Screwed screw

[biohazarus]

Hi there,

I know that I have already post a similar thread but it was just before my exam and I forgot to follow-up.

 

So my problem is that I want to draw a screw that would start around 0.120 pitch and grow up to a 0.250 pitch. It would also be conical.

 

I us the function 3d path helical, but I only manage to make regular thread. Can I make it varie?

 

Thanks for your help.

By the way, I use mechanical desktop 6

 

Alex

[fuccaro]

see here: http://www.cadtutor.net/forum/showthread.php?t=78

scroll down to the post #23

[biohazarus]

Thanks for the link but it does not seem to be the solution or I don't know how to use it right.

 

First I never used lisp and I don't seen the information that you specified in post 21.

I use Mechanical Desktop 6

When I load the window pop, I load and close, then I am have an alert that say:

Assignment to protected symbol:

DISTANCE

Enter break loop?

Yes No

 

No, seam to do nothing

Yes, seam to do nothing either but a warning is showed in the command line:

; User warning: assignment to protected symbol: DISTANCE

@0369194c DISTANCE>

 

Finally, I am not sure if it is the best application:

I need to vary the pitch and the shape of the extrusion on a cone, will it do that?

 

Thanks in advance for the help

 

Alex

[fuccaro]

using that program I generated this 3D polyline:

If it reports problems about the word DISTANCE, just replace in the code all the occurencies of the distance with distance1 or so.

I admit that is not an elegant program; I wrote it when I was very beginner lisper.

If you are unsure about using Lisps, there is a tutorial here

http://www.cadtutor.net/forum/showthread.php?t=1390

[biohazarus]

Thanks I try this next year, it is just in a few days.

 

I am wondering, since I modify the pitch, I need to modify the shape of the extrusion to keep the shape. Should I use the draft angle option on the extrusion box or do you suggest something else.

 

Alex

[fuccaro]

Try it first without to shange the shape. Post back if the result is not good enough. The problem could be too complex for this simple routine.

[biohazarus]

So after all the excitement of the university engineering games, back to work.

 

So I tried to play with the LISP.

It seam to work fin but when I try to create a 3D path only Pipe option can manage it.

 

Then if I try to make a shape, it tell me Error : unable to tag tool body.

 

Do anyone seam to know what I do wrong.

 

Thanks

Alex

[JD Mather]

I use Mechanical Desktop 6

 

Finally, I am not sure if it is the best application:

 

 

Mechanical Desktop is quite different than vanilla AutoCAD - I think you will only get a lot of confusion posting a MDT question in an AutoCAD forum. Can you attach the file as you have it so far?

 

I would use Autodesk Inventor (the replacement for MDT) for something like this. Students can download the latest version of Inventor for free from http://engineersrule.org

 

Others (in some parts of the world) can download Inventor LT for free from http://labs.autodesk.com

[biohazarus]

So thanks for all your help, but I have to unfortunatly stop my work on that drawing here.

 

The client is tired of waiting and I don't have more time to put on it.

 

Thanks again

 

Alex