Complex Surface into a Solid

Hi there, I am extremely new to Rhino, and also with using surfacing.
I have managed to draw up this kayak, but I desperately need to convert it to a solid with a thickness of 6 mm.
the outside needs to stay exactly as it is, only the inside needs to change.

i was able to join it all.

I am in panic mode now, because my project is due in a few days :fearful:Kayak joined.stp (16.3 MB)

There are so many naked edges to be repaired (the pink edges). Fixing this model will be a time consuming. Start with fixing the centerline of the hull. Getting the main surface bodies tangency average matched and joined.

You will need a good solid modeler to shell this form. Once you get into a valid closed polysurface.

I have joined the edges as best as i can now, and still nothing :frowning:
i have also tried to offset it.
and move the file to inventor to stitch the edges.
Kayak joined.3dm (13.8 MB)

KAYAK .3dm (4.3 MB)

okay, i have made some changes.
but i still cannot get this into a solid.

for the record i usually use autoCad 2D and solid edge(solids only)
learning to use surfacing was a complete mind set change.
i love Rhino now, but i am struggling.

This project is Due wednesday, i still have to do the following:

  • Run tests on Orca (i have no clue how to use Orca)
  • Assemble all the parts
  • print all drawings and hydrostatics, which i hope orca can give me

Have another look at it… Explode the block instance and use the _ShowEdges command again.

My suggestion would be, If you’re working within Rhino… Stick with Rhino. If you’re trying to solve the problem in Inventor, stick to Inventor. Fixing a problem in one package doesn’t always mean it will translate to another package without error. As an example, some filleting in Fusion 360 works well but when exported to Rhino it has errors.

Solve one side (half) of the kayak and then split and mirror it to save time. Try matching the surfaces and stitching it together.

If you’ve been sat staring at the screen for hours… Go make a cup of tea :slight_smile:


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Is this a school project? It’s a very ambitious model.

Absolute tolerance of 0.005 mm is tight for an object the size of a kayak. 0.01 or 0.05 might be more appropriate.

Did you create the model in Rhino? If so it is an impressive result for someone who is extremely new to Rhino. You need to go back and clean up the naked edges.

Or did you create the model in other software and import it into Rhino?

Or did you obtain the model elsewhere?

Thank you, i will definitely try that now.
I have only been using rhino to draw it up, from scratch, but when i youtube’d how to convert, it suggested Inventor to stitch, which i tried, but found more gaps when bringing it back to Rhino.

phew, it shall be done - in the next 24 hours

It is for Mechanical engineering - Btech.

please advise where to change the tolerance?
i created the model using Rhino, from scratch. probably started it about 4 weeks ago in between working.(30 minutes here and there)
then 3 weeks ago, i started putting more time in during weekend.
i only know how to use AutoCad 2D and Solid edge (solids) so learning surfacing was tough.
but this entire thing is my own work.
including the seat which took me the longest.


its a 90 day trial i am using,

DocumentProperties > Units

Adjoining edges outside of the tolerance can be forced to join using JoinEdge. Not that it generally does not fix the actual geometry but rather just causes Rhino to treat the edges as joined.

Thank you :smile::+1:t2:

What 2DCube means here is to use the MatchSrf command - it has some awesome settings. It can match for tangency, curvature, G1 through G4 I think. Check it out.

I had better luck with your first STP model. The last one in Rhino format was all messed up along the centerline. I have a single solid for the whole joined STP and have dropped the model into the world construction plane until I get about 104 KG displacement in ORCA. I was able to do a surprisingly complete shell of 8 mm inward but there are a lot of sloppy surfaces in the cockpit and knee well that break up so it is not a complete single shell. When doing the shell I took out the bottom of the beer can holder so had to fill that back in to restore the outer skin as a complete outer polysurface. One could hide that and stitch the inner offset surfs but this is a odd model to have been created in Rhino. It looks more like a Solid Works model for a number of reasons. One is that cylinders in SW come into Rhino as two half cylinders and I see that happening here. This does not look like a model created from scratch in Rhino by a casual user in three weeks in ‘30 minutes here and there’ at a time. I’m not that familiar with Solid Edge but maybe that gave you a good head start. Can you show a model showing your reference lines or picture frames? It seems that the surfaces are very complicated and have way to many control points. There are over 150,000 control points for 246 surfaces. Even just the hull is far too subdivided for a simple craft such as this. The hull could easily be just a single surface. If you have done this in Rhino, you really need to learn to rebuild lines and surfs as you go. I didn’t change the units or tolerance and it took a long time to grind out the partially successful shell. You might be better off starting with a much less ‘ambitious’ and complex model if you really expect to get a clean shell.

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@jodyc111 seem to be getting a lot of criticism for my work,
the last 3 weekends i have put in a solid 16 hours,
I only know how to rebuild lines.
and this is the final point, that i couldnt get through.
my email address is

I will gladly send you my progress from day 1 to where i am today to show that this is all my work.

a method i used for cylinder is i used a solid pipe and ran it through in some areas, then i split it from the original, and created a curve, which i swept through 2 rails.
and i am very good with 2D drawings, so i started everything with sketches

i know this is pushing it, but will it be possible to give me a step by step on what you have done, it has confused me.
but it is exactly what i am looking for.


Kayak hull & deck only.3dm (1.7 MB)

i started by inserting a picture frame and working from there.

All radii, i used the pipe command for (solid pipe)
and i also used the project curves command a lot.
common commands i leant was:
Project curves
sweep 2 rails

so yes, i have struggled to get this done, and the sketches i usually tried to do in AutoCad 2013 LT and bring into Rhino. for the outer body and the places for the foot rests.

the guy that works at Stealth South Africa said i can use his pictures for the picture frame.

curve network

Kayak all edges joined.3dm (13.9 MB)

i have joined all edges, to the best of my ability
please can someone help me make this into a solid.

or just send me a file, with this as a solid - i am running out of time, and offset keeps freezing my computer.

i only need it offset 6 mm.

thanks to all that have helped get to this point

It’s good work, you’ve done a lot in such a short amount of time… Rhino is amazing but it takes a while to work through some of the tweaks and tips.

Commands to run before you finalise a job:

_Check to see if there are errors: _SelBadObjects and/or _testRemoveAllNakedMicroLoops

You’ll notice than when you run the command _testRemoveAllNakedMicroLoops it removes 10 errors but still leaves some open edges.

In my experience using _JoinEdge can hinder future boolean operations. Always make sure you start with the correct tolerance. I’d say anything smaller than a large family car should be .001

Working with Rhino models can be like sketching… Do what you need to do to get the model 80% there quickly if you’re not sure how to go about it, and then use that model to section, rebuild curves and rebuild surfaces to finalise. If you know what you’re doing you can do it in one hit but it’s not always the case.

I’ll take a look at it for you