Tuesday, July 19, 2011

Roomba Side-Brush Repair

One of Chris's demands I had to meet before I could get Eva was that we buy a Roomba so our house isn't covered in cat hair. I resisted buying an expensive house-cleaning robot (unnecessary!), but I will never look back now that we have it.  What's not so great is that its little parts tend to give out. After three years, though, we have the same one, so it's not so bad.

One of the first issues we had with it was that the side-brush module broke. It started making this horrible grinding sound and the brush wouldn't always spin. We bought a new one the first time, but a few weeks ago the side brush started making the same nails-on-a-chalkboard-level-of-annoying grinding sound. I couldn't stand to have it run while I was around, but I didn't want to buy another $25 part that was obviously going to break the same way again. This time I was determined to fix it myself.

What did I find when I got the little module popped out? A teeny...tiny screw that looks like a Phillips-head screw, but it only has three "points" on its head for a screwdriver to fit into, not four. I Google'd it and found a post where someone else was trying to open their brush module too and asking what they could use. No luck. I went to Home Depot and a very friendly associate told me he'd never heard of what I was describing, and sent me to a magical place called Grainger. I'd seen it before, but thought it was a tractor-supply store. It turns out, it's a industrial supply store with 900,000 parts! The guy helping me, Duke, was awesome, and together we discovered that what I needed was something called a "tamper resistant" screwdriver head. That is sooooo just what a company that wants to sell you another part would put together their plastic parts with. So I ordered the little guy, went back the next day, and picked up my magical screwdriver head.

Back home...down to business. I took apart the Roomba, as usual, but this time the little wheel assembly screw was defeated! I didn't see anything that looked broken, so I cleaned all the fluff off of all the plastic cogs, and put it back together. Once reassembled, the Roomba still made the same awful sound. Back to Google. I found a Flickr photo-stream by someone who'd done the same exact repair. Only, when he did it, he still had remnants of the crappy plastic bearing so he knew what needed to be replaced. Ours had been ground down into oblivion and probably the dust vacuumed up by the Roomba. This guy had the perfect-sized washer to sub into his brush module, but the ones we have are all slightly wrong in one way or another.

The pictures pretty much outline the rest of the operation.

Here's the Roomba with the bottom plate taken off. The little screw that's causing all the trouble is the one in the middle of the blue part of the side brush -- not the one holding the yellow brush on. You can see the weird three-prong screw-head if you look reeeaally closely.

Here's the brush module out of the Roomba.

Here are the "tamper resistant" screwdriver heads I got from Grainger.  The were a little too big, but the tip of the screwdriver bit was pointed enough that it worked anyway.

They were designed to be put into a drill, but I'm using them in my screwdriver. They were too short, so I ended up putting them both into the screwdriver shaft and being careful to use the screwdriver in a way that they didn't fall out. Why there were two in a package, I just don't know.

This is the inside of the brush module after you get that d@96 screw out. It's a bit blurry. I'm still getting used to our camera.

Here's the hack that I put in since I didn't have a replacement bearing or a washer that would work. It was a random ring that I found in the toolbox and pulled apart with some pliers until it was just the right size and sat down flat on the broadest part of the gear.

So that's that. I snapped the top on, screwed all the screws back into place, and the side brush spun happily (and quietly) along!

Update: I happened upon a tiny washer while walking down a sidewalk at work. I saw it and though, "THAT would be perfect in the Roomba side-brush!!" How pathetic am I? So I put it in my pocket, brought it home, and have gotten around to putting it in place of the little loopy thingy I used before. It's SO much better.

The new washer
The amazing new washer placement
 So this one sits higher, and seems to be much better. Yay again!

1 comment:

  1. i'm with the same annoying problem, but i didn't understand quite weel the detected issue because my main language is portuguese and there is lack of images in this post that could help me understand better the, noise. I know that the noise is from this module because i remove the side brush and start cleaning and the noise stopped. So maybe is some mechanical part that is being forced when the brush is attached. i must say also that when i start cleaning, the annoying noise only start after half a minute.