Is it possible to stretch these complex parts?


boat.skp (1.7 MB)

I have this model of a boat that I have been working on for some time now. It will be 3D printed in 4 sections and then raced on a solar boat competition. I’ve spent a lot of time on it, and it’s the most complex model I have done so far because I’ve had to ensure that everything is solid. Unfortunately, I printed out a small scale prototype and the boat does not float; the pontoons are too small.

To fix this, I want to perform a seemingly impossible task. The pontoons need to be stretched a bit inwards to make them larger. This has to be done while maintaining the integrity of the rest of the model. Here is a rough sketch of what I need:

Is this possible? What is the easiest way? Or do I just need to redo the entire model? I have Pro, so I was thinking the solid tools may help. I have attached the file at the beginning if you’d like to try it.

Thank you.


You might need to separate the pontoon parts front/backs off as separate groups - temporarily at least.
Then you can Scale them to a given width… start the scaling and type in the desired size WITH a units suffix - e.g. 7cm - so that SketchUp knows it’s not a ratio !
Be careful to pick all of the needed skin surfaces for the pontoons…
When done explode the groups back and tidy up for solidity…


Both hull parts seem to have a straight “stem to keel to stern” line dividing both sides of eather hull.
If so, it would be quite easy to stretch the inner surface of each hull inwards with the ’ Scale’ tool.
This can be done either by a scale factor or by a given dimension, i.e. value plus units.

Best if you select the geometry that makes up an inner hull part and group it. Then apply the ‘Scale’ tool to the group and pull the middle grip on the inner side. Then type the width plus units (roughly 1/4 of the sum of both hulls) and [Enter]
Then ungroup (explode the group) and correct a couple of straight edges near stern and stem (the connecting edges of both hulls).