The Expanse MCRN Corvette - Rocinante

UPDATE 30th August 2021:
Quick update - I haven't forgotten this thing, and I do have some plans for the future - just don't have the time for it right now.
That being said, I would like to divert your attention to the two remixes (on thingiverse) that are currently up - One updates the back section with cargo doors, the other includes the Season 4 changes - landing gear and rail gun! Both are excellent additions to the design :)

UPDATE 23th June 2020:
User Freich (https://www.thingiverse.com/freich/about) spotted a mistake, I accidentally uploaded a wrong version of the PDC stand. Should be fixed now.

I have also uploaded a new version of the stand with a deeper cutout at the back, called Roci-Stand-Addon-PDCs.stl. Depending on your method of attachment for the standalone PDCs, this one might be a better fit. I recomment testing the fit by printing only the top part of the stand (e.g. in Cura by pushing the stand 41 mm into the ground).

UPDATE 7th May 2020:

Added (a very WIP version of) standalone PDCs. You can now print the sleek version of the Roci and add PDCs later, should you wish. You can even rotate them around.

These NEED to be printed with supports set to "everywhere" and the supports can be a pain to get off, especially under the gun body (behind the barrel). I used snips to clean up everything I could and the butt end of a nozzle cleaning needle to push the most resilient pieces of support out. Using selective manual supports or support blockers would probably be ideal.

You can use glue to attach the standalone PDCs to the Roci. Alternatively, slim double-sided tape could work for non-permanent attachment. I have not yet tried this, so no idea if the tolerances are right and if it will look good.

DISCLAIMER: The standalone PDCs have some rough edges (pun intended) around their bases that I need to clean up. I don't have a lot of time currently, so this WIP rough version was released based on user demand. Please keep that in mind.

ORIGINAL TEXT:
I love The Expanse and always wanted my own Roci. After a bit of searching, I found 3 models of particular interest
1) The low poly "The Expanse - The Rocinante" (https://www.thingiverse.com/thing:2060060) by SYFY (https://www.thingiverse.com/SYFY/about)
2) The beautiful "MCRN Corvette Expanse" (https://www.thingiverse.com/thing:3025517) by urbanenomad (https://www.thingiverse.com/urbanenomad/about)
3) The absolutely bonkers detailed "Rocinante fixed/sliced" (https://www.thingiverse.com/thing:3738877) by MorganCoLLC (https://www.thingiverse.com/MorganCoLLC/about)

The first one is a little too simple for what I wanted. The third one, on the other hand, is way too detailed, with parts that simply wouldn't print on my FDM printer (especially the PDC cannons and antennas). Not to mention that AFAIK the original model was made for renders and had tons of open geometries - Morgan managed to fix most of the model (mad props btw), but the front part of the ship still refuses to slice correctly for me as of april 2020 (giant hole where the PDCs would stow). I tried fixing it manually but gave up really quickly.

Urbanenomad's model, on the other hand, has just the right amount of detail, printable PDCs and antennas and no significant mesh errors. What I don't like, however, is that the model is hollowed out, which is a problem especially with the exhaust section that has a gaping hole in it. It also doesn't help printability much since you need to support the internal geometry when printing. The hollowing also doesn't help when you want to print the ship in parts and glue the parts together. There are also some unavoidable overhangs that need to be supported. Finally, the stand also has two small problems - it only fits the sleek version (PDCs hidden) and cannot be downscaled too much - the "THE" in "THE EXPANSE" starts to be unprintable even at 70% scale with a standard 0.4 mm nozzle, disappearing completely at about 55% scale even with "thin walls" in Cura enabled.

So, the changes I've made are as follows:

Deleted the internal faces of the MCRN corvette and closed the geometry at the exhaust section for both sleek and PDC version of the ship
Added the inner drive cone structure from Morgan's Rocinante
Separated the ship in parts for optimal FDM printing
Added unique keying to all parts so they are easy to assemble and glue together
Increased size of the "THE" lettering on the stand
Derived a second version of the stand for the ship with PDCs open

The new Roci now has 5 sections:

Drive (same for both versions)
Connection plate (same for both versions)
Back section (sleek and PDC version)
Mid section (sleek and PDC version)
Top section (sleek and PDC version)

All parts are already oriented for optimal printing. No supports should be needed for the Drive and plate sections. The Top and Mid parts require minimal supports under the bottom vents (and even that is optional for the mid part). The back section has vents on the bottom - set up your slicer to print them as bridges (horizontal and vertical lines, not diagonal) and they will look like awesome vents when done (In Cura, you can do this by going into the Experimental settings and playing with Bridge Settings - lower the Minimum Bridge Wall Length and crank up the Bridge Skin Support Threshold - I got mine at 4 mm and 90 % and it works like a charm). Supports can help, but are, again, very minimal.

PDC versions obviously require extensive supports, I had decent success with Cura's tree supports.

6 keys are needed for the full ship. The keying positions have unique offsets between parts, so the model should only go together in one way and look even remotely right. They have a 0.3 mm tolerance at full scale, you might need to experiment with different sizes depending on your printer, especially for different scales of the ship (for example I had to print them at 47% scale for my 50% scale Roci to fit comfortably). They are not made to pressfit and hold the ship together, just to aid in gluing the parts together.

So far I have successfuly printed a 100% scale sleek version, 3x 50% scale versions (2 with PDCs, one sleek) and a 25% scale sleek version, all of them in parts and glued them together. All at 0.2 mm layer height. The 25% scale was a bit of a PITA to put together, but it is possible.

Work in Progress, all criticism welcome.

Incoming Soon-ish:
I am currently working on standalone printable PDCs, so if you decide that your awesome Sleek Roci is not threatening enough, you don't have to print the whole thing again. Printing the Roci with PDCs already on there can also be support-intensive, printing individual PDCs is way easier and requires minimal support and cleanup.

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