The biggest let down in 3D printing is the surface detail with visible layer lines. Sometimes this can be accepted and is understood as the circumstances of 3D printing. But sometimes this is not good enough and you require a good looking model. Whether it’s presenting to a client or making a replica prop there are a few techniques one can use to finish off 3D prints to have a quality finish.
The two techniques we will be presenting here is good ol elbow grease followed by the second where we will be doing some silicone and resin moulding if you need more than one. This will then be split into two parts to make it easier to absorb.
So to start We are going to show you how we used SOLIDWORKS to design this Batman inspired prop, how we 3D printed it and assembled it, then how we painted and sanded and painted and sanded and painted and sanded (there is lot of this) till we got the final result.
So lets crack on!
This design was a simple shape which we used a few dimensions to fully define it before mirroring the shape, we then used the the extrude cut feature and sed the this option to cut the grooves. A sweet little fillet shaped it off before we mirrored it on itself to create one half of the prop.
As this is exactly the same on the other side i just needed to print the same side twice. Before we sent it to print we made a slot to put a guide block inside to line it up when assembling it.
The printing was easy as it fit neatly in the bed and printed in 3 hours. Once they printed there was no cleanup needed, we used some super glue to attach it all together and it was assembled!
We then used some body filler to fill up the seam and a nail to clear out the groove of excess filler. Now the sanding begins. We gave it it a light sand to remove any excess filler and smoothened the surface a little, we then used a High build filler primer as our base coat. What this does is the self levels and it sits in the grooves leaving a thinner layer of paint in the high points.
We then get back to sanding. We sanded this till some of the grey material was showing and hit it with one last coat of filler primer. We then gave it one last sand to get the super smooth surface we wanted. This was the step we stopped at for the moulding process but more on that in Part 2. For now we took this part right into the painting stage.
Once we were happy with the surface finish we used a silver spray paint to give it a metal look. We did a single coat of this then we wanted to weather it a little as just the silver looks flat. We used a black acrylic paint and some water to thin it and painted the entire body, then used some tissue paper to wipe it away, this left a black tone the deep groove as well as a scratched look on the surface making it look worn.
Now we have a really cool looking batarang! The biggest problem with this technique is fast repetition and consistency. If you need to make a small batch not every single one will look the same as there are too many factors at play and the print times will increase significantly. This is where silicone moulding and casting comes to play. As you are making copies of one 3D print every single one will look the same. But we shall expand in that in part 2!