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
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I'll take a stab at this one. There is no real solid `cookbook' for how to approach a mold design with SolidWorks. There are some examples in the tutorial, but they are limited in scope . They also don't cover the thought process that is involved in laying out your mold and deciding on sizes. Rather than get more scattered, I'll continue following your numbers.
1) As I told you briefly at CADCHAT.com ,I found the switch from CK to be a bit traumatic, but worth it. The fact that you sound like you have been working in a solely 2-d environment will mean that most of your old files will be nearly useless in SWX. SWX has what they call a 2-d to 3-d conversion routine. I have not had any success with it. Perhaps if you find a good VAR who can work with you on it, you may be able to convert some of your library items.
2) I completed my first job in my first week. I would say that it was about 1_1-2 months before I was truly productive.
3) Revisions go really smoothely for me. This has been a process I have done a lot of work on and I have a really solids-based way of approaching it. This is based on having a good method and will take some time for you to develop. Once you learn how to haqndle the 3-d side of it, the drawings do indeed up-date automatically. It's really sweet.
4) I don't know much about this. I use what SWX calls design tables for some of my library parts, but don't use them for mold bases. Perhaps somebody else can comment about the ability to use variables. (I think you can.)
5) I have always started my mold designs from the inside out- even when I was on the board. I place my part inside a block that will be either the cavity or the core (usually start with the cavity.) That is where I do what is called my `split' of the mold inserts. I also create core pins and slide cores at this time. Once I have my split accomplished, I often will do some preliminary sketches to see what my mold base size will be. I predict that your thought process will need to evolve when going from the 2-d to the 3-d world. As far as detailing later- you will LOVE this part. All of your details are there, you just have to pull out each individual part and make your views. I don't use automatic dimensioning, but I am still really fast. Also when detailing I often find an error or something that could be done better for the mold-maker. It is a simple matter to go back to the 3-d model and make the required revisions. Your drawings will up-date automatically.
ALSO, there are some add-in and partner products that you may want to consider. SWX sells what they call the SWX MoldBase. This contains libraries of mold bases and components. I don't know much about it because they don't include the mold base library that I use almost exclusively. (Hasco-inch) I know they have DME, National and Hasco-metric. Some people use this with success. A lot of people have taken the time to create their own mold base libraries. What I use is a partner product called MoldWorks which works inside of SWX. I like it and it has a much more extensive choice of catalogs to use. What is nice about MoldWorks is that it really speeds up the mundane chores such as adding fasteners, ejector pins and all other components. For just fasteners, SWX sells their Toolbox add-in. If you were to buy what is called SWX Professional, Toolbox is included. I don't use it.
There are also partner products available for aiding in the splitting of core and cavities. SWX in 2004 has added mold tools to the core product. I have not used these a lot yet. From what I have seen, they seem OK. Perhaps immature right now, but will get more powerful, I'm sure. The same people who market MoldWorks (R&B) also have a product which I use called SplitWorks. It is very useful, and I am starting to use it more than I did in the beginning. This uses a surfaces-based technique of identifying faces which belong on the different halves of the mold. I am still learning how to use this more productively. If you do a search of this newsgroup, you may find some old posts of mine where I expressed some frustrations with this way of working. I have overcome many of those problems. SplitWorks is a fine product. I just did a really swoopy part with non-planar P/L's all the way around. I had really good success with it and my customer was thrilled with the result.
Another product is called FaceWorks. This is also a core/cavity splitting utility based on surfaces. I have not used it.
My main gripe about people selling software for mold design is that some of them sound like they have an automatic process. I am very sorry to report that there is not an automatic mold design button or icon.
In all fairness, I must also urge you to consider other CAD systems. I know of some people using Unigraphics for mold design. I don't know of anybody using SolidEdge. One guy in the area uses VX Vision. I have seen a demo of this and it is really powerful for splitting cores and cavities- also does a good job of incorporating part revisions from your customer and up-dating the inserts. The demo-jock I had didn't do a good job at showing off it's drafting module, so I am not so sure about that. I also was not impressed with the standard component libraries available for it. This is all part of the big picture and must be considered. It is also more expensive than SWX and uses a much more surfaces-oriented way of working. This can be very powerful, but a bit intimidating if you have never worked with surfaces before. My preference is for using solids-based methods whenever possible because they are easier. There are some people who have been using surfaces-based CAD systems since before solids were widely used, and they are really good at it. I am not. They seem to look down their noses at us `puny earthlings' that don't have the same experience with this way of working. I suppose that is why there are different kinds of software to serve the different sorts of needs and abilities.
I am sorry to be so long-winded in my reply. (I have been waiting for a revised model to show up so I can complete/change my current job. It just arrived so I may not be checking back here for a while.)
Good Luck to you.
jk

