So this tip is one of maybe 4 tips about how I was able achieve repeatable accuracy. I now have accuracy to the millimeter that is repeatable for 1,000s of movements.
I expect some of these tips are known to some of you and some folks won’t need the level of accuracy I’m talking about, but you still may get some benefit from knowing this stuff.
If you have ordered the new Farmbot Express this may not apply to you as that version wasn’t designed for the level of accuracy I talk about above.
This was the first tip I was given when I got a Farmbot - wood is your enemy…
It is much better to mount your Farmbots linear rails to metal because it is usually straighter than wood and less likely to worp over time from moisture, temperature fluctuations and sun exposure.
I was told to use lengths of aluminum angle and mount the Farmbots X axis linear rails to that. But any lengths of straight metal which isn’t prone to rusting will do. At the moment I am using linear rail for the bed because I can source that cheap.
It’s also important that the 90 degree angles on your bed are exactly 90 degrees. To achieve this make sure the beds X axis sides are exactly the same length, same goes for the Y axis sides.
I recently somehow bent one of my gantry plates and that didn’t help accuracy lol, so check the 90 degree angle in the gantry plate is also correct.
Also it’s good to use a spirit level to ensure the bed isn’t warped. I think that is also specified in the Farmbot documentation.