Introduction: How to Build a Lego(R) Chainsaw

Picture of How to Build a Lego(R) Chainsaw

Having seen a 'chainsaw' instructable which was not a chainsaw, I started thinking. I had some Lego bits, including:

A motor (4.5v)
Some gear wheels
Some chain links
And some other general bits.

These parts are required, as pictured.

The tricky part was the saw teeth...

Step 1: Saw Teeth

Picture of Saw Teeth

These are the most tricky part, which is why I started on them first.

If you examine Lego chain-links, you will see that they interlock with pins spaced 6.5mm apart. There's enough clearence to get something very thin between the joints to be fixed on the same pins:

Aluminium beer-can, easily cut with scissors & sharp knives (do be careful).

A hammer
A knife blade
A piece of stiff wire (from an umbrella)
A picture nail
An abrasive stick (coarse corundum, probably)
A piece of wood

Please view the pictures for the method.

Step 2: Fitting the Teeth

Picture of Fitting the Teeth

It's best that you work this out as you do this.
Mount one tooth on one pin of a chain link, and secure it by clipping another link over the top.
Then mount the other hole on the tooth on a third link, and clip it to the first, securing the tooth.
(If anyone gets this far, and I doubt it, they'll work it out)

Step 3: And the Rest

Picture of And the Rest

I'm not going into details, this part is relatively easy.
The pictures should give you enough information.
I started with a direct-drive from the motor pinion, but later geared-down (intro picture). However, direct-drive off the motor works best.

Step 4: Action

Picture of Action

Some paper was shredded, but there was some slippage where the steel motor-shaft should grip the black plastic pinion.
Weedy, but concept proven.

Some glue on the motor pinion and this was pretty effective on broccoli.


incorrigible packrat (author)2008-03-22

Groovy! Now make a Lego Ash and a Lego Deadite, for him to carve up.

That would be awesome! especially if they were made autonomous using lego mindstorms.

sharlston (author)2009-10-29

great ible lemonie

lemonie (author)sharlston2009-10-29

Took you a while to find it! (where's this ball-mill you were going to do?)


sharlston (author)lemonie2009-10-30

its oing to be delayed as i was tublining stones and i didnt clear out the silicon carbide very good so it set in the bottom but ill clean it now somehow

lemonie (author)sharlston2009-10-30

It's clagged-up with silicon-carbide? Post a question, that'd be an original one.


sharlston (author)lemonie2009-10-31

well its dry now so ill probaly be able to chisel it out

sharlston (author)sharlston2010-11-27

Old thread but i ended up scrapping all designs and proto types as it made hella lot of noise so i had to run it outside in the shed,there was a leak in the roof and it messed up the motor

X_D_3_M_1 (author)2007-11-25


whoa... thats... creepy...

bounty1012 (author)X_D_3_M_12009-05-11

Doctor Salvatore!

Kaiven (author)X_D_3_M_12008-09-30

LOL.... That looks familiar.... Where is that from?

Flashdude (author)Kaiven2008-11-20

uhh... resident evil, if i'm not mistaken.

assassin1321 (author)Flashdude2008-12-05

resident evil 4 in chapter 1 and 2

paperairplanecreator (author)2010-08-19

dang i thought that metal was paper...

lexioux (author)2010-08-11

hehe, Auto Emo. So have to make one, its perfect for todays Emo on the go.

lemonie (author)lexioux2010-08-12

i never thought of that...


Kush_Slayer (author)2009-07-21

well this looks safe lol

xerxesx20 (author)2009-05-06

Haha love it. The fact it works on broccoli is just an added bonus! Another miraculous and semi-useful/very useful 'ible. :-)

ShampooRobot (author)2008-10-03

I want video!!

andrew13 (author)2008-06-22

and, the point of this?

Kaiven (author)andrew132008-09-30


LePyro (author)2008-08-09

now all you you have to do is to attach it to a inch lego rifle and you'll have the worlds smallest lancer!! XD

Esmagamus (author)2008-06-17

Now you've got to make all the heavy stuff. And that includes Lego dynamite!

llama lord (author)2007-12-28

ah, lemonie, you never fail to astound. {insert heavy sigh)

Rodancoci (author)2007-08-27

Hey, I'm kinda new in Instructables, (though I've made a lot of them) Well, anyway, do you know those cardboard cutters? Could you make the teeht out of them? Just asking.

lemonie (author)Rodancoci2007-08-27

You have to make holes in the teeth. It's easy with aluminium, but you'd probably need a drill for steel. Also, there have to be very thin to fit the chain-links in this way - steel blades (other thank razor) would be too thick. L

Rodancoci (author)lemonie2007-08-27

Oh, OK.

Rodancoci (author)Rodancoci2007-08-27

Is the engine a Technic engine?

lemonie (author)Rodancoci2007-08-28

Yes it's an old (and feeble) 4.5V Technic motor. I drove it a bit above 4.5V, but I don't know how much these will take(?) L

Punkguyta (author)2007-07-30

Auto-Emo, now all the work is taken out of attention seeking!

Punkguyta (author)Punkguyta2007-07-30

Also, any thoughts of making it usb compatible with built in plug and "slay"? 5 volts is enough to run that eh?

lemonie (author)Punkguyta2007-07-31

Now there's a thought (4.5V motor). I do have a spare USB cable, so maybe... L

Neo1 (author)2007-07-12

does it use batteries or an external power?

lemonie (author)Neo12007-07-12

Either. But I used an mains-powered variable DC supply L

Ben.land101 (author)2007-06-18

this would probably work on wood if you were to make the chain and motor stronger. and one question. does this thing hurt your finger if you touch it while its turned on? just curious

lemonie (author)Ben.land1012007-06-19

Well, I haven't tried that. Maybe I'll seek out a volunteer and post the results... L

Ben.land101 (author)lemonie2007-06-19

ok that sounds good

stevoIution (author)2007-05-21

Hahaha, what better to test a mini chainsaw than a mini tree(broccoli) I do remember that other crappy chainsaw "instructable" and this sh!ts all over it.

lemonie (author)2007-05-15

No, but they don't have enough power behind them to bend. Bigger motor and maybe. L

Mace42 (author)2007-05-14

that thing is so cool (i think im obsessed)

rmccue (author)2007-05-14

Awesome. Did the teeth ever bend?

Mace42 (author)2007-05-10

sweet. i want one!

Mad Cat (author)2007-04-17

Ouch! Imagine...a Lego Mindstorms robot with a chainsaw that chases after you. Of course, it would need a clown mask to make it more evil.

lemonie (author)Mad Cat2007-04-17

I just did imagine that, it was great (thanks) L

potbellypiglord (author)2007-03-21

That is the coolest lego thing i have ever seen!

Brian Henderson (author)2007-03-12

That's a really funny Instructable. I like it - great job!

hack124x768 (author)2007-03-11

Was the broccoli steamed, boiled, or raw? I would thing that boiled would just fall apart anyway, whereas raw is still pretty tough.

lemonie (author)hack124x7682007-03-11

Raw, it's still in the fridge. Given that I've already got bits of green and juice on the thing, I anticipate a mess with mushy-veg.

Jack Daniels (author)2007-03-11

i would just like to point out that you could do 2 other things here. A) use several of those razorblades instead of making a blade B) some Real chainsaws have small enough teeth that you could use them this would be a great servivle tool if build well enough

About This Instructable




Bio: I'm an experimentalist, a scientist and I have a tendency to do things just for the sake of doing them, or to find out ... More »
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