DIY Vacuum Cleaner Fix

It’s not like the vacuum just stopped working one day. I knew it was on the way out. You could hear it—that slight grinding sound. It wasn’t right. My guess is the bearing in the motor.

Well, one day it finally did stop working. That means vacuuming the rugs with a shop vac (btw—love my shop vac). Oh, the vacuum that broke was a Shark Rotator NV341. Clearly not a top of the line machine, but I found it did the job it needed to do. It had been running well for quite some time (my guess is 5 years). Also, it probably failed because some people (not saying which people) didn’t clean the bin out and clean out the filters. That’s just a guess.

OK, I really didn’t want to buy a new vacuum cleaner for 300 bucks or more—and there is no way I would plop down a ton of money for something like a Dyson. People say they are awesome, but I just don’t see how it would be worth the money. But that leaves me with really just one option—fix it.

The nice thing about fixing something broken is that you can’t make it any worse. It’s already broken. So, the first step is to start taking it apart. Surprisingly, it was fairly easy to get to the motor. Everything else seemed to work fine. I started to take apart the motor, but that was a dead end. But it was clear—the bearing (or something) would prevent it from rotating every so often. It was dead.

Next step—google. Can I find a replacement motor? There were some Shark motors on Amazon, but they didn’t match my model number. I found some on Ebay that were cheaper but again they didn’t match. The ebay motor was cheap enough, I decided to give that a chance. Maybe it would work.

It didn’t work. The new motor was bigger. There’s no way it would fit into my model. But after looking at the two motors (the original and the new one), I decided to give ebay another shot. I wanted a smaller motor. It seems that there are two kinds of Shark vacuums. There are full size models and then the “stick” style. It looks like the Shark Rotator uses the small stick-style motor.

Oh wait! I have another Shark vacuum—the stick kind. The only thing that doesn’t work about it was the rotating brushes for cleaning carpets. But the main motor works. What if I take that motor out of the stick and put it in the Rotator? Surely Shark doesn’t make THAT many different motors.

Damn. That stick vacuum was quite tough to take apart. But I did it.

Here is a look at the three motors (from left to right: the shark stick, the broken Rotator, and the oversized motor).

The stick motor was in some type of plastic shell, I had to get it out of there to use it in the Rotator. Oh, the stick motor was a little too small—but I added that large rubber gasket from the broken motor and it seemed to work.

After putting it back together, the vacuum actually works. WINNING.

But that’s how it goes with fixing stuff. Sometimes you win, but sometimes you fail. Winning is way more fun than failing.

Adventures in Spark Gaps

I wanted to build a spark gap transmitter—you know, for fun.  However, things didn’t start off so great.  Here is how it went down.

My first plan was to build this.

I like it, but it uses an ignition coil and some other thing.  However, check out the receiver.  That’s awesome.  It’s a coherer receiver (I think) and it basically detects a spark with those two bolts in the plastic sleeve.  There should be some iron filings or something in between the bolts.  When a spark is detected, the filings jump the gap and make it a conductor.  I’m not sure why the LED light is connected to a 9 volt battery though.

After that, I just did some google searches for spark gap transmitter and attempted to build the designs I saw.  None of them had capacitor values, so I just had to guess.  But they didn’t work.

I honestly thought I knew how to do this.  I tried a step up transformer with a capacitor.  Nope.  Actually, I was getting a spark on the battery side but not the step up voltage side.  How did I even pass physics courses?

Here is my attempt with a transformer.

Finally, I found a page that used an electromechanical bell.  That works.

I decided to build my own oscillator from scratch.

Homework (for me)

  • Make this more solid (the connection to the steel plate is iffy.
  • Could you replace the steel plate with a paperclip?
  • Can you change the buzzing frequency by adding weights to the oscillating bar?
  • Use a step up transformer to get BIGGER SPARKS.
  • What about an antenna?
  • Build a coherer detector.

Peltier Cooler

I have this small wine-refrigerator that is both old and not working.  I don’t really need it, but it’s nice to keep extra beers and wine in there.

My idea is to get a peltier cooler and convert this from a compressor cooler to a solid state cooler.  Of course it won’t be as efficient or cold – but as long as it gets just a little bit cooler I will be happy.

I ordered some coolers online (they weren’t super expensive) and they seem to work. It requires 12 volts and up to 5 or 6 amps – so the power supply might be an issue (it seems many people use a computer ATX power supply).  Actually, you can just connect it to a D-cell battery and put your fingers on each side of the cooler and easily feel a temperature difference (great for demos).

With a temporary power supply, I put the cold side of the peltier on a big aluminum block and then I put a cpu heat sink on the hot side.  This didn’t work – but here is a picture.


It turns out that the peltier cooler gets hot – but it keeps a temperature difference between the two sides.  So the key is to keep the hot side as cool as possible.  With this in mind, I switched it so that the hot side was on the block and there was nothing on the cool side.  I still didn’t work very well until I put some thermal paste between the peltier and the aluminum block for good thermal contact.

Here is what I get.

Pretty cool, right?

I will keep you updated.