Vaquform - making your own custom molds

[Kerry Beal]

1 minute ago, Tri2Cook said:

Fill the mold you just made to the depth you want with some material you can use as a plug? I'm generally looking for the easiest way to do things that will still get the good result so I'll have to think on this one a bit. It's not a task I've ever had need to find an easier way to do. 

Figure if I have to make a silicone mold - I might as well use it for the chocolate- I suppose I could use the gelatin molding compound.

[Tri2Cook]

7 hours ago, Kerry Beal said:

Figure if I have to make a silicone mold - I might as well use it for the chocolate- I suppose I could use the gelatin molding compound.

I meant the molds you posted above with the tools. Fill those to the depth you want with something that will set strong enough to use as a plug. I know that wouldn't be efficient long-term but it would be a quick way to test the partial depth molds to see if you like the result better.

[teonzo]

On 3/9/2019 at 1:55 AM, Kerry Beal said:

@teonzo - looking forward to your drawings. 

 

Here I am. Sorry for the delay and the crappy drawings (I feel ashamed for the bad quality but hope they are understandable).

Everything I write is my personal supposition, written without trying anything.

 

 

 

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VIEW FROM ABOVE #1

 

 

I would suggest adding an indentation running along the mold perimeter.

The indentation should leave some space on the sides, so the wood frame can lay on the exterior.

Best choice for the indentation would be a semicircular section. Radius should be small (the smaller the radius, the more rigid effect you get), but not too small, I would say 1 cm diameter is a good choice. If you get a rod/stick of semicircular section, cut 4 pieces of the desired length, glue them together to form a rectangle, then you are done once for all future uses. Just lay it on the machine and you are game.

 

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SECTION

 

 

 

Here is the section (not the same measures as the first image), just to give an idea.

If you get a wood frame with the correct measures then you can lay the mold on it and the indentation would act as a lock,  preventing the mold to move. Building the wood frame is pretty easy, you need a wood bar with rectangular section, cut 4 pieces of desired length, glue them together (something totally basic for every wood hobbyist). You can build various wood frames if you need to work with many molds at the same time. You can build them of various heights too.

If the mold perimeter does not shrink during the thermoforming, then you can use the same model for the indentation and the same wood frame each time.

The indentation should be big enough to act as a blockage, not too big to avoid 2 problems: the bigger the radius the less rigidity; the bigger the indentation the smaller space for the cavity. This is why I say 1 cm diameter should be ok.

The indentation should add enough rigidity to be able to scrape the mold as you with rigid policarbonate molds, you will not get a perfect scrape, but something decent is much better than nothing. Only case when you could face ig troubles is if you have 1 big cavity, filled to the brim (sensible weight that will bend the mold), in this case hold the mold putting your hand under the cavity.

The combination of wood frame + indentations should be enough to be able to put the mold on the vibrating table without creating a mess. The indentation adds rigidity so you should avoid the slingshot effect. The indentation should be high enough to prevent the mold from running out of the wood frame (the mold should lay in place without going anywhere).

 

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VIEW FROM ABOVE #2

 

 

 

If you have moltiple cavities on the mold, then you can add one or more other indentations, to act as a "spine" and add more rigidity.

 

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I hope I've been able to explain my idea, if not then I'll try to do something better.

 

 

 

Teo

 

[Kerry Beal]

Are you adding the wood frame after or during the molding process?

 

 

[teonzo]

On 3/9/2019 at 12:42 PM, Kerry Beal said:

Was also trying to think of a way do to half a figure without cutting it in half.

 

With old-fashioned mold making you use sand or similar: you bury half of the model in sand, then you pour the molten metal / whatever.

From what I understand this machine works thanks to all the little holes on the base, which are used to suck out the air so that the mold can adhere to the model and the machine base. Whatever method you choose to raise the flat surface level as to reach half-heigth of the model, you must keep those holes functioning. So you would have to make holes in whatever thing you use to raise the surface, and those holes must be in line with the ones in the machine base. I don't think there are lazy solutions for this, it's much quicker to cut the model.

 

This is one of the reasons why I was suggesting the 3D printer as the best choice for creating models. With a 3D printer it's pretty easy to print the 2 model halves.

A 3D printer can also solve another possible problem. If you have a cavity in your model (a negative depression, just like in the handle of the tools you used as models) then there will be problems for the plastic sheet to adhere perfectly to the cavity surface: as the sheet touches the cavity perimeter, it becomes more and more difficult for the machine to suck out the air between the plastic sheet and the model, there will always be a air sack that will prevent the plastic sheet to adhere to the model. With a 3D printer you solve this problem just adding a little hole (1 mm diameter is enough) that runs down to the base. It's really quick to do with a CAD program, plus the 3D printer has no troubles creating such a small hole, while drilling the hole on a ready model can be really troublesome.

If you find the right geek kid then you both can have fun. Geeks Kids love playing with this kind of troubles (designing the holes in the right places and so on), you have fun letting them have fun and avoiding getting mad yourself.

 

 

 

Teo

 

[teonzo]

30 minutes ago, Kerry Beal said:

Are you adding the wood frame after or during the molding process?

 

After. You use the wood frame for laying the mold and keep it horizontal. It's mandatory to keep the mold horizontal while chocolate crystallizes (especially for solid figures), it won't stay horizontal by itself in most cases due to the shapes of the models. It comes handy for vibrating too.

 

 

 

Teo

 

Edited March 10, 2019 by teonzo (log)