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Cosmetic threads - HELP PLEASE

Volpe

New member
Go easy on me guys/girls, this is my first posting!


My scenerio is that I have a top plate part model that has some tapped holes drilled into it. This part then has several bushes welded into it. Because of the welding process, we skim the top surface of the part (via an assembly cut)once the welding has been completed. This is where my problem arises. The part is cut okay, but the cosmetic threads do not change to suit. Therefore when you look at the drawing, you can see the threads standing proud. Obviously I would like to change this to suit.


Any advice will be greatly appreciated!!!
 

ankarl

New member
Threads are weak in pro/e in many aspects....

The thread is what you can read, a cosmetic feature (a surface in fact), and doesnt respond to, or behave as, normal feature operations.


There are other issues with threads discussed recently in this forum so this isnt the only thing.


I dont think you can cut a thread to display different. I've tried different ways of cutting away excess thread surf's without success (2001 and earlier versions)


Perhaps someone else got something useful?
 

cncwhiz

New member
Cosmetic threads are just that. I have played around with them without much luck. I don't even use them in pro manufacturing? As far as I can tell they are only good for looks in a drawing.
 

MOTO

New member
Why not show the theads using a helical sweep, cut. Because the sweep can be started at any height, it won't care how much material is removed.


Just a thought...


-J
 

dr_gallup

Moderator
Threads as helical sweeps have about 1000 times more overhead than cosmetic threads!

Just make the depth of the threads table driven and relate them to the finished thickness of the part.
 

tdegroot

New member
Just open up the part you made the hole in and edit the length of the cosmetic feature, although you have to do it one at a time. If I know that this is what's going to happen, I just make them shorter when crating them.
 

Volpe

New member
Morning tdegroot,


I did think along those lines, but then the part drawing would look incorrect. I did think of creating two sets of cosmetic threads, one being from the surface and the other being offset. Then I could use my layer controls to hide the set I didn't want, depending on whether I was in part drawing or assembly drawing mode.


I was hoping that there maybe some config command that allowed for cosmetic threads to be modified as and when the part is - wishful thinking I suppose!


Thanks for all your comments tho guys/girls!
 

dlongmi

New member
Volpe,


I would use an instance instead of a layer control for the threads. Layers are easier to "miss" than an instance. So, to save possible angry phone calls from the floor I would use the instance route instead.


It may take some extra work up front but I find things work out much better if the sweat is applied in the beginning of a project.
 

bjohnso2

New member
You could always make an offset surface after your skim pass
wit an offset of 0.0 and then trim the surfaces. The only thing is that
you will need to trim each thread individually, but it is not very hard to do.




I hope this helps.


Brian
 

rrleclair

New member
As bjohnso2 said, use the trim surface option to take care of your thread problem. Threads are a pain but I've found this to be the only logical workaround to this type of situation.
 

rrleclair

New member
I haven't used the trim feature in a couple months, but if it won't trim to the newly cut surface, create a datum plane through that surface (I usually go back and rename the datum plane to something like THD_DEPTH) and then use that datum to trim to
 

bjohnso2

New member
I just selected the finished surface of the part and did an
offset of 0.0. You can then use the newly created surface as your cutting
surface, and select you thread surface as the surface being trimmed.




I hope this helps.




Brian
 

Steve Leon

New member
bjohnso2 has the right trick here.

Ditch the cosmetic threads whenever there is a break in the surface, you will waste a lot of time and get nowhere trying to get the threads to appear correctly on the drawing.

Solution: Offset a surface(s) to create the look of cosmetic threads. They will always show up correctly on the drawings with the look of cosmetic threads. You might need to do some trimming operations to clean up the offset though.

It's a little more work then simply creating a cosmetic thread, but with ProE your options are limited.
 

r_jenkins

New member
A simple solution is to create a datum at the required level for the cosmetic thread and use this as the "start surf" when defining the cosmetic.
I use cosmetic threads a lot
 

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