02/13/05 With the initial design stage complete, I'm now starting on the development phase. This will include buildup and testing of the first prototype and redesign of several components (most notably the chassis, which will be carbon/aluminum in subsequent cars). Some of my experiments will work, others won't and will necessitate changes. It'll be fun :) I expect this process to take about a year, at the end of which first customer cars should be ready.
But before I dive into work on the prototype, I need to prepare the space that I have rented. It is now occupied by a rather dreary office with oppressively low ceilings, dirty walls and worn-out brown carpet. So the last couple of days I've been selectively demolishing parts of it...
When I'm done there will be two separate 'work bays', one for mechanical stuff and one for bodywork. The reason for the separation is that working with composites is a messy business, with dust and other debris flying all over the place. Keeping it away from the mechanical bits is a good idea.
Of course while working on the demolition I couldn't resist doing something with the car so I put the wheels under the bodywork to see how it would look. Click each picture for a larger version....
02/17/05 Got the suspension arm gussets in. Somebody had commented that getting those laser-cut and CNC bent was 'overkill' - not so. It's just a modern reality. The parts ended up costing me $6 apiece in quantity 32. Made the old-fashioned way they would have been $14-20 apiece. Why 32 you may ask? Because many of the parts such as suspension bits I'm getting made for two cars, the initial prototype and chassis #002 which I already have a deposit for :) Anyway, sheetmetal in general seems to be a bit of a mystery to most (I know it was to me until I started doing it) but it's actually a pretty effective way to get things done. If you have the right vendor that is - Davis Tool in this case. They're excellent for sheetmetal. But sadly they are completely uncompetitive for the kind of machining I need, not even close to being in the ballpark - despite (or maybe because of) state-of-the art equipment. Just goes to show that everyone has their specialty...
Now I need to get these welded on and then the arms should be ready for powdercoat.
In the meantime, the frame is done in California and off to powdercoaters there. In a fit of blatant plagiarism (or sincerest flattery) I've decided to borrow the color scheme from Kurt of Kimini fame and go with grey chassis, black panels and red suspension arms. What can I say...
The frame should be here in about 2-3 weeks. Cool.
02/19/05 A few things are happening. I've been working on the space I rented and the demolition is almost done. There are a few more days' worth of work but before long I should be able to shift the focus back to the car. In the meantime, I couldn't resist a gratuitous pic (click on it for hi-res 1600x1200 version or right-click and 'save as')..
The suspension arm reinforcements should be done in a couple of days, then it's off to powdercoaters for those. More and more things are coming together. Cool.
Also, someone had pointed out a potentially useful version of carbon material from SP Systems (thanks Mike). It could reduce the labor cost in bodywork and improve the surface finish significantly. I've talked to Composites Unlimited about it and they're looking into getting some samples for tests. As it is, the current body will take quite a bit of prep to get decent surface finish. Apparently that's just the nature of prepreg technology that I used. Best surface finish comes from gelcoat and wet layup but the weight penalty would be significant, about 50 lbs. There are also surfacing films and such that could be experimented with in prepreg and there is the option of going with E-glass and 1/8" core which then would allow the use of primer. Lots of things to consider.
With an eye towards production I'm having a lot of discussions with current and potential vendors to see how I can reduce costs, reduce weight and improve quality. These things don't have to be mutually exlusive (to a point, of course) - just a matter of careful design choices. Now that I have a baseline I can refine things from here. It's looking pretty exciting actually. Fun stuff :)
03/02/05 The frame is back from powdercoaters in California and is awaiting shipment to Portland.
I now need to design all the individual aluminum panels and have those lasered and CNC'd. I'll receive them already pilot-drilled and powdercoated so all I'll need to do is drill the tubes and rivet the panels in place. A lot of various brackets also need to be made so I'll have them done at the same time. They'll be attached with rivnuts. Another design item that remains are the front and rear crush structures that will also carry the radiators and serve as bodywork attachment points. I have a good idea of what needs to be done but I want to stare at all the parts sitting together to see what might be the best way to do that.
In the meantime, the frame is boxed up and ready to ship... Should be here in a week or so. Thanks again to Phil Burke for the excellent work and taking the effort to do it right.
03/10/05 Well, after much labor the shop space is now ready to use - or close enough for the moment. The frame arrived yesterday, the powdercoated suspension arms should be ready in a day or two, a lot of the bolts are here, rodends should show up today ($1,500 worth of them!), etc. Assembly is about ready to start. I'll need to migrate my whole pile of parts from the garage to the shop which will happen over the next week. Then I'll even be able to use the lift again.
Of course a lot of design and fabrication remains - all the sheetmetal panels for the frame, front and rear crush structures, body and floor mounts, interior, steerig column (this just needs to be made), shifter, gas pedal, some internal composite panels and such. Then, for production I need to design the carbon tub, the belt drive system, new diffs and probably a whole host of other items. I've got my work cut out for me! But progress is visible, tangible and exciting. I'm looking forward to getting it all done.
03/11/05 Picked up the suspension arms from powdercoaters - they look great. Now I need to press in bushings, install bearings and rodends, then they can be assembled to the frame (although I'll wait for that last step until I have the alum panels riveted). I also installed wheel bearings in uprights by heating the latter in a toaster oven to 350F - the bearings slipped right in. Gotta love CAD and CNC machining :) Speaking of which, I test-fit one of the shocks, the one that could potentially have a clearance problem to the rear rollbar. Lo and behold, it has 0.2" clearance, just like SolidWorks says. Neat. Steering rack goes right in too. Next were the Timesert inserts in the uprights and the diff mount brackets and now those are in.
I'll be able to do some assembly before fitting the alum panels but I shouldn't get too carried away with that. What I really should do is sit down and design all the sheetmetal then send it off for fab. There's a lot to be done there, from the backbone and cockpit skins to front and rear crush structures to various brackets such as gas pedal mount, instrument cluster mount, etc....
Lots of little fiddly bits still need to be designed and fabbed, too. I have a lot of them modeled in my in-head simulator but I still have to output them into SolidWorks, then out to vendors. This is fun :)