Not so long ago I published a blog post showing how I make silicone components. If you haven’t read it I recommend you go through it first. I won’t cover all the steps for making the components — I will just discuss the game-changing improvements in my setup.
You might be asking what might be such a game-changer that it deserves a separate blog post. Previously, I designed open molds and pour silicone into them. Now I have found a way how to inject the silicone into a closed mold.
Injecting the silicone makes the whole process faster, cleaner, and also, more reliable (no more trapped bubbles!). On top of that, it allows me to design more complex molds which can, e.g., make removal a much more pleasant process.
Resin 3D printers are awesome, however, the whole process is extremely messy. Especially when an accident happens and the resin leaks from the vat all over the printer.
When this happens mid-print, it usually means one thing – the resin will leak onto the precious LCD of the printer and cure. This means one thing – the UV light will be blocked by the cured parts and you will probably experience holes in your printed parts.
Usually, the people on Facebook advise you to scrape the resin away with a plastic razor. This usually works for small leaks, but it doesn’t work well on large leaks.
I experienced a resin leak recently on my Elegoo Saturn. Scraping the resin was not leading anywhere and I managed to scratch the polarizer film on top of the LCD. Therefore I stopped and I decided to make a (successful experiment): use acetone to dissolve the cured resin. It worked flawlessly!
The method is based on the observation that resin softens in an acetone bath, but the polarizer film seems not to dissolve in acetone.
Recently, I discovered Resione resins. They have a wide variety of resins. They also have a series of tough and flexible resins. They also have an EU distribution center, so the resin arrives quickly and you don’t have to care about customs. Overall, the resins seemed nice. I might make a separate blog post about their resins in the future.
When I was working on a big project (blogpost upcoming, sneak-peaks on my Twitter and Instagram) I decided to use Resione M68 — tough snow-white resin. The parts I printed were thin-wall parts (wall thickness of 0.5–1 mm). They also have a lot of internal cavities where a liquid can be trapped. After printing, the pieces looked great! However, it was a rainy day and the air humidity increased up to 80 %. The next day I found my parts deformed like this:
It seems that the Resione M68 absorbs a lot of moisture and the large flat areas between infill of the component expand, thus they form bumps. So I took one piece and soaked it into the water for 20 hours and it even cracked.
It is a well-known phenomenon, that some plastics absorb moisture. There is even an ISO standard 15512:2019 for measuring this (which I don’t have access to, unfortunately). Since my components will be exposed to the weather condition, I decided to make an experiment to determine which resins would be suitable and which not.
Recently I got in touch with the customer support of Siraya Tech – my favorite resin brand. I love their Fast Grey resin – it is easy to work with, it is low viscosity resin, which is not brittle. The only downside is that you cannot easily buy it in Europe. I hope it will change soon!
They offered me to test their Tenacious resin – the resin I wanted to try for a long time. You can find a lot about the resin on line. But I wanted to have the first-hand experience.
Tenacious is marketed to be flexible, rubber like with high impact resistance. The exact opposite you are used to with standard resins like Elegoo or Anycubic.
The resin is light yellow and semi-transparent. When you open it, it smells similar to Siraya Blu. The smell isn’t bad – to be honest, I find it quite pleasant. It is is a viscous liquid.
To test it, I decided to print tips of legs for a walking robot. The tips should be soft and provide friction for the legs to not slip on the floor. Since Tenacious is marketed as rubber-like, I thought it could be a suitable option. The resin was easy to print on my Elegoo Mars and the prints came out great. However, I was disappointed with the results. The parts were quite hard and did not provide enough friction. Even when I hollowed them to have a 3mm wall, a 2mm wall, and a 1mm wall they were still too hard for this application. And too slipper. Note that this is not the fault of the resin, rather my mismatched expectations. I revisited all the reviews and videos about tenacious and I found the cause of my mismatched expectations – when you see tenacious prints to be flexible, they are really thin lattice structures. Not beefy pieces.