Hey @whitecaps
We’re just discussing a similar problem in another thread See here.
I assume you have the same or at least similar problems:
- Bot runs the first sequence and hits the right hole. Now when the sequence is done you could potentially see that the bot is not at the real position that’s shown on the controls tab (maybe a few millimeters off from the home position). So when you start the next or the same sequence again, the needle won’t or just barely hits the hole that he should go to (example A1).
In this case it seems that your x-axis drives too far (mostly on long distances) and your encoder does not recognize that. There are a few possible reasons for missing steps. Checking hardware settings like I wrote in the other thread would be a thing to start with. If you have questions or another idea, feel free to ask or tell us here 
.
Running a homing sequence after every seeding sequence would make a temporary fix, but should not be our goal I guess. Installing endstops would not make any difference in this case, if your homing position is always the exact same. If you add endstops you won’t get any improvements because you can either home via encoder or endstop. Basically the encoders cover the functions of endstops.
Please let us know if you still want to add endstops and need guidance with that.