How to Properly Use Projected Curves and Apply Surfaces?

zach_morris

I am trying to make helmet armor, and I'm having issues with applying surfaces to the wireframe. Some parts it pinches and some it bulges. I've made several branches of the project, and I'm getting closer, but still having issues. Also I was trying to thicken the model, but I can't because the surfaces interfere with each other.

https://cad.onshape.com/documents/fd8fd40d297ee21b7a3ae93e/w/f031b1c9aa1d372b2fb83b68/e/58c7b21c10caa05d18be2ee9

MichaelPascoe

There are quite a few different approaches you could take for making a helmet shape. Here is one approach that allows you to control the head measurements at specific planes along the Z axis of the helmet.

Key points:

• Use planes to evenly control the sketch placement for the shape of the helmet along the Z axis at relevant positions.
• Constrain matching front and side reference geometry to each other with the horizontal constraint within the reference sketches. Note these should all be constrained and dimensioned well for production, but as this is a quick demo, I just copied your sketch and applied some quick horizontal constraints with no dimensions.
• Use the Pierce constraint within the loft sketches to pierce the reference sketch exactly.
• Pay attention to the loft end conditions, especially for the second loft.
• Loft the main shape of the helmet separately from the cap.
• Boolean remove the cut outs.
• Extend the split geometry past the surface so that the split will not fail.
• Model only half, then use the Mirror feature to save time.
• The render is from Onshape's render studio beta.

https://cad.onshape.com/documents/32fefe1e6d8703e65948b3dc/w/0f888b6f2d0d246cf925858b/e/608f329bb...

zach_morris

@MichaelPascoe
 
This is witchcraft. Thank you my wizardry friend. If I wanted to add in contours to the helmet (like you see in the .jpgs I added) how would you do that using this method?

billy2

@MichaelPascoe You're amazing, you should teach this stuff.

@zach_morris if your company has a budget, you should buy some consulting from Michael.

MichaelPascoe

ty @billy2

Do you mean from the reference sketch / image? The "right" way would probably use projected curves and build the helmet around them. This technique would be tricky to implement, but if you do it right would be awesome looking.

Another way, if you just want the contour details to pop, would be to to sketch a "contour", extrude it to the helmet, then use fillets to blend. Like this: