Haven't you always dreamed of having a crayon shaped like the color you are coloring with? Now your dream can become a reality! Learn how you can make a crayon in almost any shape (with some restrictions) using 3D prints and Molding Putty.
Thank you to audreyobscura for the advice on mold making and for listening to me constantly complain about this project.
You can buy a set of these crayons in my Etsy Store.
*This was my first time mold making and I was super nervous to do it, but Amazing Mold Putty is super easy to use and it was really fun once I finally dived in and did it.
Step 1: Supplies
I've made many mistakes along the way but I'll try to stick to just what worked for me for this tutorial.
- 3D Printer
- Filament - the prints don't have to be amazing but you want them nice enough to make molds with, the prints take about 1/4lb of filament so be prepared
- Amazing Mold Putty (I think one case of this should do, but you might need more) - this is the only mold making material I know that will work for this project - this stuff can go in the oven which is the reason I chose it
- I first tried Amazing Mold Rubber and while it worked to make a mold, I ultimately decided it wasn't the best material for this project. It seemed too weak (though this is when I was trying the style where the hole went all the way through) and I emailed the company but it wasn't a great thing to put in the oven.
- Crayons - you can buy custom sleeves on Crayola.com
- Cutting Board
- & something to cut with, I'm using Wood Carving Knives that my husband already had
- Wax Paper
- Baking Sheet you don't care about - I covered my sheet with Tin FOIL and put my molds on that, but to be safe I would say use a sheet you won't use for food again
- Kitchen Butane Torch (optional)
- Kitchen Scale (optional)
Step 2: Design - Prepping Letters
[I had to go through a few tests with various changes being made each time, hopefully I'll remember to cover everything here!]
I will start by stating I knew I wanted the crayons to end up being .625" wide by .625" deep by length determined by letters that are .625" high.
First order of business is finding a font to make my molds with.
I tried the one in Tinkercad and (at least at the time) the font wasn't going to work with what I wanted. I wanted something really boxy. After looking at what was already on my computer and looking on free font sites, I found Pro Lamina. I ended up having to do editing on the font to get it the way I wanted it, but it was a great font to get me going. Some edits I made included: making all the letters square, giving the "I" lines on the top and bottom, and making the middle of the W reach the top. This was just for rainbow and edits were made on a letter by letter basis. (By the time I reached the end of this project, those edits may not have been necessary, but I'm still happy with them.)
Now that I had the font, I needed to get the individual letters into Tinkercad. I used Silhouette Studio because it's a program I'm very familiar with. I took each letter individually and did any minor alterations I wanted. When it was ready I exported it as a PNG, used an online site to make it an SVG, then brought it into Tinkercad.
To get myself started, I got all the letters for RAINBOW and started arranging them to get an idea of what I was working with. After doing some initial setups, it seem liked stacking the letters was going to make for the best setup.
Looking at it, I wanted the letters to stand out more, so using the same method Jon-A-Tron used when making a name keychain, I decided every other letter would stand up a bit more than the one next to it. For every word, it would start with a raised letter, then the second would be shorter, third higher, etc. I made the letters .1" different in height.
(After tests) I decided the "details" of the letters would only go down about 1/4" deep so they wouldn't go all the way through. As much as I wanted the holes in the letters to go all the way through, it just wasn't going to work out. I also decided the holes should go in at a slight angle to make it easier for the 3D print (and eventually the crayon) to come out of the mold. To make the holes have an angle, I created a cutout separately that went in on the bottom (instead of just going straight down) just using basic shapes (second image below). I filled in the hole in the letter so that there was no hole at all, and lined up my new hole cut out where the old holes used to be (third image below). My cutouts were a little messy but as long as they sliced right, I left them.
At this point well change the full size of the letter. We need to do this in order to fill the mold with crayons as they will melt down to the size we want. (After tests) I decided to full depth of the highest letter would be 1 1/4".
Lastly, I needed to overlap some of the letters because for some reason they didn't import perfectly. So what I would do is group the letters, export, bring into slicer, and make sure it acted like the letters were attached to each other. Sometimes they would have a slight slight gap making the infill funny. If that happened I noted where the mistakes were and went back to Tinkercad to make changes.
