Swept Boss w/ Projected Guide Curves problem 4

[Zcad]

Hello everyone,
I’m relatively new to Solidworks and have been trying to master the swept boss/base feature with the use of projected guide curves. I found a great example of this process on Matt Lombard’s site

http://mysite.verizon.net/mjlombard/

where he has created a spoon shape by using a projected curve that guides a profile along its path on only one side of the spoon, creating a full spoon shape. I’ve tried to recreate it, but the spoon body will only extrude out to the side with the projected guide curve and the finish profile ends up being pointed along the guide curve. Matt Lombard has created his spoon in full (both sides, right & left) using only one projected guide curve on the left side of the spoon, and the finish profile is not pointed along the projected guide curve. If anyone has been to his site and understands how he is doing this; could you help me out?

 

[Theophilus]

I haven't had time to check it out, but I would guess he did something to mirror either sketch geometry (such that the left and right side of the spoon are defined by a centerline and symetrical across the line) or swept only the left or right side of the spoon and then mirrored the resulting body across the center.

For something like this, I would use two guide curves. One to guide the center and the other to guide the outer edge (left or right). If possible, use a spline with three points. The left point is linked to your left guide curve. The center to your central guide curve. The right is symetrical across your centerline in your sketch--sketch a construction line from the left point to the right point and establish a midpoint relation to that construction line with your center line (also a construction line, coincident with the origin). That way your right point position will mirror whatever your left point does.

Jeff Mowry

http://www.industrialdesignhaus.com

Reason trumps all. And awe trumps reason.

 

[Zcad]

Theophilus,
Thanks for the input. If you dissect what Matt has performed, you can see that he didn’t sweep the first half of the spoon body and then mirror the second half, he has no mirror body command, and only one sweep command. However, he does have a “center line” and adjacent “ninety degree construction line” in his outside rim guide curve sketch. This outside rim guide curve sketch is one of the two sketches he used in his “project curve” command. The mysterious thing about the “center line” and adjacent “ninety degree construction line” is; if I remove them from the sketch, the model still rebuilds perfectly (full spoon shape).

This spoon he has constructed is built with only two commands, a “project curve” and a “swept boss” with the use of four sketches. It has only one guide curve (left side of the spoon) which is the “project curve” line he has created. I am somewhat handy (not a master) with the swept boss feature, but I’m completely perplexed at how he is using it in this example.
I’ve even tried to construct the spoon by mimicking his exact moves, but have had no success. Every time I draw it from scratch, the spoon will only extrude to one side (the side with my “project curve” guide curve line), and the profile is always pointed at the guide curve location.

If I copy/paste his sketches into my own blank drawing, then use my own planes/ origins/ commands in the same way as his, the body builds perfectly. It’s as if he has some kind of magic sketches going on!

Theophilus or anyone, if you have the time, take a look at the spoon example in the SW Parts section of Matt Lombard’s site

http://mysite.verizon.net/mjlombard/

. And if you do, can you please let me know what’s going on there!

 

[CorBlimeyLimey]

I think you will find the “ninety degree construction line” is only being used to achieve a tangent for the spoon end of the spline.


Helpful SW websites FAQ559-520
How to get answers to your SW questions FAQ559-1091

 

[CorBlimeyLimey]

The symmetry is being attained by the sketch section geometry. The two top points of the sketch have a symmetric constraint ... so what one side does the other has to follow.


Helpful SW websites FAQ559-520
How to get answers to your SW questions FAQ559-1091

 

[CorBlimeyLimey]

Actually both pairs of corner points have symmetric constraints about the sketches centreline.


Helpful SW websites FAQ559-520
How to get answers to your SW questions FAQ559-1091

 

[dezignstuff]

Hey, this is Matt Lombard.

I think I got an email from you, and haven't had the chance to respond yet. Things have been busy.

Anyway, the way that was done was simply by using a 3 pt spline for the sweep profile. There is a centerline which follows the path, which goes down the plane of symmetry. One end of the spline uses a pierce constraint to follow the projected curve Guide Curve, and the other end of the spline uses a Symmetry sketch relationship with the centerline in the middle and the spline point on the other side.

This example is really showing its age. I would do this somewhat differently if I did it again today. Anyway, thanks for asking, and sorry for the slow response.

Matt Lombard
Dezignstuff

 

[Zcad]

Hey Guys,
Matt, CorBlimeyLimey, and Theophilus… I can’t thank you all enough. I just got in from Reno to find all the new replies. This information you have shared will be most helpful as I start up another SW session this evening. Over the past two years I’ve really been on a mission to become an accomplished SW operator (nocturnal life). I’m originally self taught, so when I get into a bind; it can be quite frustrating trying to find the answer. Without the help of generous people like you guys, I’d surely be lost in the tool box.
I wish I had some kind of valuable SW return information to offer you guys, but I’m obviously many levels behind you.

I can’t wait to successfully create that spoon from scratch. Might sound a little silly to gurus like yourselves, but to me it truly means a lot. Becoming skilled with guide curves (in all situations) and complicated sweeps, is something I‘m really working hard on.

Oh, and Matt, don’t sweat taking your time getting back to me. It’s you I need to thank… you’re an incredible guy for offering those great SW parts and links on your site.

Thanks Again Guys!

 

[Zcad]

You guys rule! I just finished building a perfect spoon. ? I never realized the power of relationships when using the sweep feature. Talk about opening a door for me.

Thanks a million!

 

[Theophilus]

Great! Glad it worked--and many thanks to Matt again--it's great to see all the models for show like that.

Keep at it and you'll grow your skills. It gets easier as you acquire more knowledge of how everything works. I'm self-taught and learn new stuff all the time.

Master sweeps and I think you've got the toughest stuff behind you. Of course, there's more to sweeps than first appears--they can be incredibly powerful.

Jeff Mowry

http://www.industrialdesignhaus.com

Reason trumps all. And awe trumps reason.