How to judge a 3D printer.

In this post I want to list the things that matter when you buy a 3D printer:

Creality CR10

Point	Details
Bed size	While many crave a huge print-bed, I have found that most things I print are small. Why? Because most 3D printers are much slower than you think. In fact most points on this list are about speed vs. quality. But if you have a fast printer that prints high quality, or if you really need to print big and have the required patience, then bed-size is still important.
Motor speed	How fast can the motors transport the extruder around the work?
Motor torque	How fast and steady can the motors accelerate?
Extruder max temperature	Will the extrude cope with the high-temperature filaments?
Extruder temperature stability	Will the extruder manage to hold temperature steadily during printing, even at higher temperatures?
Extruder temperature speed	How fast will the extruder warm up from room temperature at the start of the print?
Bed max temperature	Will the bed cope with the high-temperature filaments?
Bed temperature stability	Will the bed manage to hold temperature steadily during printing?
Bed temperature speed	How fast will the bed warm up from room temperature at the start of the print?
Enclsure temperature control	Some filaments like ABS may require the temperature around the work being managed using an enclosure and heater.
Direct vs. Bowden filament feed	The size of the print head directly affects the speed and accuracy of your printer. A big head will slow down and cause the printer to wobble if it is not rigid enough. To get around this many printer manufacturers look for ways to decrease the size of the head. One feature, the "bowden tube" allows the extruder motor to sit on the frame instead of the head. However this reduces the filament capacity somewhat which in turn affects print speed.
Interchangeable extruder head	You might only care about the standard 1.75 mm filament through 0.4 mm nozzle size. However there are lots of options out there when it comes to nozzle sizes. Having an easily interchangeable head/nozzle is desirable, and a printer that can handle the higher heat requirements of a larger nozzle/filament of course.
Multiple extruder head	Having more than one extruder provides some benefits, for example if you are printing with more than one material per part. Example usages are: flexible filament for rubber seals, washable support material, dual color prints etc.
Noise	Remember your printer will be running for a long time. Print times are usually measured in hours, and sometimes in days..
Build quality & basic features	This qill require a lot of "getting to know" the printer. Basically all sorts of small practical details such as positioning of the user interface, display size, where is filament dispensed from, how are the wires connected? etc. etc. You can often get an impression of these things by looking at printer reviews on YouTube.

3D Printed case for iMacwear W1 (DM98)

I made a protective case for the W1 Android watch.

iMacwear W1 in protective 3D printed case with servo mount.

The idea was to make a case for it that would protect it while also providing better mounting options. The current version of the case sports a native RC servo horn mount, but I am also looking at different mounting options including a gimbal mount and a simple "screw me on" mount.

I submitted the whole thing on thingiverse here if you want to check out the details. It includes source CAD file, lots of pictures and details etc.

Printing faster on Creality CR10

OK, so it is official. We are now on the 3D printing bandwagon.

The proverbial We got a Creality CR10 3D printer shipped to the shop straight from PRC, and it has had lots of use the last weeks. As a complete beginner I had a lot to learn, however yesterday I put out my first ever DIY design on Thingiverse.

The printer is awesome. It feels like I suddenly got a new super power; the power to create anything. But there is one big hurdle, and that is time. It takes forever to print even the tiniest of things!

So I have experimented a bit with settings and found some optimizations that I would like to share.

First a general note on optimizations; this will most probably only work on the Creality CR10, using gcode generated by Cura, and even using the exact PLA brand I am using (Gold Camel).

So what will affect the print speed?

1. Infill percentage
2. Layer height
3. Print speed
4. Travel speed
5. Retraction speed
6. Retraction distance
7. Raft margin
8. Raft layer count

I found the standard/default/recommended settings to be way conservative. Here are my new settings that cuts the total print speed in almost half:

	Default	Optimized	Notes
Infill percentage	10%	100%	How is this even possible? You do it by making sure your model contains the necessary structural elements by hollowing it out where you need less structural strength and filling in when you need more. This has a bonus benefit that you can shape your custom "infills" to improve the weaknesses in the structure.
Layer height	0.8 mm	2 mm	Will affect appearance, the model will look more coarse.
Print speed	60 mm/s	100 mm/s	If you go too high, the motors might start skipping steps or the extruder might not be able to put down enough PLA.
Travel speed	100 mm/s	300 mm/s	If you go too high, the motors might start skipping steps.
Nozzle temp	200 ℃	205 ℃	This provides better layer adhesion, and might be required if you increase print speed.
Bed temp	50 ℃	70 ℃	This provides better bed sticktion on clean glass with raft, and might be required if you increase print speed.
Retraction speed	25 mm/s	60 mm/s	If you go too high, the extruder motor might start skipping steps or retraction might not work as expected.
Retraction distance	6.5 mm	1 mm	If you go too low, you might get artifacts such as stringing.
Raft margin	15 mm	5 mm	There are many ways to do adhesion. I like best a clean glass plate with a small raft, and raft margin gets really important for small parts.
Raft layer count	2	1	I found 1 layer is more than enough for the raft.