modeling an injection modling part
modeling an injection modling part
(OP)
is it better to model an injection molded part with equal wall thicknesses and equal draft and then round off the width numbers on the drawing. or would you dimension the theoretical sharp corners of the molded part? How does everyone model a molded part?
thanks
thanks






RE: modeling an injection modling part
Dan - Owner

http://www.Hi-TecDesigns.com
RE: modeling an injection modling part
Regards
Pat
See FAQ731-376: Eng-Tips.com Forum Policies for tips on use of eng-tips by professional engineers &
http://eng-tips.com/market.cfm
for site rules
RE: modeling an injection modling part
Dimensioning to theoretical sharps (annotated on the drawing as need be - not actually modeled as sharp corners) may be appropriate depending on tolerance scheme.
If you could clarify your question and maybe mention what dimensioning standards etc' you typically use that may influence the answer.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: modeling an injection modling part
RE: modeling an injection modling part
However, it's still relatively immature, and a lot of people don't have the understanding of GD&T to support it. There have been threads on this over in GD&T and elsewhere.
It seems your boss may be going about it a bit backward, I'd suspect that the model may represent what they really want/need and that poor drafting created a drawing that didn't really define what they want.
If you then create a new model that meets their drawing, it may not work in reality. Now legally you should be OK because your part meets their explicitly stated requirements, however from a customer service point of view for repeat business etc. it may not be good.
Has your boss gone back to the customer pointing out the discrepancy and got clarification on what's really needed?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: modeling an injection modling part
RE: modeling an injection modling part
I'm getting a horrible feeling this could be one of our suppliers, just tell my you don't work for Doug or Dan.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: modeling an injection modling part
RE: modeling an injection modling part
I have seen to many in field failures as a result of an over zealous QC guy insisting on changing working parts to spec, when the original parts failed and where modified to the current part, but no one updated the drawing and spec.
If you have a current working part, I would think the starting point for a new mould would be to digitise the existing mould.
The big caution when doing this, especially with semi crystalline of fibre reinforced mouldings would be that a change in temperature profile within the running mould or a change in gate position or size or type might change the dimensions of the finished part.
Regards
Pat
See FAQ731-376: Eng-Tips.com Forum Policies for tips on use of eng-tips by professional engineers &
http://eng-tips.com/market.cfm
for site rules