best way to start model sheet metal part

[donmcbride]

Hi All,


A question ? what is the best way to start modelling a sheet metal part ??


the reason I ask, everybody at our work seams to have there own idea. I think that startingwith an extend wall is good to capture design intent, and also it is easy tochange to part.Where asmodeling a part using only flat walls is more difficult tochange.


So what are peoples thoughts ????


Many thanks Don

 

[cristelino]

is a true philosofy that; bielieve me

if are some complicated instance of design i recomend to make solid model first and after thet to convert in sheet metal: application/sheetmetal/driving surface etc

If tyou have manny punches;relief deformation or others specifically
sheetmetal deformations i recomend to start directly in
sheetmetal module

anyway some features can t be made in standard Proe so you must choose sheetmetal application

I can send you some parts begin with simple or very complicated

feel free to mail me

I wanna help you because i remember how complicated was for me te beginning

So cristelino2yahoo.com is my e mail adress or send me private message on this forums



best regards





Cristel

 

[pmack009]

I think you should start all sheet metal part in sheet metal app I like to start with a flat wall because you can add a lot more information in the first feature and your more likely to be able to get a flat pattern that's the hole raison for the sheet metal app?


lot of people like to start in solid just stay away from complex features our it will not convert

 

[bhayden]

Definitely start a sheetmetal part as such from the beginning.
The shop that has to build it will thank you in the end. The only
reason to convert a solid into sheetmetal is if you have a design
you're trying to convert to reduce cost or, you need to produce a
prototype in sheetmetal before larger volume drives a different
production method.



Start with an extruded wall or a flat wall depending on the design
intent of the part or whatever will make the model the easiest to
maintain/modify. If you really want to do it right have start
parts for the standard sheetmetal shapes (i.e. L bracket, U channel,
folded box, etc.). A lot would depend on your specific needs and
industry. If there are certain shapes you do over and over then
it makes sense to have more complex start parts.



-Bernie-

 

[Dell_Boy]

I have found there is no such thing as the best way because it varies
from part to part; a little planning goes a long way. Some I start in sheetmetal, some start as thin
parts and get converted to sheetmetal at some point in the modelling
process and very occasionally I will shell out a solid part
particularly if I want the option of a positive or negative shell.



However there are some limiting cases for these methods. If you have
big patterns, avoid having them prior to the convert feature because
the model will run much slower than if they are after.



If you need patterns of walls you are probably best to model these in part mode and convert later on.



A really useful technique I have found is to create a parameter called
inside_rad and re-label the fundamental thickness dimension as
"thickness". Then I relate ALL standard folds to these two dimensions
either directly or indirectly. This way if I need to change the bend
radius and/or thickness it is very easy to do regardless of whichever
construction method was used. You wouldn't believe the number of models
I have seen with different bend radii indiscriminately scattered
throughout the model.



I also do not bother with custom bend tables. I use the default ones
and just tweak the inside_rad parameter mentioned above so my developed
length matches the manufacturer's specification so I have total control
of isotropic materials from a single variable. This also makes it very
easy to shift your product from one manufacturer to another who of
course will have different tooling setup.





DB



Edited by: Dell_Boy

 

[cristelino]

is right


Dell_Boy tell exactlly what i think witht some complicate instances


If you have model in your imagination is simply to choose the way





Cristel

 

[JBAUER]

Definitiely start in shtmetal... Extruded walls work great for creating allot of geometry quickly. However flat walls tend to make for a more flexible part.


One other technique I have used is actually a technique "robbed" from robust modeling principles... that is to create datums that represent boundarys of your part. Example: A simple hat section sheet-metal part. One of the default planes might serve as the base. An offset datum from that default datum would represent the top, etc. When modeling your part those datums are used as referneces.


This has (2) benefits... The part is basically laid out before creating even your first wall feature. This aids in visualizing the part in 3d space, and aids in organizing your overall part envelope.As you build your part you may reference these same datums over and over. 2nd when you assemble this part into a next level assembly those datums will serve as stable placement constraints.


Downside of this approach as an example: In your hat section you would modify the dimension to the offset datum to control your part height. In other words the datums you have constructed and referneced as you created your features actually control the part. This is not always as obvious as other construction techniques...

 

[donmcbride]

Thanks Guys for your input


It looks like no one standard way.


Too give you some back ground, have been using ProE since 2000 at our work (5 users/two departments) mainly steel metal, we have no cad manager, but i install/update/fix problems. The overall skill level is quite low and users make basic mistakes often, so myself being the most proficient in sheet metal, was trying to get other users into a standard method of sheet metal, yes we do use a standard sheet metal start part,(including intralink parameters). But beyond that, it's open.


I am interested to see one idea on start parts with geometry in them. This was an early idea by one person ( it ended up full of relations as well difficult to modify(ie remove a wall)). Also most people I have spoken too seam to no like the idea of geometry in start parts.


Thanks again, it great getting feedback from the real world of Pro/E


Don Brivis Australia