Mold Cavity Shrink within Combine Comand

[anewenergy]

It would be great if we can add mold cavity shrink(scale) to the resulting subtraction or cut in the combine command.   Currently the the work flow prevents the molds from being created in the native Fusion assembly.  If we could make the resulting subtracted feature have a scaled size, it would help mold designers move molds out the door even faster, while maintaining the design intent.

[Anonymous]

Maybe I'm misunderstanding, but can't you just use the Scale tool under Modify to uniformly scale/enlarge the positive part that I'm guessing you're then subtract combining to make the negative mold?

Jesse

[HughesTooling]

You would need to pick a base point for the shrinkage as well, just using the centre of the part wont work.

Mark

[Anonymous]

Thanks Mark.

What about for now, just making a sketch on the positive part base, and placing a point where the desired center of scaling is, then choosing this point in the Scale pallete?

Jesse

[roambotics_scott]

This may be low(ish) hanging fruit for simulations.

Unless everything is perfect (eg - uniform wall thickness, and very well designed parts and molds), shrinkage will be nonuniform. It's hard to model that well because it's dependent on temperatures, polymer, injection points, etc., but it'd be very useful (although, perhaps, not part of the core functionality at this point ?).

[HughesTooling]

What would be useful is the ability to make a copy of a part, add shrinkage to the copy and any changes to the original would update the copy with shrinkage. XRefs in the next update might allow this by inserting a file and there will be a link so mods to the original file should update.

Mark

[roambotics_scott]

If that were automagic, it'd be great.

I often want something similar where I have the base part and then some things are applied on top of that (drafts, fillets, etc) to make it suitable for a particular material or process.

Maybe it could dovetail into the branch-merge with nicely designed dependencies ?

[Anonymous]

It's funny dependency behavior is brought up here.  Recently I discovered and (out of my excitement) posted how not only component dependency is possible, but also just simply copied and pasted bodies.  I just tried this in the below image, then enlarged the dependent pasted body.  Any modifications to the original body are then reflected in the dependent pasted body.  I then added a hole feature to the original, being sure to first scrub the timeline back to before the copy body event.  Sure enough that new hole feature was then reflected in copied body as well.

You probably know this already, but wanted to mention it since I didn't until recently.

Jesse

[Anonymous]

I have to agree to some of the previous posters.  Having desgned injection molding tools of various sizes it is not a matter of just appling one shrinkage factor to the entire geometry.  Shrinkage depends on thinkness of the part at a certain area and other factors.

Smaller features react totally differently to thin walled features for example.

[anewenergy]

Thanks Jesse,

Will take a look at it. Have a great day.

Pat

[roambotics_scott]

This would actually be a great place to partner with or consult Protolabs. They have a ton of experience with this. If you like, I can probably find the right engineer there for you to talk with.

[HughesTooling]

Thanks Jesse,

That works quite well. I the past I tried copy and paste with components, that doesn't work. Making a copy of a body inside a componet works well and it not to hard to keep track of the time line that way.

[Anonymous]

Great to hear that may work for some things 🙂 

Jesse

[promm]

@anewenergy,

Thank you for your idea, this is getting archived due to the nature of the plastic part design.  True shrinkage would require complex algorithms to take into account material properties, heating, cooling rate and so on.  Right now we do not have feature sets for plastic parts.

Cheers,

Mike Prom