Creating a mold from a customer part file by using combine, (cut from) and then split the mold

[three.amigos.john]

Let's start by saying that we have successfully performed the needed actions to get most of our desired results. Most being we have created a mold that has subtracted our customer's part file from withing the internal contents of this 3d box. What we have not discovered is a way to make a "clam-shell" mold from our part file.

1. We converted our customer part file to a mesh object

2. Created a simple 3d box for the mold and converted that to a mesh

3. Then we used the "combined" feature to cut the part volume from this 3d box

4. We then split this "mold box" into two halves

5. We used section analysis to move a face back and forth to verify that the contents of our customer part file had been subtracted from our 3d box.

Great this works but we need a mold that is split by using the upper surfaces and the lower surfaces. A forming mold not a fill mold.

I used to work in a progressive die design environment to develop steels that would form our part - although with another software. We started this process by separating the outer skin of the part from the inside skin of the part. Metal thickness was at maximum 1mm. We then projected our steel (3d box) up or down to meet these separated skins, this creating a steel that would give us an exact copy of our form.

Without knowing another path in Fusion to take with our existing project, can this be accomplish with Fusion 360 by projecting a solid to our part step file without separating the outer and inner skins? Would we have to separate the upper and lower surfaces at all? Or is there another way to do this?

We are not asking someone to design our mold for us - just asking for some help on the methodology to get this task done. The current designer is using another CAD package but i have insisted all along to our customer that Fusion 360 can do this.

A part file is attached to this message. Any help or direction would be appreciated.

Thank you,

John

[jeff_strater]

I don't know what a forming mold or a fill mold is, but I have some questions on the workflow you described for your existing jobs.  I'm a little confused about why you are converting things to mesh, and how that works.  You refer to the "combined" feature.  Do you mean the "Combine" feature?  If so, that only operates on solid geometry, not mesh geometry.

[TheCADWhisperer]

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@three.amigos.john wrote:

1. We converted our customer part file to a mesh object

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Why would you do this?

I detect some quality issues with the geometry.

[three.amigos.john]

Thank you for replying. We knew there was a hole somewhere in the customer part file, as we had to stitch and repair holes after performing the combine, cut operation.

The only reason we saved our project as a mesh object is because the original process was not working a an import step file and working with solids. We were grasping at straws to find a solution.

We will try and repair the customer file first then try our original steps.

Thanks again for the reply.

John

[TheCADWhisperer]

Is the STEP file that you attached earlier the original customer supplied file, or is it a file that you had edited in some way?

[three.amigos.john]

Jeff,

As another note. When we were first trying the methodology with Fusion we did the following:

Opened the customer stp file from my computer

Saved as a project

Created a new boy: a 3d box that would encompass the customer part

Under the solid menu, modify tab, selected: combine

For the options we chose this:

Target Body = the 3d box (representing our mold)

Tool body = customer part

Operation = cut

Selected new component, keep tools

This seems to work at first glance - both the original part and the 3d box can be selected, turned on and off

Then we used the split body to halve the 3d box

Body to split = 3d box

Splitting tools = a plane we created at the mid point of the 3d box that is parallel to xy

Great the 3d box is now split into to equal halves. But when we hide the upper half our part has been split into two sections in each half of the mold. This is not what we want.

So this procedure works as intended but is not valid for our mold. We need a parting line around the part that will act as the split in the mold. Essentially creating an upper half and a lower half that will form the part as we inject with foam. Obviously we need this mold to open to get the part out. We use a mold design that acts like a clam-shell. Opens from one side, the opposite side is hinged, so to speak.

This is the reason we tried using the mesh, the above was not what we wanted.

Further this, the question was asked about projecting the "3d box" to our part surface that represents the upper skin and once again being done for the lower skin. That's how we created our tools for the Progressive Dies. By projecting to the lower skin and from top down to the upper skin - leaves us with the part thickness we the die was closed. Kind of what we are thinking here.

Can Fusion do this? Or is there another way?

I apologize in advance for my ignorance. If Fusion can do this, where do i sign up for the training?

John

Results attached when using the solid body approach

[jeff_strater]

@three.amigos.john - thanks for the model, and the explanation - that helped.  A couple of things I noticed:

"Great the 3d box is now split into to equal halves. But when we hide the upper half our part has been split into two sections in each half of the mold. This is not what we want."

Yes, that is correct.  However, the problem in your process is not the body type, but this step:

"Then we used the split body to halve the 3d box

Body to split = 3d box

Splitting tools = a plane we created at the mid point of the 3d box that is parallel to xy"

I am not a mold designer, but I do know that this is the hard part of mold design.  Rarely can you get away with a planar parting surface.  There is a lot of skill and art that goes into designing a proper parting surface for a mold, especially in a part like this one.  But, as far as I know, converting to Mesh is not going to help you in this task.  In fact, I would say the opposite - it will make it harder.

Again, I am not a mold designer, but likely you will have to create a pretty complex parting surface, probably starting with this set of edges:

The "Ruled Surface" command can be useful for creating a parting surface, but in this model it does not work well - this data is pretty messy.  But, something like a Surface Sweep can be a stepping stone to a parting surface.  Here is the kind of thing you will need to split your mold.  Again, don't use this directly, because I have no expertise in this area.

And, this is only part of the parting surface - you would also need to do the rest of the model, and also likely have to clean up the surface before you can use it.

