Mould from design?

Mould from design?

koltonmcconkey
Contributor Contributor
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Message 1 of 13

Mould from design?

koltonmcconkey
Contributor
Contributor

Hi guys, I don't really have a design or product that I would use this for im more or less asking out of curiosity and for the fact that i'd like to know how to do it. How would I go about taking a model in Fusion and making a mould for say doing Injection moulding? Would I just take the model and move it over a solid rectangle and cut it? 

 

Thanks for the help guys I love hearing from everyone on this forum!

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Message 2 of 13

JamieGilchrist
Autodesk
Autodesk

hi koltonmcconkey,

 

essentially yes.  

make two components, one is your design, the other is you mould

use the split bodies command to split the mould, using (and keeping) the body that is your design as yout cutting tool.

split your mould into two halves through a midplane – create a midplane construction plane or use a origin plane if your mould is centered around your origin.

 

I did one of these a while ago, check it out here.

 

enjoy.

hope this helps,


Jamie Gilchrist
Senior Principal Experience Designer
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Message 3 of 13

Anonymous
Not applicable

Hi gilchrj, believe me, your method is not right for making injection molds. There are more technology involved in Injection Mold design. I suggest the member who post this question talks to a real mold designer. Get the correct ways to design your project, and let them take care of the mold.  The mold you designed is more like for Plastic Extrusion for bottles but the way is still not correct. 

 

I attached three pictures of real Plastic Injection Molds here:

 

Twins Mould-12.jpg

 

Twins Mould-18.jpg

 

Twins Mould-16.jpg

Message 4 of 13

macmanpb
Collaborator
Collaborator

Hi koltonmcconkey,
To produce a correct mold it is necessary to talk with the company. Each company has descriptions of there mold design preferences.
Your mold must be designed with there specifications. A mold must have ejectors, cooling pipes, centers and much more to get this mold fit into there machines.

 

Smiley Wink

Message 5 of 13

JamieGilchrist
Autodesk
Autodesk

Hi Kinson138,

 

thanks for adding some clarity and further detail about designing an im mould.  You and macmanpb are absolutley correct about speaking with an im mould house to get detail about their process and requirements for a good design for injection molded plastic parts.  Honestly, unless you have experience designed mould (as you clearly do), or are interested in being a mould designer, I would steer away from attempting to design a mould.

 

 As a designer the first thing I would do in designing a mould is not design the mould and let an exerienced mould designer do that 😉

Autodesk certainly has the capability with tools like Moldflow coupled with Inventor for real professional mould design.

 

Really the first steps in designing a mould is designing your finished parts correctly for injection molding;  taking into account:  material, consistant wall thickness, draft, bosses, interleaf, ribs, vents, snaps, undercuts, etc.  the design needs to consider injection points, ejector points, surface finish, runners and material flow and how that may impact the final finished part both in structural and visual requirements.

 

That said, the example i showed was to answer koltonmcconkeys question and to illustrate that you can easily create a cavity (for injection blow moulding vs. a core and cavity for injection moulding) by using your design as a cutting tool in the modeling process; only one small step in creating a mould.

 

great information and thanks for sharing.

hope this helps,


Jamie Gilchrist
Senior Principal Experience Designer
Message 6 of 13

Anonymous
Not applicable

Hi Gilchri, yes i agree with your points. First design the products, then have the mold designers design the mold layouts. These are the correct ways. Fusion 360 even with its CAM is still not suitable for mold designing. Mold designing is a separate commercial technology by itself! In Fusion 360, simple molds for resin type thermosetting plastic can also be done with the Boundary Fill Command. Inventor is more suitable for Injection or Extrusion mold designers. For the same design, materials to be used will also affect the internal systems of the molds somewhat. For example PolyCarbonate and Acrylic have different properties and will require different specifications on the mold designs itself (for the same product). In other words if the product designer is designing a product to be made in both Polycarbonate (PC) and Acrylic (PMMA) two different mold designs are needed. For Polycarbonate, a higher mold locking power is required also (maybe 250MT). For PMMA about 150MT mold locking power will be sufficient for a 280 gm product.

 

However product designers should learn the process of different plastic molding methods (Injection, extrusion or rotational to name a few). The products to be made by these methods should follow a certain sets of guidelines. Components should be used in the designs. Most of the time Mold designers have to use separate molds for the components or parts. They might even modify the original designs somewhat for economical reasons. But when Product Designers are more accustomed to the process of Plastic Manufacturing their designing skills will improved.

