As many others are, i’m in search of the Holy Grail - cutting the entire 4’x8’ sheet of plywood with accuracy and precision. To do this I went to the 12’ beam, and for awhile I did get good results, but then my motors both had gear issues. Looking at the issue I think this was mainly caused by having a sled that weighs 42 lbs. It sounds like the Max. is 40 lbs? I got my machine back together with new motors and a 32 lbs sled, but now have troubles in the corners, somewhere around the 61 degree mark from horizontal (see photo). I’ve used @dlang spreadsheet quite a bit but since we don’t have enough data for what’s good and what’s bad, its hard to tell what would fix my issue and what wouldn’t.
I have data below but wondered if anybody could help with the following questions:
Should 12’ beam solve my cut the entire sheet issues, or at least in the corners?
Do I need to go to a 14’ beam? Anybody have success with this?
What is max weight for sled? <40 lbs? Ideally get 1000 hrs of cutting time before motor replacement or repair.
Anybody else have issues going past a 61’ degree chain angle in the corners like my photo below with a 12’ beam?
If I do go to a 14’ beam are their motor cable extenders I can buy? I found some parts to build some but not all parts.
Thought: It would be nice to validate the spreadsheet dlang has put together and understand the range of acceptable chain angles and tensions to achieve desired parameters, i.e. durability, reliability, accuracy, precision. I think we should have a running spreadsheet for users to fill out with their particular specs. - frame measurements, sled size and weight, and resulting cutting accuracy and precision. Actually as I type this I guess it would be better to just have a post calibration file uploaded to GroundControl HQ so that many data points can be gathered to help understand what is the true cut area.
My current machine info:
Motor Sep: 142 in
SledWeight: 32 lb
Frame Angle: 12 deg
Spreadsheet of frame
Photo of frame angles
Photo of setup with previous successful 42lb sled