UPDATE 2020-01-13: It's done. The final version of the locking mechanism is a simple M5 screw, driven by a stepper motor. The toolheads have a matching M5 nut. See it in action here: https://www.youtube.com/watch?v=KpfY1AHpZh4
UPDATE 2019-10-20: Just a quick info: yes, I am still working on it. I finally got the milled aluminium parts and now found out my locking mechanism for the toolchanger isn't going to work. Currently testing different locking mechanisms, I will update the files here once I found a reliable solution that is also cheap and can be easily sourced.
UPDATE 2019-03-30: Sorry for the late update! I changed the file structure completely to be more modular and to save rendering time and increase performance in the preview. Content-wise, the print head and carriage got several updates and test prints, the X-gantry mounts to the Y wagons got sturdier and the bed leveling mechanism got optimized for M4x1x20mm washers to carry the load directly on the aluminium extrusion instead of plastic. This way, the leveling cannot get off if the bed gets a little too warm.
UPDATE 2018-09-23: Added blocks to go into the aluminium extrusion slots to all parts. Resized the filament drybox to match the changed size of the printer. Added stacking corners to the filament drybox for safe stacking of the printer on top.Made the E3D groove mount slightly elliptical for easier mounting and made it vertically adjustable by sliding the groove mount in its clamp up and down.
UPDATE 2018-09-15: Removed filament storage drybox, will be added later. Resized the printer to fit the upcoming syringe extruder. Enlarged the kinematic coupling for more stability. Prepared everything for the syringe extruder and started designing it. Prepared everything for the extruder mounts and started designing them. Exported all STL files I think should be final (using 0.4mm tolerance) for a first "check if it fits" print.
UPDATE 2018-09-05: nearly finished version, now with filament storage drybox, bed leveling screws, Z motors and print head parking position holders. The "single part export" code isn't up to date, will be updated in a few days.
After using the original NS3DP for a while, I noticed some features that annoyed me and that weren't easy fixes but rather larger changes. So I decided to build a new one.
What E3D showed with their tool changer intrigued me, so I wanted to include that one too, but slightly different. The Z-height of the nozzle of every tool in my printer will be exactly the same, no software compensation. In the parking position, the nozzles should sit over an ooze/dump zone and each move into and out of that zone should go over a brush to keep the nozzle clean. Four tools aren't enough, I went for 7, the maximum a Duet3D can do with the Duex5 expansion board.
Learning from the mistakes of the previous printer, the whole thing will be designed in OpenSCAD (never going back to Sketchup ever), the print volume will be smaller (300x250x200), the linear rails will be recirculating ball linear rails from Hiwin, it will be a CoreXY because Ultimaker-style can't store tools at the side and it will get a BLtouch bed sensor and some parts will have to be machined from metal. I will keep those to a minimum because I know that makes the printer harder to build for you guys out there, but some parts just have to be metal.
First of all, I designed mock-ups of the parts I would be using. An aluminium extruison, a NEMA motor, a fan, you name it. Then, I arranged those parts the way I wanted them and finally, I designed the plastic (and metal) parts around them to make it all fit together.
To keep things tidy, I put non-printed and non-machined parts (externally bought stuff, "vitamins") into separate files, so the main file only has parts to be printed or machined.
I again, like always, defined parameters for tolerances, this time separated in "printingTolerance" and "millingTolerance" so you can adjust those to fit your machines and get precise fits where necessary. Like screw holes and parts meant to slide along each other.
I also added parameters to move X, Y, Z and select different print heads to try out the movement mechanics and see if everything fits. Very useful, actually!