trajpar function thread direction

[nracingdev]

I have a question regarding a relation containing trajpar function. I am attempting to use a vss to sweep a thread path then extrude my thread from ths path. I know, "... Just use cosmetic...." however I am trying to show the physical thread for informational purposes.

The problem I am running into is that my sweep keeps going counter clockwise (left hand thread). Does anyone know how to tell my relation to sweep the opposite direction?

Relation I am using: SD5= 30+360*trajpar*4*0.875

Thanks in advance!
-chris

 

[tobbo]

i suppose SD5 is the angle of a line that sweeps thru the origin in you vss? If so, when you do your skech... sketch the line "under the horisontal line" (if its above now... ?? ) i think this is covered in another thread.


//Tobias
Edited by: tobbo

 

[nracingdev]

it is in fact above H. I will try tonight when I get home. THANKS, I tried searching last night but could not find anything. sometimes I have trouble figuring how to word a search

 

[csusie]

am I missing something or can just put a negative in
front of the 360?

it would make the sweep spin the opposite direction.

 

[cloughna]

I agree with hammerpe, you can do it with trajpar, but you will just end up writing a helical equation. Helical sweep is the way to go.

 

[nracingdev]

am I missing something or can just put a negative in front of the 360? it would make the sweep spin the opposite direction.

tried ths but doesn't work As it causes the relation to fail. I have not used the helical tool since 2001.. in fact I don't even remember how to use it. does it give you solid geometry once complete?
another question: is it possible to perform a feasibility / optimization study and allow dimensions governed by relations to be changed? if so I haven't figured it out yet.
thanks
-chris

 

[csusie]

I would then go back to tobbo's advice. But you wouldnt
have to do exactly what tobbo says, all you would need
to do is make sure the ref you are measuring your angle
from is counter clockwise from your sketched entity so
that when you increase the angle it will go clockwise.
ie you could measure 60 degrees off the vertical rather
than 30 up off the horizontal as you have now.

 

[tobbo]

haha, Corey, offcourse your right !!


//Tobias

 

[nracingdev]

made an attempt at using helical sweep last night. I was unsuccessful. pro E kept giving me error saying that section must be on same side of revolve axis when attempting to exit sketcher. I must be missing something because no matter where I put section I still got it.