10. Molding and casting¶
Assignments for the week¶
Group assignments¶
- Review the safety data sheets for each of your molding and casting materials
- Make and compare test casts with each of them.
Individual assignment¶
- Design a 3D mould around the stock and tooling that you’ll be using, machine it, and use it to cast parts.
Requirements¶
- Explained how you designed your 3D mould and created your rough and finish toolpaths for machining.
- Shown how you made your mould and cast the parts.
- Described problems and how you fixed them.
- Included your design files and ‘hero shot’ photos of the mould and the final object.
Group assignments¶
See 2019 Fablab Taipei Group site Week 10
Individual assignment¶
Design¶
It’s a coupling for mini-stepper and M5 screw, and the M5 screw is embedded to the cast.
Also, because it’s small, the mold designed to have 4 copy in one casting.
All vertical structure has min. 1 degree demold-angle.
Seperate to half for shape anddeepth of mill cartridge.
Add gas outlet and epoxy inlet channel.
Mill¶
Cut a hole and use double side sticker to holding the wax (by Dr.engrave).
It is a simple mold, so choose a properly mill , then just mill it (by SRP player).
I use a 2mm squre mill for both rough finish milling.
Half mold need a partly milling setting.
Bad holding cause many defact of wax mold.
Milling result and the mill cartidge.
Silicone mold¶
Materials for silicone mold.
Use musking tape to restore the wax mold, measure components 25:0.8 by weight follow the recipe.
Mixing and pour gently to avoid bubbles.
Demold and trimming.
Epoxy Casting¶
Same way to silicon mold, but different components and recipe.
It is 3:2 by weight.
And I prefer by weight then by volum for the ease of measurement.
But some small packages on market in twin-syringe type container are also good for ml-level use.
Insert the M5 screw, combine the two parts of mold, pour the epoxy.
Wait over night and demold.
Post-work and done.
Test to coupling with stepper.
Break it in purpose to test its strength.
Make a new set with mold holder.
