New Video: Paddleboard Grip Model Tour

Evan_Reese · September 2022

I haven't made a new Youtube video in a while, but I recently modeled up a new grip for my paddle board paddle, because my old one broke. I thought it would make a great subject for an end-to-end tour of the model. Coming in around 37 minutes, it's a pretty long form video, but I also cover a lot, like how to set up and analyze curves and surfaces, how to design parts for 3D printing, some advanced setup techniques for the Attractor Pattern feature, and lots more. Let me know what you think!

https://youtu.be/IjcFotLmCx8

Image: https://us.v-cdn.net/5022071/uploads/editor/vm/1zfsn3m9jwdq.png

MichaelPascoe · September 2022

Very informative! There is always something new to learn with Onshape.

GWS50 · September 2022

Thanks Evan....really useful

王振翊 · September 2022

太棒的影片
真的有很大的幫助

S1mon · September 2022

@Evan_Reese

Thanks for this. It's nice to see some of the other fun features you’ve been developing. I wish I had more opportunities to use attractor pattern.

As far as some of your questions about the curvature at the top ends of the splines... I have a bunch of tips and tricks that I put together for Béziers in Solidworks. I've been meaning to translate that into something for Onshape. But the short version is that you're trying to control what happens across a mirror plane. Obviously you want it to be tangent across the mirror plane, and you made yours curvature across the mirror plane, but for something to be class-A you would normally want to make this G3 across the mirror plane. This means that the curvature graph (the purple curve) should be normal to the mirror plane.

There are many ways to get G3 with a mirror. Here are a few basic ones.

Make a single curve with mirrored control points, and then split it later. This is G∞ across the mirror.

Image: https://us.v-cdn.net/5022071/uploads/editor/rr/oasldkn65h8w.png

Make a half curve, and the first 3 legs of the control polygon horizontal lines. Like your version, the curvature (first derivative) is zero at the mirror, but adding the third control point on the horizontal forces the curvature of the curvature (second derivative) to go to zero at the mirror as well. The purple curve end is normal to the mirror.

Image: https://us.v-cdn.net/5022071/uploads/editor/oy/lweo8bisx0g7.png

The third way is to do things with those same 3 legs of the control polygon. The first needs to be normal, but then there are some arrangements which will also make the end purple curve be normal at the mirror.

Image: https://us.v-cdn.net/5022071/uploads/editor/49/fmj6qtpamf0p.png

Here's a detail of the helper construction lines and constraints. This is sometimes called an A-frame. I need to make a video or step by step of this...

Image: https://us.v-cdn.net/5022071/uploads/editor/3j/wfszu91hwsd6.png

Axel_Kollmenter · September 2022

Great Job! Thank you Evan

Evan_Reese · September 2022

S1mon said:

@Evan_Reese

Thanks for this. It's nice to see some of the other fun features you’ve been developing. I wish I had more opportunities to use attractor pattern.

As far as some of your questions about the curvature at the top ends of the splines... I have a bunch of tips and tricks that I put together for Béziers in Solidworks. I've been meaning to translate that into something for Onshape. But the short version is that you're trying to control what happens across a mirror plane. Obviously you want it to be tangent across the mirror plane, and you made yours curvature across the mirror plane, but for something to be class-A you would normally want to make this G3 across the mirror plane. This means that the curvature graph (the purple curve) should be normal to the mirror plane.

There are many ways to get G3 with a mirror. Here are a few basic ones.

Make a single curve with mirrored control points, and then split it later. This is G∞ across the mirror.

Make a half curve, and the first 3 legs of the control polygon horizontal lines. Like your version, the curvature (first derivative) is zero at the mirror, but adding the third control point on the horizontal forces the curvature of the curvature (second derivative) to go to zero at the mirror as well. The purple curve end is normal to the mirror.

The third way is to do things with those same 3 legs of the control polygon. The first needs to be normal, but then there are some arrangements which will also make the end purple curve be normal at the mirror.

Here's a detail of the helper construction lines and constraints. This is sometimes called an A-frame. I need to make a video or step by step of this...

Legit advice, Simon! Part of my issue is just improvising with the script a bit. I knew I could make that area a bit better if I wanted to take the time and re-shoot that footage, but I'd already spent too much time on the video to bother adding that in. I later played with something more like what you've got in your third example. I hadn't thought of your first option there, which I like a lot! That's probably one I'll be using going forward. I'd love to see a step by step on the A-frame technique too.

tim_hess · September 2022

Love this discussion. I haven't had much need for advanced surfacing, so I haven't studied or practiced it a lot. It's great to see glimpses of what goes into creating pleasant shapes.

New Video: Paddleboard Grip Model Tour

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