Frequently Asked Questions
1. 3D Printing and Material
Q: Is it possible to drill a 3D printed part made out of PLA ?
In general not, because the material becomes very quickly too hot. However, it is possible to increase the diameter of a whole by drilling, when you want to increase it by not more than 0.5 mm.
Q: Is it possible to cut a thread into a hole ?
Yes, this is possible. I did this for threads up to M5. However, the diameter of the hole shall be exactly the nominal one, e.g. M3 = 2.5 mm, M4 = 3.2 mm, M5 = 4 .1 mm. The best way to do this is to 'print' a hole with a slightly smaller diameter and then drill the hole to the required diametrer. But consider, when printing a hole of e.g. 2.2 mm, the printed hole is by far less than 2.2 mm. This also depends on the nozzle diameter. With my 3D printer I took 2.8 mm diameter for a M3 hole, which finally leads to 2.3 mm and then drilling it with a 2.5 mm drill.
You should do the cutting three times with the cutters marked with 1, 2 and no ring and exactly in this sequence. For M3 and M4 you can also use only the 1 and no ring thread cutter.
Q: Which 3D CAD software you are using ?
I use FreeCAD in version 0.15. It takes a while to get familiar with it, but once the first hurdles are taken, it is a very easy to use software.
Q: Which 3D printer you are using ?
I use the Vellemann K8200 kit printer. It's not an high end printer and requires some experience to get the result you want. The advantage is, that you can adjust all parameters to your needs and repair the printer by yourself, if something goes wrong. I alread repaired and exchanged two times the hot end. The big advantage of this printer is the relatively large printer bed with a size of 200 x 200 mm.
Small pieces can be printed very quickly. However, printing e.g. one lever arm of the throttle took more than 1.5 hours.