May 26, 2019, 09:41:54 AM
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 Fine tune tool frame

normal_post Author Topic:  Fine tune tool frame  (Read 257 times)

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May 14, 2019, 10:26:48 PM
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pfolker


I am setting up a fanuc robot to do a little deburring by holding a part and moving around a few stationary spindles.
If I wanted to use a dial indicator to adjust the tool frame angles, what is the best method?

Today at 09:41:54 AM
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May 15, 2019, 10:41:56 AM
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HawkME

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1. Make sure you have the correct User Tool active and you are jogging in tool coordinate mode only throughout this procedure. (you can also use program movements using tool offsets)
2. Have a rigid, straight edge that you can use to align you end effector to.
3. Jog the end effector until one side is straight with your straight edge
4. Mount the dial indicator to the end effector and write down its value at a starting point on the straight edge
5. Move (tool jog or tool offset) along the straight edge a set distance and check the indicator again
6. If you dial indicator is in inches, then convert to mm
7. Calculate your angle error:  atan((indicator start - indicator end)/distance moved))
8. Adjust the angle value of your user tool. (W, P, or R depending on which side you checked)
9. Repeat the procedure from step 3 to ensure that you adjusted the correct element (w,p, or r) and the correct direction (+ or -) Any time you make an adjustment you will need to re-align to the straight edge as noted in step 3.
10. Repeat the procedure for each element (w,p,r) that you need to correct. With a deburring tool you should only need to correct 2 of them as rotation about the deburring axis should not affect your process.

This procedure uses simple tools (straight edge and dial indicator) but can also be done with more sophisticated measurement devices. There is also a 6 point TCP teach method, but IMHO this method is more accurate.

May 16, 2019, 02:07:41 PM
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pfolker


So there isn't a way to just indicate the part straight, view what the UTOOL 0 angles are, and transfer over the angles to my new userframe?

May 16, 2019, 05:14:34 PM
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HawkME

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You asked for a user tool adjustment so I gave you a method for that.

Are you instead wanting to adjust the user frame to the part? Do your parts vary or can you just teach a 3 point UF off your part?

May 16, 2019, 05:27:11 PM
Reply #4
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pfolker


My end of arm tooling consist of 3 different grippers and I am clamping on a part and maneuvering it around some deburring spindles. The spindles are my user frames, and the part is my tool frame. The grippers aren't grabbing the part perfectly straight so I would like to adjust the angles of the tool frame to compensate. I can look at an empty tool frame position after indicating the part straight, but the only position screen I see is the world frame, and those angles don't seem to be what I'm looking for.

May 16, 2019, 06:07:40 PM
Reply #5
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HawkME

Global Moderator
Ok, so you do want to adjust the tool frame. Here are your choices:

1. Follow the method I originally posted
2. Use the 6 point method to teach your TCP
3. Use trial and error to adjust the TCP angle values in direct entry until your gripper comes out straight

The angles in the position screen are the orientation of your TCP relative to the world or user frame. They will not directly correspond to a change you want to make to correct the TCP without knowing the actual position you want to be in and then doing the math equations to calculate an error correction.

May 16, 2019, 11:08:06 PM
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pfolker


Got it, thank you for all your help.

Today at 09:41:54 AM
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