What software tools do you recommend for designing a part to be printed?

[James Newton]

So I wanna try designing a custom toothed pulley to replace the
(poorly fitted) one that I have currently. It fits over the shaft of
the handle on my drill press and allows it to be actuated by my Z axis
motor. My little CNC is a hodgepodge of an X-Y table and a drill
press... works ok for what I do, which is mostly just testing motor
drivers and drilling the occasional PCB. Anyway, I'd like to design a
better one and then pay some place to print it for me; I doubt I can
cut it accurately with my own setup, and it will be a fun intro to 3d
printing for me.

I've done a little 3D cad work years ago in AutoCAD, so I think I
understand the basics, but I'd love to hear what you guys use. Now...
I'm a M$ guy all the way, but I'm open to trying a bootable *nix if
that's the way you would advise. I'd /rather/ work in Windows, or in a
program that perhaps has a Windows version so I can try that first and
then switch to the bootable *nix if that works out better.

Thanks in advance for you advice.

[Richard Rouse]

Search thingiverse ... here's a parametric pulley idea:
http://www.thingiverse.com/thing:1362

you use openscad to adjust

--
Richard Rouse
HTS Resources, LLC.
325 W. Washington St. #2-150
San Diego, CA 92103 USA
619-846-8291
rjdr...@htsresources.com
www.htsresources.com

[u]

Seems to be a lot of exciting stuff going on out there.
Sorry to miss this Sat meeting.
Cold out here in New Mexico and snow on the ground in Santa Fe.
I am using DataJack to keep in touch. 

Yes please all suggest what tools are good to use.  I am hoping
to gather all the recommendations   and  then actual downloads
of  working  toolchain tools  in one spot for the group. 
As you know I hope to put these on a USB stick  and  have that
as a  tool for all of us and a  possible  prize for fundraising for the SDMaker group.

When I ask what 3D  CAD  tool people are using  I hear  OpenSCAD  and
Google Sketchup.   Both are free   and  OpenSCAD is a powerful and very
different tool.  
Are there any other good ones??     Blender??    IO??     SolidWorks??    Alegro?? 

Have a good meeting. 

Rob

[James Newton]

So OpenSCAD appears to be a rather wordy version of the script part of AutoCAD, no GUI, just script and then a viewer for the result? And Sketchup is more like the GUI version, but no scripting? And do I understand correctly that to export STL files from SketchUp you have to install a tool:
http://www.guitar-list.com/download-software/convert-sketchup-skp-files-dxf-or-stl 

Any preferences between the two for starting or should I learn both at once?

Thanks for the link to the pulley, but I'm not sure that will work for my needs... it's a great starting point, but I'm going to have to modify it beyond the ability of the parameters to change it. 

Time to start learning...

--

James.

[Ron Garrison]

James,

I use both, and each has their pros and cons.  OpenSCAD is entirely script driven, so it is definitely the tool of choice for things like gears that are defined in terms of formulas. It is a bit of a pain for complex objects that aren't defined mathematically though because each basic component (cube, cylinder, sphere, etc. ) is initially created at the origin and you need to use a combination of translations and rotations to get it where it needs to be.  OpenSCAD is a solid modeler. 

SketchUp has a nice graphical interface, and is great for more "organic" objects, but I can't see how you would design something like a gear with it.  SketchUp is a surface modeler. This means that the objects aren't actually solid, they are a collection of planar surfaces, which can have some interesting side effects.  The easiest demonstration of this is to draw a cube, draw a cylinder with a length about the same as the side of the cube and a diameter about 1/4 the side of the cube, the move the cylinder so that it sticks part way into the cube.  The resultant STL file includes the portion of the cylinder that is inside the cube and I have seen slicers render this as a hollow space inside the cube.

Ron

[James Newton]

So I made up a little playlist of the (few) videos I could find on learning OpenSCAD. Might be valuable to the next newbie:
http://www.youtube.com/playlist?list=PLA9633900ACC80BA1
Let me know if you have seen any other good video or other type tutorials.

[Richard Rouse]

sketchup has a ruby scripting interface actually that is very
powerful. you need to set up the IDE though.

people are posting pretty complex models using openscad on thingiverse
that you can use as templates.

--

[James Newton]

Thanks for that Richard!

Have you actually used that part? I ask because it seems to have some (minor) issues. The shaft height isn't correctly calculated, for example, It's just hardcoded at 40mm. And there are errors in the set screw holes that show up when the part is larger than a few mm. I've posted the corrections I think matter on the site in the comments, but I don't want to offend anyone.

Now my next question is how I can calculate the torque required and so figure out how big it needs to be for the motor I have. That's a fun one huh? I think this will help:
http://techref.massmind.org/techref/io/steppers.htm#Estimating 

And then I have to figure out were I can get it printed... Anyone want to trade some programming or electronics work for a print?

--

James.

[Richard Rouse]

Yep, but I prefer this one:
http://www.thingiverse.com/thing:16627

I am willing to print some pulleys for you depends what you mean by
electronics work. I would like to get this board made or redesigned to
bypass the arduino shield part:
http://www.thingiverse.com/thing:11907

Actually there are many boards I would like to get made .... maybe we
should talk on phone to discuss what you can and can't do.