Contrary to what many people (non 3D printer enthusiasts) think, our desktop 3D printers generally don’t produce great looking products directly out of the printer. The prints generally require at least some post processing such as support removal, sanding, painting or smoothing. The post processing required will depend on what the object will be used for. If you are like me then you’ll think post-processing is one of the most time consuming and annoying tasks associated with 3D printing.
With this in mind my favourite post processing task is this one because it is extremely quick and easy, requires no chemicals and no special setup. I use it for parts that I want to clean up but that don’t need to look like end use consumer parts, it is best for removing white spots that are left when support material is removed or to remove any stringing on your prints. The parts we are using in this blog come from our downhill mountain bike which you can download here.
Step 1: Use a heat gun to blow on your 3D prints
Step 2: Literally nothing, it’s a one step process
1. Ok that’s not quite right but it is almost as simple as that, there are a few little things to watch out for. First thing to do is get a heat gun (obviously) and the parts you want to post process. Next find an area to to do it, a wooden work bench is good but if you don’t have anything like this then some paving or concrete outside is fine.
Warning: Do not do this near flammable materials or anything that could get damaged (ie melted). Although it is very unlikely the heat will be hot enough you can’t be too careful! Also don’t touch the tip of the heat gun or try and hold the part while you are applying heat to it.
2. Place the parts where you will apply heat. If they are small parts you may need to clamp them or hold them in places so that they do not blow away when you aim the hot air at them. Do not hold the parts while you are applying the hot air.
3. I use the hottest setting on the heat gun and keep the nozzle approximately 100mm (4 inches) away from the parts. Then slowly wave back and forth over the parts until you see the white marks disappearing.
Keep the nozzle about 100mm (4 inches) from the parts
4. Small parts are more susceptible to distortion so make sure you heat them less than larger parts. You should apply as least heat as possible, as soon as the white marks are gone remove the heat so that your parts are not distorted. I recommend testing this out first on non-critical parts if you are using this technique for the first time. Bear in mind that parts will distort at much lower temperatures then they will melt (a long thin bar for example may curl if heat is applied unevenly).
The wheel on the left has been treated while the wheel on the right hasn’t
5. Once you have removed the heat wait for a few minutes to give the part time to cool. See the before and after shots below of the difference in the 3D printed parts.
The 3D printed parts before treatment
And that’s it! I use this technique as my quick post processing technique of 3D prints when I went to make something look decent without spending lots of time on it. If I want to make it look like consumer grade then I usually post process ABS with acetone, I wrote a blog about that here.
If you enjoyed this post or found it useful, I’d be very grateful if you’d help it spread by emailing it to a friend, or sharing it on Twitter or Facebook. Thank you! –Andrew Karas is a mechanical engineer who loves 3D printing and wants to make it better for everyone, he is also the founder of Trinpy.