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Comment by nfriedly | Hacker News Reader

This probably all boils down to my lack of experience, but I just recently got a 3d printer, and most of the things I have printed have failed to perform their desired function. This is both things I designed (a replacement battery lid for a remote - the software skips the small details like the notch that holds it in place), and most of the designs I've pulled off of thingiverse (e.g. a water bottle lid - it's too tight and it leaks water).

My only fully successful prints aside from the calibration were the "hello world" roctopus and a toy car.

I expect (hope) that this will improve with time, but so far it's been a little disappointing.

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This is why it is still "early days" as far as I am concerned with 3D printing. But it is also about learning and understanding your tools.

Prints that are insufficiently strong may be because the material is not strong, or the way in which it was printed did not favor strength, or the "slicer" converted it into layers in such a way that it was not strong. Sizing is another issue, my Makerbot Replicator does not print dimensionally accurate pieces, what it worse is the X direction is more accurate than the Y direction, the Z direction is spot on. So after printing a number of test pieces where the size it "should" be was known, and the size it was, was measurable. I came up with some "calibration adjustments" that I can put into my slicer program to improve accuracy (Simplfy3D).

There is also an issue of materials, very inexpensive printers might print only with PLA which is not nearly as strong as ABS. In the middle is a PET variation I got from MadeSolid. PLA, ABS, and PET are all shorthand for the chemical formula for the material. Different materials, different properties, these days you can also print in Nylon and other high density plastics. Somewhere I have a picture of a "hula girl" that was printed in PLA and put on a dashboard of a car, she is all melted due to the heat on the dashboard.

So it isn't as simple as click, print, and use. And most printers seem to be a bit cantankerous and picky, but if you take a bit of time to methodically learn what they can and cannot do, they can do some pretty amazing things.

For engineers with new printers I really recommend printing out test pieces to understand your printer. You can test strength (tensile, shear, compression), detail reproduction, dimensional accuracy, and environmental durability. There are a lot of test printable things on the Thingaverse site. Once you know your printer you'll be able to quickly design and print a part that will meet your expectations the first time, every time.

If you want “production quality” parts, I recommend you use a laser cutter, some kind of milling machine, or regular woodworking / machine tools. If you want to make a bunch of the same kind of plastic part, you can mill a mold and cast them, cf. http://lcamtuf.coredump.cx/gcnc/

3D printing is great for making objects whose shapes make them (a) impossible to construct with a subtractive process, and (b) too complicated or subtle for your skills with clay or whatever. For example, various types of mathematical objects, https://plus.maths.org/content/3d-printing http://www.shapeways.com/marketplace/art/mathematical-art/

Keep at it! Part of the problem is designing, part of the problem is printing. If there's a reprap group or a makerspace nearby where there are people with experience, that would help you a lot.

I've tried to keep my designs as simple as possible and it's worked out alright. As you say, more complex things are fairly hard to model. Having calipers so that I could accurately measure things greatly helped me design things for around the house.

I'm probably classified as intermediate in 3d design and printing. It takes a while to get it right, there are so many factors that influence the outcome, so initially it might seem like the failures are random.

Thingiverse models frequently have issues, but you get used to opening them up, checking dimensions and fixing errors in the STLs.

When designing, at some point you get used to the fact that it takes two or three iterations to get it right. I frequently print partial models nowadays (or smaller versions of the final), featuring whatever needs to fit and then going back into the design software and completing the model.

Then there's the whole "what's the printer up to" thing, is the PLA not too old, is my printer properly calibrated, did the slicer do its job properly. That just takes time to understand as well (having a quality printer here helps as well).

Just keep going at it and eventually it all starts falling into place and you get faster and faster at designing as well as incorporating others STLs into your own designs and printing them.

I believe you might be missing the key ingredient of prototyping: iterations.

From all the success stories in the industry, 3D printers combined with competent designers enables very tight iteration cycles, and makes the interations more fulfilling to test :)

What 3D printer do you have? They are not all equal in capability and resolution.

For something like a chunky toy car, precision is not important. For a threaded screw, in particular a bottle cap, you will need good resolution and accuracy.

It's a Lulzbot Taz 5 (they announced the Taz 6 the day after it shipped :(

From what I've read, it's a decent quality printer. I've kept the software in beginner mode so far, so there's probably some settings I'm overlooking.

Looks very capable. Not cheap at all. I haven't heard of it, but then again once I bought my "Up!" printer I stopped looking at what was out there.

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