Introduction: Junkbot in Resin

About: I've always liked pulling things apart - it's the putting back together again that I have some issues with!

Seems like I'm sticking everything in resin these days!  

Mostly I've been sticking LED's into resin.  The 'ibles for these can be found which can be found here, here and here.  

You could virtually stick anything you wanted into the resin; I decided to go with a “junk robot”!  In my dancing robot Instructable I also used a couple of junk robots so if you want some more inspiration check out the ‘ible here

Junk robots are really easy and fun to make.  All you need is some old electronic hardware and circuit boards, super glue your imagination and you’re away.  I find that the older the electronic components the better.  My junk robots were made from parts I scavenged from an old video player and tape recorder, but really you could use just about anything to make them.  Just type in junk robots into Google and you’ll see what I mean.

The following will take you through how to make a junk bot, stick it in resin and light him up.

Step 1: Parts and Tools


1.  Junk!  Any old junk really.  My favourite things to use are old electronic parts like motors, capacitors and vintage resistors.  All these things can be pulled out of vintage electronics.

2.  Resin

3.  Core flute (to make the mold)


1.  Wire snips

2.  Soldering iron

3. Measuring cup

4. Pliers

5. Hot glue

6. Super glue

7. Drill

Step 2: Making a "Junk Robot"

Making your own junk robot is really pretty easy.  The main thing that you are going to need is a good collection of old electronic bits and pieces and imagination.  

You can scavenged electronic bits from different places such as 2nd hand shops (thrift shops) hard rubbish, tips, friends and family.  Most people have some type of old electrical hardware sitting around, it's just a matter of getting your hands on some and pulling it apart.

There are some really impressive ones on Google - just type in "junk robots'.  These might give you some inspiration and guidance on what is possible.  Most of the junk robots that I've made to date have only been very small ones so electronic components work a treat.

Below are some of the ones that I have made in the past.   

Step 3: Making Your Junkbot - Part 1

So first things first.  You need to gather together a good collection of junk parts.  As mentioned before, these can come from just about anywhere.  I purchase most of my vintage electronic bits and pieces from a local tip which has set-up a shop to sell off all the cool things people throw away.

I'll take you through how I made my "Lanky" junkbot 


1. First find a suitable motor.  I believe that this one is from a floppy disk drive.  Other good places to find them are; hard drives, walkmans, old tape players, toys.

2. Next make the arms.  I used some vintage resistors and bent them as shown below. 

3. If your motor has some holes in the top like mine, you can just super glue them into place.  If not, you might have to make your own with a drill and small drill bit.

Step 4: Making Your Junkbot - Part 2

To make the legs I did the following:

1. Find a couple of small capacitors.  These will be the bottom of your legs.   Take off the plastic coating.  It comes off pretty easily if you score down the middle with a Stanley knife.

2. Remove the 2 wires at the end and make sure that they are flush with the top of the capacitor.

3. Make a small hole in the bottom of the capacitor. 

4. Prepare a couple of small vintage resistors by straightening the wires on both ends and trimming.

5. Push one end through the capacitor.

6. The other end will need to go onto the bottom of the motor.  Your motor should have a couple of tabs where solder gets added.  Add some solder to both the resistor and motor tabs and solder together.

7. Now you have some legs!

Step 5: Making Your Junkbot - Part 3

Lastly you‘ll need a head for your junkbot.

1. For the head I used a trim pot that has a metal shield around it.  You will find these on most modern and vintage electronics and they make great housings.

2. Drill out the insides so the metal casing is hollow.

3. Next I added a RED LED which I trimmed around the edges and super glued into place.

4. Drill a small hole in the middle of the metal casing and push on top of the motor shaft.  Glue into place.

TIP: give your junkbot some life by slightly tilting his head and bending his legs.

Step 6: Making the Mold

Step 7: Cast Baby

Now the fun begins!  Time to organise the resin, catalyst, measuring cup, container and mould and get casting!

I have written about casting a few times in my Instructables and gave a pretty detailed description on how to do it.  You can find that here from Step 5 if you want more detailed instructions.  The one tip that I can give is be careful how much catalyst you use.  If you use too much the resin will heat up and crack.


1.  Glue your robot onto the bottom of the mold.  Position it and make sure everything is where you want it before you start to pour the resin.  

3. Mix a batch of resin, enough to over the robot totally and pour.  Leave to dry for 24 hours.

4. Once the resin is totally dry, remove the mold.

Step 8: Finishing Up the Resin

If you  used the right amount of catalyst then your resin should be clear as water and you won't have to sand.  Sanding is really only necessary if the sides of the resin are unclear.  If not, then you will need to do the following:


1. Use some 400 grit wet/dry sandpaper and sand all surfaces until smooth.

2. Next use a 600 grit wet/dry sandpaper and repeat.  You will need to use a lot of elbow grease to ensure the resin becomes clear.

3. The last part of sanding use a 1200 grit wet/dry sandpaper and go over all of the resin.

4. To get that glass finish you will need to rub the resin with a car polisher or Brasso.

Step 9: Adding a Light

In some of the photos, the robot is sitting on top of some LED's.  If you want to also have your robot glow, then you will need to make a previous instructable that I did "LED Light Globe Hack".  The only thing that needs to be done differentlyare the following:

- you don't add the diffuser to the LED's 
- Break the legs off 4 LED's and glue the tops on the LED's to the corners of the heat shield.

Thats it!  

The resin acts as a diffuser and scatters the light really well.

Step 10: The Ones That Didn't Work!

I have a couple of failures when casting these little robots.  I was adding too much catalyst which was causing the resin to heat up and crack.  The strange thing is, I was only adding the amount suggested on the packaging!

I have noticed that the ambient temperature can have an effect on how the resin sets.  On the successful one, I used about 2/3's of the suggested catalyst and this seemed to work fine.  It takes a little while longer to set but came out without cracking.

In regards to molds -  using a soft plastic like an ice-cream container makes the resin come out super smooth.  The sanding only needs to be done to the top of the resin.  The problem I had with it is most containers made from this material have rounded corners and I wanted square ones.   

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