inconsistant positioning <resolved, machine loose>
Posted: Tue Sep 28, 2021 8:04 pm
Hi all,
I have been using a knee mill that I retrofitted for about the past six months. Till recently it has all been running fine. When doing a prototype in timber I noticed that it seemed to not do what it was supposed. I thought at the time that maybe it was just a posting problem from Fusion.
For a while I have been going to increase the amperage for the servos which I did yesterday so I then went about adjusting the acceleration and max feed. This all went ok.
I then probed a part that I have machined in the past to open some holes up. This was a bolt circle pattern done on my manual mill with a readout. When I went to open the holes up it didn't seem to align with the original holes. So I set-up to check the accuracy of the axis and found them to be out up to 0.3mm over 150mm so I fixed this.
I then went and probed the centre hole of my part and the hole measure 0.5 undersize with the probe. So I went through the process of resetting the prob runout and pre travel. This was pretty much fine. I then went back and checked the axis travel again and had to readjust it, it end up close to the original set-up. I then went and re probed the hole. I ended up with the same result so I just ran the cycle again and the centre potion was 0.25 out on both x and y and the hole size was right. So I ran it again after zeroing both x and y and it was right on with the correct diameter. I did this over and over and now and again it would be out 0.25 again.
So this morning after leaving the machine I probed the hole again after homing the machine and it was out again 0.25 and the hole diameter was wrong. You can see in the images one is out in one axis the other is fine on both and the hole size is right.
I'm not sure if this problem that developed just before I made the adjustments or if it's a result of something I've done?
Any ideas?
Rob
I have been using a knee mill that I retrofitted for about the past six months. Till recently it has all been running fine. When doing a prototype in timber I noticed that it seemed to not do what it was supposed. I thought at the time that maybe it was just a posting problem from Fusion.
For a while I have been going to increase the amperage for the servos which I did yesterday so I then went about adjusting the acceleration and max feed. This all went ok.
I then probed a part that I have machined in the past to open some holes up. This was a bolt circle pattern done on my manual mill with a readout. When I went to open the holes up it didn't seem to align with the original holes. So I set-up to check the accuracy of the axis and found them to be out up to 0.3mm over 150mm so I fixed this.
I then went and probed the centre hole of my part and the hole measure 0.5 undersize with the probe. So I went through the process of resetting the prob runout and pre travel. This was pretty much fine. I then went back and checked the axis travel again and had to readjust it, it end up close to the original set-up. I then went and re probed the hole. I ended up with the same result so I just ran the cycle again and the centre potion was 0.25 out on both x and y and the hole size was right. So I ran it again after zeroing both x and y and it was right on with the correct diameter. I did this over and over and now and again it would be out 0.25 again.
So this morning after leaving the machine I probed the hole again after homing the machine and it was out again 0.25 and the hole diameter was wrong. You can see in the images one is out in one axis the other is fine on both and the hole size is right.
I'm not sure if this problem that developed just before I made the adjustments or if it's a result of something I've done?
Any ideas?
Rob