Settings: CubeX Trio in draft/fastest mode, in one color PLA.
This success is really the result of failure, but not in the positive keep-trying-and-you’ll-learn-and-succeed-eventually way that I usually talk about. No. This time our success is the result of failing repeatedly and eventually giving up. This print represents the day that we gave up on trying to make the CubeX Trio print in multiple colors and decided to use it as a large-scale one-color printer.
Back in October we did a head-to-head test between the CubeX Trio and the Afinia H-Series, which you can read about on the JMU MakerLab blog. That one-color model was the first print we had made on the CubeX Trio, and also the last successful print we did on that printer until today’s giant hand, over six months later. The problem was printing with multiple colors. Here is our first multicolor print; it was supposed to be a set of pieces for two-color puzzle with red raft and support material.
If you’re wondering how that big blue blob fits into the puzzle, the answer is that it doesn’t; it’s what got built up around the nozzle in our print catastrophe:
What went wrong with this and all of our other multi-color prints was that there was a problem with the filament-swap step. Specifically, when one nozzle is done printing a layer and it is time to switch to a nozzle with a second color, the nozzles go to the back of the machine and generate some waste material. This waste material is then supposed to be knocked off and into a collection bin by a “wiping stick”. In the video below you can see that our wiping stick can’t manage to reach the red blob and knock it off:
If anyone writes to me now to say that we just need to recalibrate the jet offset or the height of the wiping stick, I think I will scream. My infinitely patient student Zev and I spent most of fall semester doing just that, with lots of help from customer support and various printed and emailed sets of instructions. We’ve had things aligned in every way that you can imagine and the video above is just one of many examples. The blobs that get stuck to the wiping blade eventually end up getting stuck to the nozzle later and ruining the print. In the end, CubeX customer support actually told us that they were out of suggestions, and agreed to swap out our machine for another identical machine. Although the second machine was better, we still couldn’t get multi-color prints to work. Here’s our best try at printing three small cubes in three colors at the same time; note that we didn’t make it past the first couple of layers:
So I guess part of failing over and over again is just knowing when to give up. This week we decided to give up and print a one-color demo model just to prove that the machine can do something, and that’s today’s giant hand model. Although the wiping stick got the last laugh even here; the arrow in the picture below shows the wiping stick catching on the model after slipping down from its aligned location. We had to stop the print and unscrew the wiping stick to finish the hand.