Resin means, in our case, casting resin. Usually this consists of 2 components, which must be mixed and which then harden afterwards.
I have had bad experiences with slow hardening resins and so I only use PU high-speed casting resins now.
Advantages:
You can carry out several casting in one day.
They do not absorb humidity from the air so easily.
Disadvantages:
They become substantially hotter during hardening, particularly with larger parts.
Unfortunately, fast hardening times also mean short working times of only a few minutes.
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Here are some examples of parts which were manufactured from PU high-speed casting resin. |
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This part which is curved in all directions was difficult to cast. |
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Ankle Bracket |
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Parts of this size shouldn't be cast in one go, because the material would heat up so strongly that both the part and also the silicon form would be destroyed. For this part I mixed a small amount, poured this in, waited some 1-2 minutes and then mixed the next amount. I repeated this procedure around 10 times until the whole form was filled. For solid cast parts I also added a filler. I used a silicate filler because it is lighter and the parts became not unnecessarily heavy. Weight of this part is approximately 1.5 kg |
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The use of a filler also reduces the thermal reaction and the process does not become so hot during hardening. However, the use of filler also has negative effects. The casting resin becomes more viscous and does not run so well into the mould and in addition the parts become more brittle and break more easily. Therefore, I inserted several layers of reinforcing fabric during the casting procedure, in order to improve the strength. This part weighs approximately 3.2 kg and is the heaviest independent part of my R2. |
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