Transition From Integration to Pre-Production Begins Now: Thousands of Chevy Volts to be Built Early Next Year
As was reported on Friday October 9, GM completed building the last of a total of 74 pre-production Chevy Volts, which were built in the modest-sized pre-production operations facility in GM’s Warren campus. I had the chance to discuss with Volt vehicle line engineer Tony Posawatz what happens now.
Now that these cars are finished what happens next?
Interestingly enough this is probably where the intense work begins. From a build perspective, we won’t build again until early next year in Hamtramck. What we do now is we take the production intent designs that were built up in the integration vehicles and we test the living daylights out of them and continue to do iterations and iterations. A lot of it is software. A lot of it is taking some of the crudeness in fit in the body fits and tighten them up. Although we do it on math, variations occur and flushness and fit come out a little differently then they do on paper.
So we’re now tuning it. And between that time from October of this year and March of next year, we test the vehicle to confirm the production design works, tweak and fix things, and as we tweak and fix things those changes have to be incorporated in the production tooling and those things typically have a longer lead time.
Then the production tooling is in place. Those are the big heavy expensive dyes to stamp the sheet metal. Those are more significant molds and cavities and processes to manufacture plastic parts in high volume. That’s kind of what happens right now. Right now is the testing, problem-solving, refining and putting all that learning into the production tools. Come the March timeframe and we’re running Volts with production tools. And that is still an iteration process or learning process to refine it for what’s going to happen later in the year.
Are you beginning to put hardware into the Hamtramck plant?
Oh yeah, the Hamtramck plant and the battery plant are on a project plan to upgrade themselves to be ready to build in the early 2010 timeframe. So right now there are tools in toolshops being produced and as we find out, we need this or that, we’ll change it on a production tool. That’s the process we’re in.
When you first start building in March what are those vehicles called?
We call them PPVs, pre-production vehicles or validations. We have a couple more “flavors” but those are all flavors of production vehicle that we work through. This is fairly state of the industry, our terminology is a little different, but every manufacturer does these iterations or flavors of vehicles that have the next phase of software.
At some point in time for example the interior parts have a certain graining to them that you do as one of the last things. You put in a little grain into the tool, but once the tool is grained and they have this nice little texture to the plastic parts it’s very hard to change the tool if you have any functional dimensional changes. Later in the Spring we’ll actually grain the parts so that they really look like production and piece the cars together.
Right now things are actually going pretty well. We have certainly a lot of issues but that’s standard for this type of project and where we are at in the program. Issues are actually a good thing. We know no one is that good to get it spot-on or if the issues don’t properly surface they somehow surface later. If you have a lot of variation in some of the parts, and you don’t see it early enough to try to control it, to get thefir finsihs and execution elements perfect.
PPVs are not saleable?
No, they’re not saleable yet.
So you will build a few hundred of those?
No we build in the two to three thousand range. We’re finalizing that number right now. A lot of that is practicing the processing of that. Ultimately their will be a line rate of many jobs per hour when we do this so you want to get the guys actually practicing in the production environment.
This entry was posted on Monday, October 12th, 2009 at 6:35 am and is filed under Engineering, Production. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.