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Lotus Europa Forums => Technical Articles and DIY tools and tips => Topic started by: gideon on Monday,March 25, 2019, 06:27:54 PM

Title: S2 chassis front box CAD model
Post by: gideon on Monday,March 25, 2019, 06:27:54 PM

Here is a link to the CAD model of the S2 chassis front box that I prepared in Fusion 360.  Using this link you should be able to view the model, and download it in a variety of formats.  I have checked the dimensions of this against the two S2 chassis that I have by cutting plywood templates of the front and back faces on a CNC router.  It is now very close to the original dimensions and, in so far as I can tell, not more than about 1mm different anywhere.

https://a360.co/2JT7O79

I haven't included the holes for the brake cylinder, as I have not yet decided what I'm going to do there.

I will probably make further changes before this is done - I might add holes for cleco rivets during assembly.  Those hole could become spot welds. 

Let me know if you want the flat patterns, I think I might need to add those as one or more extra links. 

The model was prepared assuming 16 gauge steel at exactly 1/16 inch thick.   In principle it should be easy to change the sheet thickness, or to change the bend allowances.  The external dimensions should stay the same, and the flat patterns will update to reflect the changes.  In practice there might be a little tidying up required.

Title: Re: S2 chassis front box CAD model
Post by: lotusfanatic on Monday,March 25, 2019, 10:53:02 PM

Fantastic work!

Title: Re: S2 chassis front box CAD model
Post by: Certified Lotus on Tuesday,March 26, 2019, 03:26:59 AM

Impressive. Are you an engineer?

Title: Re: S2 chassis front box CAD model
Post by: Chuck Nukem on Tuesday,March 26, 2019, 06:35:51 AM

Excellent! Thank you!

Title: Re: S2 chassis front box CAD model
Post by: gideon on Tuesday,March 26, 2019, 08:46:13 AM

Certified - I'm a software engine so not a proper engineer, as my old boss used to say.  I have been teaching myself to use Fusion 360.  It offers a lot for the money (free for non-commercial use), but it's definitely expert software so the learning curve is steep.  It supports sheet metal design, which is exactly what was needed for this job.

Title: Re: S2 chassis front box CAD model
Post by: Grumblebuns on Tuesday,March 26, 2019, 12:20:44 PM

Gideon, to keep this fantastic effort from getting lost in the Garage section, I suggest you post a duplicate in the Technical section for future reference.

Joji Tokumoto 

Title: Re: S2 chassis front box CAD model
Post by: shootingsight on Tuesday,May 07, 2019, 09:31:28 PM

Excellent.  I plan on doing the engine bay of my S2.  With luck, I can find engine CAD models and start to see what would fit in there as a replacement.

Title: Re: S2 chassis front box CAD model
Post by: jbcollier on Thursday,May 09, 2019, 08:45:38 AM

The original design is a double box design which would be stronger even if you have included a diaphragm (looks like you may have).

Title: Re: S2 chassis front box CAD model
Post by: gideon on Thursday,May 09, 2019, 11:05:35 AM

John, this is very close to the original design of the S2 chassis, based on the two chassis that I have in my garage.  It shows the same number of pieces of steel, cut and folded in the same way and welded in the same places.  The only significant difference is the bottom plate, which is shown cut and folded so that it can be welded to the backbone.

If you're just looking at the image that I posted then please click on this link to the 3D model viewer

https://a360.co/2JT7O79

Let me know if it doesn't work.  You should be able to rotate the 3d model and see all the detail, including the horizontal flange on the front face, and the two horizontal pieces that get welded to the front flange and the rear face.  The toolbar at the bottom has options for an exploded view and cross sectional views