[ExI] towed evs again

spike at rainier66.com spike at rainier66.com
Mon Oct 23 17:35:48 UTC 2023

-----Original Message-----
From: spike at rainier66.com <spike at rainier66.com> 

>...With the axles located fore and aft, as in a delivery truck, it looks to me like we have a configuration which can be guided by a Tesla (rather than "towed" in the conventional sense) and maaaaybe can be controlled well enough to gently push the Muskmobile to the Sierras and back on a single charge.  ...

Side note: this has all be a most enjoyable (if exhausting) design exercise, which illustrates design gradients, a concept which engineers learn in school.  This is a concept about how a design criterion drives another and another then another until a kind of design stability is reached, like water flowing down a slope into a pond.

We started out with the notion of a little Tesla pulling a camper, which leads to a camper with powered wheels to make it kinda self-propelled, which led to pushing the Tesla so it can go from Palo Alto to the Sierras and back without a charge, to discovering oscillating instability, which led to active controls, which led to separating the axles to dial in oscillation damping, which requires a steerable axle, which led to separating the axles further until they were located fore and aft, which now leads to allowing drive motors in the hubs themselves.  

Reasoning: the disadvantages of that configuration does not apply.  It dials in unsprung weight, which makes for a harsh ride (remember your old Blue Bird school bus?) but since no one is back there in the camper, that doesn't matter.  So... if we pay the price of a steerable axle, there is a design gradient which cascades all the way down to a camper that looks like a delivery truck with no front window, with in-hub motors, and pleeeeenty of batteries, plenty.  My best design doesn't actually push the Tesla, but it does pull itself, as it is guided by the Muskmobile.

All those batteries are not cheap (that alone will be getting up close to 6 digit numbers) and will dial in a lotta weight, however... they bring along some advantages, such as the ability to charge the rig in a standard campground.  My camper is already wired to accept 50 amps (sheesh what did they think I was going to do in there?  Run the AC, the microwave and a Hoover vacuum cleaner all that the same time?) so a prole could theoretically pull into a campground, sign up to stay a coupla days, guzzle down 300 kWh in that time span, give the campground a nice 50 dollar tip to cover the cost, everybody wins.

Alternative, take your 300 kWh glamper up to the Sierras, boondock out there where no power is available (my favorite spot has no utilities) and get all the way back to Palo Alto on a charge, assuming one doesn't get too carried away with the speed.

All those batteries weigh a lot and cost a lot, but before you trash the whole idea, consider the alternative silliness on which the numerous rich childless proles spend their money: ocean cruises, private aircraft, yachts, big house, fast car.  

Now think of it this way: Ocean cruises: kinda sorta fun, for a few days, everything to do, anything you want, but after a while, you don't really want.  It is kinda boring out there really, even if you can do anything you want, if you don't want.  OK then, scratch that.  

Big house?  Why?  Just more to dust, scratch that, and hell, we spend most of our time in front of our computers anyway, ja?  Well doncha?  Scratch that big house notion, far too silly.  

Private aircraft?  OK so... you buzz around up there for a while, and oh boy isn't this fun?  Eh... well, not really, but at least it is expensive, noisy, and you might die, so there are those redeeming qualities.  Scratch.  

Yacht?  Hmmm... also boring, once you party for a while, realize it is lonely out on the sea even if you take along a few bikini-clad friends, and sure, it shares with the plane that it is expensive and there is no quick access to medical care so you might die far from where Max and company can get you on ice, so there is the tantalizing danger aspect.  YeeeeahNo, don't think I want that, thanks.  

Fast cars?  Where can you go to turn that baby loose?  The local freeway?  That solution to your excess money problem has the double bonus of personal risk plus you might kill someone else?  

Emmmm... What else is on the menu please?  Do you have anything for those of us who are environmentally conscious?  How about... a glamper which one can guide to the Sierras with a dignified Tesla for some nice fishing and hiking, enjoying natural beauty, that kinda thing?  It is still absurdly expensive, but not so much in operational cost, just high initial cost.  You lose the danger advantage mostly, but not everyone likes putting oneself and others at risk.  I don't like risk or spending a lotta money, but I do love camping and hiking in the mountains.  That is my idea of fun.  I would probably opt for that brand of silly, as soon as I figure out some scheme to make a buttload of money.

Keith that self-propelled glamper notion isn't as silly as it first seems.  It has a limited fan base of course, but all the crazy expensive dissipations available to modern people are self-indulgent silliness of some sort.  The self-propelled glamper is perhaps as much as 30% less silly than what it first seems.  


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