SolidSmack - Latest Comments in Ask the Reader: How Do You Model? Plus A Top-Down Modeling Challenge

Re: Ask the Reader: How Do You Model? Plus A Top-Down Modeling Challenge

DebrasextonMohn — Thu, 23 Jul 2009 21:33:47 -0000

I'd like to see a spur and worm gear with a gear arm assy top down please.

Re: Ask the Reader: How Do You Model? Plus A Top-Down Modeling Challenge

joshmings — Tue, 28 Oct 2008 10:03:27 -0000

John, hi. yes, this is one thing you need to watch with top-down design. I recommend that all parts that reference other parts be fixed. If it's not, then if the unfixed part moves, th references will stay and change the shape (intent) of the part.

However, keeping parts unfixed can be used while conceptualizing to test out different ideas.

Re: Ask the Reader: How Do You Model? Plus A Top-Down Modeling Challenge

john — Sun, 26 Oct 2008 17:30:13 -0000

hi, (sorry for my english)
with the top down method:
if a part references another one then the part is fixed and i cant mate it.
im a new user.is there a way to avoid this ?
thnx

Re: Ask the Reader: How Do You Model? Plus A Top-Down Modeling Challenge

joshmings — Sat, 23 Aug 2008 22:50:08 -0000

You all have had great suggstions. I'm considering some scenarios to show
and will definitely go over the 'pitfalls', the do's and don't's of top-down
and bottom-up. Thanks for letting me know what you're interested in seeing.

Re: Ask the Reader: How Do You Model? Plus A Top-Down Modeling Challenge

Brad Moon — Fri, 22 Aug 2008 15:04:05 -0000

I also agree with Ivan, who suggests, "something mechanical with assembly motion, moving parts... engine, scissor lift, adjustable conveyors". Adjustable conveyors preferred.

That said, I would like to know more about the pitfalls of TDD that Jeff B refers to.

Re: Ask the Reader: How Do You Model? Plus A Top-Down Modeling Challenge

Chris Booth — Sat, 16 Aug 2008 07:46:07 -0000

I agree with Ivan, who suggests "something mechanical with assembly motion, moving parts... engine, scissor lift, adjustable conveyors". For me, top-down design comes into its own when you really NEED to use it, when you couldn't even imagine the shape a part should be unless you see the rest of the assembly going through its planned motion.

For example: If you go to the Wolfram Demonstrations Project ( http://demonstrations.wolfram.com/ ) and search for "Hoberman" you'll find some examples of mechanisms where the design of one part is very much dependent on the design of other parts, and also the overall results of motion for the mechanism as a whole are difficult to forsee without constantly simulating the motion during the design process.

Here's the sort of thing you could do with these mechanisms: Watch the web preview of the "Ring of Hoberman Rings" example. Can't you just see how you're really looking down on a new type of connected parasols for sun terraces suspended overhead that does away with those annoying poles that either get in your way as you walk around or else go right through your table?

Re: Ask the Reader: How Do You Model? Plus A Top-Down Modeling Challenge

jeff_bare — Wed, 13 Aug 2008 08:57:51 -0000

i began my life as a confident slightly self-centered Top-Downer, but i have sense been converted to a Bottom-Upper. Current job uses a vault and parts get handed around more then baby in need of a diaper change. now maybe 10% of the time when i'm doing a presentation and the parts are all mine, i'll do a combination.

Re: Ask the Reader: How Do You Model? Plus A Top-Down Modeling Challenge

John — Wed, 13 Aug 2008 08:55:25 -0000

My first choice would be something with Weldments since that's about 90% of what I do. Thanks for all of your informative posts - I really love this site!

Re: Ask the Reader: How Do You Model? Plus A Top-Down Modeling Challenge

Catch 22 — Wed, 13 Aug 2008 08:28:02 -0000

Hi Josh-

Bottom Up is my preference. Why? Because In Context External References don't belong in our universe. Ever Checked In a Part file with these References into an electronic vault? A worm hole opens up and you're transported to the 4th dimension.

Devon

Re: Ask the Reader: How Do You Model? Plus A Top-Down Modeling Challenge

Daniel — Tue, 12 Aug 2008 21:12:09 -0000

Hi Josh,

How about an assembly that shows the dangers of leaving in context relations, ie circular relations, broken relations, too many relations, etc.?

Daniel

Re: Ask the Reader: How Do You Model? Plus A Top-Down Modeling Challenge

Dale Dunn — Tue, 12 Aug 2008 19:31:00 -0000

In order to showcase the strengths of top-down parametric design, there should be configurations for different sizes and quantities of toast.

Re: Ask the Reader: How Do You Model? Plus A Top-Down Modeling Challenge

CharlesCulp — Tue, 12 Aug 2008 17:00:25 -0000

I model with a mouse in my right hand and my left on the keyboard shortcuts.

Re: Ask the Reader: How Do You Model? Plus A Top-Down Modeling Challenge

Marijn — Tue, 12 Aug 2008 16:34:01 -0000

haha I prefere bottoms-up when you go there :)

Re: Ask the Reader: How Do You Model? Plus A Top-Down Modeling Challenge

JeffMirisola — Tue, 12 Aug 2008 15:04:33 -0000

Do you remember "Weird Science"...?

Re: Ask the Reader: How Do You Model? Plus A Top-Down Modeling Challenge

listrophy — Tue, 12 Aug 2008 14:59:57 -0000

Stapler! =) I kid, I kid.

I always finish up with bottom-up assemblies, but sometimes I'll start with top-down designs. If I need a bunch of parts and subassemblies to fit into a small space, top-down is the way to go. But once that design is perfected, I convert it to bottom-up. When dealing with configuration management and ECR/ECNs, the last thing you want is one part to auto-update another.

Re: Ask the Reader: How Do You Model? Plus A Top-Down Modeling Challenge

Marijn — Tue, 12 Aug 2008 14:41:31 -0000

I made a bbq in my middle technical school and I still use it, it is rusty like hell. But it is pure craftmanship the bbq works always and the rust wont get true the metal!
So design a DIY (do it yourself) bbq!

Re: Ask the Reader: How Do You Model? Plus A Top-Down Modeling Challenge

joshmings — Tue, 12 Aug 2008 14:27:46 -0000

Dang, good one! That is cool to think about. interesting what shapes control design.

Re: Ask the Reader: How Do You Model? Plus A Top-Down Modeling Challenge

Ivan — Tue, 12 Aug 2008 14:27:07 -0000

hmmm... you could do something mechanical with assembly motion, moving parts... engine, scissor lift, adjustable conveyors

Re: Ask the Reader: How Do You Model? Plus A Top-Down Modeling Challenge

Kyle Mason — Tue, 12 Aug 2008 14:11:05 -0000

I'm thinking of some great big funky wine-rack. Don't ask me where that came from.

Re: Ask the Reader: How Do You Model? Plus A Top-Down Modeling Challenge

lukeseed — Tue, 12 Aug 2008 14:03:41 -0000

Top down may make things faster when designing but becomes a nightmare once in production.

Re: Ask the Reader: How Do You Model? Plus A Top-Down Modeling Challenge

Ocell — Tue, 12 Aug 2008 14:00:14 -0000

I'm looking forward to the post, I wish I could read it now, you've got me all fired up for it!

Toasters are always fun design exercises. (No really, I'm being serious) A few nice parting lines in the shell, plenty of sliding/lever relationships for parts, and all driven by the dimensions of a slice of bread!