huangyhg

detailing complex geometry
we have a part that is very complex. our vendors can make if from a parasolid, but we have yet defined it on a drawing. the part has three features; one end is slotted and flat, the other round and tapered. in between is a complex twist extrusion. overall length is about 2 inches. how can we detail the twist? does anyone have sample drawings?
thanks,
stumped in seattle
can you show a pic of it?
you can try section views or call out the twist, similar to a screw thd.
hard to tell without seeing it.
chris
solidworks 07 3.0/pdmworks 07
autocad 06
my initial thought would be showing sections at intervals along the twist like ctopher said.
this is how i've seen it done on pre cad drawings for aerofoil type shapes.
depending on what standards you draw to this may be a case where model based definition makes sense (asme y14.41).
if nothing else you could give outline/interface information on the drawing, along with material notes, tolerances etc. you'd then refer to the model file on the drawing as defining anything not on the drawing. if you go this route you need to carefully consider how you are going to control the 'rev' of the model etc but it can make sense.
you could put a note on the drawing saying that the cad model controls the shape within some tolerance band.
"wildfires are dangerous, hard to control, and economically catastrophic."
ben loosli
sr is technologist
l-3 communications
nice haiku, chris!
to define the twist:
1. take as many sections as needed. (is the section a constant?)
2. define the distance between the twist (path).
3. define the diameter that the twist (helix) follows.
heckler
sr. mechanical engineer
swx 2007 sp 3.0 & pro/e 2001
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thanks heckler!
chris
solidworks 07 3.0/pdmworks 07
autocad 06
thanks guys. i believe we will pursue the model based definition. however, this is a medical device and design controls may dictate more robust documentation.
also, the twist i described was not created with a helix. it's less pronounced. sort of like grabbing a piece of licorice, twisting 10 degrees and raising one end.
archusdsr,
i'm in a medical device company with fda approved products, and iso-9001/iso-13485 certification. there are no requirements for "robust drawings". only that you fully document what you make and change. we have many parts that are defined in the way that looslib suggested. have at it.
matt
cad engineer/ecn analyst
silicon valley, ca
asme y14.41 is a "robust" standard. the problem is that most cad systems don't have the features to support it completely. i would get a copy and look it over.
david
i've obtained a copy of the ansi y 14.41 and believe that is how we will proceed.
thanks for the encouragment matt. hearing from the industry helps immensely.
phil
also, you are right david. the standard is rather robust, but sw2005 does not appear to be able accommodate the requirements. does sw2006 or sw2007?
don't ask why we are still on 2005; there's not enough room here...
phil

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