Diary of the noob - 3D printing


So, now I almost feel like a pro so I can give advice how to successfully print your 3D terrain. Almost.
 I started with printing a longboat form Eslo terrain Boats kickstarteer. With one glans I gauged that supports are not necessary for this model so I started printing. Half an hour latter everything went south. First, right side of the model started to curl and lift it self from bed. Then same happend to right, stern part.
Model is ready to lift off with both stern and prow part off the hot-bed

Rest of the model looked little bit melted and sluggish. Few minutes latter model just gave up and separated itself from hot-bed. I returned to Cura, used magic right button on mouse to rotate model until I can see beneath and find out a lot of red marked surfaces. Cura marks with red surfaces that needs support. I added support to raft and now I have my long boat to transport my Heritor and his crew in ghost archipelago (Frostgrave expansion).
Successful long boat full of Frostgrave cultist beside its unsuccessful predecessor 
This happened because without support protruding element are heated from the bed, so they don't harden enough before new layer goes atop of them and while hardening simultaneously, those layers start to shrink and pull apart from the bed.
Even if you feel like a pro, you noobnes can show its ugly had from time to time.

Now lets go back to todays theme - how to print perfect 3D printed terrain.
There are three parts in this process:

1. CAD/3D model
The model you print has to be solid, solidly made without unconnected parts. I started to model my own terrain even before my 3D printer arrived. I tried to take in to account the peculiarity of 3D printing process, by making models with slopes not bigger then 45 degree (to avoid the need of support). I tied to avoid overhangs and break down model in the fashion to avoid overhangs (again because of supports). Even with all this precaution some thing got under the radar. Mostly the thinness of details. Some details have to be exaggerated to be visible on the model. Sometimes designers, used to work in some other branches of 3D/CAD design, just forget the peculiarity of 3D printing process.
For example, long boat from Eslo terrain has some overhang issues that could be mitigated by clever design without ruining its overall design (putting some sprits below middle and front benches). Front bench has an element (hank of filament below it) that is not connected to main hull.
Strings of filament under benches could be avoided by clever design
 If I put support inside model, not just outside, this would not happen, but those supports would be very hard to remove. This also could be mitigated by custom cooling fan for extruder, but, I think, designers have to have average consumer on their minds when designing, not enthusiasts.

2. Slicer
Slicers are the programs that convert 3D model in to the layers and let printer know how to print it (layer thickness, temperature, speed of printing...). There are several slicer programs on the market, few of them are free (Cura, Slic3r).
This is probably the most crucial part of 3D printing.  I'm using Cura for Wanhao, so I have all parameters of 3D printing set by manufacturer for their optimal value. Even with it, I have to tweak few things depending of model I print. If model is simple putting higher speed will save some time. Most prints will look OK with 0.2mm layer, but for more detail and smaller parts, thiner layers are better. Even with thiner layers, first layer should be between 0.2 and 0.3mm to mitigate not perfect bed leveling.
Supports and build plates are important parts of model preparation for printing. Small overhangs and bridges, are usually printed without problems. But when you have larger overhangs and bridges you have to make a decision would you put supports or not. Advance (payed) programs have options to manually put/remove support.
Rudder and benches are not perfectly printed on this model, but I made conscience decision to printed it without support knowing I would have more work on this boat after printing. If I put supports, they would be hard to remove under benches and probably would leave some traces of material.
Left overs of support on stern of this ship are hard to remove
When I start printing I printed everything with brim. Brim is middle solution between skirt (just the line around object) and raft (solid plane around and below object), but after problem with 0.4mm printing I abandoned brim completely. Now, if part is small, with small foot print on bed or with lots of external support, I print it with raft. If its object with decent footprint, I print it with skirt. Main purpose of the skirt is to remove excess plastic form extruder (this plastic is consequence of pre-heating extruder), and to show you is initial layer is OK - is bed leveled enough.
There is no universal advice for successful slicing of 3D model. Most of it comes for experience, but no pro is doing slicing routinely.

3. Printing on 3D printer

First and foremost - bad leveling. Good leveling of the bed is a basic necessity for any 3D printing. I'm doing it with plasticized paper I received as a gauge with the printer.

I'm doing it before every print, even if I had just finished a successful print before. The main reason is that you have to use some force to remove printed object from the bed, and the can disrupt leveling of the bed. My bed is leveled good when I sense resistance when sliding gauge below extruder but not hitting extruder with gauge end. With time this become a routine.
Other important thing is to keep your PLA (if you print with PLA) dry. For me this is not a problem because my printer is in my bedroom, and my house has central heating (famous for drying inside air), but if your printer is in a room without permanent heating, depending of time of year, your PLA (and your print) could be ruined because it absorbs moisture from air.
You have to keep your machine clean, without dust, and from time to time you have to lubricate axis with machine oil.

Regarding mods and upgrades, my MOSFET arrived from China, and I started printing some mods (knobs for bed leveling for example) but I don't plan to do it immediately. I'm satisfied with how machine is working, so I'm little reluctant to disturb things at this moment. I will probably put MOSFET on it's place in next few days (I'm short few wires for that modification).

This post concludes the series of 3D noob diary. I'm not felling that I'm noob any more.
But if my noobnes show his ugly head again, you will read about it in the


PS While I was finishing this post, my printer was diligent printing first floor of Forge from Pirates kickstarter. Day before I printed base floor and it took around 5 hours. I sliced all elements for whole building in Cura, and did not look how much time each will take. So, my printer start first floor around 8AM. 4 hour latter it was little shy then 2mm in hight of the model. It took 9 hours to finish just wooden floor boards of the 1st floor (around 2.8mm of hight of the model. I looked at Cura and it estimate for whole model was 13 hours. At around 5 PM I switched off hotbed because I have to leave the house. All at all it took 18 hours to finished object that is similar in volume to first floor.
2AM shot of the model
I think the problem was that model is not optimized. The wooden floor boards are not solids with surface texture, so they was printed layer by layer of wood texture in whole volume. Wooden planks on gable was not totally merged with gable wall, so printer had to print wall and then planks.
Not optimized 3D model
This one goes to point 1 of the above text - 3D model that is not optimized can take a lot of your time and few extra meters of filament.
After this print I went back to some of my designs to add solid boxes in places that are enclosed/not visible but had volumes of air inside model.
For every expiriance you can learn something new and usefull :)