Upcycled Dryer Motor Makes Budget Disk Sander

At the most basic level, most shop tools are just a motor with the right attachments. But the details are often far from simple. [DuctTapeMechanic] took a junker clothes dryer, yanked the electric motor from it, and converted it into a disk sander. The price was right at about $10. You can see it all after the break.

As you might imagine, having the motor is only half the battle. You also need a way to mount the thing securely and a way to affix the sanding disk. While this doesn’t pose the same challenges as, say, a drill press, it does take some thought. The motor in the donor dryer didn’t have threads on the shaft, so a bolt and some welding time took care of that. We suspect that’s tricky because you need the shaft and the bolt to be concentric and level.

Once you have a threaded shaft, the rest of the build is anti-climatic. A little carpentry and a little electrical. We would probably cover up the electrical connections a bit more. It seems like you’d want to know which way the motor spins so you could use a reverse thread, if necessary. From the video, we think the motor he has was spinning the right way, but we don’t know if that’s always true.

There’s something satisfying about building your own tools. If you work on smaller things, we’ve seen a miniature sander that might be handy to have around. If you want to go the other way, try finding an old floor polisher instead of a dryer.

40 thoughts on “Upcycled Dryer Motor Makes Budget Disk Sander

  1. You can buy shaft adapters which attach using a set screw for a few dollars. A weld like that is not likely to be sufficiently concentric or safe. That is not an enclosed motor. Any moderate usage will get a fair amount of sawdust into the windings and around the bearings. A fire hazard. If you just enclose the motor it won’t properly cool. There’s no insulation over the quick connects. Only a small area exposed but it’s 110 volts and not acceptable. You need the proper motor for this application. Being cheap is fine. Reusing materials is fine. Being unsafe isn’t fine. Sure, I did stuff like this. When I was 7 years old and had no competent supervision. There needs to be a higher standard here..

    1. I did appliances for a living. These motors are exposed to copious amounts of very fine lint regularly. Lint is much more flammable than saw dust. I have never seen charred lint in around or on dryer motors. Just lint.

      Even if that weren’t the case, dryer motors have self testing thermal fuses built in.

    1. I wish these Hackaday articles would come with safety warnings. Even if the disc wasn’t wobbling, I just wouldn’t trust a tiny layer of MDF holding that disc safely and be sure it won’t ever burst in my face. I like how he just takes high voltage, runs a big enough motor , puts no protection , and is willing to just put his hands and face near. If I can find a sander for 200 CAD$ online from a decent retailer , I’m sure there’s a ton of chinese builds out there that are probably under 50$. I would trust those way more than this contraption.

      1. “I wish these Hackaday articles would come with safety warnings.”
        Why??
        Aren’t we all adults here???

        Growing up we had a pedistal grinder my father build from a washing machine motor. He tapped both ends of the shaft, one side left hand tapped.
        Two gear clamps and an old peace of steel I-Beam cut into a couple of peaces of other scrap for the feet and the grinder was done.
        With a brush on one side and a stone on the other side, and yes you had to unplug it to turn it off.

        You need a few deadly tools in the shop, or it’s just not as much fun.

      2. Just no!
        We do not need more safety warnings. One general warning “life is dangerous” is enough.
        We have an organ called “brains” to think about safety the precautions necessary if we build something. Of course it is really important to use it appropriately.

  2. First post mysteriously deleted. OK. This is a good example of the things NOT to do. I count four ways this is unsafe. How many can you find? Yes, I saved $10 but got injured, an electric shock and started a fire. Good example.

    1. Eyah, I hate to dog people for exercising their creative muscles, but this seems like a not awesome idea.
      I count a dozen+ used disc sanders local on Craigslist at the moment. The cheapest one is Delta for $65, and the most expensive one is still hundreds of thousands of dollars cheaper than facial reconstruction surgery.

      1. Also, the hazard fraught has a number of bench grinders starting at like $20, although at that price they’re best suited for grinding TIG electrodes and not much else. Quality they are not, but at least their shafts are concentric and made of a solid piece of stock and since they know their cheap wheels are bound to fly apart they even put a semicircular shield around them.

      2. Hundreds of thousands cheaper than reconstructive surgery? But… surgery is free here! Welcome to state funded healthcare!
        If that’s your best argument against this, you might as well give up.

        1. I’m not sure,
          are you referring to Canada,
          where there is a 10 month waiting list for pre-natal care?
          B^)
          When the government pays for your healthcare, the government decides your healthcare!

          1. Oh yeah? I remember Canadians having heart attacks in the US. Americans did a good job fixing them up. Few weeks later in Canada, they receive a bill for $80 000 US.

            Canadian healthcare might not be the best, but you will not die on the street sick if you are poor or go bankrupt due to health emergency. For that level of service, you must move to Greatest Country on Earth ™.

