topic Re: Making a mold in Fusion Design, Validate & Document Forum

Making a mold

evanp4509U4JZ — Thu, 09 Apr 2020 23:35:14 GMT

What would be the proper way to create a part from this surface? This is the "skin" of the mold we use for thermoforming Kydex. I want to "recreate" the Kydex holster for a presentation. My thought was to simply "thicken" the blue surface. That doesn't seem to be the case. What would be the right way to derive a solid of .080" thickness from the blue surface, as though a sheet of .080" thick plastic was pressed onto this surface taking the shape of the surface on the blue surface (inside) and being .080" thick perpendicular to the entire surface?

Thanks in advance.

Re: Making a mold

jhackney1972 — Thu, 09 Apr 2020 23:55:04 GMT

The surfaces do not have any draft angle on the edges. The sides, and many of the interior surfaces, are square to the adjacent surfaces so it cannot be thickened. You also cannot copy the surface, patch the two surfaces together and stitch all together because of the same reason.

Re: Making a mold

evanp4509U4JZ — Fri, 10 Apr 2020 00:15:26 GMT

Any idea how to arrive at the desired end result? I need that internal geometry for the part. When we thermoform it I get the desired result. Is there a way to make fusion recreate the thermoformed part?

Re: Making a mold

jhackney1972 — Fri, 10 Apr 2020 01:03:30 GMT

When a piece of plastic is thermoformed over this, it deforms in itself as needed, the Fusion 360 surface cannot do this. I personally do not see a way to do what you desire. I created a simple surface which does not have 90 degree edges to itself and it will thicken easily, even the sharp corner. It is attached.

Re: Making a mold

evanp4509U4JZ — Fri, 10 Apr 2020 01:46:02 GMT

Well bummer. That means I'll have to accept the boss's way of thickening/extruding/offsetting each individual surface and fixing all the discontinuities manually. It took about 7 hours. Any idea of a software that can do this in a more automated manner?

I am always confounded by the abilities of things. Things that I think should be easy are impossible and things that I marvel at are considered commonplace.

Thank you for the help.

Re: Making a mold

TheCADWhisperer — Fri, 10 Apr 2020 13:50:12 GMT

@evanp4509U4JZ wrote:
... Any idea of a software that can do this in a more automated manner?
I am always confounded by the abilities of things.

The basic issue is not a software issue.

The basic issue is that the part is poorly modeled by the human.

If the part were modeled correctly this would work fairly easily.

Re: Making a mold

TrippyLighting — Fri, 10 Apr 2020 15:15:50 GMT

@TheCADWhisperer wrote:

@evanp4509U4JZ wrote:

... Any idea of a software that can do this in a more automated manner?

I am always confounded by the abilities of things.

The basic issue is not a software issue.

The basic issue is that the part is poorly modeled by the human.

If the part were modeled correctly this would work fairly easily.

Period!

Re: Making a mold

evanp4509U4JZ — Fri, 10 Apr 2020 16:16:24 GMT

Not trying to be arguementative but what is the correct way to model it if I need the geometry represented by the surface? The product molded from that surface fits the application perfectly. The surface wasn't generated to be thickened. The surface is what the part interior is within the mechanical limits of the material and the process. The hope was not to create a product friendly to fusion but to use fusion to enhance the product we currently create.

Re: Making a mold

TheCADWhisperer — Fri, 10 Apr 2020 18:55:42 GMT

From what I saw - the geometry is not physically possible in the real world using the thermoforming Kydex process you describe.

Not even if I ignore stretching.

There are several areas in the geometry that I will wager are not real world.

Re: Making a mold

evanp4509U4JZ — Fri, 10 Apr 2020 22:01:23 GMT

LOL. Don't know what to tell you. That surface is derived, in the Fusion 360 "surface" work environment by selecting offset from the "create" sub menu and a value of 0.000", from the surface of the actual mold we use. Tester products were molded from that mold Thursday and are awaiting trim and assembly for confirmation. That particular mold is designed the same way we have created molds for that series holster for 3 years. The molds are then machined on a Haas VF2SS or Laguna Swift 4x4 router, depending on mold material dictated by product demand and projected ROI. Fusion 360 CAM provides the G code. The holsters are molded from heated .080" Kydex in a proprietary press of my design. No, it doesn't use pixie dust or hocus pocus. It is hydraulic/pneumatic.

Sorry to have offended your expertise.

Re: Making a mold

laughingcreek — Fri, 10 Apr 2020 23:08:13 GMT

More to the point, fusion has difficulty offsetting near tangent edge and surface conditions, which this model has a ton of. it also has some other weirdness you can see in some of the pics.

if it only needs to be rendered visually, you can export a stl and thicken it in a mesh editing software. it will still take some massaging to get a nice result.

Re: Making a mold

evanp4509U4JZ — Sat, 11 Apr 2020 02:50:01 GMT

Awesome. Thank you for the explanation. I really am trying to learn this stuff. I'm not here to try to piss people off.

Knowing the problem, I will investigate further before asking questions in the future.

Again, thank you and jhackney1972 for pertinent responses.

Re: Making a mold

evanp4509U4JZ — Sat, 11 Apr 2020 02:56:29 GMT

Thank you for the example. I don't have fusion on the home laptop. I'll check it out at work Monday.

Thanks again.