Hi forum, I wanted to share my experience, hoping it might help others who are dealing with similar challenges.
When I received my new Monport 90W 700x500 CO2 laser, I was quite disappointed with the accuracy of the X and Y axes. The X axis was slightly better than the Y axis, but I eventually realized this might be due to the larger pulley on the transmission belt drive.
After contacting the Monport support team, who were very responsive and did their best to assist remotely, I tried adjusting the belt tension and backlash settings in Ruida. Unfortunately, there was no significant improvement. I then replaced the transmission belts with new HTD 3M belts, thinking the original ones might be of poor quality, but the new belts didn’t fix the issue either.
The offset I was dealing with was quite frustrating. It’s worth noting that the Y axis behaved very differently depending on whether it traveled to the cutting position from the back of the laser or the front.
After closely examining the old belts and comparing them to the new ones, I found that the belt profile didn’t fit the HTD pulleys very well. You can see that the area between the teeth is already slightly shiny from the aluminum of the pulley, but the teeth themselves remain black.
I was searching for belt profiles with better accuracy than HTD profiles and discovered that RPP belts are designed to work on HTD pulleys while providing a better fit, less backlash, and reduced noise (ringing).
Here is an example of how these different belts fit the pulley.
I’d definitely recommend switching to those RPP Megadyne belts on the transmission between stepper and axis belt drive if you’re dealing with backlash issues that can’t be fixed by simply adding more tension (which isn’t ideal anyway).
Here’s the final result at a cutting speed of 100mm/s. I believe the remaining backlash is caused by the long belts which still are HTD belts, but it’s a level I can live with - especially at these speeds.
Best regards, Richard
