Re best practises and how you should do it!

Hi

First of I aint a qualified CAD operator ..I am an engineer who had some training in college and learn as I go.

I used to know how to use the Xrefs correctly as I worked with a very experience bloke who gave me pointer on the right way of doing things ...but that was well over 5 yrs ago and now I am finding myself in need of my limited cad skills.

I am currently working on a shell for a ship and have to generate a form work etc for it.

The form work has some common sides etc...I have each frame for the ship on a different layer, of which there is about 20 per section

I have set up the common sides as references which are locked and a sepearte layer so I cant do anything to them. I then trace over the common sides and trim accordingly.

I am getting slight inconsistancys in the profile at the top and bottom of the profile less then a mm. I know its not something that matters but the perfectionist in me want to know how to do it with out this happening and why its happening.

After each profile is created I then move it to the side and repeat.

There is a quick sketch to try an help understand what I am on about.

Should I be making the references Xrefs altogether ...so that I can purge the drawing each time I start a new profile.

Any Input would be appreciated!

bbb.pdf

Hi,

When you draw your hull section, you use same baseline and centerline position ? You use template for the section ?

Bye

Pascal

I do mate ..maybe I am being pernickiedy about it but I dont like making even small errors..

Ok I am also a perfectionist sometime and autocad sounds dont work like I want.

What do you use to draw your shape arc, spline, pline ?

If isn't confidential, could you post part of your drawing ?

I cant sorry mate ..there is a confid agreement involved plus something else.

some of its drawn using a script and pline command for some of the more flat sections but rhino has a kick ass means to get a nice smooth curve between points and we then operate on it in Cad as the I tried spline etc it did not get the line through the points given by the designers.

If you are doing this on a regular basis wouldn't it be a good idea to buy a program designed specifically to create hull profiles given the accuracy you are so intent on achieving? On the one hand you want to be as accurate as you possibly can but on the other hand you are using tools that defeat that very purpose. It's like trying to dig a perfectly round hole with a snow shovel.

I understand,

one tip, you can display the control polygon to pilot your spline curve

type splframe and set 1 now when you select your spline you see control polygon point

but like ReMark said curve are limited in autocad and I will be better to use an adapted program.

For my personnal use, I work with delftship sometime see link below

http://www.delftship.net/delftship/index.php?option=com_content&view=article&id=29&Itemid=10

maybe is an alternative solution ?

Have a nice day

Pascal