Seed planting -- vacuum pump and Z-axis motion`

Okay, I decided to work on seed planting for my two FarmBot Express 1.0.
Problem1: On both units, the vacuum blows out air instead of sucking. What to do? Switch the tubing to an inlet instead of outlet on the pump. Or switch wiring? Or what?
Problem 2: On one of my units, the vacuum motor stays on for a about a half second (enough time to blow all the seeds out of the tray) before triggering a lock.
Problem 3: Using the default Pick up Seed sequence, the default positioning has 50 for the Z-axis. After setting home, my Z=0 is with the z-axis at its highest. So if I want it to get anywhere near the seed tray I need to enter like -190 to get to a safe position above the seeds. The problem, though, is that after going to the safe position, it scans upwards looking for seeds, I guess. Of course, if it was working in the reverse order all of the seeds would be blown out of the tray.)
The vacuum part was preassembled so it isn’t anything I have messed with…yet!

Please disconnect both tubes and change their placement. If that doesn’t help, you may need to clean and disassemble the diaphragm of the pump.

Please see our guide for fixing e-stop button problems. I’m happy to help if this does not fix the issue. Unfortunately, there was a manufacturing issue on our end for v1.0 that requires end-user intervention.

The default sequences are a good starting point, but they do require slight modifications from the user since every device has slight differences in size and seed tray placement. I am not sure I understand the issue entirely- can you tell me if you have modified the default sequence at all? If so, can you send me a screenshot?

Alternatively, you can contact support ( for direct assistance. Please have your order number (or use the email you used to purchase the device) ready to verify your purchase.

One last thing to add- you may find this documentation entry helpful.

So, I switch the hoses ( on both Farmbots) and that fixed the vacuuming problem. I made the wiring change for the stop button. That was the first thing I tried but then forgot about the fact that it didn’t work.

However, the vacuum pump on one of the units still just turns on about a half a second before tripping the interlock. So I guess I need that motor to be replaced unless there are some software settings that might fix it.

I guess, I have figured out my planting sequencing problem. My issue was with the definitions of “Offset”. I also had a problem with the Z-axis motion running at 25%. It moved a few centimeters then stalled. I cranked the speed up to 80% which is a bit fast, but seems to work.

One thing I noticed that after a z-stall the z-home seems to have changed to that location. Even though the planting sequence is suppose to reset the Z-home. It for some reason skipped over that step. (I guess it assumed it was already home.) I will need to purchase a few more planting eedles. I have crumbled a few.


Does the unit turn off or go offline when this happens? If so, it is most likely defective and can be replaced under warranty. Please email to make a warranty claim.

One thing to keep in mind is that the Express, unlike the Genesis model, does not have encoders, so it cannot correct for step errors as easily. It’s a good idea to regularly run a FIND HOME operation to reset the bot’s internal step count.

If you still can’t get things dialed in, we can provide motor tuning support via (FarmBot staff only provides motor tuning support via email).

I just spoke with the team about your issue. One point they mentioned is that a small percentage of solenoid valves are “sticky” and do not disengage properly- if you think this is the case, we can send you a replacement.

Have you ever seen the device dispense water even when powered down? If so, the valve may be defective.

No, no water when it is off. So I think the valve is working properly (if not somewhat directionally challenged. The weeding screw alters the spray so that itt is not centered but probably good enough!)