When you think of making models using an Additive Technology, one of the things that certainly comes to mind these days is that you can make parts in colour.
Some technology is better suited to this, such as PolyJet technology using the Stratasys J55 or J850 (which I’ve created all sorts of content for on our blog in the past), but you rarely think of FDM technology as an option. In this 3D Printing tech tip video, I’ll show you how easy it is.
3D Printing Tech Tip: Using pauses to add colour to your FDM prints = Happy St. Patrick’s Day!
Watch this video and get step by step instructions for what you need to do in order to make colourful FDM prints, and we did it by making a massive and very festive Shamrock sign using our Stratasys F900 in ASA White, Black, Orange, Green, Blue, and Light Grey!
Follow along using your own 3D printer:
Step 1) Design your part correctly
Printing FDM parts in colour is done by printing entire layers of a part using a single color, so the first thing we need to do is create a multi-tiered model. In our video, we’re using an F900 printer running with 0.020” thick layers, and in order to achieve good solid colour in our end print we need at least 2 slices per colour. As a result, in our CAD, we’ve created a base white section that is 0.060” thick, and then each colour step up from that is extruded out 0.040” from the last color.
The same would be true for any other layer height, so if you are running your F370 at 0.007” layer height, for example, you would create tiers that are 0.014” in extruded height from the previous layer.
Step 2) Prepare your model in GrabCAD Print
Open your model in GrabCAD Print, configure your modeler so that you’re on the correct machine and with the correct layer height chosen, and then import your model and get it oriented as you designed it to be printed on the tray; in our case, this would be with the back of the sign flat on the print bed.
From there, you then slice the model, and in the Slice Preview you will notice on the bottom of the menu an option for “Add Z Pause.” In order to set this up correctly, you will use the slider bar on the left hand side of the screen to move to each first layer of a new tier, then clicking the Add Z Pause button. The reason why we choose the first slice of each new tier of the model is because this will tell the machine to stop before printing any part of that layer. Once you have all of your pauses in place, click the print button to send the tray over to the machine, and then we’re off to the printer to start the build!
Step 3) Start your print, and keep an eye on it so you can change the cartridges at each pause
Once you start your build, assume that the longest portion of printing will most likely be the first colour, since it applies to the entire x/y of the part. In our case with this Shamrock sign, that portion plus the support raft took about 3 hours to print. After that, your printer will pause, and then you can walk over to it, unload the spool, load your next color spool of the same type of material (I would recommend lining them up in order to ensure that you don’t mix up which color is next!), and once that next colour is loaded, press play.
Pro Tip: Some colours may require a bit more purging from one to another, so if you are concerned that one (such as blue) will discolor the next one (such as white), it never hurts to do additional purges of material to try and fully clean out that tip, but when all else fails, you can reset the tip colouring by loading black and then going into the next correct colour, as black will fully purge out the previous colour.
More options to consider
This process isn’t difficult, and while we did it with a relatively goofy application here in producing our Shamrock Sign for St. Patrick’s Day, there are plenty of actual real world applications that you can use it for in your facility. I’ve listed a few in the video, such as adding text to jigs and fixtures to identify the parts the correspond with and critical alignment features, adding your company logo to models, and creating colourful prototypes, but some other interesting possible options are:
- Adding scannable QR codes to all sorts of models
- Creating visibly different colored textures to the finish of a model
- Creating signs to label a variety of items or areas of your facility (less expensive and quicker than working with sign vendors)
- Highlighting critical areas of your model of note, such as mounting bosses that need to visibly stand out (perhaps in the case of calling out certain mounting bosses that requiring heat set inserts)
- And plenty of other possibilities
I hope you all enjoyed the video. We had a great time making it, and hopefully it helped you push the envelope a bit further as far as what you’re capable of doing with your Stratasys FDM Printer. These machines are capable of accomplishing so much. Most of the time we’re limited by our own imagination to what is possible and I hope that you can take these instructions and go design something truly incredible!
Happy St. Patrick’s Day from TriMech!
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