Modeling Stragety with Grasshopper

Hi Group,

I've been working with GH for about one week, (I have no idea why it took me so long to take a look a GH!!!) going thru many tutorials and diving into the primer. I'm slowly getting my head into the grasshopper workflow but I could really use some advice from the experts. I've had exposure to SW and Inventor so I'm familair with the parametric modeling front....on an intermediate level.

I see Grasshopper as having the ultimate potential in parametric flexability and it has been a dream of mine for quite a number of years to see Rhino with parametric capability. It's like the holy grail of modeling for me to see this in Rhino!

My Question is this.... (this is probably really simple to the advanced users)

How would I go about constraining the blade profile curve to the outer and inner circles in the attached picture so that when the radius is changed in either disk the blade profile curve as a whole will follow and also change pitch but remain positioned within the two disks? I do plan on using the rotate command to create a "polar array" of the blade profile after the initial logic is setup.

I'm wishing to use GH and Rhino for parametric mechanical type designs as you would SW or Inventor.

Any advice would be greatly appreciated!

Craig

Attachments:

GHForum.jpg, 432 KB

Replies to This Discussion

Permalink Reply by Craig Wilkins on August 20, 2011 at 9:39am

Another note... If I where to set up a pitch slider for the blade profile how would I set a GH definition that would allow me to change the blade pitch and have the inner disk change and the outer disk remain constant. The outer disk radius would act as a overall positioning scale for the blade profile and the inner disk that are constrained to each other.. I hope I'm not confusing everyone with my descriptions.

Craig

Permalink Reply by Chris Tietjen on August 20, 2011 at 1:36pm

Here's a stab at it with an ellipse for a foil. The sliders attached to the output of the circles will give you the adjustment of the angle which you can read in the 'Angle of attack' text panel. Everything pertinent to making adjustments is labeled. Let me know though if something isn't obvious.

Chris

Attachments:

PropCircle.gh, 12 KB

Permalink Reply by Craig Wilkins on August 20, 2011 at 2:05pm

Chris, Thanks for the reply....

I'm gonna dive into this and force it to sink into my brain!

I did have a wip definition for this puzzle but I was too embarrased to post it. I've got to pay some more dues first;-)

I have a quick question for you.... how do you set the background labels and colored boxes to help organize your work?

I've noticed this in many of the more complex definitions on this site and it's a must as they become more complex.

GH is great fun!!

Thanks again!

Craig

Permalink Reply by Chris Tietjen on August 20, 2011 at 2:19pm

Select a component or components and hit ctrl-g to group and then right-click to open a context menu. The top line of the context menu is where you enter the descriptive text for the group. In the case of the text panel do the same thing (right click; top line). I wouldn't be too embarrassed about your own efforts. The quickest way to learn is to have some people hammer on your work. Certainly no judgement here.

Chris

Permalink Reply by Jonah Hawk on August 20, 2011 at 2:41pm

I took the a similar approach with slight differences. Then I was off on a tangent to generate a airfoil definition according to the 4 digit formula:

http://www.aerospaceweb.org/question/airfoils/q0041.shtml

I'm going to start another post discussing airfoils formulae

Attachments:

SquirelCageFan.gh, 14 KB

Permalink Reply by Craig Wilkins on August 20, 2011 at 3:47pm

Jonah,

Thanks,

These examples are great!

Permalink Reply by Jonah Hawk on August 23, 2011 at 4:59pm

Here is the airfoil thread. Instead of the ellipses, you could put in foils... or maybe that is not the form you are looking for...?

http://www.grasshopper3d.com/forum/topics/airfoil-formulas?commentI...

Permalink Reply by Craig Wilkins on August 23, 2011 at 5:37pm

Thanks Jonah,

This is excellent info. For my own uses I'm trying to take GH in a more mechanical than architectual direction. It's giving me a headache but it is slowly sinking in.... what a great tool!

Craig

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