RepRap: Blog

As is often the case, I had my Mendel running a week or two ago, and I was sat mesmerised for far too long watching it work. Fortunately, whilst this was happening I had an idea I thought was worth sharing.

Our Mendel happened to be printing a particularly complex part, I think it was one of the extruder driven gear. I made the casual observation that on the lower fine layers, it does a pretty good job. But once you get into the middle layers, it needs to do quite a lot more in air movements compared to the fine layers, as the extruder cannot get to where it needs to be smoothly because of the low density of the infill. The issue with this is that with present extruder designs, and even with reversing, we still get some ooze that makes a bit of a mess. Annoyingly, the reversing and inair movements start at the outline of parts, and the ooze typically spills over a tiny amount, making the part surface a little blobby. It also makes sense that this problem is particularly true for intricate areas of the part, such as the gear teeth.

Thus, It would be very beneficial to vary the increase the infill density within the intricate regions of parts. Not only would this help with ooze, but intricate areas would automatically strengthened with more material. I also suspect that if this was implemented we could also reduce the infill percentage in simpler areas to speed up build time.