injection mold designers using SolidWorks

I've been using cadkey 2D for designing product, mold assemblies, and mold
inserts since 1996. Our largest mold frame is a t-series dme mold 15 X 18 ,
two cavity. I will be switching to a 3D software, which one I do not know.
that's why I'm looking and trying to get some questions answered.
1] what was it like to switch over to SW. The time frame, converting old
files that you already had over to SW.
2] how long before you seen that you were using part/assembly/drawing files
from SW in a reasonable amount of time.
3] how about revisions, i know with 2D it takes forever in a days age to do
revisions.
4] can you use variblies instead of actual dimensions in excel that will
control a given shape. example say i have a standard block with a length,
width, and height. i will use this block alot for certain products. the
length may change or the height. can i set the length to X and the height to
Y and than input any numbers to get what i want?
5] the most important question. the thought process in a mold design. i have
a product and place it in a blank mold frame and than place all my eject
pins, support pillars, springs, runner system, ect. i need to know if i can
still start out with creating an assembly to view to make sure that
everything is fine and than detail all components/inserts/mold frame later.
I know that SW works in a sketch world first, than create to final part. I'm
just not sure how?

I guess the most important thing to me is how to start a mold design,
because it seem difficult with SW. If you could add any input of how you
would go about doing this please let me know.

Thanks

 

You probably had some "MAJOR" circular referances. I've been using the
cavity feature to design molds since it was introduced (SW96). In fact,
without the cavity feature SW is usless for mold design IMO. That's what
it's for, works real good to.

Regards

Mark

 

JK's feedback was good, but I'll throw in a little from a different
perspective.

Switching from 2D to 3D is usually traumatic, no matter which package you
wind up using. It seems the longer you've used 2D, the more you have to
"unlearn". It's a completely different way of designing. Forget about
drawing lines and arcs and views, and start building parts from features.
That was the biggest hurdle for me.

You can start making simple parts efficiently in a week if you get
someone to help you with some modeling best practices. Sometimes you can
get this info in a class, and sometimes not.

Done correctly, revisions can be very easy. Or they can be frustrating.
That depends mainly on your modeling skill, whether you have created the
model in a way that is easy to change or not.

You can use "design tables" in Excel to drive part dimensions, as well as
other stuff. These are very easy to use and set up. You can also write
equations in SW to drive dimensions.

As far as the thought process for mold design, I would recommend you take
a look at MoldWorks. MW builds the mold for you based on your input, and
gives you the option to change things - move, add, remove standard or
custom parts. JK said correctly that it doesn't "automatically" design
your mold or even the inserts, there will always be decisions that a real
live designer who knows which end of a mold to squirt plastic into will
need to make. MoldWorks and SplitWorks, help automate some of the dull
repetitive tasks in splitting cav/core and building a mold. You will
need to understand some surfacing to make this work well, but you will
not spend your time designing pins and plates with holes in them each
time you need a new or custom mold base.

MoldWorks will even check that water lines don't run into pillars and
make 2D drawings of all your plates for you.

matt.


(sparky100) wrote in

 

I did the same thing you are contemplating 3 years ago. Very glad I
did. Because I had a good grounding in 2D, and had played with
various 3D CAD applications, I had a heads up on extruding, cutting &
revolving 2D shapes which is the basis for most solids work.

I'll recommend several things:

1. Do NOT attempt to learn Solidworks on standard work hours. Study
the tutorials with Solidworks at home (even on a Laptop: the single
license allows you to install at work and at home). Try the basic
standard simple part examples they show, step by step until you are
comfortable with that 50-100 page Tutorial booklet. It covers the
basics including making a scaled up (for shrink) cavity set from a
part solid.

2. If you feel you need further training after the tutorial, then get
it from your Solidworks dealer, but that training will go much faster
if you have the tutorial's basics down pat, and you can then ask more
profound questions of the teacher. I found the tutorial relatively
easy to do in a few days on my own.

3. Organizational issues of running Solidworks in a multi-user office
needs some thought on how to control drawings, etc. PDM works in the
SWKs Office Pro may be worthwhile eventually.

4. Learn how to build up assemblies correctly using sub-assemblies
with proper mates & configurations in both parts & assemblies. It
makes doing changes and fixes easier and allows faster rebuilds &
screen redraws in complex situations to keep your work speed up.

