DIY Vibro-scalpel




With the rising cost of health care, I'm sure you have found yourself wondering about how difficult a kidney transplant could really be. Just like dropping a tranny on a 1989 Ford Tempo right? With this instructable, you can make those DIY hobby knife, health and pet care dreams come true. A DIY vibro-scalpel! Now you too can cut tomatoes like a hot knife through butter, amaze your friends, and run a lucrative cosmetic surgery practice in your spare time. You can't afford to live without this miracle item. Construct and use this tool at your own risk. (Note: Do not use this device to cut living tissue unless properly licensed by the appropriate governing agency)

Step 1: Collect the Proper Components


If you are like me, then you are too lazy to brush your own teeth and have relied on the ministrations of an electric toothbrush for years. The trouble with these and any other consumer item is that they become obsolete. Electric toothbrushes are no exception, and the slim, mouth-friendly models of today mock the clunky jaw spreading antiques of yesterday. As the NiCad batteries in my old Philips sonicare (with quad pacer) gave up the ghost, I upgraded to the latest, slimmer sonicare. Not one to throw anything with any remote possibility of usefulness out, I saved my old toothbrush for the day when it could be retasked to a new, more glorious application. That time has come.

These toothbrushes are a marvel of engineering, waterproof, powerful, and oscillating at high frequency the Philips sonicare can cut through plaque and tartar build up with ease. If this unit can cut through mouth funk, then why can't it cut through mouth too? No reason, no reason indeed. So I set out to marry my trusty X-acto knife with my outdated but hard working Philips Sonicare toothbrush to yield an amazing new tool, the vibro-scalpel.

Search for vibro-scalpel on the series of tubes know as teh Internets, and you will find a variety of hits, all of which involve role playing games of some type. So the idea isn't that new I guess, but the implementation appears to be.

Materials List:

To build your own vibro-scalpel you will need the following (quantities in bold).

1x Electric toothbrush motor body (Philips Sonicare HX4511)
1x Electric toothbrush head compatible with the above motor body
1x X-acto knife, the small size #1

Required tools:

Hacksaw (not Jim Duggan)
Hand drill
5/32" Drill bit
13/64 Drill bit
Propane torch

Below you can see the X-acto knife and toothbrush used for this project, as well as a close up of the business ends of both.

Step 2: Take Everything Apart

Once you have your knife and toothbrush, take them apart to get an idea of how the whole thing is going to work and to prepare for the irreversible modification. See below. Also, this is a good time to clean the crusties out of your toothbrush head. Yech.

Step 3: Prepare the Brush Head for Knifing

Now you will need to cut off the mouth-guard on the brush head. Take your hacksaw and carefully cut around the guard behind the toothbrush head. Try not to cut too deep into the rubber seal. Previously this seal kept your drool from getting into the rest of the toothbrush, and in the future it will keep tomato juice, blood, and puss out of the rest of the toothbrush.

Once you have the guard cut off, then you will need to cut the bristled toothbrush portion off. Again, get your hacksaw out and cut that thing off. Try to cut as close to the bristles as you can so that you have a longer section of plastic to interface with the X-acto knife. Using the X-acto knife you want to then whittle the shaft of the plastic brush head so that it is the same diameter all the way to the seal.

Step 4: Machine the X-acto Knife

Now that the toothbrush head is ready for action, you will need to machine the X-acto knife to mate with the toothbrush. The first thing to do is to drill a 5/32" hole into the handle body from the top, tapped side. So, unscrew the blade and blade holder ferrule. Chuck up your 5/32" drill bit, it should fit nicely through the threads in the top of the handle. Now, drill down into the handle about .5 to .75 inches. Be careful not to mess up the threads in the handle that will hold the blade. See pic below.

Once you have drilled into the handle, cut off the majority of the X-acto knife handle with the hacksaw. You should measure the length of the plastic stub on your toothbrush head, measure the depth the threaded blade holder on the X_acto knife extends into the X-acto handle, and calculate the right length to cut the handle off. For my knife and toothbrush that was about 1 inch from the tapped end of the X-acto handle, with the blade and ferrule removed. See pic below. Once cut, the 5/32" hole you drilled previously should be visible, concentric to the handle body.

Now take your 13/64" drill bit and drill from the cut end of the handle back towards the threads. If you are using a different toothbrush head, then measure the diameter of the plastic stub on the head before drilling the hole in the cut X-acto ferrule. You want the drilled hole to be slightly smaller than the plastic stub that will be forced into the drilled hole. Stop drilling once you get close to the threads. You may need to hold the small piece of aluminum handle in a pair of pliers when drilling. It helps to press down on a workbench when drilling.

Step 5: Put It All Together

Now that the X-acto ferrule and toothbrush head are ready, it is time to put it all together. You should take the X-acto ferrule and start to push it onto the toothbrush head stub. It should be a real tight fit, and you should not be able to get it all the way on. See pic below.

Once the X-acto head is started on the plastic stub, get out your trusty propane torch or other preferred heat source (cigarette lighter, thermonuclear device, etc) and gently apply heat to the metal X-acto ferrule. As you apply heat, grab the X-acto ferrule with pliers and apply a downward force. As the metal heats up, the plastic will soften and the ferrule will slide on the rest of the way. Stop heating and stop pushing when the X-acto ferrule gets down to the rubber gore seal. Let the whole assy cool.

Step 6: Test That Bad-boy Out

Now that the X-acto ferrule is melted to the plastic toothbrush head, you are ready to slice, dice, and whatever comes after dice. Assemble your newly created vibro-scalpel, and find an appropriate item to cut. Perhaps a tomato. Below is a video of my attempts to cut a tomato with and without the vibro-scalpel powered up. Obviously, when powered up the vibro-scalpel when powered up makes short work of that tough Roma tomato. Think of what it could do for that goiter you have been carrying around for the past 20 years.



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    38 Discussions


    3 years ago

    Your description was brilliant! I'm still laughing! Will share. I've been fascinated by this kind of thing since I was little (proto-über-geek) in science fiction e.g. ultrasonic blades, plasma, exploding wire. I'll probably try to come up with one so I can do some selfie brain surgery, remove 3/4ths of my neocortex so I can believe everything on TV and have tons of friends! :P


    7 years ago on Introduction

    You should add the fact that Leaf Cutter Ants are known to vibrate their jaws at around 1,000 times per second to better cut through tough leaves.


    I'd like to try it out with a lockpick head. A lot of pickguns use an up-and-down motion, but I have heard tale of some that simply vibrate. Maybe worth a shot.

    7 replies

    Reply 9 years ago on Introduction

    Thanks for the link, another great use for the toothbrushes. I'll have to give the vibro-pick a shot.


    Reply 9 years ago on Introduction

    up and down motion is used because that is the orientation of the pins in the tumbler. any other motion is wasted energy. any vibration will work, though, if at least some of the vibration is parallel with the pins.

    I was thinking about it, but the main idea of making your own is saving money. This toothbrush doesn't look cheap to begin with.


    I have the exact same toothbrush as the authours, and lemme tell you they aren't cheap. I got mine for about £100 i think. Also, using this as a pickgun would be pretty effective since all you need to do is rattle all the pins in the tumbler until they lock into place.


    Reply 10 years ago on Introduction

    The toothbrush is not cheap, as pointed out. However, the sealed nature of the unit and the eventual decline of the internal batteries gives you a cheap source for these as people throw them out. There is an instructable on here somewhere for opening and replacing the battery cells, but most people will just buy a new one. When mine went south I bought a newer, easier to fit in your mouth model myself if that is any indication. I will give the pick gun idea a try one of these days.


    What would be way WAY cool, would be something like this (a vibro-saw) that could be used to cut rough stone into usable size and shapes for use as building materials. Same with a vibro-drill. All made out of easily aquired, cheap materials. If you'er not sure what I'm talking about, read Robert A. Heinlein's "Farmer in the Sky". Leigh

    1 reply

    This thing is terrific, in that it inspires terror. I'm getting images in my head of the vibrating components of a sex toy being integrated into a sword... This can only end in tears.


    10 years ago on Introduction

    I bet this would be amazing with a real scalpel blade on it instead of the much heavier, stiffer xacto blade.


    10 years ago on Introduction

    Great ible! I thought of this when I saw my first electric brush. Shot down by Mum. Lol. I loved the 2001 reference too. ( I'm afraid Dave. Dave, my mind is going....)

    2 replies

    Reply 10 years ago on Introduction

    Appreciate the comment, but where is the 2001 ref? Great film BTW. I'm pretty sure I wrote this, and I can't find it. My mind is going.... -Jon


    Reply 10 years ago on Introduction

    Were you saying you couldn't find your own reference? It is in photo 1 step 1. There is a comment box around the LED switch. I love this knife. Thanks for putting this up. Also your technique of drilling the hole by going through the top, inside the threads, is one of those "duh why didn't I think of that" moments for me. I probably would have struggled putting a pilot hole in the bottom and hoped the bit didn't slide off the flat edge while I was getting it started (no drill press).