Project number 2 for this month, Aero Trailer!
 

I am gettin excited about building some aero stuff!

Getting the F-150 to do patterns, prototype and testing this weekend, and already looking forward to the next product to develop :-)

I was looking at an old post and something jumped out at me, it was the image indicating the various cds of following a car and towing a trailer, the lowest portion made my jaw drop! .31 cd to .12 cd!

Any how, Ive had another idea for a while, to build a "pusher trailer" and installing an ev motor - Or 10hp diesel - Or both. (the Diesel would be on a clutch and only be used for droning down the highway right in its effeciancy "sweet spot"

And or just the Diesel and a gen head and use it as a range extender for pure EVs.

Some neat ideas I want to monkey with are:

making the tongue variable length and deploying it based on vehicle speed (over 45mph it would "tuck" in close to the car, under 45 when more clearance is needed for turns etc, it would extend 20 to 24 inches.

Figuring out a good looking, removable, and effective gap seal for the tow car to REALLY make the aero work.

Seeing if I can get the damn thing actually built in the next 2 weeks :-)

So again, I ask: Input, suggestions, ideas, criticisms?



So again, I ask the gurus what they think

Trailer looks good. That can be built pretty cheap too and can attach to many different cars

pusher
 

If you haven't read everything already on the internet for Range Extender Pusher trailers you'll want to do that.Especially Mr.Sharkey's Porsche 944 / VW RXT-P.
AC Propulsion Inc. has done a number of 'wake-rider' RXT-G trailers which you may also want to inspect as well as the all-new PRU RXT-GP Diesel pusher.
To get the lowest drag you're gonna need all-compound surfaces which require massive amounts of man-hours to fabricate ( I'm in over 800-hours on mine so far ),so I don't know about your 2-week target.
The telescopic tongue feature will require some clever engineering especially for the gap-fillers.
My gap-fillers are on the trailer itself and there is a symbiotic reinforcement feature do to this placement which really helps when striking killer pot-holes 'n such,and in 'roll.'
If you have a Scan-Gauge or such,you might cobble up a prototype trailer body and 'road-proof' it as in the JEEP Cherokee vs Prius comparison on the Stunt-Busters You-Tube clip.

Thanks for the input AeroHead!

Im somewhat familiar with the pusher trailers over the years (maybe aware is a better phrase, never drove with one etc)

I have the misfortune of having done a few car bodies from scratch, lots of cheese graters and foam, which is what may well happen with this one, BUT I have been doing a LOT of research into 3d routering and the concept of having it built in cad then "cut" in slices in wood, assembled, sanded and voila, trailer body mold (almost)

I think the articulation will actually make the gap filler easier to excecute. when its in "town mode" at lower speeds the gap filler would essencially be obsolete, but when she tightens up toward the car, less gap to fill.

I think this week I will do an unpowered "boxy" one with somewhat square sides with sanded edges to measure FE increases or deficits, then work on the power part.

Id love to hear your guess on increase on an otherwise modified prius c, and or unmodified 2004 Pontiac vibe with good gap seals? :-)

I especially liked Mr Sharkey's Rabbit-on-Rabbit range extender from back in the day. :D

http://www.mrsharkey.com/evgfx/push0.jpg

The rear Rabbit was, IIRC, a non-turbo diesel with an automatic trans that he could control shifting, ignition and fuel from the front car's driver's seat. It had some reliability and driving issues as I recall, but it was a definite view to the future. :thumbup:

If you are going to use a diesel generator why not put it on or in a trailer hitch cady?
That way you don't have an extra set of wheels, no trailer to register and pay for, no low hanging stuff to mess up under vehicle aero any more than it already is.

What is the Tow Vehicle (TV)? I can engineer you up a sliding tongue system, I think it is a great idea. Put an open Kammback "receiver" fairing on the TV and pull the trailer up into it.
Couple the mechanism to the TV's Vehicle Speed Sensor (VSS), so it will automatically move as you indicated, but progressively. Reality is you will not see more than a couple of degrees deflection above 25 MPH, so engineer for that. If you want to be sure, build a test jig and go driving and you'll see.
I'd design it so it will work automatically, but will be easy to override manually in case of a malfunction. I'd install a pair of sensor bars to let you know before you start bending things.
It combines a couple of very easy things, since the trailer can now have simpler front.
Open Kammback is also simple.
Why are all the cool projects clear across the country? :D

Because you live in a hell-hole that is the Detroit of the west? :D

You can keep the bay area. I live far out in the sticks about half way to Mt. Rainier. :P

If the trailer is an appropriate weight, the CG/tongue weight shift will be beneficial too.
Lighter tongue weights at low speeds are more maneuverable but not stable at speed. Not a problem with this concept.

todayican, your pix look nice. The devil is always in the details. How many wheels and what type of hitch for starters? Two weeks sounds fast to me...

