Making a Customized Heart Pendant (or key chain! or dog tag!) in Stainless Steel - with 123D and Ponoko’s Personal Factory

Need a customized gift for a special someone, whether it be for your mom, your husband, your wife, yourself? With Autodesk’s 123D and Ponoko’s Personal Factory combined you can make and have your own custom design that YOU create for a small portion of the price most custom gifts would run.

It’s a pretty great thing to create a model in the computer and hold the object in your hands in just weeks!

Below are photos of the actual printed pieces in Durable Gloss Black and regular Durable plastic  from the video version of this tutorial (

In this tutorial I’ll show you how to model a basic heart pendant in 123D then finish the edges. Afterwards, if you want to get a bit deeper in an add-on tutorial, we’ll customize it with initials, then upload it into your Ponoko personal factory and send it to get print out in the material of your choice.

What you’ll need to start:
Download the 123D application (currently only for Windows)
Download the pre-made initials (you will need to create a free 123D account or log in with Facebook, and this will also provide you with access to an entire library of free 3D models.)

Once you have the 123D program installed open it up.

If the “Get Started” dialogue box appears either click close or open an empty file.

Now you are in 123D with a blank canvas in the center.

In the lower right hand corner make sure the sketch grid and precise input buttons are on (highlighted in blue when active).

When making a model with specific thicknesses/dimensions (as in this case) click the little blue logo that represents the Application menu in the uppermost left-hand corner and click on “options” that is at the bottom of the opened menu box.

There are a few things you could play with in the Application options, but we’re just going to go to Controls check the box in front of Snap Bar and click OK. This turns on the scale in the lower right hand corner of the canvas that tells you the dimensions you’re working in. It also gives you a useful scale for reference.

You can change the units easily in the Snap Bar by clicking on where it says the units of measurement and selecting which you’d like to work from. You’ll only have to do all this once, then you’ll be set next time you open the program to create a model.

I’ll be modeling in millimeters.


Go to the upper right-hand corner and click on the right of the viewing cube (which represents the left side of the face) so that we can start modeling from the left view. Normally you can start from any chosen view, but in this case we’re orienting to the position the text will be in when imported.

If you don’t want to add text, then feel free to start from any orientation.

Go back to the logo in the uppermost left-hand corner, click the logo then “Save As.” Name your file and save it somewhere you will be able to find it later. *Save regularly by clicking the save icon on the bar in the upper left-hand corner.

In the top command toolbar left-click on the Sketch icon that has the picture of a pencil and choose Spline.

*Notice that when you hold your mouse over an option it will often give you a description.

From here we’re going to sketch out a heart.

Using the Snap Bar scale for reference zoom in and out using your middle mouse wheel (or the zoom tool represented by the icon with the magnifying glass with a + and - symbol in the toolbar on the right). This will help you know how large your sketch will be in the units of measurement that you chose.

I’m aiming to make my design approximately 3cm/30mm high.

The Spline tool is great for a heart because it has no straight lines. First, make half of the heart by clicking points along the shape of the heart (don’t worry if it’s not perfect, you can adjust later). When you’ve put in the last point double-click on that point. Go through the steps again to create the second half of the heart, making sure the first and last point connect with the other half. On the last point that connects the two halves right-click and choose “OK.”

The heart should now have a filled in look. It will also have little round points on the lines you made called control points. You can move these around to adjust the heart’s shape to your liking. When you’re done adjusting the shape click on the little X with a pencil “stop sketch” icon to the right.

Now it’s time to Extrude the heart, which means to push/pull the 2D drawing into the 3rd dimension.

Click on Create in the top toolbar, represented by an icon with a cube and an arrow pointing upward. Then choose the Extrude option.

Again, 123D has a handy built-in description of what the option does.

Click on the center of the heart to select it.

Using the viewing cube in the upper right-hand corner left-click to rotate the heart so that it’s at an angle.

Once selected the heart has an input box where you can specify how far you want to extrude it. In this case I’m aiming to make this piece in Stainless Steel, which has a minimum wall thickness requirement of 3mm.

When done inputting the thickness then right-click on the heart and select OK.


*Updated for 123D Beta 5
Now that the basic heart is complete, we’re going to make a hole where you can attach a cord, jump ring, key ring, etc.

Go to the top toolbar and click on Primitives, which has the basic cube icon. Select Cylinder.

Click on the front of the 3D heart to place the center of the cylinder. Make sure it’s not too close to the edges of the heart.

You’ll again have the option to put a specific radius into the input text box. I’m going to select 2mm for the radius, so that the diameter of the hole will be 4mm wide, which is large enough for a leather cord or key ring. Press Enter.

A yellow arrow will appear. For this part go to the viewing cube in the upper right-hand corner and look at your heart from an angle by holding down the left mouse button over the cube. Click on the arrow and pull it back to where it looks like it’s opening a hole through the heart. Click when it’s gone all the way through the heart. Press Enter.

After Beta 5 the cylinder will generally go through the model, and will cut the cylinder where the other part of the heart ends (creating a separate piece) instead of automatically creating a hole (just in case you don't actually want a hole!).

Go to Create in the top toolbar, click Combine.

There will be a little blue drop-down menu, choose Cut from the options.

Click on the heart, then after hovering over the heart for a moment there will be two icons with green boxes and arrows side by side, choose the one on the right. This is the icon that represents the option to select the piece that will be cutting the first piece. Click on the cylinder.

Right click, click on OK.


And voila! you’re a 3D modeler!

Now you have a 3D heart model that could be printed out as-is and used as a keychain, pendant or dog tag!

Read on if you’d like to smooth out the heart’s edges or add initials.

The technical name for making rounded edges is fillet. I know this sounds kind of like cooking up a fish, but in mechanics it basically means to round out an angle.

Smoothing out the angles gives your piece a more tooled feel, and also is better for comfort of a piece you may be handling often.

Click the edges of your heart, hold down CTRL to select all sides you want to fillet. 123D is an intuitive program, so it will automatically come up with the fillet icon near or on where you’ve selected. The icon looks like a cube with one edge rounded. There will be a couple other options, but select Fillet.

Input the radius in the text box that comes up. (tip: If it gives an error exclamation point at the bottom of the screen that means the amount you want to fillet the heart is not mathematically possible.)

In this case I’m going to fillet the edges 1mm. I also separately did the same to the hole and added a fillet of 0.5mm. Now it’s good to go!

Don’t be shy about doing this tutorial again with different shapes, it’s pretty easy to get it to the point of a printable object! I highly recommend you play around in the program on your own, and has links to some great video and PDF tutorials.

Don’t forget to show us on the forums all the awesome things you create!

To add initials/text onto the heart pendant / keychain go here: Drawing 3D Text / Initials on Top of the Heart Pendant / Keychain

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  • 0
    Richard Puckett

    Nice tutorial.  But when I try to upload to Ponoko I get a dialog saying that it's too small to print.  This seems to be a common issue, do you have a work-around?  Thanks!

  • 0
    Rich Borrett

    Hi Richard! The "Too small" message you're seeing is just a warning - you can click on "OK" and continue :)

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