1 Topic by pirvan (edited by pirvan 2015-02-21 07:17:38)

  • pirvan
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Topic: BMW i8 Concept Model

I'm a big Mini Z fan, and own probably 60+ Mini Z Autoscale bodies.  One model that I wish Kyosho would make is the BMW i8 hybrid.  So this is my attempt at making a BMW i8 Concept car autoscale body for a mini Z chassis.

First of all, the BMW model I have was modeled in Solidworks, using surfaces only.  That means this is not a solid body, rather it's just curved, open surfaces.  Obviously useless for printing. 

http://www.soliforum.com/misc.php?action=pun_attachment&item=7986

So the first thing I needed to do is turn this into a solid.  Letting NetFabb enclose everything automatically, produced a almost usable STL, but it enclosed everything as a solid, which I didn't want.  I wanted to have a true shell, a skin with open windows and wheel wells that could be fitted to an RC chassis.  SO what I needed to do, it basically thicken up the existing surfaces into solids.

Solidworks has an option to thicken a surface, but unless that surface is fairly simple, and the only thing it was capable of thickening on this model were the wheel wells.  So I exported an STL of the model as it was.  I then imported the STL in 3D Studio Max.  3DS Max also has a feature that lets you thicken up a surface, called "shell", that  almost always generate a shell, but it's not forgiving of errors.  a triangle out of place or an intersecting face can wreck havoc with the shell surface.  What may appear as a perfect surface before thickening, can turn into a horrible looking shell with weird bumps and craters.

Anyway, after hours (more like days) of back and forth work between Solidworks, 3DS Max and NetFabb, I managed to get a pretty good model.

http://www.soliforum.com/misc.php?action=pun_attachment&item=7987

Here are a few shots of the first print.  Considering how complicated this model is, it didn't turn out too bad.  Next time, I'm printing it at 1:28 scale, which is what a Mini Z car is.  This model is smaller, 1:35.  The slightly larger print should help make the model beefier.

http://www.soliforum.com/misc.php?action=pun_attachment&item=7989

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To print or, 3D print, that is the question...
SD3 printer w/too many mods,  Printrbot Simple Maker Ed.,  FormLabs Form 1+
AnyCubic Photon, Shining 3D EinScan-S & Atlas 3D scanners...
...and too much time on my hands.

2 Reply by pirvan

  • pirvan
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Re: BMW i8 Concept Model

So the 1:28 scale model is printing right now.  There is nearly as much material in the support structure as there is in the model itself.  It also doubles up the print time:

Without support:
Estimated Print time:  4:34 hours
Filament needed:   10300 mm

With support:
Estimated Print time:  8:48 hours
Filament needed:   19250 mm

To print or, 3D print, that is the question...
SD3 printer w/too many mods,  Printrbot Simple Maker Ed.,  FormLabs Form 1+
AnyCubic Photon, Shining 3D EinScan-S & Atlas 3D scanners...
...and too much time on my hands.

3 Reply by jagowilson (edited by jagowilson 2015-02-22 01:53:15)

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Re: BMW i8 Concept Model

You might be able to fix that with some settings adjustments.  Things like the beam above the doors can maybe(?) be printed without support, using a fan and good bridging settings. But it's a matter of whether or not you can tell your slicer to not support bridges...

Prints look good though as always!

4 Reply by machinistjoe

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Re: BMW i8 Concept Model

Nice work! Your workflow looks a lot like mine. Solidwork's stl exports have always been buggy, as least for me.

I am thinking of creating a 1:25 Datsun 510(Vintage Nissan Bluebird) body for my xmod. There is a file on Thingiverse, but I  think that fitting and scaling the squat little Datsun to the relatively long and narrow xmod chassis might warrant a whole new design.

5 Reply by pirvan (edited by pirvan 2015-02-27 15:24:46)

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Re: BMW i8 Concept Model

Solidworks STLs have never been an issue for me with the stuff I made, that is with solid bodies, but this had been modeled entirely with lofted, open surfaces.  The only solid body in the whole thing were the tail lights.  So it had no volume.

If you ever tried to thicken a surface, you know that it can't handle curves in multiple planes so, thickening it up in Solidworks was out.  That's why I exported the model to STL as is, which ended up with many inverted faces, opened that up in NetFabb to fix all those inverted faces and triangles, then opened the fixed STL in 3DS Max to thicken it.

Round about way of doing things, but it worked.

To print or, 3D print, that is the question...
SD3 printer w/too many mods,  Printrbot Simple Maker Ed.,  FormLabs Form 1+
AnyCubic Photon, Shining 3D EinScan-S & Atlas 3D scanners...
...and too much time on my hands.