In this Instructable, i will go over the process of making a 3D printed monogram cake topper. I will be using Solidworks, but i assume similar features will be present in most other CAD programs. One major step that I learned along the way, was to "dissasemble" text vectors, that are otherwise impossible to edit, into sketches that i could play with.
My sister is getting married, and asked me if i could make her a 3D printed monogram, and of course i said yes. I did however run into some problems, so i felt it was worth making an instructable, in case others are in the same situation.
So let's get started.
Unfortunately i never got a picture of the monogram on the cake, but if i find one that one of the guests took, i'll of course add it.
Step 1: Tools
As mentioned, i used Solidworks for the drawing process. I haven't used that many other programs, but i am quite sure most high-end CAD programs will have some of the same features.
The model will be printed, and the files should work on any kind of printer. I used a SLS (selective laser sintering) nylon powder printer, but a hobby FDM printer is certainly also an option. Ideally i would have used our epoxy SLA printer, since the surface quality is a lot nicer than the SLS printer, but my sister wanted the monogram in black and not too fragile, so SLS was the better choice.
I should probably mention i work at a 3D printing service, and have access to a lot of nice gear.
Step 2: Designing
My sister wanted a monogram that said T&M, and it had to be "curly and cute"... Designing this is a lot easier if you have a chance to talk to the "customer", and go over ideas and thoughts continually.
First decide on the size. Height width and depth. Then start trawling through fonts, until you find one they like. I ended up using a standard font in windows, called Edwardian Script, which will be edited later on. A good source for more fonts is dafont.com
From now on, the steps will be for Solidworks exclusively, but I hope you can find inspiration to use this in other softwares also.
Step 3: Make the Text Sketch
Open up a new part in SW, and make a sketch on any plane you like.
Draw a square, the size you agreed on for the monogram. Make the square "for construction", so it doesn't include it in the solid parts. This is just a guide, to make it easier for yourself.
Then click the text feature, and make write the text. Position it at the origin, if it isnt already.
Uncheck the "Use document font" option, and go to the font settings.
Find your desired font ( i also choose the wide option to make the print a little sturdier) and set the height. If it doesn't align with the guide box edges, don't worry it will be fixed later.
Step 4: Dissolve the Text
While in the sketch, right click on the text, and choose "Dissolve sketch text" (Or rightclick on the text and type "v") This will create a whole mess of splines, with an hundreds of line points, but this is good, this we can edit. When you zoom in, you can quickly see it won't be possible to extrude this text as it is. There are overlapping splines, and these have to be trimmed before we can extrude.
Be careful when you trim, you don't want to trim something important, but remember to check every single corner. There can be tiny little loops, that will make the sketch unable to extrude. This is because the dissolve text feature is not perfect, so there's a bit of manual work. A hint for panning over the text, when you're zoomed in: click down on the scroll wheel on your mouse, while holding ctrl.
Step 5: Close the Gaps
My sister didn't like the last loop of the &, so i removed that as well. This left me with a few gaps to close. To do this, you need to draw a spline, which will adapt the shape of the autogenerated one.
You need to be careful where you start the new spline though. It has to be at one of the endpoints of the existing (probably trimmed) splines. Choose the spline tool, and start it somewhere where the dot is not a cross, but a fully colored blue dot. Draw the spline by using some of the existing spline points, so you get a shape that matches. Don't use all of them, thats not necessary, just until it looks good. Stop the spline at the next endpoint.
You then need to delete the two previous splines, the ones you share end- and linepoints with. Last, you need to make a tangent relation, in the endpoints, so it doesn't make any corners.
Step 6: Move the Letters
When the trimming is done, it's time to move the letters into position. Select one letter at a time, and use the move Entities command, to move them in place. Get them so it looks right, don't try and fit them in the guide square yet. I overlapped the T and &, and connected the & and M, to make a stronger print.
Step 7: Extrude and Fillet
Now you can extrude the monogram. Hopefully. I spent a long time fixing errors, because i had missed some of the loops the Dissolve text feature made, and it took some time to find them all. If it complains about invalid geometry, check if you share endpoints somewhere.
When it's extruded, it's time to fillet as many corners as possible. I found that if you start by filleting the y-direction edges, BEFORE the face edges, it's so much faster and easier. I used a variable size fillet, to save time. How big is it, is entirely up to you, it's all an appearance game. After that, make a fillet over both the front and back face.
Step 8: Baseplate
Now, create and extrude a base plate, that the text can "stand" on. Make sure it overlaps the text a little bit in the bottom of the letters. I made mine 5mm.
When you extrude it, make sure to NOT merge the results! This is so that you can fillet the base before combining the text to it. I included a picture of how my feature manager tree looked by now.
Step 9: Scale the Letters
Now it's finally time to squeeze the letters a bit, so the width fits the cake. In the scale feature, uncheck "uniform scaling", choose about origin from the drop down, and start fiddling with the right axis. It's easiest if you show the text sketch, so you can see the guide box you made first. When the text fits inside, you're golden.
Step 10: Supports and Print
Finally, make some kind of support to stick into the cake. I simply made four 3mm holes, that i could press some grill skewers into. The reason i didn't just draw some spikes, was because my sister wanted it so she could have it on a shelf afterwards, and also because it would be more expensive to print.
When all is done, send the files for printing (or do like me, and get a job somewhere with a lot of lovely printers, so you can do it yourself ;) ). Do yourself a favor when you save the STL file, and open the options, and save it in fine quality, instead of the default coarse quality.
Step 11: All Done
And there's your cake topper! Because of the thin walls and many corners, it is not recommended to throw this down a flight of stairs to test the durability. It is rather fragile, but it looks great and did the job nicely. My sister was happy, i got to learn some new things, the cake was great and the wedding went perfect. The monogram is going on the shelf, and everyone is smiling, so it could not have gone much better than that.
Another lovely way to utilize the power of mass customization, and a happy wed couple. Spread the love people :)
Also i have this entered in two contests, the Wedding and the Epilog contest. If you feel it's worth it, it would be awesome if you'd vote for it. If i could end up winning a lasercutter i would lose my mind. I have a million ideas i could then realize, so here's hoping