Need Some Modeling Direction

[suelflow]

I need to model an open chock for marine use and have no idea how to go about it. See attached picture.

 

[Eltron]

You're going to have to use the sweep and loft functions. Check the Help and go through the online tutorials, and you should be able to figure it out.

Dan

http://www.eltronresearch.com

 

[Theophilus]

And Surfaces.



Jeff Mowry

http://www.industrialdesignhaus.com

Reason trumps all. And awe transcends reason.

 

[Updraft]

It appears symmetry should also play a role; half-symmetry at least, perhaps even quarter-symmetry.

- - -Updraft

 

[ctopher]

If you search around, I'm sure you may find one already modeled. Is it for class?

Chris
SolidWorks 07 4.0/PDMWorks 07
AutoCAD 06
ctopher's home (updated 10-07-07)
ctopher's blog

 

[suelflow]

No it is not a class project, although it would make a good one. It is for a dry dock we are designing. It is not for shop drawings, so it does not have to be exact but I would like to make it close. My thought right now is to draw sections and connect them with a loft.

 

[MadMango]

Mooring chocks come in all flavors, so I think it's safe to say you have some creative license to be able to model something that has the proper scale without taking more than a few minutes to create.

"Art without engineering is dreaming; Engineering without art is calculating."

Have you read faq731-376 to make the best use of Eng-Tips Forums?

 

[Theophilus]

I generally prefer sweeps with guide curves to lofts (easy to keep your surface smooth), and work with surfaces and the part's symmetry instead of solids. This way, you can construct surfaces larger than you need, they can overlap each other, and you can trim down to the size you want, Knit, and form into a solid. Then mirror across symmetry planes for a complete, finished part. This part--if it doesn't need to be held to a perfect standard--could probably be done within fifteen minutes or so (if experienced with surface modeling--sweeps, trimming, etc.).



Jeff Mowry

http://www.industrialdesignhaus.com

Reason trumps all. And awe transcends reason.

 

[suelflow]

Unfortunately I’m not that familiar with surface modeling. I’ve always been a solids guy. As to a sweep, how do you do that when the profile changes along the path? That’s why I was thinking loft.

 

[Theophilus]

Depending on the specific geometry you need, using a partial ellipse is great. Path to guide the ellipse center, one guide curve each to guide the major and minor axes of the ellipse. In ProE, they use something similar called conics (which I'd really like in SW), but a quarter-ellipse will cover most of what you need (or half-ellipse, or full ellipse--depends on your final geometry).

The other thing you can do is use a spline for a profile and control the tangency of the ends so you can later mirror your geometry properly.

In this case, however, I think you could simply use a dimensioned arc. Sweep the surface, Trim to shape, Thicken, then add a full radius (or similar) to create the ski-tip shape. Then extrude the base (which will overlap part of your ski-tip shape) and use fillets to merge the bodies. Mirror along lines of symmetry to complete.



Jeff Mowry

http://www.industrialdesignhaus.com

Reason trumps all. And awe transcends reason.

 

[MadMango]

You sure you don't need bitts instead of chocks? I spent 6yrs in the Navy, bitts were much more common.

"Art without engineering is dreaming; Engineering without art is calculating."

Have you read faq731-376 to make the best use of Eng-Tips Forums?

 

[suelflow]

We are using bitts, open chocks, closed chocks, roller chocks, capstans and cleats. Most are easy to model, it's the ones that curve in multiple directions while changing shape that make me scratch my head. I appreciate the input, it is taking me in another direction I was thinking of and into an area where I have less experience. But that’s how you learn.

 

[TheTick]

my advice...

Start with good layout/skeleton sketches. When there's surface geometry floating through your model, it is best to anchor it to good layout sketches. Layout sketch entities should be copied into other sketches, not consumed by individual features.

As was said: sweeps w/ guide curves are usually preferable to lofts. With that, swept conics (parabolas, ellipses) behave better than splines. Use pierce constraint to tie section sketches to guide curves.

Sweep, then trim. The natural contour of a surface may not match the outline it is trimmed to. Extend your sweeps (and even lofts) to their natural progression beyond the face edges of your model, then trim to size. Many lofts suck or fail because the desired end-result face edges are used to generate the loft.

Surface-intensive models have a much higher feature count. Be content with this fact. If you try to over-economize on feature count, your model's robustness will likely suffer.

Use folders in your feature tree to keep related features together and organized.

Honesty may be the best policy, but insanity is a better defense.

http://www.EsoxRepublic.com

-SolidWorks API VB programming help

 

[macduff]

Do you have an actual part? Maybe you should have it scanned and model around that scan.

Macduff
Colin Fitzpatrick
Mechanical Design Engineer
Solidworks 2007 SP 4.0
Dell 390 XP Pro SP 2
Intel 2 Duo Core, 2GB RAM
nVida Quadro FX 3450 512 MB

 

[suelflow]

No such luck. Were new to this and don't have a scanner. Nor do I think we'll get one any time soon. Oh, and the thing weighs 500-1000 pounds.

 

[CorBlimeyLimey]

The Chock weighs 500-1000lbs?

 

[suelflow]

The one in the picture is 12" and weighs 435 lbs.. Mine is 36" so I just extrapolated.

 

[macduff]

And how in the heck are you going to model it then? Are you scaling it from a drawing or picture?

Have a good day,

Macduff
Colin Fitzpatrick
Mechanical Design Engineer
Solidworks 2007 SP 4.0
Dell 390 XP Pro SP 2
Intel 2 Duo Core, 2GB RAM
nVida Quadro FX 3450 512 MB

 

[ctopher]

Suelflow,
You wrote it does not have to be accurate, just model a block approx size, then use the freeform or shape tools.

Chris
SolidWorks 07 4.0/PDMWorks 07
AutoCAD 06
ctopher's home (updated 10-07-07)
ctopher's blog

 

[MattBD]

You could always take photos, put them in a part file and work that way. I saw a great tutorial video for this at Camtasia Studios.