11/06/09 Having stared at the floor on the car for a while it became obvious that I need a second molded piece to it, a 'top'. Sometimes seeing things in the flesh and visualizing various solutions is what it takes. Now I need to design it and get it and made. Have to figure out production solution for radiators first though, the current ones are too large.
In the meantime we've modified the tailpipe to properly fit the car and the bodywork. One step further along towards having this beastie fully track-ready.
12/02/09 The initial trimming of the bodywork is done although we still have a bunch of tweaks to do. Now I can go about devising a mounting method for it and the floor. Overall the car is starting to look fairly complete.
We've had quite a bit of interest in the car lately. I'm not ready to take orders yet since some things need to be finalized before I know exact costs but it's close. Those wishing to be put on the list should e-mail me with contact info (at this time there is no deposit needed and no obligation).
12/7/09 Before further testing can take place a few things need to be addressed. Top of the list are chain guides, bodywork and floor mounts. There is quite a list of smaller tweaks too - for example this first prototype was built to use the existing dp1 prototype exhaust. Convenient, yes. But it causes the engine to sit 1" too high (to clear a frame tube) which in turn makes the intake touch the bodywork. Yes I could make a lower profile intake but making a more production-like modification, even though more difficult, is the better way to go. Drops the CG a bit too. The other thing is plumbing, for serviceability I've decided to reroute it completely. So the car had to come apart, at least part way.
It only took Tristan about an hour to pull the engine, disconnect all the plumbing and wiring, drain fluids and pull out the seat. The goal is to make the car easy to work on and we're definitely taking notes while doing all this. Improved access to hoses and such will make servicing simpler.
The general plan is to get the prototype more production-like, test it on a dyno up to 160 mph or so to make sure the chains stay on, then take it down to warmer climes for actual track tests. Once it's proven and any issues we discover are solved, it will come apart once again to be powdercoated, painted and generally made complete. A second car will be built around that timeframe as well. Then come springtime the goal is to deliver the first customer cars. Response has been very encouraging so far. Ball is in my court.
12/10/09 A minor change has been a swap from wheel bolts to studs - makes it much easier to mount the wheels because there's no need to try and align the wheel, the rotor hat and the hub while threading the bolts in.
The new engine mounts have been made, tweaked and installed. To clear the new engine location a couple tubes had to be cut out and then an external triangle bolted on. In production the frame will be wide enough and the exhaust routed so that everything just fits. But for now this is fine for the prototype.
Coming up with better radiator mounts and rerouting the plumbing is next.
12/18/09 The plumbing is moving forward. For the first attempt, in a rush to get the car done, we just kind of threw it together and it looked the part. I also didn't like that the coolant lines were running under the drivers's feet. The fact that the radiators were zip tied to the frame wasn't particularly elegant either. The goals for the production version are to run all fluids away from the driver, provide accessibility for service and inspection, use aluminum tube as much as possible, properly mount the radiators, etc.
We've made good progress towards all of that. After doing the dp1 exhaust Tristan has no problems fabricating shapes from mandrel bends. The result looks very clean.
Oil is pretty much done, water is next. The specific routing of the lines is particular to this prototype chassis and will be different for the production frames (as will the radiators themselves) but this is a good test of the general layout strategy.
12/28/09 As the year draws to a close we still have lots to get done. Progress is being made though - the prototype's plumbing is now figured out and production version is being developed based on that, the chain guard design is in its 6th iteration (getting there), the myriad of other details are getting taken care of, etc.
One of the challenges is keeping documentation in sync with the design progress. With just three people in the effort (M, Tristan and myself) it is easier to manage than in larger groups but still attention needs to be paid to details. Of course outside vendors are critical and coordinating with them requires being on top of it all, lest wrong parts be ordered at the wrong time (or else not ordered). Just following up takes constant effort and vigilance - when production finally takes off one of the first hires will be an expediter/project manager. Right now most everything we do is with an eye towards duplicating it consistently and accurately (while not slowing down the trial-and-error prototyping, and keeping track of which is which). I've been in larger companies that accomplished far less with much more. Still, if we are to have customer cars come springtime we better stay on it. No rest for the wicked.
01/04/10 While Tristan is fabricating the chain guides I've been working on some of the bodywork - in particular the 'cockpit liner', or what is essentially an all-enclosing seat.
The liner will be made in two halves and then installed in the frame one half at a time. The side facing the engine will have fire-resistant shielding and act as a firewall. An EPS 'bead seat' will be used to fit the driver to the seat, as is common in formula cars.
The bulges on the sides provide elbow room for the driver to do his/her own belts, a simple thing that makes a big difference in being able to run the car without having a crew. In terms of safety, the initial impact protection is provided by the crush zones all around the car (there will be front and rear bolt-on structures for that, as well as an optional driver-side one). The chromoly frame maintains the survival cell integrity and the cockpit liner, along with the 'bead seat', constrains the driver's body and limbs and provides cushioning and intrusion resistance.
Some work still remains on the details of the design but it's pretty much there. Floor and body reinforcements are next, then all the molds need to get ordered and parts made.
01/07/10 The detail design of the cockpit liner is pretty much done, I've sent the files off to Contactscale for a quote.
I've gotten a surprising amount of comments on this thing, people seem to like it. We'll see how it works out in actual use.
Got a pretty good quote on doing laser-cut frame tubes so that is a promising direction. Still a number of things to sort out though, not the least of which is a streamlined way to convert SolidWorks 3D files to something usable by the laser. Right now I have to convert every tube to a sheetmetal part, flatten it and export a 2D DXF. The vendor already has the software for converting 3D files, they just don't have it up and running yet. It's going to be yet another learning curve. Unless I find a vendor who already has it figured out.
Other things in the works - there have been lots of requests for suspension parts for people's own projects and so yes, all the dp1/4/2 pieces will in fact be available for purchase soon. Uprights, brakes, pieces to fabricate suspension arms, bellcranks, etc. Also additional car models are being discussed based on the dp4. Yes, I know, I need to get at least one car ready and available for sale :) But have to think ahead too.
01/09/10 The prototype chain guards are pretty much done. What's still missing is the guide portion - UHMW channel that keeps the chain reasonably constrained. It's back-ordered for another week or so. The need for guides is demonstrated by the fact that in the picture below, there are scuff marks on the aluminum both above and below the chain - it moves around quite a bit.
I'm also working on roller-based constraints to be placed strategically.
In production this will all most likely be CNC-bent sheetmetal and look somewhat different but for now it's fabricated from aluminum angle. Should be good enough for the prototype.