Curve profile sweep

[haroldm]

Hi guys, i am having a heck of a time trying to figure this one out and i thought someone on the forums might be able to give me a hand. I have put a file up on the FTp named "curve_sweep" and basically what i am trying to do is sweep this profile around a curve that is projected on a wavy surface..i guess it looks like an extrusion but i am going to cut it out of solid billet, but first i need to model the part!

i would appriciate any help that anyone could give me. When i try to sweep the profile i always get errors. Thanks guys.

[cobra95kev]

Haroldm,

What folder on the FTP did you put it? I can't find it.

 

Thx

[haroldm]

Hey Kevin, the part is just in the X3 directory, it is called "curve_sweep"

[JohnW@Kauffman]

haroldm,

 

I think I've got it, but couldn't upload it to the FTP, so you've got mail.

 

edit; no I don't have it. The profiles aren't matching up.

 

[ 03-10-2009, 10:39 AM: Message edited by: [email protected]. ]

[haroldm]

Hey John, thanks for the help, i have wrote you back. basically i can get that same result but i am not sure if the edge should look like that? or maybe it does..??

[Ocean Lacky™]

haroldm.....check out CURVE_SWEEP-OCEAN LACKY

[Kannon]

and... you also got a email from me also..

 

did it with surface-swept.. and used 2 rails..

[Ocean Lacky™]

quote:

---

did it with surface-swept.. and used 2 rails..

---

Me too

[haroldm]

hey guys, thanks for the help, but it is basically the same thing i am running into with help from the other members. Did you see how the part seems to dip in the middle and then flair up towards the round ends? I am not sure this is the way it is supposed to be? i know the material has to go somewhere when it reaches the crest, so maybe that is just the way it is? I only have a side view of the part from the customer, so i suppose i could say that they probably dont know the part will do that either, but it is the same result from many different members, so i think that is just the way it is. Maybe that projected flange just looks funny. Thanks for the help guys!

[Ocean Lacky™]

haroldm....I put up another attempt Curve_Sweep-Ocean Lacky-2

 

See if that's any better. I swept each entity individually. it SEEMS a little flatter?

[haroldm]

So am i imagining things guys? Am i the only one that sees something funny happening on that part? Maybe sweep is the wrong way to go? it is certainly the easiest, but maybe there is just not enough information tom accuratly sweep that profile?

[Ocean Lacky™]

adding a couple more cross sections May help. I'd try rotating them 90 degrees and maybe sweeping in 4 sections.

[Jason B.]

Harold,

 

You have mail. See if this is what you are looking for.

 

 

- Jason

[haroldm]

Hey Jason, thanks for helping, did you use additional profiles? That looks much better, but i just wish i had a front view on the DWG to compare it too.

[Jason B.]

Hi Harold,

 

I used the existing profiles but did not sweep anything. This geometry does not lend itself to a sweep option. You will get incorrect geometry. I used several extrudings trimmed to the potato chip surfaces at their proper levels of offset and I also used face offsets to obtain the correct geometry. At least what I see as the correct geometry.

I understand your frustration with insufficient information and my suggestion would be to send this file in any way you can back to the customer for final approval by them before cutting anything. That way you have something to fall back on if the final product is not what they expected.

 

- Jason

[haroldm]

Thanks jason for the effort, but upon further inspect, the model that you made, from the top view, or bottom view depending on how you rotate it, was not the same thickness all the way around..arrgghh..this job is not fun..haha..thanks for the help guys, i will keep trying.

[Jason B.]

Harold,

 

Your right.

 

I fixed the lower geometry to be consistantly .0625 as is your original profile. But the top is actualy different from one side to the other in your original profile and mine matches it. Let me know if that looks better.

(sent email)

 

- Jason

[haroldm]

Jey Jason, im off to lunch, will check it in a bit, thanks again for your help.

[JDowe]

Analyzing the 2 profiles they are not the same

the tops are unequal arcs - a sweep surface

using the 2 along profiles and one along gives a

surface that analyzes as good - the distance

between the 2 along splines is not constant

all the way around

[John Summers]

It looks like the surface is OK as designed, like part of a ruled surface which has all elements parallel. Make a 2d toolpath of the racetrack and project it to the surface.

[haroldm]

hey guys, thanks for checking out my problem, so are you saying john that although i can use the geo to project a toolpath, i cannot make a solid model of the item?

[John Summers]

The surface is OK as it is. If you want just a part of it, make a trimmed surface. When you 'remake' a surface like this one, you end up distorting it. Trimmed surfaces were invented in the first place to avoid this kind of distortion. A trimmed surface is an original 'good' surface, and a boundary that says 'I only want this much of this surface'.