It's a Kossel! It's a Monster! It's huge!
And it prints!!!
UPDATE 11 Jan 2019:
Back from Oslo, where I built most of the 20x20-based version of the Monster Kossel v2 at present. Due to delays and lack of time to get all required parts for the build, I was forced to leave before it had its first print - all it was missing was a heated print bed wired up, attached to the frame and Redeem on a Replicape B3A configured. The Replicape in there will (I was told) be replaced by a Revolve when those are available. Looking forward to more pictures and feedback from Bitraf members finishing and using the printer.
UPDATE 7 Dec 2018:
It's confirmed I will be building a second Monster Kossel at Bitraf in Oslo in the first week of January 2019. I will try to document the build with lots of pictures and/or videos. It is meant to serve as a test platform for Elias Bakken's Revolve prototype (i.e. verify the board is able to print) before he sends it out to be mass-produced.
UPDATE 16 Nov 2018:
added 20x20-compatible corner frames for those who have difficulty sourcing the 15x15 extrusions for the triangle frame. These have not yet been printed, but I will be building a printer with those parts in early January 2019.
Manga Screen 2 holder is currently still a WIP part. Currently it has not been printed, as due to location the screen on the top would not be accessible to me. I may revisit that design at a later date to fit it on the bottom frame instead.
It's the Monster Kossel v2!
The reasons for the original Monster Kossel were simply that I like a delta frame. I also like to print model airplanes, and deltas are easy to make taller. Thus a delta with 350mm diameter bed, and 1 meter towers. Print volume is 350mm diameter by 440mm tall. You can fit a 230x230mm square on the plate and have a bit of room left around the corners. And you can go real high.
The version 2 came about because the Monster Kossel v1 was functional but needed an extra feature to keep the lady in the house happy: enclosed build chamber with air filters to keep the home healthy (I don't have a garage or basement to put it in). While I was redesigning it, I also figured, well, let's build it with a bit more thought into everything that was clunky:
I remixed a number of objects, and re-included a few of the parts I'd designed for v1 under this single Thing here, to simplify people's lives when wanting to look for files.
The v1 was working, but I had to go get 2mm steel wire to setup as cross braces between top and bottom of neighboring towers to prevent torsion. I probably didn't put the 2040 openbuilds in the right direction. But I made the whole thing beefier by moving to a T of 2040 serving as rails for the rollers still, backed by a 20x60 to add torsional rigidity to it. Corners top and bottom are also massively redesigned to be able to keep things aligned a lot tighter with less flex.
Easy to open enclosure.
I like to tinker with my printer, try new things, fix things. I need to be able to get in to change stuff when needed. So, the panels needed an easy way in and out, that still gives a decent airtight enclosure. Queue sliding panels from the corners into the OpenBeam triangular grooves. Simple, easy, no fasteners needed. Just some joints on the tower corners to get a semi decent seal.
If it's going to not cause issues with the lady for running at all, might as well run it all the time. So it's designed around the Replicape, my board of choice. Using Noctua fans, even in full operations it's quieter than the average desktop computer, thanks to the TMC drivers in stealthchop. It will be upgraded to Revolve as soon as it becomes available. Note that if you're enclosing the printer, you can reduce the noise level further by installing a liquid-cooled hotend instead of air-cooled, to maintain performance even as the build chamber temperature climbs.
Better bed fastening mechanism.
The v1 has one flaw bigger than the others, and that's the way the bed is held in place. I remixed other delta bed holders for it, but... I found the solution of plastic tabs sticking out with a grip on top very unsatisfactory. My bed has wings with holes on the sides for mounting. I re-designed the bottom corners to be able to mount the bed using the wings and into the corners.
- Detacheable motor frame.
The Kossel Mini, Kossel XL and the v1 suffer from the same annoyance when it comes to maintenance: the motors are pretty much locked in unless you manage to take off everything from the frame, with a great change of misaligning things during unmounting. No more. There is now an inner coupling for the motors that can be removed with 4 screws. No need for awkward tilting the printer over to get to the bottom screws of the motors. It's the same frame that the bed mounts on, too. So anything with wiring can be unmounted from the bare chassis quickly and with a minimum amount of fuss.
