[r0b0tb0]

Hello everyone!

I am working on a project where essentially I am cutting off some material from furniture parts made of MDF using a spindle motor with a mill tool attached to Techman TM12 cobot.
Offline all works great but when executed on the real part there are inaccuracies due to some TCP wobbling/trembling. This is most prominent on the curved segments as well as when going from one segment of the part to other - curved to straight line or the opposite.
For generating the path I use the Techman PathNode post processor.
I tried different approaches to optimize the CFP settings with no satisfactory outcome.
Attached is the project with the curve and generated path.

Best regards,

Borislav

[Jeremy]

Did you try increasing the rounding to 10 or even 50?

CFP->"Program events"->"Set rounding".

Jeremy

[r0b0tb0]

Hello Jeremy,

Thank you for replying. I have watched lots of the videos on RoboDK's youtube channel and I think you are doing great job there!
Actually I have tried with increasing Set rounding value but never got up to 50. I'll try and see the result.
Initially there was some issue with the cobot holding the path firmly but after an update from TM it got much more stable. The straight segments are OK now. As for the curved ones they said I shall consult you guys to optimize the path.
They also suggested much lower values (than the default ones) for Fast Move Speed which on some occasions helped but in general did not result in reducing the trembling/wobbling of the TCP.

I also have another a bit more complex 3 dimensional path (for the same project) that needs to be improved. Shall I post it in a separate thread?

BR,

Borislav

[WattUp]

Not related to the issue, but just curious. Your Spindle assy appears to be attached to the EOAT only with a clamping block. Aren't you concerned about it getting loose and losing position? Might be best to add a keyway to the block and shaft.

[r0b0tb0]

Hi,

You are right, this is currently not the best configuration. It is more of a prototype one and will be improved once we get good results. The current configuration allows me to easily rotate or move along the spindle along the Z axis of the flange and this way find the most suitable position for the concrete task. This will not be possible if there is a keyway that will prevent it. We have also taken some measures against getting the motor loose.
Why do you ask, have you experienced any issues of this sort?

[Jeremy]

As you are only using an educational license, I can't really give you much support on this. (And is this really a research/educational project???? 150 euros licenses are not meant to be used for projects where the end-user is a company.)

找出多少是由RoboDK引起的and how much of this is caused by the robot itself would require a bit of work. I don't think the robot/program we generate properly accounts for the payload of the tool right now.

You can always send a video of the robot's behavior so that I can see if I see anything obvious.
Otherwise, you can change the distance between the points, reduce the speed of the tool, and play with the rounding.

Jeremy

[r0b0tb0]

Hello Jeremy,

I will not hide the fact that we are using educational license. I assume full responsibility about that. It initially started as a cooperation project with a person from our local university but things changed while working on the it. As this is our first project ever with offline robot programming software it is currently in proof of concept stage. Once we go beyond that stage I guarantee purchase of the full license. Things so far don't seem to be working as expected (either because of lack of knowledge or improper programming) and that is the reason I contacted you.


Borislav

[Jeremy]

What are we supposed to do with this?

Like I said previously if you can provide a video recording of the robot I can potentially identify the issue.
One potential issue could be the lack of payload setup in the program.

Jeremy