Machining fixtures making short-run production a piece of cake

21

That is encouraging. I look forward to measuring similar results over the next few days of set-up. What testing method did you use to determine homing repeatability of the X and Y axes?

22

I used two different methods using the stock Onefinity controller

First I performed testing to see the general repeatability of the sensor treating it as a probe wired to the controller where I created a g code program to run the axis toward the sensor at a feed rate of 50mm/min, when the sensor was activated it would stop and I had it record the offset from machine 0, then it would back off 10mm and run again with the following results (this is the Onefinity measuring itself in mm):

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I then reconfigured the switch as a limit and changed the homing configuration to use the proximity sensor instead of stall homing. Homed it one time, move it 100mm away from the sensor and used that to zero the dial indicator. Ran the homing cycle again, back off 100mm and measure delta, repeated about 20 times with no variation in the measurements. Moved on to rebooting the controller then homing the machine followed by backing the axis off 100mm and again no delta in the measurements. Started thinking the digital indicator was playing tricks so I went to the mechanical dial indicator, same results. I moved the dial indicator base in a couple mm and re-zeroed the indicator just to make sure I wasnā€™t hitting a odd spot in the equipment but the results remained the same throughout.

23

Thank you for sharing the process, I appreciate it. It seems similar to what I had done when I set up my first build.

Are you indicating off a tool/shaft in the collet, or a part of the frame/mount?
After homing, are you moving the 100mm in one direction/along one axis towards the indicator?

I have my Masso controller set a Z>X>Y homing sequence. It means I canā€™t test in the Y axis direction as the indicator would be hit during homing. If I remember, I may have indicated therefore in the X direction. Also, I think I indicated off a flat surface of the mount or Z assembly, making sure the surface hit the probe at a 90 degree angle each time.

Homing repeatability for my new ATC build is important as the machine coordinates will need to precisely locate my tool setter, and more importantly the tool rack positions. I think for my repeatability testing this time I will locate the indicator an XY position from home. For example, using MDI command X100Y150 (or similar) after homing. I also was thinking of creating test positions by creating a few G54-G59 work offsets. So after homing I would use MDI to select a work offset, then go to work origin, and it would move to the test indicator set up there. I was thinking this would be like it having to find a tool holder position on the rack.

My next next update will be all about numbers, and the results of testing such as described above.

24

Wow Derek, that is encouraging. Thatā€™s some pretty impressive repeatability. Iā€™ve got a bunch of prox sensors I bought when I had my X-Carve but never used them. Might have to reconsider my homing process and maybe work on mounting these sensors Iā€™ve got.

25

I was using the spindle body as it was the most convenient spot I could get the dial indicator set up and oriented where I could see it.

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26

@TMToronto Tom, does the ATC use actual machine coords (dim. from home position) to locate the tools in a library, or do you have to dedicate one of your work coords to the tool change process? (hope that question makes sense, it does in my head. :rofl: )

27

I understand your question.

I 3D printed my own holders, and instead of forks will use the ,pick and place, arrangement for the holders. Below is a section of the Masso manualā€¦

Defining the Tool Position

  • The Center of each slot is defined by the Slot #: X, Y position parameter box.
  • :grinning:These coordinates are used to define the tool position and are Machine coordinates.
  • The values are defined in the native unit of measurement, either metric or imperial that you have set under general settings in the F1 Screen.
  • Because each tool holderā€™s position is defined by both an X & Y coordinate you can place the tools anywhere on the table.
  • When using a Pick and place tool holder you can define multiple rows of tools.

INFORMATION: Tool slot coordinates can be located outside of the machineā€™s soft limits.

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