SkyKing, I would welcome any and all ideas on the "tongue articulation System"!

KamperBob, I am thinking a single wheel, 1000lb trailer spindle, hub, wheel. Using a 145/60/15 LRR car tire.

The trailer will have a 2" od section that goes into the receiver and have an automotive U-joint (To allow the trailer to turn on 2 axis, up and down / left and right, but not side to side because of the single rear wheel.)

This 2" section will "sleeve" a 1.5" section square tube so as the trailer "pulls in" toward the tow vehicle the structure will remain sound. I know there is lots to do, but in the internet world where I have spent the last 12 years, fast is good!

I am actually between businesses, sold my share of an internet company and am looking to get something up and testing so I can get to profitability fast.

I am going to try like the dickens to get the first F-150 aero shell AND the basic trailer prototype framed out this weekend :-)

I'd go with a pair of wheels for ease of hook up and engineering. The savings in RR is not significant on a lightly loaded rig. It does present a cost savings, but it is harder to sell something that takes two people to hook up, and falls over without a kickstand. It can be loaded without being hooked up and I would definitely make something that can have utility as well.

Rinspeed just 'docked' theirs. An aero boat-tailed version would be more our speed...and minus the dubstep musik. http://www.youtube.com/watch?v=y1EKfnfoI9s

Sky King I hear ya on the 2 wheels, I want to go with one for now for a few reasons:

1) Better aero
2) Better rolling resistance.
3) (big one) I will be experimenting with the trailer "pushing" with a 10hp diesel, an ev drive system, and a combination of the 2, and using a single sprocket is SOO much easier to get right and not as "lossy" as an axle driving 2 wheels.

On the good side, I sat down with my thoughts for a minute and figured out how to make it a simple one person affair. :-)

Just put 2 kickstands (Lets call them "landing gear" form here on out SkyKing) at the same linear point (but outboard) of the single wheel so they would pivot on the same plane.

So the un coupling is kick, kick, lift. Easy Peasy :-)

I did not realize it was for propulsion primarily. My mind goes trailer = cargo as well.
Did you get my PM?

Food for thought: a motorcycle might provide useful donor parts for the project. A center stand might be adaptable to help balance it unhitched for example. I salute the project ambition. Lots of challenge factor. I really look forward to seeing your clever solutions. :D

I thought I read somewhere that single wheel trailers have a problem going faster than 45 mph with the castering wheel wanting to shimmy. Come to think of it, you couldn't power a castering wheel, so you'll have to articulate the tongue.

Fixed rear wheel and articulating tongue TC :-)

I like KamperBob's line of thought...

http://i337.photobucket.com/albums/n...e/cycletow.jpg

*Scaled Composites has a 5-axis router which is CAD-CAM linked and can render an entire fuselage from a foam billet.
*A neighbor 'cheated' with a 'scaling-pantograph' router which followed a small-scale pattern of which the pantograph scaled up to full-scale at the cutting head (reverse-tasked fiducial).
*On the Prius,you could take a look at my thread '2011 Prius to get full boat tail/faired trailer.'
On page-3 #25(permalink) is a rendering I did for my friend's Prius.There is no reason why the trailer would not cut drag in half.
*It should be the same for the Vibe/Matrix.
If I can get Jaray's,Lay's,Kamm's,and others 'templates' posted I think you'll see where I'm coming from.Most any vehicle could go to Cd 0.12 but it would be a very comprehensive project.And it would require the complicated surfaces.

pogos
 

on my 1-wheeler I have castor'd pogos kinda like the U-2 used under its wings which slip into a square tubing receiver (like old VWs and Mercedes jack sockets) on each side of the nose.

shimmy
 

I've pulled mine in excess of 80 mph and she tracks perfectly.Mine is motorcycle-based utilizing the swing-arm 'n coil over shocks.Much like Burt Munro did to haul his bike to the beach and back,using the front fork/axle as the pivoting attachment for yaw and pitch.She leans on curves too!

hitch
 

By using the trailer,we can do a complete boat tail,which can be rather 'long' if attempted as a cantilevered structure married to a hitch-mounted cargo platform.
Mine extends 11-feet beyond the trucks rear bumper.