[three.amigos.john]

Jeff,

Thank you for your input. Yes we already have experienced the fact that a mesh part would not work. And we agree it would simply make it harder. We also, as you have seen, found that a flat planer parting line would not give us the desired result. Actually we knew this but wanted to see what Fusion could do. As I stated in the first post - we kind of talked our customer into the fact that Fusion could handle this with ease.

We know now and then from our experience that a complex parting line for a part like this does not come easy. It involves plenty of work.

Creating a spline around the part as a start for an effective parting line is good advise. This in fact is one of the crucial steps in our mold development. Tedious work indeed. Taking this to the next level means that a ruled surface around the part has to be "x" angle and cannot be flat to the xy plane. This is done for several reasons, not limited to ease of mold opening, shut off and so on.

That leads us to the unanswered question of projection, can we project or extrude a body to a surface, in which the body that is projected will join itself to the desired surface? Solid or surface model we can work with either.

One last thing: customer part files always have holes or surfaces that are untrimmed making our task that much harder. In a perfect world it would be great to receive a model from the customer that is in perfect shape.

Thanks again for all your help.

John

[TheCADWhisperer]

@three.amigos.john Is something like the Attached what you are after?

[three.amigos.john]

CadWhisperer and Jeff,

Yes we do receive the part files from our customer in "as in condition" if you can think of it that way. Sometimes the part file has holes, untrimmed surfaces and overlapping geometry contained in it, this all needs correction. Not to worry though, if the clean-up process gets too involved we either ask for a cleaned up version or clean it up ourselves, with a cost. If we alter the part file (in the clean up process) we will always send back to the customer for the "buy off" process.

To CadWhisperer:

Yes your follow-up methodology represents the kind of mold making we do. Not totally accurate but a very good example.

For our design we would reorient the part (more flat to the xy plane) from what you have shown but that's minor. Also, along the parting lines; 360 degrees around the part, the mold would have to be a steeper angle than what you have shown. These two issues are minor but all in all this looks like it is the process we would need to follow.

I downloaded the file you altered this morning (I had to wait for support site maintenance to be completed to respond) and uploaded that into Fusion. Great job at showing us that Fusion can do this. It looks good.

Now comes the million dollar question...... what was your line of progression to get to this point? We understand that if you do not want to answer, because of monetary issues. And this really is your work to get to this point, we get it. This why we replied to this thread early on to Jeff - point us in the right direction so that we can learn the methodology in creating a design like this in Fusion.

As for right now by using Fusion to get this far, we are confident that we have responded to our customer that Fusion can handle the design process.

Thank you for the insight and we await your rely.

John

[three.amigos.john]

Posted messaged said:  I replied to myself....... let me know if you have seen this reply

John

[TheCADWhisperer]

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@three.amigos.john wrote:

For our design we would reorient the part (more flat to the xy plane) ...

Now comes the million dollar question...... what was your line of progression to get to this point? We understand that if you do not want to answer, because of monetary issues.

point us in the right direction so that we can learn the methodology in creating a design like this in Fusion.

As for right now by using Fusion to get this far, we are confident that we have responded to our customer that Fusion can handle the design process.

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I didn't spend a lot of time on deciding the angle, but quick example was to try to avoid any undercuts.

First thing I did was rotate the model to avoid undercuts and move closer to the Origin.

I didn't use Fusion 360 - I used Autodesk Inventor Professional.  In Inventor Professional this literally took seconds.

I will create a video on the process when I get a chance.

I suspect it can be done in Fusion 360, but not sure as Fusion does some wonky stuff sometimes with Projections (which will be critical in this case).  I used to have to jump though more complex processes in Inventor Professional before tools were added to automate the process.  My ancient techniques should work in Fusion (I will try to work up an example) if, and that is a big IF, Fusion will Project the edges correctly.

Check back (and keep involved in the discussion or I will assume that you have moved on and abandoned this effort).

[TheCADWhisperer]

@three.amigos.john 

>> See Video<<

I forgot to mention that all of the faces on the split side also need to be Offset as surface bodies in Fusion and stitched.

(I don't know if any of this functionality has been added to the new Product Design Extension - I don't see it listed.  If not, it will all have to be done manually as I described.)

[three.amigos.john]

Jeffery,

Sorry I have not replied the last week. I am also retired and don't seem to have enough time to give as I am working as Assistant Manager at a local golf course.

Thank you for preparing the video. I did watch that. Looks like plain vanilla Fusion 360 is just not powerful enough to handle a complex part like the one we have been looking at. I really did suspect that a more robust CAD modeler would be required.

I understand that you created runoff surfaces by extending them. We did this as well in the progressive die sector by over projecting them so as to create our form outside the print size of the part, the next station which could have been a blanking station would then trim the excess off, less the carriers.

The gentleman (his name is also Jeff) who is designing for the customer now is going to retire as well. That is why they want me to take this position on. He is using another CAD package that will do the job just like your Inventor Professional. So far I have not attempted to learn that package - as we were still in the process of fact finding. We now know that Fusion is not the tool to use.

So for now I am not going to pursue this in Fusion when there are tools that will work easier and are more complete. Except I will try to extend the surfaces as you have done to see what kind of results can be obtained but not holding my breath.

Too bad the customer does not have Inventor Professional. I have been using AutoDesk products since 1994. I still have several licenses of older products, Inventor Series 11, Mechanical, AutoCad Vanilla and so on. They are all good products.

Thanks again for your input and time.

Happy retirement to you,

John