Tool change position and tool offset

[grsabourin]

Hi,

I have set on my machine the tool change position above my tool setter. This position is mostly in the middle of the range of X axis, far away on Y axis and completely up in Z. In have few questions regarding move to tool change position and tool length offset

1 - Is it possible to modify z axis speed when entering in tool measurement operation. It is currently slow and take long time to go down to measure the tool.

2 - I had strange reaction of the machine when it move to the tool change position. Example. I finish probing my stock plate and ready to begin with mill tool. The machine is on the beginning of X axis end at the end of the Y axis. My tool change position is in the middle of X axis and at the beginning of Y axis. I start tool change operation and the machine move to tool change position. The machine goes to upper position in Z and begins to move X and Y at the same time to go to the right position. At a moment X and Y axis seems blocking and the machine stop moving. After that I loose all reference. At the beginning I was thinking it is a mechanical problem but if I do exactly the same thing (starting at the same position with x and y simultaneous) by jogging, the machine move perfectly. Can it be a software issue?

3 - My machine uses basically imperial units (mechanic and software setup). I'm using it metric unit. When I do a tool offset measurement with a metric program loaded the operation is completed successfully and the resulting measurement is in mm. On the tooling page if I check my tool offset the value is in mm but the software expect a value in inch (as indicated in green on the top). If I do test (as in your video) with the current value the tool offset is not good because it is using mm value as a inch value. If I convert the mm (TOL) to inch manually it is working. Are there a way to have this conversion automatic or at the end the best thing for me will be to completely redo the setup of the machine for metric units.

Thank you

[venom51]

1. Yes. You can adjust the probing speed on the WC Offset tab. There is a Probe Fast FR and a Probe Slow FR setting.

2. This is a stepper stall. I assume your tool change position is at some far left or far right position on the table. That leaves the table weight hanging unsupported and adds additional friction to the movement. Mine will do it if the ways are not lubed well. Your manual jogging doesn't react the same way because the acceleration rate is lower than it is when the G-Code commands a full feed rate or G0 movement to a location. Reducing the accel rate in Mach may help as well as making sure as the mechanicals are all in good working order.

3. Mach assumes that all tool table values are assumed to be in "Setup units". This is independent of the use of metric or imperial units for motion (G20/G21). G20 and G21 control the units within a gcode program for coordinate system motion only; they do control the interpretation of tool table values.

MSM allows you to enter tool table values for diameter in either metric or imperial units as a "ease of use" feature for a human. However, the internal value is always stored in the machines setup units. It is Mach that gets the values at run time and makes the assumption about the units for tool table values.

As you have figured out, the operator is responsible for setting up the tool table to match the gcode motion mode

[grsabourin]

Thank you for your very complete and helpful answer.

May you give me information where I can modify the machine acceleration in Mach?

[DaveCVI]

Hi,
Motor tuning is done with the mach dialogs: main menu bar, config, motor tuning.
Dave