I repeated this for all the words until I had all the colors of the rainbow! (I did PURPLE instead of doing either Indigo or Violet. I grew up with purple so I just did purple.)
Step 3: Printing!
This is straightforward, but be prepared if you are going to print all these words, it takes about 1/4lb of filament and 6 or more hours.
Also, don't be too stingy on the infill. When all my tests were done and I went to print all of them, I reduced the infill to 5% and didn't realize until they were done that parts of the top of the letters caved in because there wasn't enough infill. To be safe, my final prints had 15% infill.
I don't think you'll need a skirt. I used one for one of my sets and it got disconnected and reattached mid print and just made a mess of everything.
Step 4: Making Molds
Get your Amazing Mold Putty, it's time to make your mold! Lay out some wax paper. It's nicer to work on than whatever surface you have.
So this stuff is really easy and fun to use BUT you only have about 3 minutes to use it once the two parts touch. Do no dawdling here.
I found it best to work in small amounts while I filled in holes and cracks and then worked in bigger amounts later.
So to start, take an equally small amount of each putty and quickly mix them together. (When I first tried this, I actually used a kitchen scale to weigh it to make sure the amounts were even. The more I did this the less I felt I had to, but it can be helpful when you get started.) Mix until the color is uniform, but try to not take any more than 1 minute. That leaves you with 2 more minutes.
Take your small amount and roll it snake-like. Shove it as firmly as you can into the holes on the top of the letters. Really smash it in there and make sure it overflows. You want the mold as solid as it can be despite working in small amounts so make sure your putty overflows over the top of the letter (Image 5).
Continue mixing and filling holes. Don't forget the crevices along the sides of and between some of the letters. You don't want to accidentally partially fill it and not be able to fix it/fill it in later.
Once all of the holes and crevices are filled, you can mix bigger amounts and cover the rest of the letter. Make sure you get all the sides and top but leave the flat bottom exposed. Pay particular attention to edges as it's easy to push the molding putty around it and miss it.
The mold doesn't have to be super thick, you just need it sturdy.
I found if I accidentally mixed too much putty while working on one word, I'd use it on the next one, but once you reach the last word you have to use up all the putty you've mixed up.
When your mold is ready, I recommend setting it on its bottom as it needs to be able to stand up on its own in the oven.
Give the mold time to set. It needs to set about 30 minutes but you can always give it more to be safe.
When it has set, carefully pry the 3D print out of the putty. Don't rush yourself. It is best to carefully pry the sides off one at a time. Then starting at either the top or bottom of the word, work the word out of the putty. You don't want to pry out those little bits in the holes. If you crack the mold, you can fix it (next step) but if you tear those bits out, it is going to be much harder to fix and you may have to redo the mold.
Step 5: Fixing Mold
After you get the word out, you may see weak spots or you may have accidentally torn it. No worries, you can just fix it.
Check to see if there are exposed holes or if you think some areas might be too thin (hold it up to the light). Make a note of all the areas and put your #D print back in. Mix up more small amounts of the putty and cover up the weak spots. Let it sit the appropriate time and then again, try to pry it out carefully. Repeat as needed.
By the time I got to the point of covering all the words, I'd wasted enough putty that I was being pretty stingy and had to add to a couple of the molds a couple times.
After using the molds (later) you may accidentally tear your (stingily-made) mold. That's okay, assuming you didn't tear out the little bits again. You can either wrap the mold in tin foil and continue to use it or fix it with extra putty.
Just like before stick the 3D print back in the mold and fix any cracks or holes.
Let it sit and you're done!
Remember, you don't want the crayon to leak out.
Step 6: A Look at Molds
Here is a look at my set of finished molds, a bunch of failed molds, and lastly my very first rainbow crayon compared to two at the end.
Step 7: Making Crayons
(I've made so many crayons at different times so you may see different crayons during different stages of this process. I think I've made three blue ones now.)
Preheat your oven to 200 degrees F.
Now that you have your molds, it's time to make crayons! But how many crayons do you need? Well, after all my tests I keep mentioning, I've figured it out for you (here is where a scale comes in handy again).
