Wooden moulds for Resin casting of Darwin parts

Ok this is just the start of what i'm working of making moulds for resin casting. Starting with the offset motor holder on the extruder. Please check it out and let me know if you think this can work. I belive i can make nearly all the printed parts using this and other methods

These instructions and Plans are still being worked on. just wanna get some feedback before i get too far ahead.


basicly the idea is to print out these sheets stick them to a piece of mdf (with a gluestick). Cut them out. Then line them all up, clamp and pore the resin.

To Be Done:-
better instructions (including photos)
Top Plate for drilling out the semi-circles in the top
Drill holes for clamping all the pieces together
Pins for holes in the finished mould
Try out the mould
Compare to on a working machine to make sure it fits

helps if i attach the file....

Edited 1 time(s). Last edit at 10/02/2007 11:06AM by moonspud.

interesting approach. good luck with it, and please let us know how it goes! not to discourage you, but adrian has made castings from the printed parts, and we should be using those soon to make molds. it would be interesting to compare the two techniques.

also, it seems these moldings would be a good candidate for being lasercut. how are you creating them? if you're using a cad program that creates DXF files, then its super easy.

good luck!

using autocad and pulling the dimentions from AOI.(on that note does anyone know an easy way to get a dimention from AOI? i'm currently drawing a box or sphere next to the mesurement i want and using the sizes from it)

my idea behind these is that anyone around the world can build these without access to the orignal parts using common woodworking tools

Edited 1 time(s). Last edit at 10/02/2007 11:45AM by moonspud.

i've build a test mould of this. i used plaster of paris (still waiting for my resin to come) to test the mould but it stuck to the mould and broke up trying to get it out... for my second attempt i sprayed the mould with silcone spray, it still did the same thing. any ideas? would the resin not stick as bad or be strong enough to be extracted with out breaking?

Feeling extremly stupid, but then again I never where any good with 3-d problems...

Which part are you trying to make? are you making a negative?

Is it one of the extruder parts on:
[reprap.org]

?

mimarob Wrote:
-------------------------------------------------------
> Feeling extremly stupid, but then again I never
> where any good with 3-d problems...
>
> Which part are you trying to make? are you making
> a negative?
>
> Is it one of the extruder parts on:
> [reprap.org]
>
> ?
it's the motor holder, part B in that pic.
if this works it will come out of the mould a usable part (not quite perfect but good enough to use to print better ones)

i've cast my first successful part!! using easy cast resin and painting the mould with clear laquer and the coating it with silicone spray.

the pic attached is this first part in it's raw form. it is very rough becuase i reused the same mould i used for the plaster attempts which wasn't in the best condition. but this was a proof of concept cast to see if this idea would even work.. the dags haven't been cleaned off it yet and the mould was slightly out of whack and the holes haven't been added. but it shows that it's possible. also the brown discolouration on it is from the laquer not being properly dry...i was in a hurry to see if it would work!!

Plaster of paris has the problem of being very rigid but also brittle. Good for casting soft materials like rubber or unhardened clay, but problematic when trying to cast hard resin.

What works really well is a latex rubber mold, with an exterior "mother mold" of plaster to provide support while the resin hardens. Then you can pull of the plaster supports, and peal off the latex mold to reveal a perfect part (as long as there are no bubbles in the resin). I have produced some excelent reproductions of vintage toy parts using this technique. Somewhere on the internet or at a well-stocked hobby shop you can find detailed instructions on how to make a mold like this.