So about one month ago I got my FLSUN i3 plus 2017 kit. It is not my first kit (got an Anet A8) and as so this is coming from someone who has a bit of experience with kits and fixing things.
Regarding the flsun kit is a very cheap and almost complete kit. I say ALMOST cause there is one piece that you'll have at least to get that being a blower fan and support for it. I tried to print without it and overhangs fail. If you have one of this and can print a benchy with a good front without the blower fan please ping me.
Also missing, regarding tools, is one of those flush cutters that usually comes with printers
Lastly, but most important, I don't know how hard it is to include a handful of crimp connectors or the cables that go to the PSU pre crimped. This is just basic safety.
In my kit there was a defective screw that binds the extruder gear to the shaft. After talking with the seller they provided to send me a free replacement gear and screw.
The assembly instructions for a cheap china kit are far from perfect but still coming from an ANET A8 this ones are alot better to understand. This is by no means as easy as a Creality CR10.
Regarding the "extras" that are usually shown as options in sites like Gearbest, ebay, or aliexpress there is options for touch screen, autolevel sensor and cyclops/chimera hotends.
My suggestion is for basic stuff just get the autolevel sensor, if you want a dual extruder you could get the cyclops/chimera. The touch screen is like very optional as in fact it even has less functions than other screens. This is due to the fact that the touch screen is different board altogether that sends commands to the main printer board. It has its own firmware.
When it comes to printing that's when you will have problems if are not experienced with 3d printers. The default Marlin configuration that comes on the firmware just sucks. If you slice a model with a slicer that doesn't set acceleration, jerk and some other settings it will use the printer defaults that are awful.
The easy way to set it working is to use Cura 3.1.0 and choose the CR10 4S and modify things like bed size, offsets, retraction and speeds.
The hard way, that I still haven't done due to lack of time, is to flash marlin with my own custom settings.
TBH I didn't try to use the slicer and software that comes on sdcard because usually that versions are old as hell and my preferred slicer is cura. Also I distrust the origin of the software as I'm mindful of security reasons
Also on my TODO list it to install the dual extruder. Another problem that I can predict with this is that you are unable to mount the sensor and the blower fan with the new carriage for dual extruder. For the sensor you can find a solution that you can print but then again reconfigure marlin sensor position values. For the blower+dual extruder there is one item that you can also print but in my opinion is just not good enough.
So after installing a blower fan with v3 clone it printed just a great test benchy and some other small prints. I'll be further configuring and testing this printer.
I got some money for Christmas and bought an Flsun C Plus dual extruder/auto level/touch screen kit. Haven't put it together yet, though. Anything I need to know? I already built a Mendel90 from scratch several years ago so I have SOME experience building 3D printers but I am a bit rusty and never used an auto leveling system or a dual extruder system before, nor do I have any experience with Chinese kits. I figured it wouldn't be a simple "plug 'n' play", but will I likely have to modify it heavily to get it to work? I wanted something with a bigger build area and dual extruder capability (my Mendel90 only runs a single E3D-V6 from a Melzi board, and has a 200 x 200 build plate).
Had a hard time finding a metal carrage for the i3 plus , somone on the facebook posted it, figured other people would also want to replace the acrylic y carrage with a metal one etc. Search " flsun upgrade"