Introduction: Lego Microtome

A what?
A microtome is a machine which cuts (usu.) biological specimens into very thin sections. The sections are typically mounted on microscope-slides.

This was an idea I had, I did it, and I've demonstrated it with garlic
It creates slices 250 microns thick*

*calculated



If anyone is actually thinking of building one of these see the last step. You can also PM me if you need more

L

Step 1: Construction: Base and Mount Runners

The specimen sits on a platform which is cranked forwards by gears. The mounting plate is driven by a rack and pinion mechanism geared very low from a hand crank, such that it moves .25mm with each turn of the handle. The platform rests on the red smooth-faced strips, which were lubricated with Johnson's Baby Oil (paraffin).

These images show the base of the device and the red runners for the specimen platform, also the final drive to the rack.

Step 2: Construction: Mount Plate

The plate upon which the specimen is mounted is essentially two smooth runners (lubricated as the previous step), and a rack.
Being Lego, the plate can be easily customised to hold a variety of samples.

Step 3: Construction: Upwards Towards the Gear-train

Not much to see in this step, I tried to get LDD to work but it hangs ever time (without fail). Perhaps using red instead of black would have been better?
In this sequence you see the front rails that hold the blade assembly being added (yellow and grey)

Step 4: Construction: Gear-train

Most of this is low-gearing from the hand-crank.

Step 5: The Blade

I hacked a disposable Bic safety razor for a blade (note that once these blades are out of the plastic, the word "safety" no longer applies - I cut myself twice through carelessness.)

Step 6: Construction: Finishing

In this step (for the purposes of publishing) I got tired of tedious image-editing, and I'll probably never feel like improving the look of these...
All the way to the end:

Step 7: Additional

With the rack-drive movement can be a little "lumpy", which is why I oiled it. A screw-drive would be better, or something with a worm-gear in it.
The gear-train to the blade cranks is a bit too long: all the gears make it a bit loose. It would work better with lever connections.
The blade assembly (grey) needed glue - it picked-off afterwards, but it's not strong enough without.
As you can see from the video it does work, but I needed to be a bit careful.

Your main considerations are:
A good solid platform that is fairly tight
Similarly for the blade
A lot of reduction from the crank. I work out 3 x 5:1 giving 125:1

Disposable razors tend to be held together with little plastic rivets. You can find these as round blobs on the underside - cut these off with a sharp knife and carefully prise the thing apart with the knife. These blades are very sharp and you'll tend to see blood before you feel anything.
To glue it on - I put the blade and Lego on a sheet of cling-film stretched over a tile, and carefully dribbled 2-part epoxy down the edge.

Best wishes

Comments

author
dianadianadiana made it! (author)2015-12-19

So, I'm about to attempt this as a gift to my histotechnology prof.. Wish me luck!

author
Punkguyta made it! (author)2010-04-06

 Impressive lemonie! Good work

author
lemonie made it! (author)lemonie2010-04-06

I should get the Lego out again, and probably will.

L

author
Punkguyta made it! (author)Punkguyta2010-04-06

 Ever since I was a kid I have been dying to get my hands on one of those lego mindstorm robotics kits (I've played/programmed with them before, they're a hoot!), but alas never have as they originally cost over $350!!!!

Do you have any good ideas for implementing something similar with regular lego? Like how would I go about making a robot/remote control car out of plain legos? I have a giant blue tub of lego from when I was a kid, and I'm sure super-glued together would make one hell of a sturdy frame if designed right?

What kind of software do you use to design lego builds? I know there is software that basically lets you build something on the computer first, before you try it, so you can make sure it will work.

author
ForgerOfPie made it! (author)ForgerOfPie2011-09-02

If you want something a bit cheaper, maybe you should try something like Arduino. It's not Lego-manufactured, but I've seen plenty of Arduinos users that have hacked lego Technic motors to control them. Mail me if you want resources.

And come on, this is INSTRUCTABLES.COM! I know you can find SOMETHING on here.

author
lemonie made it! (author)lemonie2010-04-06

Go find the lego website (old link step 3) and they'll let you download Lego Digital Designer for free. I'm the sort of person that builds stuff, rather than designs though.
Yea, gluing a frame would work, I think what you want maybe that liquid-glue for making models with (kit military & such). The RC bit, I'd just pull from something else.

L

author
Cheezpaper made it! (author)2011-05-20

Put a bug in there. Watch the yellow goo gush out.

author
lemonie made it! (author)lemonie2011-05-21


Cruelty to insects is not one of my favorite pastimes. Still, I appreciate that you had an alternative thought about this.

