Introduction: Hot Glue Casting: Instructables Robot {L.E.D. Backlit}

About: I am an Electrical Enginnering student . Just love using things lying around to make new stuff!! :D I have been around here since 2009, though I started posting some of my own only since 2012. I believe Instr…

This Instructables is not only about The Instructables Logo - The Robot, But it also about HOT GLUE CASTING!!!...It shows you how you can make your very own Instructables Robot model!!!.. Which could also double up as a cool night light!..

After seeing one too many instructables on How to make the instructables robot, I have been wanting to make one of my own, in my very own way!!!

Now, hot glue is used as an adhesive by most people, but I decided to use it as a casting material... and It turned out really great!!!...

For some amazing pics of it, roll over to the last step!!!... :D

Step 1: Gather the Supplies!!!

  • Hot Glue Sticks. {Buy it from your local crafts store or see here.}.
  • Sugru {Red}. [Buy it , or win some by posting some awesome instructsbles!!!...  ;) ].
  • M-seal {epoxy} (optional -- may use sugru or any other epoxy in it's place). {Any epoxy from your local hardware shop would do the job!}.
  • Elmer's glue (or fevicol or any other similar glue from your local crafts store!).
  • UHU super glue (optional). {Buy it here}.
  • Clear Tape / Electrical tape (optional). {From your local crafts store!}.

  1. A Hot Glue Gun. {Buy it here}
  2. Cutter Knife.
  3. A pair of Scissors.
  4. Soldering Iron with Solder (optional). {Buy it here}

  • Double Layered Cardboard ( The one, usually used in packaging of heavy goods).
  • Black Chart Paper.
  • A female USB port.
  • A male to male USB cable.
  • A  5.5X2.5 mm female dc jack  (Only in case you are planning to use more than 25 L.E.D.s as I did!).
  • A power supply (Only in case you are planning to use more than 25 L.E.D.s as I did!) {I used a SMPS!!!}.
  • A Power Switch (3A, 250V -- ratings actually depend upon the supply voltage in your country).
  • Connecting Wires.
  • Pet Bottles {or any other sturdy plastic would do the job!).
  • L.E.D.s {The more, The Better!!!... I used 40 L.E.D.s -- 3.6V, 18mA}.
  • Yellow (water based) Paint.
  • Black marker pen.
  • Aluminium foil paper
  • 10 ohms resistors (at least 0.25W)--3 pieces
  • A bowl (to be used as mould for the body!).
  • A glass (to make the cavity for the L.E.D.s!!!).
  • Cellophane paper (optional).
In case you are not able to get anything, just leave a comment...

Step 2: The Head

Now, for casting things, the first thing required is a pattern that needs to be copied!... If I had my way, I would have used 3D prints as pattern for each body part... But as I didn't have access to any of those 3D printers, Here's what I did for the head...
  1. Take a piece of thin cardboard andcut out two strips of 6X3.5 cm and two strips of 6X4 cm.
  2. Make two cuts of 3.5cm each on the two strips of 6X4 cm so that the cuts are 3.5cm apart and have a thickness same as that of the cardboard used.
  3. Now, arrange these cutouts as shown in PIC-3.
  4. Now on any metal surface, put some oil (so that the hot glue doesn't stick to it!.) and put some clear tape on the insides of your mould.
  5. Pour the hot glue from the gun inside the mould ti fill it almost completely.
  6. When the glue is bit dry (say after 5 minutes), place some L.E.D.s (I placed THREE) at the top such that, the L.E.D.s are completely submerged in the mould, but their legs are still out of the mould.
  7. After glue is completely dry, rip apart your mould, and you should then get something similar to as shown in PIC-5.
  8. Now, take an empty Ball-pen refill, and cut it in lengths of 4cm, and colour them black with a black marker pen, and put these in place of robot's ears with the help of a super glue.
  9. Now cut open a pack of red sugru and make the eyes and the area around the ears of the robot. (You are free to do this in your own way!... But remember to keep a template of the robot in front of you while doing this!!!).
  10. Use again a black marker pen to make the eye brow(s) and the lip(s) of the Bot!.
  11. Now connect the L.E.D.s in parallel and you should get something as shown in PIC-1.
Done!!!.... :D

Step 3: Body

For the body:
  1. Take a suitable Bowl -- to be used as mould for the body (mine was 10 cm in diameter)  (In case of a glass bowl, BEWARE!.. thin glass might break when hot glue is poured inside it!.. sadly, I'm saying this from experience!!!).
  2. Now take a suitable glass (of base width less than that of the bowl!) and oil it's outer surface, and also oil the inner surface of the bowl.
  3. Place the glass inside the bowl (in the middle of it) over a small circular disc, conjured out of any epoxy based material (my PIC shows sugru, but later I decided that since after the casting, the disc would be of no use,so,  I should rather use M-seal, which is an epoxy, much cheaper than sugru, but a t the same time, much creepy to work with!!!).
  4. Pour in hot glue from the gun (This part here, really required some great muscle power!!!!).
  5. After the glue is dry, take out the the glass first, and then your cast from the bowl! (Now you see, why the proper oiling is required!!!).
  6. Cut apart any extra protruding glue from the body!.
  7. Make the (outline of) buttons , the front rectangle (I really have no idea, for what purpose that is for!!) and the Belt (not shown in the PIC--but Drawn later!!!)  with help of a black permanent marker pen.
  8. Fill in the Buttons with some silver water based colour!.
Done!!!... :D