  3. The wobble is probably coming from the skewed bolt that he MIG welded onto the motor shaft. Or MIG tacks, hard to see if he actually ran a bead on it. I’d hate to have my face nearby if that weld fails. Lets not talk about the welding of the galvanized brackets either, at least he was outside. What’s that old saying? A man gets a MIG welder and suddenly everything is a nail? Something like that.

    1. The only sensible reason to do this is because you enjoy it.

      The skills required to build this are always in demand and can earn you enough money to buy a purpose-built tool in short order.

      1. I agree, mostly. However, it is also fun to learn what are the minimum parts to which a tool can be deconstructed into, to see how it ticks, so to speak.

        Also, in many less developed areas of the world, this would be a legit tool if nothing else is available.

  4. Well, I have to agree that there is a lot of danger in this build. However, if you read all of the commentary and make your design safer, it might be a win for some low budget shops.
    Upcycling is going to become extremely important in the future if our civilization breaks down even a little. Some people suggest buying a cheap Chinese knockoff. What if China stops exporting for any reason?
    I have taken apart a few home appliances in the past. I save and reuse as much as possible. I cut off any flat metal panels and bend and cut them with my shear. Sometimes there are small reusable sensors, motors, and activators.
    The controllers are useless. I wish someone would put out a line of appliances that all operate using an Arduino or something opensource. That way I could just pop it out and reprogram it for some other use.

  5. this video touches on the thing that absolutely aggravated me as a kid when i really only had $10 to spend on tools, and could have, would have actually used this as an alternative to just buying a used or hazard fraught sander.

    this guy built this with a $300+ welder setup. as a kid, i had a corded drill, a bucket full of spare parts, another bucket of sand paper, and some drill bits.

    brag about a $10 build when you can manage it without any tool costing more than $30. because that is who is going to build this.

    1. Indeed, I don’t mind calling it cheap if they used a nailgun type tool – which is just a more convenient hammer and nail combo – as its still accessible to those with only the basics. And as pointed out not doing a great job.. I mean a simple enclosure wouldn’t be hard, and the disk really needs to be made of just about anything else…

      Could do a build a like this more properly with common odd’s and ends – the plastic lunchbox etc is a ready made enclosure that just needs a few holes put in it. A fan to cool the motor isn’t hard to get – could even just create some openings to point your rooms fan onto it.. And that disk material… even a scrap of the horribly thin steel most PC’s and white goods have as a case would be better – hammer a bead round the edge and some ridges for stiffness. However being a dryer motor it probably already had a perfectly good drum you could with hand tools and work trim down to use – which would then mount to the shaft properly too!

  6. The naked motor just shows when it needs cleaning, a toot of air now and then. Every shop motor I’ve seen that is air cooled the windings and bearings are hidden. But they still get just as dirty in a wood shop and become a little oven cooking the motor because nobody sees or takes care of blowing it out now and then.

    I did this years ago with the adapter mentioned above1/2 or 3/8 shaft to a wheel friendly thread and nut. I used it with a wire wheel on large rusty metal held sideways no shield. The motor was held with both hands. More speed and power than a hand drill by far.

  7. Many AC motors can be wired to run in either direction.
    I don’t have a decent welder. If this had been my project, I would have gotten the motor running and then forced the shaft up against a drill bit held in a vice (or found some other way to make a centered hole in the shaft), and then tapped the hole. From that point, many hardware stores have disk sander attachments for power drills that can be cannibalized for a sandpaper holder.
    That said, I don’t like exposed large diameter things spinning at high rpm, and AC motors like this are usually about 1800 rpm. I’d want a belt and a couple of pulleys to get it down to 600-900 rpm or even less, and all of a sudden it’s no longer a simple project.

  8. That’s certainly the “Sergej Machansky” way of making stuff – with an electrical power shock for free if you are lucky to touch any of the cables or connectors.

    I mean for god sake just use any kind of casing or cover it with duct tape or at least put a cardbox over it (both last not ideal but better than nothing).

  9. While probably unsafe for those who don’t practice safe work habits and/or use ppe, these are the kind of things that worked for most people in the last century who didn’t have access to internet shopping or big box hardware stores. I grew up with a washing machine motor strapped to a workbench with an arbor adapter and a grinding wheel. It was the only one in the neighborhood and everyone used it when something needed to be ground. May be hard to believe, but nothing happened other than a lot of jobs getting done.

    That said, bench grinders and sanders are pretty cheap relative to what they cost back in the day, so I would recommend purchasing one if your need is more than temporary. Other than the safety factors, it’s just easier to do a good job.

  10. All the idiots claiming these are unsafe due to using a drier motor… I’ve been using a drier-motor-powered disc sander since I was 7; I’m 51 now and inherited the sander from my father, who at 80 does not have steady-enough hands for using power tools. I concur that an MDF (or HDF) disc is a bad idea. Mine uses the steel disc/mount you would use to attach to a radial arm saw. The drier motor came from a mid-60s drier and actually predates my birth, but I wasn’t allowed to use power tools until I was 7. Echodelta is correct that a shot of air from the compressor is all it needs to stay clean.

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