[I printed a Spitfire... and it flies :)]

Wow, that's a beautiful one.

One tip: don't leave it in your car in the sun. I have had several PLA-models warping even in moderate weather (about 15°C, and a light sun with thin high clouds).

[Smooth walls]

Couldn't this be caused by underextrusion or irregular extrusion too?

Possible causes of underextrusion that I experienced:

- White teflon insulator on the nozzle is worn out and deformed internally, causing an irregular flow. (If this is the case, replace it.)

- Dirt in the nozzle (if so, do an atomic pull).

- Irregular filament diameter.

- Filament is near the end of the spool, and/or wound too tight, so it acts like a tough spring resisting unwinding. I often manually unwind and straighten a few meters of filament, which greatly improves results.

- Irregular friction between the filament spool and the spool holder (black cylinder at the back), causing a jerky movement of filament, and thus irregular flow.

I am not saying one of these things is the cause, but they might be worth examining?

[Two manuals: Excellent bonding of PLA to glass + Improved atomic method to clean nozzle]

Hello all,

I developed a method to get a better bonding of PLA to a heated glass bed by treating the glass with salt water first. So I named it: "the salt method". Since using this, I made about 1000 prints in PLA, often very difficult ones (100% filled, very long and thick, with big overhangs and chamfers), without any bonding problems and without any corners lifting. Often models that I could not print by using the glue stick method. The only failure was an inverted prism (top down). With this "salt method", PLA sticks to the glass rock-solid when hot, but come off by itself when cold. (This method probably only works for PLA.)

Furter, I improved the well known "atomic method" to clean the nozzle: the standard method works very well in cleaning, but it has the risk of damaging the printer due to the hard pulling. My approach is much more gently, but with equal cleaning results. The disadvantage is that it takes more time.

I have been using both methods for some time now with good results: the salt method for over a year, and the improved atomic method for over a month. So I wrote a manual about each. See my personal page at: "www.uantwerpen.be/geert-keteleer". And then go to the "Manuals & 3D-models" section. Both manuals are PDF-files of about 2MB.

There you will also find and improved horseshoe clip for the Ultimaker2 bowden tube: it is much easier to grab, without risk of dropping it. Feel free to print it and try it.

I hope these things are usefull. Everything is published under a Creative Commons BY-SA license, so you can use it for free (also for commercial purposes) and further improve it.

I would welcome comments on how well these methods work for others too.

Geert