Frustrated farmbot express owner who can't get his robot to move along the x-axis

I bought a FarmBot express XL early last year (I think it was one of the first to ship) and I have had an incredibly frustrating time using it - to the extent that it has basically never been useable - because I simply can’t get the robot to move properly along the x-axis. It just seems that there are too many variables and too many things to try to adjust, and while I occasionally make progress by adjusting one variable, inevitably something else then crops up and the robot gets stuck.

At the risk of detailing a litany of problems, here we go:

  1. The basic issue is that I can’t get the robot to move smoothly along the x-axis.
  2. I have found working with the rubber tracks very difficult. After a year and I half they feel very brittle and I’m worried that if I keep trying to manipulate them they will snap. I also have no idea where I can buy a replacement, since the store doesn’t seem to sell them.
  3. As the rubber tracks have hardened I have found trying to re-thread them more and more difficult to the point that it’s almost not possible to do so.
  4. I have probably made some small mistakes in positioning the end pieces, but it’s getting harder and harder to fix the positioning by small amounts because I already have holes and it doesn’t seem possible to position them in a new position that is slightly displaced from the previous position.
  5. I wasn’t able to install tensioning cables when I first built my raised bed (I actually had it built for me at a local lumber yard). I have recently started installing tensioning cables but it’s not easy with plants in the raised bed.
  6. Last year I read a topic where somebody indicated they had experienced similar issues, and they suggested installing aluminum tracks. I did that, but it didn’t make much of a difference.
  7. I have tried adjusting the width of the gantry, the height of the two sides of the gantry, etc.
  8. I have also noticed that the position of the z-axis along the y-axis can cause the robot to move away to one side or the other if the z-axis isn’t in the middle, but while positioning it in the middle helps, it doesn’t solve the issues.

As I setup my farmbot last year and started using, I realized that the biggest compromise that had been made in creating the farmbot express was not using proper aluminum tracks like the genesis has. I deeply regret not having bought the genesis, but it doesn’t seem like there are any options to convert an express into something more like a genesis (at a minimum to use aluminum tracks).

I’m an electrical engineer with reasonable but not great mechanical skills but I have just not been able to get the x-axis to work reliably despite investing 50+ hours in trying to solve the problem, and as a result my farmbot has basically mostly been gathering dust. I am making another effort to try to get it working, and the first thing I’ve been doing is installing the tensioning cables. I’m probably going to adjust or remove the aluminum strips and attempt to adjust the positioning of the end pieces and the rubber tracks but as I indicated above I’m worried that will not go well.

I’m wondering if there is anybody who can point me to any comprehensive information that can help me figure out how to get this to work, or if there is anybody who had found a way to install a hard metallic track system into an express system.


Chapel Hill, NC

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Hi @nawwar

I do agree Express kits do have a lot of problems, and I’m not happy either. The lack of aluminium rails is one of the biggest: I had to invest a lot of time figuring out how to overcome the issue, too. Below you’ll find a report of the solution I have in place now: it’s not perfect (summer heat can bend the tracks) but it can be a starting point.

Farmbot Express floating frame




@nawwar thank you for a detailed report of what you have tried with your installation. I’m sorry you have had such difficulty getting the bot to work reliably along the X-axis.

Here is my advice with my current understanding of your situation:

  • Having square, straight, and parallel supporting infrastructure is very important for both FarmBot Express and Genesis systems. We try to emphasize this in the documentation because both machines will experience problems if the bed changes substantially with rain/thermal expansion, or if it is not square/parallel to begin with. With Express systems, the bot can run off the bed where things get too narrow, get jammed where things get too wide, or have trouble moving over rough surfaces. With Genesis systems, the bot will get stuck at the joints between aluminum extrusions if the extrusions change angle or a gap forms from shifting supporting infrastructure. Thus, you are on the right track to add some tensioning cables if you have noticed your bed is bowing outwards. Once you are able to get your bed back into shape, you may also consider adding a couple extra posts into the ground to further reinforce it, or sanding the top edges to ensure they are smooth. If you share a few photos of the bed, especially looking down the long edges, I can offer additional recommendations as there may be other issues such as inadequate lumber sizing.
  • The rubber belts should last much longer than 1 year in outdoor environments. If one of them breaks on you, please email with a reference to this forum thread and I will send you replacements free of charge. And for reference, we do sell them as well: GT2 Timing Belt — FarmBot, and the generic name for the part is “GT2 Timing Belt” which you can find from many other suppliers such as OpenBuilds and Amazon.
  • Can you explain more specifically how your FarmBot fails to move along the X-axis? Does it run off the bed, get jammed, stall frequently, appear to not have enough power/torque to overcome friction, or something else?
  • If you go into the help panel of the app and submit a feedback report with “nawwar” in the description, I can login to your account and check out your motor settings to make adjustments and offer additional advice on the software side.
  • While it is possible to upgrade an Express bot to run on aluminum extrusions like Genesis, that upgrade would be significant in terms of cost and effort. And, if the underlying problem is with your supporting infrastructure, it is unlikely such a change to the FarmBot hardware would fix your issues.
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