How to change Mammotion LUBA blades: switch the mower fully off, remove the safety key if your model has one, turn it upside down on a soft surface, and fit every new blade with a new screw, using the M2.5 Allen key named in the LUBA user manual. The manual also says all cutting blades should be replaced at the same time.
The short answer
- Tool: an M2.5 Allen key, listed under “Tools needed” in section 9 of the LUBA user manual V1.2.
- Power: the LUBA must be turned off before you replace, inspect or clean the blades.
- Parts: replace all blades together, use new screws each time, and choose parts made for your model.
- Interval: the same manual gives two figures, every six months and every three months or 150 hours of mowing, so the shorter one is the safer plan.
What the LUBA manual says about blades
Section 9 of the LUBA manual, “Cutting blades replacement”, covers when and how to swap the blades. It says blades can be replaced when they are damaged or worn out, and that they must be fixed securely and flexibly. It also recommends replacing all cutting blades at the same time when the mowing result no longer looks as good as before.
The manual does not give a single interval. Its opening line recommends changing the blades every six months, while a later note recommends every three months or 150 hours of mowing, and adds that thick grass may call for more frequent changes. Our reading is that the shorter figure is the safer guide, especially in a season of heavy growth.
The safety section of the same manual adds that you should not touch the blade disc until it has come to a complete stop, and that you should set the mower to off before you clear a blockage, do maintenance or examine the product. Read the LUBA user manual V1.2 (PDF) before you start.
Tools and parts to have ready
Gather everything before you start. Knowing how to change Mammotion LUBA blades is mostly a matter of preparation, so lay the parts out first. Our robot mower maintenance kit guide lists useful basics. The list combines the LUBA manual with Mammotion’s UK blade guide. That guide mentions a screwdriver, but the LUBA manual names the Allen key, so follow the manual for your model.
- An M2.5 Allen key, as named in the LUBA manual.
- Work gloves. The UK guide says to always wear them, because even worn blades are sharp.
- A soft mat or blanket to turn the mower onto, so the chassis and sensors are not scratched.
- A soft brush or plastic scraper to clear grass and soil from the disc. Mammotion’s US maintenance guide advises against metal tools.
- New blades and new screws made for your model.
How to change Mammotion LUBA blades, step by step
The steps below follow the sequence in Mammotion’s UK blade guide. The blade procedure in the LUBA manual is shown with photos that the text version of the manual does not capture, so compare these steps with the pictures in your copy before you begin.
- Power off completely. Set the LUBA to off and wait until the blade disc has stopped turning.
- Remove the safety key. Do this if your model has one, before you turn the mower over.
- Turn the mower upside down. Place it on a soft mat or blanket.
- Put on gloves. Handle the blade edges only after the steps above are done.
- Remove the old screws and blades. Do not reuse the old screws.
- Clean the cutting disc. Brush off grass and debris, check the disc for damage, and remove any old washers stuck to it.
- Fit each new blade with a new screw. Tighten so the blade is secure but still pivots freely.
- Check the blades. Confirm every blade moves freely before you turn the mower back over.
For a wider routine, see how to clean a robot mower. Mammotion’s US winter maintenance guide for the LUBA 3 AWD, a newer model, adds cleaning advice that may help with the disc before you refit it. It recommends a soft brush and a low-pressure washer, warns against high-pressure washers because they can damage seals, bearings, sensors and connectors, and says to let the mower air dry for at least 30 minutes before you reinstall the discs. That guide is for a different model, so use it only as a general reference and check your own manual.
Fitting the new blades and screws
The most important detail in how to change Mammotion LUBA blades is the screw. Mammotion’s UK guide says the screws are single-use and that old screws should never be used with new blades. Each new blade should get its own new screw, and every blade should be checked for free movement afterward. If a freshly fitted blade still causes heavy vibration, the guide advises replacing the whole set of blades and screws.
The LUBA manual text we could read does not give a torque value for the blade screws, so this article does not give one either. Use the tightness shown for your model and do not guess. A blade that binds or wobbles should be taken off and checked rather than forced into place.
How often to replace the blades
Mammotion’s sources give different intervals. The table lists each one so you can see which fits your mowing season.
| Source | Suggested interval | Notes |
|---|---|---|
| LUBA user manual V1.2, section 9 (opening line) | Every six months | Replace when the blades are damaged or worn. |
| LUBA user manual V1.2, section 9 (note) | Every three months or 150 hours of mowing | Thick grass may need more frequent changes. |
| Mammotion US maintenance guide | Every 1 to 2 months in the mowing season | General guidance, not specific to the LUBA. |
Our guide to robot mower blade replacement covers the general signs of wear. Whatever interval you choose, replace blades sooner if they are chipped, bent or visibly worn, or if grass tips look torn after mowing. The UK guide also advises checking blades for micro-cracks or deformation after the mower hits a large stone or a concrete edge.
Safety warnings
Heads up
Do not touch the blade disc until it has come to a complete stop. Turn the LUBA off before you clear a blockage, do maintenance or check the product. Remove the safety key before turning the unit over. Do not use an electric drill or driver, because Mammotion’s UK guide says it can damage screw heads or the cutting plate. Do not straighten a bent blade; replace it.
What to check before you buy replacement blades
Before you follow how to change Mammotion LUBA blades, our reading is that the most important check is the match to your model. Look up the part list in your manual or on the manufacturer’s support site, and buy blades and screws as a set. The manual’s safety section asks for Mammotion original spare parts where possible. The UK guide also mentions certified compatible parts, but check any non-original blade against your manual before fitting it.
Compare the new blade with the one you removed, including its shape and mounting hole position, before you fit it. Keep the old set until the new one is confirmed to sit correctly on the disc. The robot mower maintenance checklist shows where blade changes fit in a seasonal routine.
Frequently asked questions
Do I need to replace all LUBA blades at once?
Yes. The LUBA manual recommends replacing all cutting blades at the same time when the mowing result no longer looks as good as before.
What size Allen key does the LUBA need?
The manual lists an M2.5 Allen key under “Tools needed” for blade replacement.
Can I reuse the old blade screws?
No. Mammotion’s UK guide describes the screws as single-use and advises a new screw for each new blade.
How do I tell when the blades need changing?
Look for chipped, bent or visibly worn blades, grass tips that look torn, an uneven cut, or more noise than usual while cutting. These signs are listed in Mammotion’s US maintenance guide.
Sources
- LUBA Robotic Lawn Mower User Manual V1.2 (Mammotion): section 9 on blade replacement, tools, intervals and the safety section.
- Mammotion blade change guide (UK blog) (Mammotion): steps, gloves, screw advice, safety key and micro-crack checks.
- Robot lawn mower maintenance (US blog) (Mammotion): wear signs, disc cleaning and general interval guidance.
- LUBA 3 AWD winter maintenance (US blog) (Mammotion): disc cleaning, drying time and the high-pressure washer warning, for a different model.
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