Repeatable Farmbot Accuracy


#1

I have the first version of the Farmbot and I found in order to get repeatable millimetre accuracy I have to rehome and recalibrate it after every single move. This is my number one pain point with the Farmbot as I can’t use the seeding tray without recalibration or I break the seeding needle when it hits the side of the tray :frowning:.

I documented the problem here: Improving FarmBot accuracy

What improvements have been made to fix the repeatable accuracy problem or if none when is this on the road map to be fixed?


#2

What version kit do you have? With encoders on all of our bots we are able to get pretty repeatable accuracy.


#3

Hi Connor, it’s version 1.1. I am running the latest software. I have endstops installed. Have there been any hardware improvements specifically for accuracy since v1.1.


#4

Ah. starting with 1.2 i believe, we began shipping optical encoders. These will be way more accurate than just using encoders. However i lived without working encoders for quite a long time, and the bot was what i’d describe as “accurate enough”. Are your belts tight?


#5

Yup changed the belts to steel core they are tight but not too tight it’s only the X axis which moves out by a mm after each movement. How do I check what type of encoders I have?

Thank you so much for your assistance :slight_smile:


#6

@connor what do I need to buy from the store to get the optical encoders?


#7

Motors that have a encoder mounted look like this

  1. You need dual shaft motors
  2. You need encoders, I use myself a cheap avago encoder for like 15$. If you don’t have much experience with those, you can try to get encoders from US Digital that fit to V1.1. You can find all data here in the hardware docs. Please note that the encoder Resolution was 200 lines per revolution and is now 360 lines per revolution. But this is not a problem at all and easily set up in the webapp later on.