Previous posts:

EasyConfigure - Modular/Configurable System Intro

EasyConfigure - Hardware Components

EasyConfigure - BASH scripting

EasyConfigure - MQTT test setup

EasyConfigure - Remote sensor unit preparation

EasyConfigure - Configurator

EasyConfigure - Sudden Impact Monitor

 

 

Intro

We all received Electrolube PU Resin as part of the challenge kit so I decided to try it out (It's probably not intended for casting hard plastic casings - looks more like it should be used to pour directly over the electronics components to protect them)

Since I don't own and have no access to 3D printer I decided to try making a mold and then casting some kind of housing for my Sudden Impact remote device. This is not looking nice but I'll share it anyway Please note that this was the very first casting for me.

This is just a test and it will probably fail but this resin should be used before June 2015 so it seemed worth trying. I will probably end up using a strengthen TicTac box - it fits very nicely.

 

Making the mold

I started out with some school clay. It was used to make a mold. This kind of white clay dries very quickly, especially if you put your mold into oven for a couple of hours (I set it to heat up to 50C). I made a hole inside this peace of clay that should fit my remote sensor unit easily.

2015-05-06 14.07.54.jpg

With a sawing thread I split this blob into two pieces.

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Two pieces are then placed in the oven to dry and become solid. I didn't make a horizontal cut evenly so it looks like the holes are skew - they should be fine when put back together.

2015-05-06 18.08.57.jpg

 

Casting the PU resin

I placed the TicTac boxes to make the inner bound for PU resin. Small spacers are visible through these boxes. These spacers will define the wall thickness. Spacers will leave holes in final PU case.

2015-05-06 23.40.03.jpg

Then I carefully mixed the two PU components and poured the resin into molds. I should end up with two halves of my sensor unit casing after PU resin cures completely and I remove the extra PU.

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I did this step late in the evening (or very early in the morning) so I will see the result and continue writing this post in the morning.

 

Removing the mold and extra PU

 

After I removed the clay mold and TicTac boxes I was a bit disappointed. It turned out that resin pulled the TicTac boxes up so I ended up with too tick castings and too shallow to place my board + battery

However, I do like the Electrolube Resin very much. Too bad it comes in bag and not in two separate bottles, this way I had to throw away the rest of resin.

2015-05-08 12.29.51.jpg

My intention was to make it look similar to this but much prettier and with enough space inside

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I also made a photo of leftover resin just to show how fine this resin is (click the image to enlarge). If only I had a proper mold, I think that it would have turned great.

Please note that small scratches all over the resin are from a plastic pot where it cured. These scratch marks are really, really fine.

2015-05-08 12.30.13.jpg

 

Conclusion

Electrolube PU resin is great (if you have a proper mold)! I will use TicTac box instead...