blackhawk
01-23-2009, 10:00 PM
I have an upgraded PRT Alpha with Aspire. I recently ran into a problem when running a 3D finishing toolpath. I used an offset strategy in Aspire to create the toolpath. The first time that I ran the file, my part came out incorrectly. I checked the code in the editor and everything seemed correct, so I don't think the problem came from Aspire.
So,I ran my.sbp file again and watched the actual code values and compared them to the red position window as the file progressed. At line 1500, the Y was off by only .003, but then continually got worse as below:
line 2200 was .010" off
line 2700 was .022" off
line 3000 was .049" off
line 4000 was .163" off
line 5000 was .270" off
line 5450 was .169" off (starting to get better)
line 5500 was the last line of code sending the machine back to the 0,0 start point. It truly returned to the exact zero where I started. I know because I measured the position of the Y carriage to a relative point using calipers before starting the file.
I ran the file a third time and the values were getting off identically as before. Around line 5000, I hit the space bar and paused the machine. While paused, I measured my position with calipers again and it was off exactly the amount that the red position window was saying (about .300"). So, the red position box was accurately giving the position of the Y car.
Now this is where it gets weird...I resumed the cut and now the commanded positions started to match the red position window values! So, I let the file run to the end and when it went back to its 0,0 home position, the Y car went to rest past the Y zero point by .300 inches. This is about exactly what I had measured during the pause. So it seems like the pause reset the red position box to match up with the code, but the physical machine position did not change.
I ran several other different files after this with no problems. I also had never seen this problem before now. I can run the bad file over and over and it repeats exactly even if I re-toolpath it in Aspire. I have also re-toolpathed the finish cut with a raster strategy and the raster toolpath works correctly.
It just seems like the Shopbot control can't handle something about the offset toolpath. I was running about 3 IPS, so not anything super fast. Any ideas?
So,I ran my.sbp file again and watched the actual code values and compared them to the red position window as the file progressed. At line 1500, the Y was off by only .003, but then continually got worse as below:
line 2200 was .010" off
line 2700 was .022" off
line 3000 was .049" off
line 4000 was .163" off
line 5000 was .270" off
line 5450 was .169" off (starting to get better)
line 5500 was the last line of code sending the machine back to the 0,0 start point. It truly returned to the exact zero where I started. I know because I measured the position of the Y carriage to a relative point using calipers before starting the file.
I ran the file a third time and the values were getting off identically as before. Around line 5000, I hit the space bar and paused the machine. While paused, I measured my position with calipers again and it was off exactly the amount that the red position window was saying (about .300"). So, the red position box was accurately giving the position of the Y car.
Now this is where it gets weird...I resumed the cut and now the commanded positions started to match the red position window values! So, I let the file run to the end and when it went back to its 0,0 home position, the Y car went to rest past the Y zero point by .300 inches. This is about exactly what I had measured during the pause. So it seems like the pause reset the red position box to match up with the code, but the physical machine position did not change.
I ran several other different files after this with no problems. I also had never seen this problem before now. I can run the bad file over and over and it repeats exactly even if I re-toolpath it in Aspire. I have also re-toolpathed the finish cut with a raster strategy and the raster toolpath works correctly.
It just seems like the Shopbot control can't handle something about the offset toolpath. I was running about 3 IPS, so not anything super fast. Any ideas?