Value of 0 or 4
  • 3) Select what Reference Tool you are using. Options are the Touch Probe, a Tool from the Tool Library or a designated Tool that's not in the Tool Library. The designated Tool can also be the bottom of the empty spindle for example.'
  • 4) If you are always measuring Tool Heights at a fix location, enter the machine coordinates of this position here. Note that this can be a fix Tool Setter (TT) or a movable TT placed at a fix location or if no TT (fix or movable) has been selected in the Guided Setup, this can be a manual touch off with a block, on top of the vise etc.
  • 5) This setting is for machines that have a Touch Probe and a TT when the TP is measured on top of the TT. Most TT's have a harder spring than the TP so when the TP is measured on top of the TT, it's usually the TP that triggers and not the TT. With most TP and TT's this is not a problem as the axial pre-travel of a usual TT or TP is just 1-2 micro meters and can be ignored. However there are some TT's (especially the wireless ones) that have a significant pre-travel before they trip. For that case this configuration parameter gives two options to compensate for the pre-travel distance of the TT. One option is just to enter here the actual pre-travel distance that then can be used to correct the TP height offset measurement. The second option is to touch off the TP at the base surface the TT is standing on and specify the height of the TT from the trip point of the TT to the base surface.

• Now Save the configuration and the Tool Library Manager will come up again.

• Now it's important that the Reference Height is being established with the Set Reference Height Button before any Tool Height Offsets can be measured:

• Also important is that every time a new tool height offset needs to be measured and the machine table has been moved up or down since the last time the Reference Height was set, the Reference Height must be re-established again with the Reference Tool before the new tool height offset can be measured
  
  Measuring the Tool Height Offset of a Tool is as simple as pressing the Measure Button displayed in the row of the tool

I hope this clears things up a little and shows how simple Tool Height Offset measurements are with the ProbeApp.
If any of these steps are still unclear or don't answer any of your questions, please post it here.

-swissi

[lavrgs]

Glad I asked - I didn't fully understand the meaning of "fixed Z reference. Maybe the term floating Z reference should establish the differences between knee mill and bed mill to avoid confusion. The detailed procedure above is what I do with the current reference tool, reestablishing the offset after table moves. I was interesting in making my probe the reference tool. I'll go back and reconfigure ProbeApp to recognize the TP as one of my probes.

[swissi]

Glad I asked - I didn't fully understand the meaning of "fixed Z reference. Maybe the term floating Z reference should establish the differences between knee mill and bed mill to avoid confusion. The detailed procedure above is what I do with the current reference tool, reestablishing the offset after table moves. I was interesting in making my probe the reference tool. I'll go back and reconfigure ProbeApp to recognize the TP as one of my probes.

All you need to do is open the ProbeApp Tool Library Manager Configuration page and select the TP as your Reference Tool and Save the configuration.

But keep in mind that anytime the length of the Reference Tool changes, it will invalidate the Height Offsets of all tools in your tool library. That means you have to re-measure the height offset values of all tools when you change the Reference Tool. This includes any changes that might happen with the overall length of your TP. If you replace the TP stylus for any reasons or change the TP tool holder or the position of the TP within the tool holder, you MUST re-measure the height offsets of all your tools again.

-swissi

[lavrgs]

The benefit of using a dedicated Master Tool has an appeal. Rather than change the TP to the master tool I'll assume I can measure it and use it for setting XYZ. I only use it for XY now.

[swissi]

The benefit of using a dedicated Master Tool has an appeal. Rather than change the TP to the master tool I'll assume I can measure it and use it for setting XYZ. I only use it for XY now.

Yes if the TP is not your Reference Tool, you can measure the TP like a tool. However if you are using a TT that has pre-travel before it trips, point 5) from my post above still applies:

5) This setting is for machines that have a Touch Probe and a TT when the TP is measured on top of the TT. Most TT's have a harder spring than the TP so when the TP is measured on top of the TT, it's usually the TP that triggers and not the TT. With most TP and TT's this is not a problem as the axial pre-travel of a usual TT or TP is just 1-2 micro meters and can be ignored. However there are some TT's (especially the wireless ones) that have a significant pre-travel before they trip. For that case this configuration parameter gives two options to compensate for the pre-travel distance of the TT. One option is just to enter here the actual pre-travel distance that then can be used to correct the TP height offset measurement. The second option is to touch off the TP at the base surface the TT is standing on and specify the height of the TT from the trip point of the TT to the base surface.

Let us know how that worked out.

-swissi

[lavrgs]

I’m either going to have to change my wiring or fake the system by measuring the TP as an unused tool and put that value into the height offset for the TP.
Bottom line is that currently I cannot use the TT and TP at the same time. EDIT Using the TP does seem to work I will have to do some verification testing. Initially the entry from the unused tool didn't get saved into the TP offset, so I had an offset, fortunately ABOVE zero.

[swissi]

I’m either going to have to change my wiring or fake the system by measuring an unused tool and put that value into the height offset for the TP.
Bottom line is that currently I cannot use the TT and TP at the same time.

You can check which of the probes (TT or TP) has the weaker spring load by placing the TP on top of the TT by hand und push down slightly and see which one moves. Most likely it's the TP that has the weaker spring so you can connect only the TP to touch off the TP on the TT.

Let us know if that worked.

-swissi

[lavrgs]

I have the touch probe working to set XYZ. Thanks for the help!
I will need to run a few checks to build my confidence. I probed a part to set XYZ and installed a tool, defined which tool it was and carefully approached 0,0,0 with reasonable results. I may do some fine tuning although in the past the Z position based on my TT was not perfect. This could be due to several factors including operator hyper-casuality i.e. not making critical parts 9-)
I thought I had written up what I did but I can't find it - I can't activate both TT and TP. Using PrbeApp I measured the TP by measuring an unused tool #18, and loaded the offset into the TP #14