Robovac 11S side brush noise

Like many of you it seems, my Robovac 11s started getting horrifically loud and one of the side brushes stopped rotating a few months ago. I was fairly convinced that the side brush motor was just gunked up with pet hair, having noticed a ridiculous buildup of it in while cleaning out a wheel arch after Dustin decided to go clean up the garden one day. I submitted a warranty claim, expecting to just send it in for repair, only to be generously told I’d be sent a replacement and that I didn’t need to send the old one back.

Now that Dustin 1.0 is out of warranty and been replaced I thought I’d open him up and have a dig about, perhaps give my sister a nice Christmas present if I could get it working again.
Sure enough, pet hair EVERYWHERE. Took every single piece motor apart right down to the vacuum assembly and motors to clean and brush and scrape off grime. Now all the bits work fine again, almost like new!

Except for one thing, the noise. Oh my god, the NOISE. The side brush motors now give off an even louder whirr than ever before. I think it’s likely due to my inadvertently having wiped off half the grease/lubricant while cleaning out all the hair.

Anyone had a similar problem? Do I just need to re-lubricate the gears? And if so, what with?

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I would do so.
Without lubricant the wheels will produce noise of course.
Because you know already how to dismantle this procedure will be a quick one.

Any idea what kind of grease? Don’t wanna corrode the {nylon?} gears.

Google will help you!

I have the dreaded stripped side brush gear issue as well. Has anyone found a replacement source? I have contacted a supplier in China via eBay but I need the ID of the gear. The OD of the large and small gear were in another post, 21.1mm 40 teeth large gear and 5.7mm 10 teeth with the large gear having a 20 degree taper. I have not verified this but I’m searching based on this but need the ID.

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Hey guys :wave:t2:

I’ve done a search and found this link that may help,

Courtesy of @TheDude :metal:t2:who posted this on a previous thread.


Yes this might be a solution.
Depends how much they are asking for only 1 wheel.

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Yes, i think you would find these gears in most hobby shops too.

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There are many offers at amazon with a lot of different gear wheels.
But I remember one forumner said, they all will not fit.
The hole for the axis can be altered easy by thrilling or filling.
If its to high it can be grinded down.
The diameter and the number of teeth must be exactly the same.

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I have two Eufy robovacs “Sweep” (11) and “Soo” (11s) both have had side brush issues, both damaged gears in the reduction gearbox attached to the motor, on the right side when viewed from behind. Luckily I managed to pick up a pair of spare assemblies from Fleabay for about £6 each which are no longer available .

When Sweep broke his side brush gears he stripped the final driving spur gear. Being a hoarder I kept the remains of it. When Soo damaged her’s it was the smaller driving spur gear that lost a tooth so I have for now utilised the intermediate double gear from Sweep’s box as a replacement . This leaves me with one good spare motor set.

So off I go to Fleabay for some more replacements as this seems to be a common failing and found nothing under EUFY but I did manage to find some what look to be identical side brushes for another robovac but with a filter board on it: I have ordered two, I expect them to turn up in several months…

In the meantime I will be looking for a set of plastic gears. For those who have not measured them they are: primary gear helical 0.5 Mod 42 tooth, intermediate gear pair: helical 0.5 Mod 9 tooth driving Spur gear 0.5 Mod 10 tooth, final drive gear 0.5 Mod 46 tooth. Using those numbers the ratio would seem to be 21:1. I still need to do a trawl of the Chinese sites to see what else they may fit. The only other clue is on the gearbox outer is the part number: 0018203 and “RC” and “B2”.

I don’t know if you can see the stripped gear teeth:

In the meantime Soo has just finished her run round and I can report the swap over of the intermediate gear seems to have worked.

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Measurement in mm would be helpful for all Europeans outside of UK! :smile:

0.5 Mod (Metric Module) are metric gear sizes :wink:

The imperial gear sizes use DP (Diametric Pitch)

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Now I got it, thank you!
Learning by asking! :grinning:

I think I have found the supplier of the central double gear:

The shipping is a bit steep if you only want a dozen or so.


The shipping is pure price gouging!!! :astonished:

The manufacturer is in China (where else :slight_smile: )
If you got a friend in Shenzhen
(best would be he/she works in a company there) and you can ask him/her to order some.
Much easier for a Chinese and he/she could send those items in a very simple letter
(consignment) to USA/Europe.

if you have a rc car or hobby shop nearby you can always bring the gear to them and have them order the gear for you in Metal. I did this for a friend who had a different robovac where the gear also stripped.

Chinese company confirmed will not send me less than 1000, so next ploy: 3D print one.

The Stl files are here:

I have just tried printing off those gears and (other than I need to setup my printer again and fit the head cooling fan) they look like they will work :wink:

Tank: hat might be a good alternative to 3D printing.

The issue will be do you want the gear to strip if there is a problem or the motor to burn out…