5. Do learn all the basics and construct a mold on your own, even if
it is just a little 5x8 DME base for practice before you look at the
various add-on "Mold Works" type packages. Various users have had
both good and bad to say about the packages. I don't use one of those
packages, as I don't do that many molds.

6. Give yourself time to learn, before you give in and promise to
meet deadlines! With 2D, it tooks me 6 months to get reasonably
fast, and similarly, it took me 6 months to get up to speed in 3D on
SolidWorks. I produced my first simple molded parts inside of a week,
and my first complex plastic part in a month, but it was laborious as
I learned a lot of things the hard way.

7. Come back to this group and ask lots of questions once you have
done the tutorial work.

Good Luck - Bo

 

Bo
i'm still trying to under stand the design intent of creating a mold
assembly. wear would i place a blank mold from Mold Works , say 12 X 10 six
plate stripper mold in a part file or an assembly file. i will most likely
would create each mold plate to get use to SW. from there do i create all my
components on part files than place them into assembly or can i create all
my components in the assembly with the blank mold frame.i like to see if
ineed to move or resize the components to make it fix, form, and function.
if you do not mind that you e-mail me your e-mail address if i have anymore
questions. my e-mail is

thanks scott

 

There are many ways to do a mold layout in the planning stage.

The "blank mold" from Mold Works or other sources is a SolidWorks
Assembly File, where the individual part files are also supplied.

Typically, you will design the cavity differently depending on whether
the cavity is embedded directly in a cavity plate or in/on an insert.
Then the cavity inserts would be placed in the mold assembly drawing
and located with reference to the parting line and the center of the
mold.

It is often desirable to do layouts of the cavity inserts/parts before
"cutting" holes in the cavity plates, so you can move them around and
get your positioning right for details like slides and cooling lines
approximately right before modifying the cavity plates with insert
holes.

If we reply to each other here, then other people get the benefit of
the questions and answers. Makes the forum really worthwhile.

John Kreutzberger is a full time mold designer who replies here on the
forum, and he has a boatload more experience than I do. I do more
part designs than molds. I still need to mock up a preliminary mold
design, even if I send it out to a toolmaker who will do the design,
as I need to confirm basic sizes, functions, and fit with various
molding machines.

John has had experience dealing with the various mold & cavity add-on
software for SolidWorks which you might find useful which I have not
used.

Bo

 

John Kreutzberger

How long have you been using SW and does it meet your requirements for mold
design. Have you looked at other software. What kind of products/molds do
you design. I have started working with SW for about a month now and it
seems to get a little easier each time. See you design molds you know shrink
factor comes into play with designing molds. Say I have a product in a Part
File, how do i add shrink to it without effecting the product itself.

 

Another way is to create a config in your part file. Add your shrink to the part in that config.
For me, this eliminates having multiple copies of parts to keep track of.
I leave the "Default" config as is, and add a config called "Scaled .012 - IN".

MT

 

John told me some time back that he had used SolidWorks since the late
90s. He is a contract mold designer and does all types of parts as I
understand it.

Myself, I do the application of shrink factors in the cavity cutting
process (in that dialog box). This way any change to the part is
instantly reflected in the cavity & its related parts & assemblies
which are derived from those cavity parts.

One of the key items for me is to set the center of the sprue on the
intersection of 2 primary planes (XY, & XZ) and the Parting Line on
the 3rd Primary Plane (YZ). I then design inserts or cavities so they
"start" on the YZ plane, so it is very easy to keep mates assigned to
the right places for minimum hassle, when I later change a
plate/insert thickness or such. Mates to planes result in fewer
errors in my estimation, than when you mate to plate surfaces which
sometimes get botched, with editing.

Configurations used in both parts and assemblies, helps minimize the
numbers of files and what amounts to a flow chart to keep all the
variations straight in my mind. A configuration which just shows what
you need to work on minimizes horsepower to revolve, etc.

There are lots of techniques for working with larger assemblies which
I've seen written here in the user group and you can search the past
postings for suggestions on those.

Bo

 

John,
Why never scale from centroid, only from origin?

 

All of my plastic parts are designed with flat parting lines. Hence,
I set the parting line of my parts, specifically on one of the primary
planes when I first design my part. That way, the part, the
cavities/inserts, and the mold all have the parting line set on a
primary plane and it makes mates much more secure. I know they are
right.

Bo