Rotary 3D printers: a step before scara or?

I was contemplating lately at different styles of 3d printers. I've seen before rotary 3d printers concepts but never thought they are a serious contender in the FDM 3d printing space. What are these types of printers bringing to the table?

For what I can tell they get rid of the linear XY gantry just like a scara but have working areas smaller than what scara can do.
Also printing at the center of the build plate seems problematic.

Are the scara's arms that are "in series" a weak point compared to the rotary type? Are they sturdier hence better with precision?

I have also seen that there is open source code for rotary printers in Marlin, at least the R-360 has it's Marlin-based firmware on github. There is also a very nice rotary-like printer floating around these forums and I am sure there are many more.

Sorry for being all over the place with the questions above

---

RepRap Lander concept on Concept Forge
RepRap Lander concept on RepRap Forums
My Things, mostly experimental stuff

... for Scara's you should look for parallel types - they have both motors on the base plate and has a nearly uniform error-map over the complete working range.

The greatest benefit for rotary printers would be the small foot-print, if you design a foldable frame, so the machine can be 'minimized' if not in use ... but this could be done with the parallel scara too ...

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

By parallel-types are you reffering to Morgan? because i find the benefits of the second pair of assisting arms to be small in comparison to the wasted potential work area of a single-arm scara.

Regarding these Rotary new wave of printers they seem to have few mechanical parts and yes, they are very compact for the usable working area. But I believe the downside is software, they are at lease as difficult as scara to calculate so I guess 32 bit no less for these puppies.

---

RepRap Lander concept on Concept Forge
RepRap Lander concept on RepRap Forums
My Things, mostly experimental stuff

... some ten years ago we did a comparison for the errors and accuracy mapping for high precision scaras and 'parallel scaras' (like the Morgan) for micro-assembly - the serial scara has a diverging accuracy over the working area, while the parallel type was much more accurate and nearly homogenous over the complete area ...

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Was this accuracy loss due to the serial alignment of the joints, accumulating aver the links? In this case the parallel scara would be awfully similar with the polar turntable style I asked about in this thread.

Thank you.

---

RepRap Lander concept on Concept Forge
RepRap Lander concept on RepRap Forums
My Things, mostly experimental stuff