mold tools

I need to add another example...

Matt,

It would be helpful if you didn't publish in Edrawings 2007. You're not going to find many people that can read it

Mark

If I had to make the tool, I think I'ld prefer to make "c.EPRT", or if there were some reason why another part made it desirable to have the edge of the cavity on the parting line, I'ld pick "b.EPRT".

I did a part with a semi-circular parting line like this a year ago, but I didn't worry about the angle, & your arc angle looks to be about

90 degrees which is not going to be a problem in self-aligning with the opposing cavity.

When alignments get really tight, I use the external PCI or Progressive Interlocks, or the T-Interlocks with Stripper Plates.

Bo

matt wrote:

Hmmm. Meant the X-Interlocks.

Bo

Bo wrote:

No one wants to comment on the mold tools?

Draft analysis,parting line and shut off surfaces routines are generally useful. For the shut off surfaces to work, one needs to learn when to designate a loop as `no fill' and then create surface(s) manually to deal with what's there. I have found it valuable to be able to generate a knit surface for the core and cavity this way.

Major problem is that the parting surfaces that SW automatically generates is almost always completely useless-if not downright laughable. Furthermore, although it's possible to use the (vastly improved) SW surfacing tools to manually create what amounts to a parting surface, I have not found a way to jump back into the SW mold tools to have it create the core and cavity inserts once I have bypassed their parting surface creation step. No problem for me since I always go into assembly mode and use the knit surfaces I created with the shut off surfaces to proceed with core/cavity creation that way.

In summary, the failure of the parting surface feature seems to short-circuit any attempt to fully utilize the mold tools as SW intended.

jk

I don't use them much, being a part designer instead of a tool designer. Every once in a while when I design a part that seems to be tricky to mold, I will go through the exercise of generating a core and cavity. My vague memory is that JK got it right in his description. (And Bo made the same choices I would make on your abc question.)

Jerry Steiger Tripod Data Systems "take the garbage out, dear"

Jerry-you're my hero. I can't imagine any of the people I work with analyzing their product designs with molding in mind. They always seem to resent the fact that I point out problems to them.

If you ever need any mold design help-please don't hesitate to contact me.

k

Jerry- Mold tools are helpful when applied to non planar parting lines IE: a part shaped like a mouse. I have experimented with the tools, and found I have much more control & time savings just locating the part in the mold, and creating each half of steel manually, then using the cavity command. This method is very quick and easy to change. It's great that you are looking into how the part is going to be laminated, i commend you for it.

Regards,

Erik Hinson Design Engineer Prestige Mold Inc.

Doesn't do me any good to design a whiz-bang part if it can't be molded! Doesn't help me out if the mold costs too much or it takes too long to build the tool!

We usually have our tool designs done by the mold maker or their favorite tool designer, so we're not directly involved in the selection.

Jerry Steiger Tripod Data Systems "take the garbage out, dear"

Jerry, your note is exactly why the part designer NEEDS to plan the tool as he designs the part.

Some things are routine, and you don't have to think about them, UNTIL your new design starts pushing the limits of things is when it turns critical.

Limits can be stress, thin or thick walls, bonding, ejection, warpage, gating or making sure a complex part stays on the ejection side (all the time), and lots of other things.

In my case, undercuts of all types can dramatically reduce assembly times and parts and inspection while increasing quality, if done right. Some calculations, material analysis, ejection planning, Mold Flow analysis and hard thinking about the WHOLE process from molding, to ejection, to assembly and even packaging and shipping are a part of the product cost.

I've found that many toolmakers will attempt to default to the easiest way for them to do something, as opposed to how I know I must have it done to work best, for a particular new design purpose. Hence, though I don't do the mold design, still I do the cavity layout so I can talk real issues with the solid models with the designer-tool maker. This has kept everyone on track with fewer wasted hours and remade tool parts.

The most recent "stretch" I did in ejecting severe undercuts worked to a tee, though there were a couple minor areas needing adjustment to handle deformation during ejection, which I missed.

The payoff, in the end for me was no gluing or ultrasonic bonding with great cost reduction.

Bo

Jerry Steiger wrote:

If I were a mold designer I would disagree strongly with that. As John K points out, he gets a parts where part designers can't even design a plastic part that can be manufactured much less design a mold to make it.

I never dictate to the mold builder how the mold should be made. That's his gig, and he usually has a few things that I hadn't considered. I make the part so its manufacturable and let him decide how to do it. Sometimes I leave areas indeterminate knowing that the mold builder has options. Locking him into one solution when there are several possible.

Plus, if every part designer were a mold designer, who would need mold designers.

The best process I ever worked with had tooling engineers right beside the part modelers. Everyone got involved from the begining. Not every company has that luxury, but it makes for better parts, better molds and far less redesign.

Perhaps I should have said that you have to plan the specific special details (if any) that are essential to part function.

When I need a seal surface, I can't have a parting line, bubbles or knit line on it. When I need undercuts, I need to understand how I am going to strip the part, or release the undercut. When I need options in the part for various product models, I have to plan those options generally without hopefully just replacing a couple core pins and sleeves.

Some of these things are simple, but save me from producing a whole additional mold. The mold maker & his designer sometimes don't look @ options that reduce the number of tools (like when I'm trying to save funds on a startup deal).

Bo

snipped-for-privacy@veriz> > Jerry, your note is exactly why the part designer NEEDS to plan the