Swerve Module Maintenance?

What are people doing with their swerve modules between seasons for maintenance? I’m sure some people are buying new ones each season, but for those of us planning to reuse them, what do you plan to do?

We’ve now run 5 events on our mk4i’s, and plan to do 2 more offseason events. I’m definitely thinking a disassembly, inspection, and reassembly makes sense, but what else might you do? Replace some/all bearings? Wash and degrease gears to remove dirt/lint?


Disassembly, cleaning, inspection, and reassembly makes a lot of sense.

I would check the bearings, but I think that gear wear would be a more likely thing than bearing wear.


I’m not that worried about the bearings, honestly.

My biggest concern areas are:

  1. The belt - Not sure if there is a good way to inspect this or if this is just something that needs to be replaced periodically. There were a few failures of belts in past seasons and I’m not sure all of them were traced to some specific cause (like unintentional rubbing on some other part of the robot)
  2. The Gears - look for evidence of wear on all the gears, especially the bevel gears given their exposure to grit and grime off the carpet.
  3. General cleanliness - debris can cause problems in a lot of areas, so cleaning is probably really good preventative maintenance.

What process/product would people recommend for cleaning off gears covered in grease? For our particular circumstances, its white lithium grease I’m asking about, but if there’s differing methods for various types of grease, I’d love to hear that too.

My goto is Brake Cleaner.


Any kind of parts cleaner automotive solvent would work really good.

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I would thoroughly thoroughly thoroughly check the x contact azimuth bearing. At least some of them I saw were not sealed/shielded both sides and well (as well as installed with the shielding in the wrong orientation). Dirt happens.
That would be my “big ticket” replacement item if easily sourced, as long as gears look good, plates are flat, and belt seems ok.


If you have access to an automotive part cleaner that would be best but brake cleaner will also work.

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Many of those belt failures were traced to the swerve modules running 9mm thick belts which just weren’t strong enough. Mk4is run 15mm belts which break significantly less often, but I do remember someone posting about a 15mm belt failure here.


Brake cleaner does work, but since it is mostly acetone it doesn’t hang around for long while you’re trying to use it. My go-to is mineral spirits: it still cleans off grease well but hangs around long enough to collect the waste and dispose of it.
And I get to keep brain cells a bit longer into the season.


I agree that the 15mm belts are much more robust. I’m not sure it is necessary to replace them each year. But I would certainly inspect them. I’m not an expert on spotting belt wear, so replacing them periodically might be the easiest thing to do. The replacement period might be 2 or 3 or even 5 years. I’m not sure.

We had a 15mm belt fail this year. It happened in practice, on modules that has seen about 5 competitions (3 season events, and 2 off-season events).

The belt was technically together, but the bands had broken and it could (and did) slip frequently.

I’m sure in some circumstances the belts could last several years, but after than experience - I think I would be replacing them every year for the rebuild. I’d hate for them to fail when it counts, and the replacement cost isn’t insane imo.


If you are running Falcons, do not forget to tear them down every season to inspect for damage, loose shaft problems, and to reapply loctite.


I plan on doing an ACI (Analytical Condition Inspection) in the fall.

I’ll do a dirty layout to see if we can discover anything from distress and wear that will be visible from the accumulation of material, grease, etc.

After that we will clean the parts and do a clean inspect for wear, defects. and emerging failure mechanisms.

We will then reassemble with all new bearings, fasteners, tread and any needed replacement parts. The motors we use will depend on if we intend to reuse the modules in a 2024 robot and which brushless motors have been made available at that time.

I saw at least 3 of these fail in season. I believe they were the bearings from the module supplier and saw heavy use.

ThriftyBot has replacements for sale example is below. This is completely independent of the the statement above about failures as I don’t know who provided the ones that failed and I’m a big fan of the Thrifty parts.


While I generally encourage supporting our amazing suppliers like SDS, these timing belts are available from other sources.


From a software perspective, you can also redo offsets for the CANCoders. It shouldn’t be the top priority as it usually isn’t an issue.

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If you take the modules apart you should 100% redo the offsets.
No if and or buts about it.


In that case for sure, completely agree!

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So far I’ve had 1 team report back with any issues with the sealed bearings and that looked to be a factory defect. Always looking for more feedback from teams who used them though. 5010 installed them for the 2023 season, never had to touch them once.

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