The Dual is not simply a double Nimble.
There are a few clever little tricks .going on. So how do the Nimble and the Dual relate to each other and how to make a Dual out of a Nimble. These seem simple questions but they are surprisingly hard to explain. In this post I will give it my best shot and illustrate using photos.
The Dual Nimble
The Dual Nimble is designed to fit on top of the E3D Chimera or Cyclops hot end and allows the printer to control 2 filaments. The base of the Dual is shaped in such a way that the hot end can be mounted with the fan facing forward, or facing backwards. We could not make it ambidextrous, this was the closest thing.
We decided to not create a completely new design for the Dual, as most of the parts of the Nimble itself would fit. No point in re-inventing the wheel (hob) is there?
So how does that work exactly. Well, the Dual base is a unique part, clearly. But all the other parts are standard Nimble parts. The gear and worm sets, the sleeve clamps, the breech blocks and of course all the metal parts for the stepper side of things are identical. The interesting thing is that the upper housing parts are standard Nimble as well. The two housing parts closing the top of the Dual are actually the top and bottom shell of a single Nimble.
The following images can clarify. Again, we used a two colour Nimble to show you what is going on.
Top left, a Dual base with a few parts and a complete Nimble.
Top right, the Nimble is opened and the worm gear, including the bearings, are placed in the Dual base.
Bottom left, the gear shaft and the integrated hob, again with the bearings, are placed in the right hand side of the Dual base, and the bottom shell of the Nimble is placed over the left gear.
Bottom right, the last (top) shell is placed over the right hand gear shaft, closing the Dual. All that is left to do is mount it on the Chimera/Cyclops and close the breeches.
In essence, by designing 1 part we have increased the possibilities of the parts and this trend will continue with the other types of Nimbles we are developing.