【转帖】cross sections derived from splined object or surface

yang686526

cross sections derived from splined object or surface
guess help! should go here ;-]
i've been trying to muddle through this for a bit but so far no luck on a solution. the problem is that i need to generate drawing and templates from a splined derived object. the object might be something like a canoe or boat hull that has been shaped using splines. i need to be able to generate a series of cross sections that are used to build the object in the real world. these cross sections would be the same as the bulkheads in boats or airplanes and would then be skinned.
i know this can be done but i'm drawing a blank on how so i hope this is a easy head smack type problem ;-]
eng-tips forums is member supported.
have you tried section views on the drawing?
can you show a pic of the model?
chris
solidworks/pdmworks 08 3.1
autocad 06/08
i'm unclear as to what you are asking.
are you needing to know how to draw the splines, how to create the 3d model from the splines, how to section a 3d model, or how to create sections in a 2d drawing of the model?

i think i got it. you created a part model from splines and now you want to make section views on a drawing. similar to making a series of sections that in turn would be the ribs on this canoe:
you got it smcadman. the lines going from the front to the back of the canoe would be the splines and i need to derive the side to side or cross section. the cross sections are then created out of say mdf wood, spaced on the z per original and then that is skinned with foam or composite which is a buck we can then pull a mold and make parts from.
i actually have several bodies i need to make sections of but i had thought the canoe shape would be common enough to get a good idea.
i have been able to create cross sections in dwgs but i need to be able to print these full size (about the size of a car) or be able to generate dimension tables to be able to create by hand. i could space the larger ones over several drawing sheets and cut and tape together but it would be nice to just have a table. i'm using sw2007 but it won't generate dims from the cross sections. any ideas?

perhaps pattern points along section curve in sldprt and then pull these into slddrw for dimensioning?
(along the same lines as rollupswx said above) you could radiate lines from a central point at certain intervals of degrees, trim them with your rib spline lines, and dimension all those (polar).  you could also do this in a cartesian format.  either way, i'm thinking it might be a lot of drawing and plotting work, the scale you're operating with.
  
jeff mowry
this is beginning to smell of work!!! the horror!.
i was hoping there was a way to auto dim a section on the dwgs and that it was just operator failure (me) not getting it right. on some of the complex shapes the cross sections would be taken about every 4 inches. i have a (bad)feeling that theo and rollup are on the mark.
bit of a toss up on what to do. i have a quote for 3d milling a foam plug for about $35k. i'll have to play with this a bit and try the suggestions and see how much work that will be. i have a feeling it might not be much cheaper in the long run.
thanks
if your tolerances are large enough you could try optically projecting the drawing onto the sectional pieces of wood and tracing the contours.  two options for that would be printing the sections to transparencies and using a traditional overhead projector, or alternately using a lcd / dlp projector to directly display the sections.  you would need several reference dimensions so that you can get the scale and keystone just right.
it is just and idea, and maybe a bad one.
eric
you could also produce a scaled-down rapid prototype, have it 3d-scanned to produce a series of points at selected 'slice' positions, and then rebuild the model using a set of curve through xyz points.

if you can do without exact dimensions on a drawing, you can do what is used many times in woodworking.  first if you don't have a large plotter you could go down to kinkos and print full-scale sections.  next use 3m adhesive spray and spray it onto hardboard or plywood and cut them out on a bandsaw or jigsaw and have re-usable templates.