3d print settings for tough parts

I show my settings for printing high-strength parts from PETG PCTG PC-PBT CF PA 12 CF and other technical filaments using a 3D printer for my high-performance Stirling engines.
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Thanks to Baptiste (alias Olympio) we now have a Discord server: https://discord.com/invite/TDABS5z2mT
It would be very nice if we could discuss there everything about Stirling engines, 3D printing and more, thank you very much Baptiste.
It’s amazing what’s possible with modern 3D printers and today’s technical filaments.
With the right printing parameters, the plastic parts can deal with pressures of over 12 bar and temperatures above 100°C.
That is why I am trying to develop a high-performance, fully 3D-printed acoustic Stirling engine.
All design documents and 3D models will be published as open source, so that everything will be easy for anyone to build.
Using any heat source, everybody can therefore generate their own low-cost electricity.
The heater and the two coolers are still made from metal using conventional methods, but the plan is to gradually start printing them as well.
If you’re interested in the acoustic Stirling engine, you’ll find lots of videos on my YouTube channel, Myengines, with detailed information on how they work and complete building plans.
The output is still low, but thanks to improvements and, above all, the forthcoming pressurisation, it should reach the 300-watt range, as with my mechanical Stirling engines.
As the thermoacoustic Stirling principle requires no moving mechanical parts – apart from those needed for energy conversion – continuous operation around the clock provides enough backup for a solar plant during periods of low sunshine.
For my further development work, I need a lot of components, some of which are subjected to high stresses.
I’ve just printed the entire Feedback Loop using a range of filaments, from the rock-hard PC-PBT CF – which is almost comparable to aluminium – right through to the budget-friendly PETG.
To ensure this, I only use completely dry filament, which I print straight from my homemade drying boxes.
I set the nozzle temperature slightly higher than normal, by about 10–20 degrees, and the extrusion rate 3–10 per cent higher than in the datasheet.
As a result, the prints may not look perfect, but they are stronger and more tight.
I’ve built a housing with a circulation filter for my budget printer, but I don’t want to expose it to temperatures much higher than 40° to avoid damaging it.
As a result, I’ve occasionally had problems with warping when printing large, solid models and working with tricky materials such as nylon.
To achieve maximum strength and tightness, I print parts subject to heavy loads with 4–8 outer layers and a solid infill.
For larger prints, I also like to use a 0.6 mm nozzle; this provides greater strength and is particularly useful for fibre-reinforced filaments.
It’s also possible to gain a bit more strength by arranging the layers skilfully, but I need to experiment with that a bit more.
There are a number of helpful videos by relevant experts on this topic here on YouTube.
To ensure a perfect tightness, I seal all the prints with Dichtol, although you can also use standard varnish or epoxy resin.
I have achieved very satisfactory results with these measures.
Fibre-reinforced high-tech filaments such as PA12-CF, PC-PBT CF or ASA CF offer even greater strength and temperature resistance, but also involve greater effort, higher costs and a higher degree of difficulty.
That’s why I’d like to start by working with standard PETG and PCTG and explore their limitations.
My experience with PETG has been absolutely satisfactory, and I haven’t managed to cause even quite thin-walled parts to burst with my 12 bar pump!
PETG is my absolute favourite filament; it’s very easy to print with, good value for money, has excellent layer adhesion, is easy to post-process, is strong, and the fumes are relatively non-toxic.
The only drawback is that the support structures are a bit difficult and messy to remove.
That’s why I’m really looking forward to trying out the PCTG – apparently it’s supposed to be even better.
Any help is very welcome—it would be great if you could help join the development of the thermoacoustic engine!
As always, I’d like to hear your feedback, suggestions and thoughts in the comments, on Discord or at ownenergy.org.
Your help is absolutely important for further development work!
If you'd like to support the project further, becoming a member on Patreon or YouTube would be a great help.
Every cent from this will be invested in the development of the open-source thermoacoustic Stirling engine.

Thank you very much for your interest!