If you want to make a crayon that is made up of letters that are .625" squared you need about 3.5grams per letter (also, more is better than less). For your information, 1 Crayola crayon is 5 grams.
So, for the word BLUE, you need about 14 grams of crayon or 2.8 crayons worth.
Prep your crayons by getting the paper off. I've had some issues with this and the best results I got were when I firmly cut along the length of the wrapper. I really cut into the crayon. Then the paper should peel right off.
Next, cut your crayons up. The smaller the pieces, the more the color will blend when melted. So, cutting it into about 4 pieces is good. I wouldn't go smaller unless you have to.
Now put the crayons in the mold. Group same color pieces together so you can have blocks of color when done.
People melt crayons anywhere from 200 degrees to 250. I would say you wouldn't need to go higher than that.
At 200 degrees it seemed to take at least 20 minutes to melt. You need to keep an eye on it because as soon as it is all melted, get it out of there. The longer it sits in the oven melted, the longer it has for colors to bleed and blend together.
If you melt more than one crayon at a time, be careful, they may take different amounts of time and once one is all melted, you want to get it out of the oven.
Once melted, take it out and let it harden completely! This process has been done over and over again and to get the best results with your homemade mold and crayon, let it harden and cool and then move onto the next step. It's not as easy as just popping it out.
Also, once you take it out, if you see any bubbles, especially big ones, I suggest carefully popping them with a toothpick. Otherwise, you'll have hardened bubble holes.
Step 8: Getting It Out
So (let's say it together) after many tests, I found this to be the best way to get the crayon out.
If you try to take it out after it has cooled for a little while, the crayon will break when you take it out. If you try to take it out after you have let it cooled, you will break probably the mold and the crayon. So, the solution?
Take a bowl of water and heat it in the microwave for 30 seconds to 1 minute. You want it nice and hot.
Put your mold in the bowl of hot water. Let it sit.
After a little while of sitting, check it. Try to carefully peel the mold away from the sides of the crayon. If it's not coming, heat the water up more and let the mold sit longer. Just keep carefully checking it. Don't rush! You've wasted all this time already, don't break the crayon in the home stretch!
Once you can get the edges all clear of the crayon, just like taking the print out of the mold, carefully pry the crayon out. You just have to take your time and reheat the bowl of water as needed.
And, it's out!
Step 9: Rainbow or Crayons With Distinctive Colors
Now, if you want certain letters in your word different colors, you have to be more careful in the crayon placement.
I tried two methods for this and this is what gave me the best results.
Cut up all the crayons you need, about 3.5 grams for each letter. Lay it all out so you are organized.
Start by filling in the bottom of the mold with the colors where you want them. Keep working your way up the mold a little at a time until you use up all your crayon and fill your mold.
Stick it in the oven and remember to take it out as soon as they are all melted.
Step 10: Finished Crayons
Here is a look at each mold and the crayon I made with it.
Step 11: To Melt or Not to Melt
Now that your crayon is done and out of the mold, the question is to leave it as it is or try to give the exterior a shiny smooth finish.
It looks great right out of the mold, but if you make this you'll see (or actually feel) that it is grainy feeling and feels like the crayon is coming off on your hand (and it will at least at first). You can leave it, or you can very, very, VERY carefully take a kitchen butane torch to it and melt all the sides. You don't want to go overboard or you'll completely ruin the crayon, but you can smooth it out and get rid of the 3D print layer lines.
You have to be very careful about the small bits (like the arms on the E) as they will melt easily and then your letters will lose their details.
I found I got the best results when I turn the crayon onto different sides and carefully melt it. Try not to melt it so much that it drips down and distorts the crayon shape. Make sure you blow on it and give it a little time to harden again before tipping it on another side or it will get smashed.
The last two images will show you the different between a plain crayon and the melted ones.
Step 12: Some More Looks at the Crayons
Also, here is a look at the back of the crayons. When they come out of the molds the edges stick up. To fix this the best I could without wreaking them, I took my wood carving tools and shaved the edges down a bit.
You don't have to do this, but they will look nicer and the wax tends to rise up so those edges will look even worse with the extra wax there.
robertbettis made it!