Step 4: Hands and Legs

For the LEGS:
  1. Take any suitable thing which can serve as a pattern for the legs (like a thick sketch pen or a marker or something as shown in PIC-2).
  2. Wrap this thing with silver aluminium foil (make sure that there are no/less creases or lines on the foil!).
  3. Now wrap this foil with clear tape so as to make it a bit sturdy! (wrap another layer of tape in case necessary).
  4. Pull out the foil covered with tape from the pattern and put it aside safely.
  5. Cut a circular disc out of the cardboard of diameter equal to the inner diameter of the body cast you've made earlier.
  6. Cut in this, two small circles of same diameter as that of the pattern you are using for the legs.
  7. Put the foil covered with tape in these circular holes (you should now get something similar to PIC--6,7).
  8. Pour in hot glue in these moulds and get the legs in a similar fashion as you got the face!. (but do not throw away the circular cardboard base!... you'll need it in some time...).
  9. Put in some L.E.D.s in the legs in siimilar fashion as in case of the head!.. (don't forget to connect them all in parallel!).  {HERE, MAKE SURE THAT THE WIRES COME OUT FROM ONE END (FOOT) OF THE LEGS AND THE LEDs ON THE OTHER END HAVE LONG ENOUGH LEADS SO THAT THE WIRES FROM THE REST OF THE BODY PARTS CAN BE SOLDERED ON THEM!!!}

For the HANDS:
  1. Now here, the pattern has to be made first free hand with the help of any epoxy of your choice (I used M-seal). {as in PIC-8,9).
  2. Let the pattern completely dry. Then to make a mould from this pattern, again use epoxy (BUT REMEMBER TO OIL THE THE PATTERN AMPLY!!!..... OR YOU MIGHT END UP WITH THE HAND YOU'VE MADE TOTALLY GLUED TO THE MOULD YOU ARE PREPARING!!!). {I made the mould in two parts as shown by PICS--10,11).
  3. Now oil the insides of the mould properly and pour in hot glue in both the halves and QUICKLY close them two (PIC--12)!!!.
  4. Open the mould after say 10 minutes to take out the hand (PIC--13,14).

Make the markings on the hand and the legs with help of the black marker pen. (similar as in the Robot's official logo!!!)

DONE!!!... :D


Step 5: L.E.D. Back-Lights and Spotlights!!!

For the four spotlights :
  1. Take a pet bottle (similar to that in PIC--3) and cut apart the top and bottom parts of it.
  2. Now, fold the middle portion (of appropriate length--I took 4 cm) into a cylinder (keeping in mind, that the base of this cylinder should be large enough to accommodate the number of L.E.D.s you intend to use in the spotlights--I used 4!!).
  3. Now cover the insides of these cylinders with silver duct tape/aluminium foil and outer surface with black paper (PIC--4,5).
  4. Now take another piece of thin cardboard , place the L.E.D.s on it in groups of four, make their connection (in parallel!!) and finally, cut them all out. (PICS--6,7).
  5. Now just attach these L.E.D.s at the bottom of the cylinders and you're done!!! (PICS--8,9).
  6. Also, here I'd like to mention that I forgot to paint these white L.E.D.s yellow!....So, I used a yellow cellophane paper to make front covers for the spotlights to make them give out yellow light!!!....(PIC--10).

For the L.E.D. Back-lights:
  1. Now take some L.E.D.s (I took 19) and paint them all yellow with a yellow water based color paint (PICS--11-16).
  2. Put these L.E.D.s (after they dry out) on a cardboard, and connect them all in parallel (PIC--17,18,19).
  3. Cut the cardboard away and you should get something similar to that in PIC--20!).
  4. Putting these 19 L.E.D.s in the body now, is quiet a task in itself!.... for this, just plug in your glue gun, without any glue stick!....when it's just hot, touch it on the inside cavity of the body cast, you prepared earlier and immediately place the first LED in it's place!.... when the glue dries out, the LED would remain at it's place!....repeat for all the rest of the LEDs!...

DONE!!!.... :D

Step 6: Assembly!!!

Now finally the amazing part !!!
  1. First attach the head carefully with the body with help of hot glue/any other glue  (the wires from the head should go inside the hole on the top of the body and the head as whole should finally cover the hole on the top of the body!)
  2. Now attach the hands and the legs carefully. (the legs should be first placed in the circular cardboard which I told you, not to thro away!).
  3. The wires from the head+body should be soldered in their suitable positions (so that all the L.E.D.s in the circuit are still in parallel!!).
  4. Now cut out six 8X5 inches pieces from the cardboard.
  5. Out of these six, make holes for the legs of the Bot on two, exactly in the centre!.. (PIC--3,4). Paste these two pieces together first.
  6. Cut a 16X13 inches piece from the black chart paper and paste it on one side of the two cardboard pieces pasted together, so that the carboard pieces are exacly in the middle of the black paper.
  7. Make holes in the paper for the legs and then place the Bot in place!.. (PIC--6).
  8. Make four holes in four corners for the spotlights and place the spotlights in place, securing them with super glue and also giving them a certain slant angle with help of Ball pen refills or any other thin sticks, piercing the cardboard base. (don't forget to paint the sticks black!)  {PIC--7,10,11).
  9. Again, make the connections so that all the leds are connected in parallel finally and also, place a switch in the circuit, if required!.  ( PIC--9).
  10. Paste the rest of the carboard pieces (with proper allowances cut for the female USB and dc ports and the switch.
  11. Fold the paper and paste it accordingly so as to get the final product!!

DONE!!!!!... :D

Step 7: !! FINISHED !! :D

Congratulations now you have the famous Logo of Instructables - The Robot (bereft wheels!!!) right on your desk ! And it also doubles up as nice and cool night light  :D
Power it with either a SMPS ( switch mode power supply ) OR via USB!!!   :D

I hope you enjoy making this as much as i did creating it !!
And though it took me several hours of planning and myriad of failed attempts, it should now be just a matter of few hours for one to make this, provided they've got the right tools and other things....




And please ask if you have any questions!  

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