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Sparky,
When you do begin this try NOT to use the cavity feature that SW has with complex parts. I did a mold design using the cavity feature and it absolulty killed SW & my computer. Changing a feature would cause a 35-45 minute rebuild. I went back and redid the features that I cavitied out to use in context sketches and it made a huge difference in rebuild times.
sparky100 wrote:

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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

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I agree, Mark. That's why I use the cavity feature after preparing the insert instead of first.
jk

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Yes, I'd be willing to bet Mark is right. Of all the different types of users, mold and forming die designers seem to be the most susceptible to this because of all the necessary incontext references. Finding circular references can be tricky. The way I do it is to go through each in context part and list out the references. I make a grid with a column for each part and a row for each part. Part A references Parts B and C. If Parts B or C ever reference back to A, you've got a circular reference. The problem is that its not always that simple, there could be 4 or 5 parts in the loop. Depending on the assembly, this analysis sometimes takes an hour or more. Chances are if you've got the problem, your incontext references are a bit out of control, and it might take a long time, but 45 minute rebuilds that should be 15 seconds is a big deal.
I've submitted an enhancement for SW to graphically list out the in context references in an assembly to help troubleshoot this kind of thing, but I don't expect much to come of it. Might be a good API project some rainy day.
matt.
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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

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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.
snipped-for-privacy@innovativemicroplate.com (sparky100) wrote in

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snipped-for-privacy@innovativemicroplate.com (sparky100) wrote in message

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
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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 snipped-for-privacy@innovativemicroplate.com
thanks scott

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Scott
I found the problem with Mold Works is where the initial Assembly mates are. One thing you might consider is redefining the mates using the parting line as the initial mate.
Another thimg to consider is to replace the screws with you own library to save on space. Make sure your screws and other common components are set to read only.
Make an Assemlby file for all of the components. and a part file for each plate. and cavity component.
Kevin

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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
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What I usually do is create a sub-assembly of all of the molding inserts ; slides, etc. If I am shooting for a specific mold base size, I will make some sketches in this sub-assy to make sure it will fit. (these sketches can be hidden later.)
Then, I'll create my mold base. (I agree with the guy who said to do this with SWX alone before getting involved with any add-in products.) If you want to show all fasteners and leader pins, bushings, etc.- you will have to learn how to do a derived feature pattern- piece of cake after the first couple. Anyway, when you have your mold base created, then add your sub-assy to that assembly and create your pockets.
Finally, you are then ready to add your ejector pins and insert mounting bolts,supports,etc.
Have fun,
jk

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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.

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After applying the shrinkage factor (always from the origin-never from the centroid!) , I then save it with a slightly different file name. That leaves the original part intact.
Some people do this a little differently, though and I am considering making a change in my process. What they do is open a new part file and insert the molded part as a base part. Then they apply the shrinkage factor and proceed with their split. This alos leaves the original part file intact. The advantage to this method is that any changes made to the base part will be reflected in the part referenced in the core/cavity split. This would work well in a situation where the part is being designed in-house. As a consultant who doesn't do very many part designs, it's questionable whether I will see a big advantage to this second method, but I am always interested in finding better ways to do my job.
In that light, I do occasionally look at other software packages. In my original post to you, I mention one that I considered and why I chose not to investigate it any further. Being a 1-man operation, it is difficult to justify a lot of jumping around between software platforms. The learning curve and expense would be prohibitive. I have no second thoughts about my move from Cadkey to SolidWorks (11/98), but I realize there are people having good success with other software.
jk

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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
On Tue, 25 Nov 2003 09:52:54 -0800, "John Kreutzberger"

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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
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snipped-for-privacy@tilikum.com (Bo Clawson) wrote in message

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

It's more predictable. Also, when inserting a revised model into my split, it is handy to mate the planes from the new model with the planes from the old one. This always works when shrink is from origin. It could cause problems if the shrink was done from a centroid because this centroid could have shifted slightly due to the revisions that will need to be incorporated.
You know, one of the reasons I haven't responded much to general mold design threads like this in the past is that people all have their own way of thinking and doing things. There is no general procedure for mold design with SWX, so we have all had to devise our own. Mine works for me, but is constantly evolving.
YMMV.
jk
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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
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