The E-series Build.

[Ekh]

I would expect a stamped structure that re-creates a tube geometry (a full tube) to be as good as or better than a frame when given the same tube diameters.
A stamping would typically add flanges to the 'tube'. Having said that, I don't know the full tubes are being recreated exactly the same.

However, since it's a process involving some software, they would have already repeated the process with the stampings in place. It's setting up the process and method of analysis that takes the most effort. I'm sure they didn't want to go into that much detail for the public, since everything said costs them a lot of talk-time.
Generally speaking, for the crash tests I saw, just the beam-strength and a related deformity direction (for each structure) were the only attributes of each tube that affected the overall results. So long as the replacement segments are the same or stronger and with about the same relative strength to the rest of the structure, they will meet or beat the prior result.

But as I say, re-running the simulation again with an updated solids model is a trivial matter. So I'm expecting they did that. In fact I would have expected they did a comparative study early on while deciding what frame designs and manufacturing processes to use.
In any case classic automotive engineering has standard relative expectations for this type of change to a design.

Roush may have had some input to this decision -- but EM is NOT, repeat NOT going to compromise on safety. It would be terrible business sense to do that.

 

[pistonboy]

I suspect EM intended to use stamped frame parts from the beginning, but it would be too expensive to make stamping dies for prototypes.

The prototype company probably used tubing they believed (through experience) to be very close in strength to the stamped frame piece.

 

[Ty]

You were a lass before you were a lad? I would never have guessed

.. I see what you did there.


Yes, I were but a wee lad.

 

[Ty]

Hey Ty, I knew a guy with a speech impediment and he would say "weel" for the word "real " too. [Grinning face]

Wait, what?... oh, real ass. Lol.

 

[TCBronson]

Yep, I hope this means they actually tooled up one of the presses at the plant, and that's where they did it.
But I think it more likely they had the tooling fabricated by a contractor near the assembly location, and stamped everything for the 25 mules as the verification.
At least you know tooling for this was done. It's a really big deal, getting that tooling design for stamping is usually a big development cost to get to a final verified geometry.
Then making all the tools needed for full production, is also a 'big deal'. But yet more predictable than final design.

So if the tooling was fabricated by a contractor is that something they would be shipped down to Shreveport to use in full production?

 

[TCBronson]

I suspect EM intended to use stamped frame parts from the beginning, but it would be too expensive to make stamping dies for prototypes.

The prototype company probably used tubing they believed (through experience) to be very close in strength to the stamped frame piece.

That is a reasonable explanation why the change from tubular to stamped.

 

[Kuda]

.. I see what you did there.


Yes, I were but a wee lad.

Glad you lads figured that out!

 

[Ekh]

Sure would like to know exactly which insurance companies were involved.

It was a group from IIHS, if this is the same event I found out about in January.

 

[AriLea]

So if the tooling was fabricated by a contractor is that something they would be shipped down to Shreveport to use in full production?

So don't quote me on it, but yes. The tool stamp sets can be shipped. But I think this run of 25 has been stamped by a contractor, just my guess. Typically for this size company like EM, they contract their first tools to be made by a contractor business. This is done using a 'build plan' which includes the graphic solids files, possibly even post-process cutter paths etc. EM will eventually need more than one tool set per part, and those will be made the same way, but possibly with the target presses in mind. Building a few of the 25 Elios proves-out the tooling build plan is complete. And of course proves quite a bit toward the rest of the Elio assembly/build plan.
I expect right now EM has only one stamping tool set for each part, and that's enough tooling to get the 25 built in ? Detroit ? plus the 100 where ever that gets built. I do hope they ship the tooling to Shreveport to stamp out for the 100 lot run right there.
Someone else here worked at the Shreveport factory when it was making Hummers. And he can likely say how many tool sets are needed for 1000 Elios per day. (probably did say already)
At some point in time EM would evaluate the costs of making their own tool stamp sets. I suspect they won't find that cost effective until there is a full production online and generating cash flow.

 

[Ekh]

So don't quote me on it, but yes. The tool stamp sets can be shipped. But I think this run of 25 has been stamped by a contractor, just my guess. Typically for this size company like EM, they contract their first tools to be made by a contractor business. This is done using a 'build plan' which includes the graphic solids files, possibly even post-process cutter paths etc. EM will eventually need more than one tool set per part, and those will be made the same way, but possibly with the target presses in mind. Building a few of the 25 Elios proves-out the tooling build plan is complete. And of course proves quite a bit toward the rest of the Elio assembly/build plan.
I expect right now EM has only one stamping tool set for each part, and that's enough tooling to get the 25 built in ? Detroit ? plus the 100 where ever that gets built. I do hope they ship the tooling to Shreveport to stamp out for the 100 lot run right there.
Someone else here worked at the Shreveport factory when it was making Hummers. And he can likely say how many tool sets are needed for 1000 Elios per day. (probably did say already)
At some point in time EM would evaluate the costs of making their own tool stamp sets. I suspect they won't find that cost effective until there is a full production online and generating cash flow.

Thanks for this. Useful expertise in this group, for sure.