It may work, but I don’t like how much hackaday is cheerleading this concept, plenty of issues no?
http://hackaday.com/2014/08/28/thp-semifinalist-theta-printer/
http://hackaday.com/2014/08/28/thp-semifinalist-theta-printer
It will definitely “work” but it will have the same issues as other printers. One of the huge challenges of independent heads is registration requirement for all of the heads to the platform. Getting z-distance right for one head is doable, two heads locked together is harder but also doable, and multiple independent heads, means you need some way to fine tune each heads position.
Converting Cartesian to polar coordinates is easy, caveat the discussion about accuracy. But that is well within the ability of existing platforms.
Speed should not be too much of an issue, heating the build plate will be harder if the plate has continuous rotation but assuming it doesn’t (plate goes back the other way when it needs to unwind), build plate heating won’t be an issue. You have to get tricky about drawing things around the max rotation point though.
That said, it is “different” and that certainly makes it a conversation starter.
I don’t see how this smashes the cartesian agenda at all. The two heads are not fully kinematically independent as they are both tied to the same bed rotation and therefore you can only really print multiples of the same object or the extruders can collaborate on a single object but only if that object has an order of rotational symmetry that is matched to the number of the extruders or a multiple thereof.
This is no more useful than putting two X-axes on a cartesian machine?
not to mention that print resolution and speed varies with respect to R. It is a problem with deltas and r theta printers.