Calibration + test cutting results

[RavenWall]

The baby and some important stuff at work kept me some weeks from cutting. And today… We found some time, finally!

Last thing I did a couple of weeks ago was installing the final sled. So today another round of calibration and fine-tuning. Put some super slippery green board for optimal results (and it’s cheap )
I didn’t rerun the complete calibration, since I was fairly sure about the measurements. I only did the test pattern and remeasured that one.
After that I did some test cuts:

I was quite surprised with the accuracy.

Cut in the middle is perfect. On the top left and right too.

The cut far bottom right and far bottom up:

• Vertical is perfect
• Horizontal not at all… 20 cm became 20,5 (on both side), So 2,5% off
• Some lines are not straight…

Then I come to the bottom left which is overlapping with the far left cut:

• Vertical is perfect
• Horizontal is 20,2 cm instead of 20.

So horizontally on the bottom, there is something strange. It seems to me like maslow is correcting something, but does an overestimation somewhere. Anyone a clue?

FYI:

• Chain sag: 39,91
• Rotation radius: 134,7

[Dustcloud]

Hi! Life does get in the way of the Maslow obsession!

Are you running the standard Maslow Benchmark Test Pattern? The squares in that test are 100 mm.

More information about the calibration benchmark test

The calibration benchmark test is a tool to help us measure how well calibrated a machine is. We came up with the test as a “before and after” test to check if a change to the calibration process made the machine more accurate or less accurate. We wanted a test which would let us compare apples to apples instead of cutting different shapes in different places. The test can also be a good way to test how well calibrated your machine is. Right now a good calibration score is something in the neig…

How are you evaluating the measurements? Aside from the squares in the corners, there are also long horizontal and vertical values to be found.

[RavenWall]

I should have known there would be a standard test pattern on the forums.

I just used a 20x20cm and put it at some “critical” places to check the “usable” area. I just noted that the horizontal length became less and less accurate on the bottom towards the corners. In fact, for the moment only 40 cm of the bottom corners are not usable.

[Dustcloud]

With the standard 10’ top beam, you will need to really optimize the sled’s freedom of movement in the lower corners, as there is not much outward force available from the outboard chain down there. Wax and polish the sled base, and be sure there is no unnecessary forces at play, like the control wires, screw heads, or the dust collection hose. Try “driving” the sled around the 8’x4’ work area perimeter with the GC manual controls to see if there are any hang-ups. If you are serious about using the entire 8’x4’ space, at the minimum you will need to provide an apron for the sled on the bottom and sides. At the top you may find that the chains are so tight that the support is not needed there. Many folks bent on getting good results over the full sheet have widened the top beam to 12’. I did this, raising it as well, and the sled now has a much better “out-pull” down there.

Getting back to the Benchmark test, you can get acceptable results with your present set-up, as the maximum width is 1905mm (75”). When you use that test, you will be better able to communicate with the community, as it is widely used.

Good luck, and keep us posted.