Bill of Materials
- 3x OpenBuilds 20x40x1000mm V-Slot extrusions
- 3x OpenBuilds 20x60x1000mm V-Slot extrusions
- 9x OpenBeam 15x15x450mm extrusions
OR 9x OpenBuilds 20x20x450mm V-Slot extrusion (if you use the top_corner_2020 and bottom_corner_2020 printed parts)
- 9x OpenBuilds V-Slot mini V wheels
- M3 screws in 5, 8 and 20-25mm lengths. Suggested M3 kit
- M5 screws in 5 and 30mm lengths. 9x the 30mm (for the carriage rollers), 57x the 5mm
- 6x 360mm tubes (6mm diameter), carbon is lighter, but aluminum would work too
- 12x rod ends. Traxxas or Igus. Note Traxxas uses M4, Igus M3 threads
- 12x threaded rod caps in M3 or M4 depending on rod ends
- 3x bottom_frame_corner
OR 3x bottom_frame_corner_2020 if you prefer using 20x20mm extrusions instead of 15x15mm for sourcing reasons
- 3x top_frame
OR 3x top_frame_2020 if using 20x20mm extrusions instead of 15x15mm
- 3x motor_frame
- 1x effector_e3dv6_igus
- 1x effector_e3dv6_igus_clamp
- 3x carriage_v_roller_thick
- 3x Kossel Carriage with belt tensioners or any other compatible carriage (same joint spacing & same hole pattern)
- 350mm aluminum heated bed (Mine is from here
- 1x 40mm_e3d_cooling
- 1x frame_bottom (if you have a Replicape board to put in it)
- 1x frame_top
- if you have a Manga Screen 2 (or want one), the whole frame set
- 1x Ultibots' FSR kit for probing with the nozzle
I'm not going to cover the essential electronics here. Needless to say if you're building one, you should know what you want to power it with. Being a Replicape/Redeem contributor I'll be powering it with the Replicape and Beaglebone Black until the Revolve comes out.
Assembly instructions will not be detailed. This is not a printer for beginners, nor for the faint of heart. You should be building one because:
- you want a big volume printer
- you don't mind tinkering
- you want to own your platform, not a generic out of the box system
- you have the know-how
If you've build a delta before, specifically a Kossel Mini, then everything will look, and feel, familiar. I've loosely based myself off the excellent work done on the original Kossel Mini by Johann Rocholl. It was my first printer and I really love the elegance of its design and the hypnotic effect of the kinematics.
Note: The OpenBuilds double L brackets don't align properly to fit bolts through into the grooves when aligning the 2060 and 2040 into a T, so I will instead recommend a 5mm M5 into a relatively tight position holding nut (but loose enough you can slide it up and down by pushing on it) between the open rails of the 2040 where it meets the 2060. It works plenty well if you put 3 of them in place on a 1m length, one in the middle and one at each end.
I sliced with S3D which made supports easy to remove. But any slicer will work if you have the right settings.
Make sure to print with at least 3 perimeters, 3 top and 3 bottom layers. I went for extra sturdiness and printed 3 perimeters and 4 top/bottom layers to make sure it doesn't flex.
Printed mine in PLA, but PET or any other material that is relatively warp-free will work as well.
As you may notice, there is a .blend file.
That is the original source. I imported STL meshes into blender for the OpenBeam, OpenBuilds and other MiniKossel parts and worked my way up from there.
I know it's a big departure from the Kossel Mini openscad files, but I don't have the know-how or the time to rework my way through OpenScad to make the files that way. The STLs I posted are the ones that I sliced to print my machine.
I remain open to suggestions or requests for modifications, but do note that since it is based on the Kossel Mini which is GPL, this project is also distributed under the GPL. Don't like it? You're free to remix it!