Hello,
Are there any demos, tips, or best practices available? I'm going to be creating a master part which drives the rest of the plastic housings (children).
I appreciate any advice.
Thank you,
Brent
Hello,
Are there any demos, tips, or best practices available? I'm going to be creating a master part which drives the rest of the plastic housings (children).
I appreciate any advice.
Thank you,
Brent
Klaus,
How do you account for the shrink? Do you scale the plastic part that you insert into the assembly? Is it an added configuration in the part or done on a separate copy of the part?
Jerry Steiger
I usually scale the part (and save it to a new configuartion) before i insert i into the assembly.
Then i do a cavity cut with 0% scaling.
@ Brent: remember to calculate the correct scaing factor, if you wan't to scale the part before you are doing a cavity cut.
e.g:
If the part has to molded in for example PP with a shrinkage factor of 1.7% you have to scale the part with 1.017293998 in order to get the correct scaling size.
if you just scale it with 1.017 (what i know that many people does), it actually gets to small, because SW does not take in account the shrinkage of the shrinkage.
to calculate the correct shrinkage factor to use in SW you have to do it like this:
A= shrinkage of PP = 1.7
1 * 100 / 100 - A = 1.01729...
Klaus,
I've noticed that a lot of tool designers just scale by 1+shrink, rather than by 1/(1-shrink). Fortunately most of the parts I design use amorphous materials, so it doesn't matter much if they use 1.006 or 1/(.994)=1.00604.
Jerry Steiger
yea, i know it is a little overkill to do it that way. Specially if the molded part is done in ABS or so.
I just think he should be knowing it :-)
Brent,
Are you looking for advice on how to build the master model, like what kind of detail to put in the master and what kind to put in the children? Are you looking for advice on how to design plastic parts in general? Are you looking for advice on how to design the molds to make the plastic parts?
Jerry Steiger
Hi Brent.
When i do mold design, u usually do it this way:
I start with making a cube. fx 100 x 100 x 100 mm (depends on the size of the molded part) which i save with the name ''xxxx_Master''
Then I insert this Master-part into an asssembly, and then insert the plastic part intp the assembly, and Mates it into the Master part.
Then i do a cavity cut.
Then i open up the Master-part, which now contains the cavity from the plastic part.
I now model all the parting surfaces, shut-off surfaces etc, using the surface tools. And I always drive almost everything with linked values and equations.
When i am finish with all those construktion surfaces, i split the Master part into several bodies, so i now have a multi body part containg e.g. 6 solid bodies.
Then i give all the different bodies names ( e.g. cavity, core, stripper ring, slide etc), and uses the Save Bodies feature to save the bodies into new parts, so i can do some individual modeling to the parts.