Community
Inventor Forum
Welcome to Autodesk’s Inventor Forums. Share your knowledge, ask questions, and explore popular Inventor topics.
cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

Expressions with trig functions

24 REPLIES 24
Reply
Message 1 of 25
BZimmerman
2085 Views, 24 Replies

Expressions with trig functions

I am trying to create a flange on a sheet metal part whose length and angle are based on the length and angle of another flange. I need to write an expression using trig functions and the existing dimensions from the other flange. I want an expression to read something like (d7*cos(d8))/d15. When I enter this info I get an error. Please help.
24 REPLIES 24
Message 2 of 25
Anonymous
in reply to: BZimmerman

if i understand you correctly, you are trying to do
"(d7*(cos d8))/d15" the cos of
d8

       
               
               
               
msk
Message 3 of 25
BZimmerman
in reply to: BZimmerman

You got it
Message 4 of 25
Anonymous
in reply to: BZimmerman

it just looks to me  like your parentheses are
in the wrong place, then.  That should fix it

       
               
               
        msk
Message 5 of 25
Anonymous
in reply to: BZimmerman

Go to Help and query for "expressions".  This
should assist in getting the syntax correct.


style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
I
am trying to create a flange on a sheet metal part whose length and angle are
based on the length and angle of another flange. I need to write an expression
using trig functions and the existing dimensions from the other flange. I want
an expression to read something like (d7*cos(d8))/d15. When I enter this info
I get an error. Please help.
Message 6 of 25
Anonymous
in reply to: BZimmerman

Although I love math sometimes this is more complicating then just making a skecth on the flange controling the dimension. Project edges and use a driven dimension to calculate the second flange dimension. Make inventor do the work. Works will although if it is a complicated part this maybe more difficult. If you would like an example reply to this and I will post one in CF. Good luck.
Message 7 of 25
BZimmerman
in reply to: BZimmerman

The Syntax is correct. When I substitute the actual values for d7, d8 and d15, I get the correct result. For some reason Inventor does not like to use the parameter names when using trig functions. I would think it should be capable of that.
Message 8 of 25
Anonymous
in reply to: BZimmerman

What are your input units?

--
Cory McConnell
BJ pipeline Inspection
Message 9 of 25
BZimmerman
in reply to: BZimmerman

I am not quite sure what you mean. The math is real simple, it is the program that wont compute it. I am simply trying to use parameter names in my equation so that the length and angle of one flange will update if I change the parameters of the other flange. The part is a box where two perpendicular edges of the top of the box have flanges at different lenths and angles. The eqaution solves for the overall depth of the flanges to be equal.

Ex, 90 deg + acos(1.5 * cos(170 - 90 deg) / 0.8)

where 1.5 is the length flange A (d7)
170 is the angle of flange A (d8)
.8 is the length of flange B (d15)
The eqaution sloves the angle of flange B
Message 10 of 25
BZimmerman
in reply to: BZimmerman

No units. They should come from the parameters.
The actual eqaution I used is 90 + acos(d7 * cos(d8 - 90 deg)/d15
Message 11 of 25
Anonymous
in reply to: BZimmerman

What units is 90, d7, and d15?

--
Cory McConnell
BJ pipeline Inspection
Message 12 of 25
BZimmerman
in reply to: BZimmerman

90 deg, d7 and d15 are inches
Message 13 of 25
Anonymous
in reply to: BZimmerman

See attached for the equation

--
Sean Dotson, PE
http://www.sdotson.com
Check the Inventor FAQ for most common questions
www.sdotson.com/faq.html
-----------------------------------------------------------------------
"BZimmerman" wrote in message
news:f184abd.10@WebX.maYIadrTaRb...
> 90 deg, d7 and d15 are inches
Message 13 of 25
Anonymous
in reply to: BZimmerman

That formula gives deg. You need to change the units of your parameter to
deg. See below


--
Cory McConnell
BJ pipeline Inspection
Message 15 of 25
BZimmerman
in reply to: BZimmerman

Where Am I looking for this equation?
Message 16 of 25
BZimmerman
in reply to: BZimmerman

See Below? Where?
Message 17 of 25
Anonymous
in reply to: BZimmerman

If you are on the web based forum you must be logged in. Then click on the
poster's name. The attachment should appear.

--
Sean Dotson, PE
http://www.sdotson.com
Check the Inventor FAQ for most common questions
www.sdotson.com/faq.html
-----------------------------------------------------------------------
"BZimmerman" wrote in message
news:f184abd.13@WebX.maYIadrTaRb...
> Where Am I looking for this equation?
Message 18 of 25
BZimmerman
in reply to: BZimmerman

When I click on the name all i get is the text message you wrote. I don't see anything about attachments. Sorry, but I do not use this forum too often.
Message 19 of 25
Anonymous
in reply to: BZimmerman

B-

Try this as it works for some who have difficulty seeing
attachments on the HTTP side. To see a file from the web-based
interface, go to the thread, and, instead of scrolling down to
the post, go to the "Message Thread" Pane and click on the
poster's name. The lower pane will reset itself at the top of the
post, and you should be able to download the file.

or

Two things Under Tools>Options> Security Tab ... uncheck "Do not
allow attachments to be saved or opened that could potentially be
a virus."

And when you are using the Web, be sure to click on the name in
the top right before clicking on the attachment in the lower
right.

or

First Left Click on the message in the upper right pane. After it
reloads the thread, you can Right Click and "save target as" or
Left Click and it should prompt for a save location.

or

If you are accessing the newsgroups from the web-based [HTTP]
interface, in order to have access to an attached file in any
post but the first post, you need to find the right
name/date/time in the "Message Thread" pane, directly above this
pane. Click on the name, and that will cause the selected message
to appear here. You will then be able to download/view the
attachment,
--
Anne Brown
Manager, Moderator
Autodesk Product Support Discussion Groups
Discussion Q&A: http://www.autodesk.com/discussion

BZimmerman wrote:
>
> See Below? Where?
Message 20 of 25
Anonymous
in reply to: BZimmerman

Here is a text version of the params dialogue...

d8 deg 50deg
d15 in 1.0in
d7 in 1.0in

stuff deg 90 deg + acos((d7 * cos(d8-90 deg))/d15)

--
Sean Dotson, PE
http://www.sdotson.com
Check the Inventor FAQ for most common questions
www.sdotson.com/faq.html
-----------------------------------------------------------------------
"BZimmerman" wrote in message
news:f184abd.16@WebX.maYIadrTaRb...
> When I click on the name all i get is the text message you wrote. I don't
see anything about attachments. Sorry, but I do not use this forum too
often.

Can't find what you're looking for? Ask the community or share your knowledge.

Post to forums  

Autodesk Design & Make Report