L

author
michaelgohjs made it! (author)2010-02-27

cool... btw can u please tell me the gear ratio u used between the blade crank and the shaft to move the garlic (i m familiar with lego parts) 

author
lemonie made it! (author)lemonie2010-03-06

Step 7, 125:1

L

author
michaelgohjs made it! (author)michaelgohjs2010-03-24

thx alot .. its gona take alot alot of gears and worm gears 

author
flashcactus made it! (author)2010-01-19

superb!
I WANT ONE!!!

author
dissonum made it! (author)2009-08-23

Excellent! As a histotech, I was shocked (SHOCKED!) to see the word "microtome" on the website. Very awesome.

author
astrong0 made it! (author)2009-08-15

dude you could add a motor to it and make it automated (to a degree)!!

author
lemonie made it! (author)lemonie2009-08-15

Yes. comment Jul 21: I considered the motor drive, but preferred the control of one's hand. L

author
El Mano made it! (author)2009-08-02

That's awesome!

author
lemonie made it! (author)lemonie2009-08-02

(the pictures were the worst part...) L

author
scoochmaroo made it! (author)2009-07-21

Looks like it could easily be automated? I mean if I were using it to cut garlic and not samples. I have way more garlic around.

author
lemonie made it! (author)lemonie2009-07-21

I thought about a garlic press / mincer, but you know what they can be like to clean. I considered the motor drive, but preferred the control of one's hand. L

author
scoochmaroo made it! (author)scoochmaroo2009-07-21

totally! I finally invested in a mandolin. I'm going to throw out those chopper things. They look so promising on tv.

author
fusion made it! (author)fusion2009-08-01

i wanted to get a mandolin as well, times being what they are and realizing that i only needed it for very thin things, i got the titan peeler with the slicing attachment. works great. plus the julienne. it was a good substitute for the 50$ truffle slicer i was going to get. i'm probably going to do this for dehydrating truffles tho.

author
corey_caffeine made it! (author)corey_caffeine2009-07-21

yes but didn't you love his nuts?

author
madhops0620 made it! (author)madhops06202009-07-23

:)

author
conrad2468 made it! (author)conrad24682009-07-21

Itll dry your sweaters............wine coffee cola.......

author
Rotten194 made it! (author)Rotten1942009-07-22

Slap Chop! You're gonna slap all your troubles away with the Slap Chop!

author
swimmer95 made it! (author)2009-07-29

its to hard to see the pictures!!!! and i want to build it!!

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lemonie made it! (author)lemonie2009-07-29

Yes, I wanted to use LDD but it wouldn't work. Had trouble getting the contrasts with a camera, but couldn't improve on this. L

author
swimmer95 made it! (author)swimmer952009-07-30

well i got about half way and then i couldnt finish because i did something wrong early

author
swimmer95 made it! (author)2009-07-29

how do u get the left rail on!!!!! help me!!!

author
lemonie made it! (author)lemonie2009-07-29

Step 3: I had two images the wrong way around, sorry about that. The 5th shows the grey piece with connectors that form part of the front rail guide for the blade (the other side is almost identical). Image 6 shows the rest of this assembly (yellow & grey) and image 7 shows the same piece (complete) for the other side - that one is easy to fit a a complete unit. If this isn't what you're asking about, let me know which step. L

author
ReCreate made it! (author)2009-07-24

Wow, 200 Microns O_o

author
lemonie made it! (author)lemonie2009-07-25

Didn't I say 250? L

author
ReCreate made it! (author)ReCreate2009-07-25

about 200 Microns...

author
Dr.Paj made it! (author)2009-07-21

I've made one of these before. I only used a spool from sewing string, and a eyelet with a long screw (for hanging things such as swings etc.) and just screw it into the circular opening of the spool. You then would place the object you are cutting (carrot, union, human finger, etc) inside the spools hole. So when u twist the eyelet clockwise it slowly moves the object you are cutting forward. Then cut what protrudes from the end of the spool with a razor blade. This way is way less cool, and its a little more dangerous because you have to handle the blade by hand, but its much faster, and it doesn't require Legos.

author
lemonie made it! (author)lemonie2009-07-21

I think I see that idea, what were you slicing? L

author
Dr.Paj made it! (author)Dr.Paj2009-07-24

Anything that fits in the spool that is easily cut by the razor blade. Mainly vegetables so you could look at the cell structure under the microscope.

author
lemonie made it! (author)lemonie2009-07-24

Hmm, I almost bought a cheap microscope, cheap and not finding a web-cam to go with it were the only things stopping me...

L

author
luvit made it! (author)2009-07-22

i was looking for instructions for a guillotine...

author
Fashim made it! (author)Fashim2009-07-23

Why?

author
luvit made it! (author)luvit2009-07-23

to cut cigars?

author
Fashim made it! (author)Fashim2009-07-23

Ok

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lemonie made it! (author)lemonie2009-07-22

That's different, but probably easier to do (model not full-size) L

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maxxxem made it! (author)2009-07-23

Nerf stephan cutter woot!!! hook up the gears up to NXT i am so building this

author
isacco made it! (author)2009-07-23

Very good instructable! I rated it 4. Congratulations!

author
Cat on my Lap made it! (author)2009-07-22

Get an immunohistochemist to give you a tissue sample to cut. If it does so nicely, then you'd really be in the market!

author
Jayefuu made it! (author)2009-07-22

Very cool lemonie. I like :D

author
Arbitror made it! (author)2009-07-21

Not bad for Lego!

author
Jayefuu made it! (author)Jayefuu2009-07-22

Lego >> Knex. Lego is way cooler.

author
lemonie made it! (author)lemonie2009-07-21

Yeah, try doing this with KNEX? L

author
Thinkenstein made it! (author)2009-07-21

This is a great idea. A very creative use of Lego parts. And what a beautiful job of cutting it does!

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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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