3/9/17 Another update so soon? - well, lots is happening and this is a good place to talk about it because much (though not all) is D2 related right now. First, the trailer - the first thing was to determine whether we can achieve reasonable tongue weight (180-300 lb range). CAD says we can, but reality is the ultimate judge. So we got it to a point where a car can be loaded, and did so.
Just as a refresher, the reason we're doing this is that we want to make our cars more usable and hassle-free. If you're going to track your car, especially far from home, trailering is awesome. The freeway drone is much easier in a 'civilized' vehicle, and should anything go wrong you can still get back. Problem is, normal solutions involve buying a car trailer ($5-30K depending on how fancy you want to get) and something to pull it with ($10-60K). Then you have to find a place to store the whole rig when you're not using it, deal with maintenance and all manner of other hassles.
But our cars are light. And compact. So if you could have an enclosed trailer that you could park inside a single car garage spot and tow with your daily driver, that would make things a whole lot easier. Would also help if it didn't cost a whole lot. So this is why we're doing it. This particular trailer has a customer and the customer has very restrictive requirements. It has to be towable with a V6 RAV4 (3,500 capacity). It has to fit through a 92" wide garage door (car is 80"!). There is only 7' of vertical clearance and the car has to be loaded/unloaded by a single person while the trailer is in the garage. Available length is 214" (like a full-size sedan or SUV). And the trailer has to be able to carry a set of wheels/tires and at least two gas cans. Easy, right?
Well I'm not one to back away from a challenge and the customer has put good money down to say he's serious, so we're doing it. Initial tests are promising - the trailer is 90.3" wide overall and the car does fit on it. Clearances are tight but non-zero and as we say, clearance is clearance. There will be an electric winch with its own battery (and a circuit to recharge it from a 4-pin trailer harness). To help center the car as it's being loaded, I've come up with a 'roller pad'. When the wheels reach it, the car can be easily moved sideways if it's not dead-on. Not shown are features to prevent it from falling off, but they will be there :)
Worked pretty well while test-loading, though some details have to be worked through. The tongue weight is reasonable. Keep in mind there's no winch, battery or spare wheel set. Nor is there an enclosure yet. But we're in the ballpark, and one of the many advantages of using Torflex axles is that tongue weight increases with ball height so it's a simple (ish) adjustment. The generous departure angle gives options for rake. At least we have the means.
In other D2 news, we're moving along the composites learning curve. A few more test pieces made and a few more things learned. It's all about the process and the materials. We're getting there.
The new wing rib design has optional spar holes (we can either machine them open or leave them blocked) which facilitates the D2 front wing installation.
Yet another benefit of having machining (and other processes) inhouse - we can do what we need, when we need it. This is a big motivation for the composites stuff. We don't need it often, but when we do it has to be on our schedule and terms, not someone else's to whom we're just a low-volume customer. This is exactly why we brought machining in, and it's the reason we're still here today. Very literally wouldn't be otherwise.
Final item of the post is D2-derived, though not D2-applicable, yet. We use our GTX uprights on the D2 and recently, within a week of each other, two customers came to me looking for centerlock uprights for their existing cars that could handle a lot of power. GTX was a perfect jumping-off point and gave birth to the GTC (for 'centerlock'). Both applications are full-on race cars. One is the Enviate Hypercar, the other is a race team running an LMP style car with the latest generation of the Hartley V8 (which they have licensed and are putting into production, with the benefit of 10+ years of development). Both are high downforce, high power machines. My approach is the usual - utilize off-the-shelf stuff when appropriate, custom-make stuff when it provides an advantage. So the GTC is built around the ZR1 Corvette wheel bearings, modified for pin drive and adapted to a GTX-derived upright design.
The first parts to be made are the longest-leadtime ones, due to the need to send them out for splining, then heat treat, then plating. It is the hubs themselves, made from high strength alloy steel. Each starts as a 47 lb billet and eventually becomes a ~4 lb part. The Fiat had its work cut out carrying 8 of the billets - like two big guys in the back seat!
Figuring out how to hold this big a piece in our relatively small lathe was a challenge, as were all the thread-cutting operations (right-hand and left-hand). I'm lucky to have Tristan who can do all of that so all I have to worry about is how i'm going to drill the CV bolt holes using our relatively small mill :) The progress is neat to see.
And so it goes. Much more, soon.
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