In May 2016 I started to build my own 3D printer (using one I already had, as you do). The design I chose was called "CloverPlus".
After a shaky start, it became my main 3D printer. Reasons included it was much smaller than my Robo3D printer, and (after tuning) it was much more accurate as well.
This repo is a clearinghouse of everything about that printer so you can build one if you want, but mostly so I have a place to put things so they won't get lost.
"Make" on thingiverse: https://www.thingiverse.com/make:208007
I'm still using an ancient build of Marlin (1.1.0 RC5) on an ancient RAMPS clone, but it works just fine. You can find details of my Marlin config on MARLIN.md.
My printer is a hodge-podge of parts from different versions, parts that just fit, or parts I've designed myself.
The main upper and lower chassis pieces are from CloverPlus v2.
Using the Z carriages from Mystereon's V2, but not using optical endstops.
Clamps from CloverPlus v2.
Effector is Kossel mini Effector for E3d v6 Hotend. Collar is, I think, either E3D v6 hotend complete mount (with groove) for Kossel mini 3D printer or Mini Kossel groove mount.
Quick Change Universal Spool Holder, on a long piece of old 5/16th rod and attached to the top of the printer using a pair of any-angle rod clamps.
Case for the RepRap Discount display is the Case for the Full Graphic Smart LCD Controller.
The case for the RAMPS electronics is Dasaki Ramps 1.4 Enclosure / Box / Case.
The CloverPlus Smooth Rod Brace, designed by me to reduce z-axis sway.
Although I started the design using 5/16 smooth rod, I quickly came to my senses and switched to standard 8mm smooth rod.
Standard LM8UU bearings.
Some MK8 kockoff from Amazon, connected to a beefy (but ungeared) stepper.
Power supply is an old XBox 360 PS from a second-hand store. Control hardware is a basic RAMPS 1.4 setup.
Some random 217mm carbon fiber arms, I can't remember where from. I should use shorter arms, but these were cheaper at the time.
Some random 120mm (3mm thick) borosilicate plate. Previously I was using a 7-inch round mirror from a craft store.
Some random V6-clone from Amazon. Cooling is currently handled by a Haldis cooling shroud.