Help with 'draft' in surfacing

[KENAT]

If I could get some ideas on this one I’d appreciate it.

I have a step model of a cover that I’m trying to recreate in SE so we can make some changes. I’m using surfacing to do it but haven’t used it much before so am having some trouble.

The biggest issue I’m having right now is adding a taper/chamfer around the part where it steps down in size. The attached jpeg hopefully shows what I mean.

http://files.engineering.com/getfil...6-4cb5-a8de-3e3515f2233f&file=surfacing_q.jpg

Anyone have any ideas? I’ve tried a few things including trying to sweep a surface round the parth where the horizontal surface meets the top part at the desired angle (tried doing similar on solid after a Boolean with a swept cut); cutting back the bottom part and then doing a swept surface from the outline of top to the outline of the bottom; and a bounded surface, adding in surfaces to try and get the edge I needed – however none of them have worked.

I’m open to novel approaches, maybe even quite a big change in the way I’ve modeled it so far. (I tried uploading it to engineering.com but it didn't work, maybe at 6MB zipped it's too big)

I’m still on V19 64bit if that makes much difference.

Thanks to anyone that can help.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[beachcomber]

Can you upload your SE model or is that the 6MB file?
How big is the step file?

bc.
2.4GHz Core2 Quad, 4GB RAM,
Quadro FX4600.

 

[KENAT]

The SE file is the 6MB file.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[KENAT]

Doh, hit submit by accident.

This should be the step file, zipped, just over 1MB.

http://files.engineering.com/getfil...f65-8ad9-23cb37b34bbb&file=imported-model.zip

To make it worse, the ID folks used SW and my colleague managed to create a similar feature in SW. I find it hard to believe there's not a way to do it in SE but there isn't it'll be more fuel to the 'use SW' movement and tha associated extra work.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[Peter]

Which edge do you want to be chamfered? Have you posted this question on the Solid Edge bulletin board?

 

[KENAT]

I haven't submitted it on the Veeco Bulletin board.

Take a look at the initial PDF, it shows where I want the chamfer. The Step model already has the 'chamfer', it's putting it into the SE file I'm struggling with.

Just noticed the logo on the step model, that was an oversight, I should have removed it.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[KENAT]

Oops, forgot to say thanks to both of you.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[Peter]

I see in the model that there is a tiny fillet or chamfer, I did not look closely enough to tell which, in the original model. I think you need to get rid of that and then you will be able to do it.
Another method might be to draft from an edge but I am not sure how far you want to go up the seam.

 

[KENAT]

Peter, at the moment the SE model doesn't have any of those features. It has a perpendicular 'step' as I attempted to show in the PDF. Something like the step file is what I want to end up with.

Essentially I came up with a shape with I want a 'step' part way up, angled at the back. I off-set the initial shape to get a smaller inner set of faces. I then put a plane through and trimmed the larger shape so it was only below the plane, then trimmed the smaller one so it was only above it. This leaves a sharp step, I want the step to be angled more, and then I'll apply raddi/fillets around it.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[KENAT]

Well, I found a way to do it, but it's not elegant. Basically instead of joining the 'small top' to the 'large bottom' (ooh err missus) with a single feature I used a total of 4 sweeps. I did the front horizontal portion of the gap with the flat plane as one sweep from the edge of the top to the edge of the bottom, then repeated for the rear angle plan portion, then did each curved side separately.

It's not elegant to other suggestions are welcome.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[Peter]

There is a lot of discontinuity in the surfaces of the original model.
How about this method to get 1/2 half?

 

[Peter]

Helps if I attach something

 

[KENAT]

I had trouble telling what you did.

My method appeared to work until I tried to do a boolean to create a solid and couldn't. I found a discontinuity in my drafted surface.

Thanks for your help so far.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[KENAT]

Well, I may be onto something, at least the follow up boolean worked. I did sweeps at the horizontal gap at the front. I did a sweep on the angled gap at rear. This left the curved areas, essentially the fillet between the horizontal and angled portions.

Sweeps on here would not work. If I did the full profile it failed. If I did the front first then the rest, I got a discontinuity, same if I did the curved portion by themselves, the wouldn't close with the front sweep.

However, a bounded surface worked on these areas like a charm!

By the way, is it common when doing offsets and the like for small areas offset from rounds and the like to 'bubble' in the wrong way, looking like a dent? I had several and had to delete the faces and replace with bounded surfaces.

http://files.engineering.com/downlo...4ca4-a754-5012dd2a471c&file=surfacing-fix.JPG

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[Peter]

That model looks better. In my experience, the "bubbles" occur when the surfaces are not fair.

 

[KENAT]

Thanks for your help.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​