Drawing Lines on a Sphere / Loft / Rotation....

andy_manko

I am brand new to Onshape, learning how to use this tool to 3d print for my hobby of making model airplanes.   My current project requires several 1/2 spheres with lines on them (these would be glass in real life for a tail gunner...)

I can get the shape no problem done as a loft, or rotation but I am having trouble figuring out how to add the lines on the shape.  

Any thoughts on how I can do this?

Thanks!

john_mcclary

Draw half of the dome. Then revolve around the vertical line.
If you want it hollow, then offset the arc to be the thickness of the glass. Or use shell after you revolve.

andy_manko

Thanks for the comment, what I am trying to do is get lines on the surface of the sphere, both horizontal and vertical.  

Getting the hollow sphere is step one, how do I add detail to the surface of it.  

Appreciate your help!

john_mcclary

Depends on what you want in the end. There are a handful of methods. Do you want to make metal bands (you mentioned a gunner seat on a plane. I'm imagining WWII bombers)

andy_manko

That is exactly what I am going for, WWII bomber ball gunner and canopy.  

I would like to get the detail look of metal strips.  

The scale is small and I will paint them eventually.  But I want some scale detail.

Having lots of fun playing and learning with Onshape and 3D printing, but some of these finer points are hard to figure out.

I really appreciate your help

john_mcclary

Do a "thicken->new" on the outside of the cannopy.

Then make some planes to represent the outside edges of the strips. Then use "split" to cut the strips.

Take advantage of patterns when you can.
Then when you have all of your strips. Do a "Delete Part" and remove all the chunks where you don't want metal.
Then do a "boolean->union" on the rest

andy_manko

I have done the thicken, and added a about 26 planes to cut across the Sphere.  This is were I am now lost.  I do not understand what I need to split.  When I try to select a section to split, all it does is select the entire surface.  I think I am missing a step here.  

Again, thanks for all of your help, I will eventually figure this out.

john_mcclary

yes it will slice the entire surface.
you will need to split many times.
like cutting a loaf of bread

then use boolean to glue the pieces back together

this is why patterns will come in handy.

andy_manko

Ok, now I get it.  Wow, this is a ton of work for such a simple thing!

john_mcclary

Meh, there are probably simpler ways, but this is the easiest to understand, and explain.

The more I think about it, you could try and create your slice plane and sketch an arc on it instead.
Then sweep your plofile. Instead of thickening and slicing.

try both ways and see what works best for you

larry_hawes

Will this work? The line sizes can be changed of course but perhaps some variant will work for you...

https://cad.onshape.com/documents/b4b57eddb180d17d2e5f5f4b/w/203138b6081dcee9cfd7d2b7/e/276a5ea7dbf0ad6be1d5c1f8

andy_manko

Larry, that is exactly what I am trying to do!  How did you do this?

Is there a way I can resize it to be 2" diameter?

Thanks very much!

larry_hawes

nO AUDIO aNDY BUT HERE'S A DECENT WAY TO SEE HOW SOMEONE has created a model. Pull back all the features and repeat them one by one. There's a couple features that I abandoned, like the 2 additional planes but a step by step approach might get you there.

http://www.youtube.com/watch?v=cO6dObdkyyI

larry_hawes

Here's a stripped down version. Rudimentary but maybe workable.

http://www.youtube.com/watch?v=qv5klCDYBas

https://cad.onshape.com/documents/b4b57eddb180d17d2e5f5f4b/w/203138b6081dcee9cfd7d2b7/e/276a5ea7dbf0ad6be1d5c1f8

andy_manko

This was all great information!  Here is my current file.

https://cad.onshape.com/documents/c700458fe9664ca7df3bd189/w/8d8146432e0b2567e86a832c/e/1b56ad45c1ae49ef0c048af2

Still have to figure a couple of things out, but this has been a great learning experience.  

larry_hawes

Much more elegant solution. Nice work and thanks for posting...