From Kickstarter page:
Rather than mechanical endstops the RappiDelta Jr. utilises slotted optical sensors which prove more repeatable homing and ultimately better prints. One of my stretch goals is to be able to offer auto bed leveling to further enhance the functionality and ease of use.This delta projects wants to deliver cheap simple printer, with few easily assembled printable frame parts.
The remainder of the mechanical parts can be assembled quickly and easily with a couple of hex keys.
Once assembled the printer can print on a 17cm diameter circle and up to 17cm tall. These dimensions have been chosen based on my experience of what is actually reasonable to print as well as being based on a similar size to other entry level printers. In future you can increase the build volume by using longer uprights, and if required longer delta arms. The basic model has no bed heater and as such is limited to printing PLA (this is actually my preferred plastic!) but other options are available to allow the printing of ABS and other plastics that need bed heating. There is also an option to have an SD Card reader and LCD control panel to allow printing without a PC, something that I have found invaluable when developing my prints as it allows on the fly adjustments.
Junior has a bigger parent:
Junior had a (canceled) Kickstarter: