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Old 09-30-2009, 06:49 PM   #41 (permalink)
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void

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Originally Posted by Cd View Post
Phil, in post # 27, you have a bed cap that fills in the void behind the cab. Why the switch ?
Cd,if post# 27 deals with the original aeroshell,that got destroyed by goats many moons ago.The construction was very light and couldn't stand up to the rigors of jumping hooves.Oh well! What's on the truck now ( since 2005) is "poco-loco" a Chrysler Marine sailboat hull I got from a neighbor who retired it and offered it to science.I Sawsalled it to fit the truck best I could,although she needs more sweat equity before she fits like the original cover.She does have compound curvature,is VERY strong,and since she's tasted 39-mpg HWY,with all her shortcomings,she's a keeper!

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Old 10-10-2009, 04:37 PM   #42 (permalink)
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Project Update # 8 ( SR-71/YF-12-A look out! )

Hello all,just checking in with latest report.--------- At almost 290 hours into the project the aluminum belly and recycled stamped steel wheel houses are complete now.The underside of the trailer is now as smooth as the top of a Lockheed SR-71 Blackbird except for the Howard Hughes' hated pop-rivet heads.I've gone from a surface irregularity of 75-mm ( 3-inches ) to under 1-mm.-------------- Also,the fiberglass axle fairing has been fitted although is only taped in place as I work out other details.This fairing will be "foamed on " with Great Stuff expanding foam insulation which will bond like Gorilla Glue and also weatherproof the otherwise empty- voids inside the fairing skin.------------- The leading and trailing wheel/tire fairings are designed.Three of them have full superstructures and are foamed.One has been net formed to it's aerodynamic shape and awaits a coat of polyurethane spar varnish to allow automotive body filler and fiberglass.I needed extra attachment hardware before I could proceed with 4th unit.I purchased material last night but weather too cold today to use any of it.------------------- The leaf-spring/shackle fairings are requiring the most energy.What I originally wanted to do really aggravated frontal area and interference with the wheels/tires/fairings.The wheel bearings are the only "moving" parts to speak of with the trailer and the source of most breakdowns.Since I'm going to pull the thing about 7,000 miles in December/January,I don't want to take any chances with depriving airflow to these bearings.Anyway,I've been noodling with a more Rube-Goldberg approach to these fairings which will minimize frontal area and maximize airflow.It's all tentative.------------------- I photographed the build progression of one of the rear wheel/tire fairings and Al is going to help me later,to get them posted over at the DIY Forum.I'll use "Rapid Prototyping" for that thread.Whole car bodies can be created this way and if you've contemplated some "scratch-built" mods this is one way among many to realize your designs.----------------- I will wait 'til the first five fairings are dry-fitted for next photos.--------------- My hope is to pre-test the trailer without the gap-fillers before the December departure for comparative results.-------------Also,I'm springing for a 3-inch rise receiver hitch adapter for Gilkison's Highlander,as we want to do an independent mpg test run with his vehicle pulling the trailer also.--------------- PS the final tailfin design waits on the leaf-spring fairing design,as they will give me fin area below the beltline ( ala Dr. Morelli,GM Sunraycer, and the new VW 317 mpg car) and will affect the final area of the upper fin.More soon,Phil.
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Old 10-10-2009, 07:58 PM   #43 (permalink)
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Quote:
Originally Posted by aerohead View Post
Cd,if post# 27 deals with the original aeroshell,that got destroyed by goats many moons ago.The construction was very light and couldn't stand up to the rigors of jumping hooves.Oh well! What's on the truck now ( since 2005) is "poco-loco" a Chrysler Marine sailboat hull I got from a neighbor who retired it and offered it to science.I Sawsalled it to fit the truck best I could,although she needs more sweat equity before she fits like the original cover.She does have compound curvature,is VERY strong,and since she's tasted 39-mpg HWY,with all her shortcomings,she's a keeper!
Goats.
Eating your truck . Bahhhhh. I would have loved to see that.

Why couldn't you just repair the holes ? The design was superior and would have saved you the effort of creating this new ( inferior ) design.

As it is right now, you could easily just fill in those gaps. In fact, you posted an image earlier that looked as if you were actually doing so ( there were spars in place, but they were uncovered. )
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Old 10-12-2009, 06:24 PM   #44 (permalink)
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Goats.
Eating your truck . Bahhhhh. I would have loved to see that.

Why couldn't you just repair the holes ? The design was superior and would have saved you the effort of creating this new ( inferior ) design.

As it is right now, you could easily just fill in those gaps. In fact, you posted an image earlier that looked as if you were actually doing so ( there were spars in place, but they were uncovered. )
Cd,the thing was utterly destroyed,with no hope of restoration.The goats crushed it by jumping on and off it through one night.All their weight was concentrated on the very small surface area of their rear hooves with each jump,and by morning light the shell appeared as though they had been at it all night.She'd been to 115 mph and did okay but I never would have thought she'd have to stand up to something like that.
The "new" shell is strong with compound curvature lacking in the original.In the tuft study she shows perfect flow on the passenger side which has the fairings.By December I hope to have fiberglassed all these areas and dispense with the unsightly crap that's been there since 2005.
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Old 10-17-2009, 05:42 PM   #45 (permalink)
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Project Update #8 most recent photos ( fairings )

I've roughed in the driver side of the trailer and you'll be able to see where I'm going with the fairings.
The wheel and leaf-spring fairing length are limited by the 22-degree Mair' convergence angle of the body,extending as "far" as the body behind them.
The innermost fairing is really a strake,to give me additional aerodynamic "mass" terminating at the actual tail.
All the fairings respect the SAE minimum "approach","break-over",and "departure" angles,with a terminal slope up from the rear of the tires at 10-degrees.Theoretically,I should never suffer a ground strike with these angles.
I took photos both with and without the tail to help me "think" about the fin.I need something to be able to see the trailer in the mirror.With the under-body "fin" area I need less topside.
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Old 10-31-2009, 02:28 PM   #46 (permalink)
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Project Update # 9

Just a quick heads up.
I'm at 342 man-hours into the project.Six of the fairings and the two strakes are ready for glass.
They're durable enough for testing now, but any road debris tossed up from the tires would pit them so I'll wait 'til they're glassed.
I've begun the plug for the leaf spring/shackle fairings.These must be hollow as they will encapsulate the deflecting suspension which means that a mold will have to be made from the plug and then the actual parts made from wet layups in the mold,as axle fairing was done.
Good news for me is that the mold will produce parts for both sides of the trailer.
Yesterday,I welded in the hinge support for the access door and welded up the access door frame.This area will receive foam board and fiberglass skin.
This forward access borrows from the 1934 William Hawley Bowlus' Road Chief trailer "wingless airplane" which would in 1935 begin the morphing into the Airstream "Clipper."
The front opening leaves no seams on the flanks.Awkward yes,but something I'm willing to live with.
I have a photo of the fairings and when Al gets free,will post.
With a good weeks work,the trailer could be tested independently of the gap-fillers.
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Old 10-31-2009, 05:03 PM   #47 (permalink)
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photo: fairings before glass

Here's pic of fairings with Bondo smoothed down and ready for glass.
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Old 11-11-2009, 12:49 AM   #48 (permalink)
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Aerodynamic "mass" ?

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Originally Posted by aerohead View Post
I've roughed in the driver side of the trailer and you'll be able to see where I'm going with the fairings.
The wheel and leaf-spring fairing length are limited by the 22-degree Mair' convergence angle of the body,extending as "far" as the body behind them.
The innermost fairing is really a strake,to give me additional aerodynamic "mass" terminating at the actual tail.
...
With the under-body "fin" area I need less topside.
The fairings for the wheels I get; and I see the additional lower fairings/fins but not clear on their purpose.
Not understanding what you mean by "aerodynamic "mass"".
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Old 11-11-2009, 07:57 PM   #49 (permalink)
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mass

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The fairings for the wheels I get; and I see the additional lower fairings/fins but not clear on their purpose.
Not understanding what you mean by "aerodynamic "mass"".
itsmedc,that's a good question,here's my best shot.

When viewed from the side,the trailer front has more "frontal" area ahead of the axle than behind it with the trailer's rear.
Also,because of the ever-increasing tumblehome as well as downsweep of roof, upsweep of diffuser,and sides and roof melding into each other at the very back,the drag coefficients are different between the front and rear of the trailer.
To keep the center-of -pressure behind the C.G. I need some "fin" area,to increase the aerodynamic "mass"of the trailer body the air will see for yaw control in crosswind and side gusts.
This is what Dr.Morelli came up with for directional stability with his CNR concepts developed at Pininfarina.
Hope that helps,gotta go Al
s closing.
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Old 11-21-2009, 03:41 PM   #50 (permalink)
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Project Update # 10 ( inching ahead )

The project is at 399.5 man-hours now.
* Welding is finished,the tongue is complete.
*The door has been foamed, glassed,and mounted on its piano hinge.
*I have begun fitting 3/4-inch plywood floor/deck panels.( I will be doing an EV range-extender battery-trailer simulation test in New Mexico and need a robust floor to support the pack weight ).
*The axle fairing is bonded on and has been floated out with body filler.
*Six fairings have been floated out with body filler.
*The two strakes have been floated.
*The "plug" for the spring/shackle fairings has been floated and awaits final sanding before I can create the mold from which the actual fairings will be cast.
* All the other fairings will require sanding before primer and top coats.
I need to have the other fairings and strakes bolted up before I can complete the floor,as access would otherwise be blocked.
I spent some time at Purvis Bearing Co. in Denton going over the wheel-bearing issue.I had re-packed and attempted to adjust the pre-load and just could not satisfy myself with results.
The bearing people told me that "loose" is better than "tight" and not to overdo the grease,as it will actually increase operating temps.
I played with the castle-nut position and ended up taking a composite cut-off wheel and making a 7th position for the pre-load cotter-pin location.
The washer retains some "slip"as recommended but the tire/wheel cannot wobble as much as with the standard nut pin locations.Freaky!
When I get the "bottom" on the trailer I'm going to do some shake-down runs and monitor the hubs with my infrared pyrometer to make sure I don't overheat anything.
There is much bodywork to do to arrive at a "factory" finish,but I need to jump on the gap-fillers if I'm to make my new deadline.The body of the the trailer is "there" aerodynamically,and could be tested as it is,it's just that I'd like it to look like someone else made it.
I've got a few pics and if Al gets free,will post after awhile.

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