Message 7 of 13

CGPM
Collaborator
Collaborator

Fusion is fine for injection mold design but I do agree to leave that up to someone with experience doing it.  I did art to part injection molding without cad or cnc for 6 years and would have been ecstatic to have Fusion and a cnc mill back then.

Message 8 of 13

Anonymous
Not applicable
Hi CGPM, I know exactly what you meant. Before CAD and CNC times molds took long time to design and make. Very expensive too.
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Message 9 of 13

Oceanconcepts
Advisor
Advisor

I don’t want to discourage you from exploring, as I was wondering how to get to molded parts myself a number of years back. But injection molding is a high volume process, and very dependent on materials used and the machinery available, so it ends up being highly technical when it comes to mold design. We make parts, for instance, from plastics that a densely filled with reinforcement materials- that requires different mold designs compared with using generic thermoplastics. Injection mold design, other than maybe very simple parts, is best left to specialists, in my opinion. This is distinct from some other molding processes, like casting urethanes in silicone molds, which are very friendly to small shop do-it-yourself type operations.

 

But I think what you would really want to know is how to design a part that could be injection molded- that’s a whole subject in itself, with the considerations about draft, wall thickness, parting lines, and so forth. This is something that Fusion is well suited for. Quick Parts (now part of 3D Systems) has excellent introductory tutorials on designing for molding here: http://www.3dsystems.com/quickparts/learning-center

 

- Ron

Mostly Mac- currently M1 MacBook Pro

Message 10 of 13

Anonymous
Not applicable

Hi Ron, 

 

That is a very good reply to the original question. In fact what I would like to say here is that some of the designs could not be made by injection molding at all. For example, my avatar here is actually an Injection Molded product. By using special effects it looks like a picture but it fact it is a real product. This product looks complicated and it does required post assembling by using Acrylic Glue to glue the eyes, nose, and even the tubes.  Simple design that looks like easy to be made by Injection Molding sometimes could not be made at all. 

 

One example is this pen holder that I designed but this one could only be made by other methods rather than Injection Molding. It is due to the moving "8" inside a big "8". If Injection Molding is to be used, the Double "8" will have to be made and assembled in a different manner then attaches back to the body. This is made as a one piece operation using other methods:

 

888 Pen Flower-1.jpg 

 

This product could be made by Injection Molding, in fact it was designed for one pass injection molding without any post assembling. With a separate lid and body- a two part design which can be made within just one mold and one molding cycle:

 

LuvMeSweet Flower Pot-2.jpg

 

By using "Boundary Fill" in Fusion 360 simple Molds for Resin type Thermosetting plastics could be made. It is perfect for making jewelry, and other parts. Like the other member mentioned here, the CAM of Fusion360 is also good for making molds. I did talked to my mold makers about the CAM of Fusion 360. Due to present limitations of the CAM which lacks some features that they are used to, they did not think Fusion 360 CAM could have the parts that can build an accurate mold. I am not a mold designer, so I would not discuss what they meant by that. As long as they can design a mold layout for me and could made the mold successfully it is fine. But believe me, molds had to be tested, polished, modified even after the CNC process by using hand polishing, electric arc method (the old ways) and many ways to make it work. 

 

At one time, I was planning to use PC to make a product but found that it was very hard to get a uniform flow inside the product itself. Lots of air pockets were found inside the bodies. I then switched to Acrylic and the mold had to been modified for that purposes.

 

Hope this will give the original member who posted this question some great inspiration on how to start his "Plastic Product Design" adventure!

 

 

 

 

 

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Message 11 of 13

Anonymous
Not applicable

Hi Koltonmcconkey,

 

The last step to send files to your favorite Mold Makers/Designers is to export  STEP files (.stp)  to them. Your next job is to discuss with them on changes that will be required. Yes. your first time will be very frustrating since you might be more used to 3D printing then injection molding. These are two different kinds of manufacturing. If you can control the cost of the molds, your manufacturing costs will be much much lower than 3D printing. Which is basically a very high cost operations.

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Message 12 of 13

CGPM
Collaborator
Collaborator

Another type of molding similar to injection is bulk molding compound.  Much higher performance resins without the need of a molding machine or ancillary equipment.  You just need a mold that you can heat up, stick some resin in, clamp it together, and then eject the part out of when done.

Message 13 of 13

TheCADWhisperer
Consultant
Consultant

If your interest is more towards modeling techniques and not so much production-ready mold tooling - you might check out this tutorial

http://forums.autodesk.com/t5/post-your-tips-and-tutorials/toy-car-core-cavity-mold-tutorial/m-p/515...

https://fusion360.autodesk.com/projects/toy-car-core-cavity-mold

 

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