As an alternative to building a full raised bed, you may consider mounting your FarmBot to wooden posts only. However, this will make track alignment trickier and the structure may be less stable without the additional support of the bed boards. Care will need to be exercised to install posts in a sturdy fashion.
This is the estimated time it will take to setup wooden posts only.
Dig your post holes. A post hole digger and pick axe can help greatly. Your post holes should be roughly 1.5m apart as discussed further in the next steps. Keep in mind that the outer dimensions of your supporting infrastructure must not exceed 1.5 x 3m.
Position your posts such that you will be able to access all sides of your FarmBot and garden.
Install short (500mm) wood posts for the first track. The top of the posts should protrude at least 60mm from the ground, with at least 60mm of mounting width in the direction of the planned track. Space the posts 1500mm apart, center to center, unless you are using shorter track extrusions, in which case space the posts that far apart.
To ensure the posts are aligned properly and the same height, you may want to use a level. If you are setting up multiple track extrusions (more than 1500mm in total length), it is best to install the end posts first and tie a guide string in between these two posts to ensure middle posts are properly aligned.
Once you have positioned your posts, bury or secure them however you like, though it is critical to ensure that the posts will not significantly move once installed.
Depending on the planned width of your FarmBot, space the second track’s posts the appropriate distance away from the first track’s. Keep in mind that the outer dimensions of your supporting infrastructure must not exceed 1.5 x 3m.
Parallel or bust
It is critical that the distance between the two tracks is consistent. If it is not, there will be harmful forces placed on the gantry and tracks as the gantry moves across the non-parallel tracks.
You can use shims or other spacers to better align track plates in case your posts are not perfect.
Once you have positioned the second track’s posts, bury or secure them however you like, again ensuring that they will not significantly move once installed.
Your wooden posts are now ready for FarmBot installation!