"Toybox" trailer project

[Guest]

The original frame was design for it's intented load.

A lot of old airstream trailer have "[@!#!$] sag" because the owners decided to mount a motor cycle to the rear bumper, or haul peaches to market in it.

The trailer design like an aircraft, has a weight to strength ratio for fuel efficent usage.

Barry's super trailer, has the ability to go in to a combat area, with a high rate of survibility. Plus it's going to handle and Brake like a German Sedan.

These option have a draw back due to the added weight, and added fuel to move them.

The disc brakes seams to be over killer, because the trailer brakes will be "Amped" down not useing the maxium braking power. Ususally, you want the trailer to slow not lock up. so, you are carring all that weight on six wheels for extra braking ability, never to be used.

[DizzyDale]

Dear Barry,Thanks for the explanation,makes sense but it sure seems like you coulda used some thinner wall tubing.diz

[Barry Wolk]

To be honest, I simply copied what works on other trailers. You should have seen me crawling under trailers at the various Concours we attended. I saw I-beams, rectangular tubing and other configurations.

I had an engineer do the load calculations and 1/4" wall tubing was necessary to attain "structural" status for a platform that is 30 feet long. The overall length is 36 feet so "Brooklyn Bridge" strength is necessary.

This is the original frame.

[Barry Wolk]

I posted this on another site.

Tow vehicle? Hmmmm. I really wanted to use my '77 Town Car beefed up for full-pull but my retired Secret Service buddy said "Don't do it", so I'm not. He knows Lincoln products from all angles as Presidential limousines were his responsibility.

I don't think that I'll need as large a tow vehicle as some people think. There are many offsetting factors.

DRAG

The Spartanette style trailer was the "Cadillac" of travel trailers and was often towed cross-country behind 1/2-ton pickups and everyday Ford, Chrysler and GM products.

It was well known for its towability up until there was an aluminum shortage. The trailer packed on 2000 lbs of steel in roof panels and trim on top of the base weight of 5200 lbs shortly after mine was built.

The lightweight body was a product of the Spartan Aircraft Company and was designed by aeronautic engineers and was wind tunnel tested. The body has the cross-section of an airplane wing and a full belly pan making it much more slippery in the airstream.

I've seen box type fuselage very similar to the Royal Spartanette on planes still in use by commuter airlines. The planes look like they stuck a motor, wings and a tail on my trailer and made it fly.

ROLLING RESISTANCE

A low CD coupled with trailer-specific tires inflated to 110 lbs of pressure make for a nice roller. What makes this trailer even more movement friendly is the Dexter Axle Nev-R-Lube bearing system. It is unusual in that the bearings are basically back-to-back instead of being spread out on a spindle, facing each other, as is typical on most trailers. The bearings are finely ground packages that are preset at the factory in a clean-room environment and permanently lubricated and water tight. The package is secured into the hub on a very short spindle. This package offers the lowest rolling resistance of any commercially available trailer axle.

There is just one caveat. You must use wheels with a 0" setback so that the tire is exactly centered on the bearing pack virtually eliminating side friction. The tires tend to act as gyroscopes, enhancing the ride.

110 pounds of tire pressure would normally produce a rough ride but the other piece of the puzzle has that covered. The axles are fitted with Firestone air bags of the size used on semis. The air bags are coupled with a ride-height valves on each of three axles. Putting more pressure in the center and rear air bags allows me to add tongue weight and the opposite adjustment fine tunes my exact desired tongue weight, even to a negative tongue weight to remove the trailer from the hitch.

I haven't actually weighed the trailer but I think it weighs about 6500 lbs. I can roll it around the shop with one hand. This is all done without a tongue dolly. In fact there isn't one as the trailer rides level at all times. The on-board battery bank and 12-volt compressor keeps 5 gallons of compressed air at the ready for the suspension. I regulate the air pressure and dial it up to 80 pounds to bring the trailer level with absolutely no front support fore of the front axle. I have jack lifts up front but those are only for stabilizing and lifting.

BRAKES

I thought it very important to have good brakes as I am carrying precious cargo, ME! I wanted the trailer to have the ability to stop both the trailer and tow vehicle and have the capability of stopping well, on it's own. With today's break-away requirement the technology became available to stop a runaway trailer on its own.

This was very important to me as I once lost trailer carrying a very heavy wolmanized light pole I had constructed. As I exited the freeway on a cloverleaf exit the trailer came loose and passed me on the left. As dumb luck would have it the load shifted on the first big bump and leveled out the load so the nose of the trailer stayed slightly upward and the soft soil safely brought it to a stop. Hooked it back up and went on our way. I don't think I'd be so lucky again.

24,000 lbs of disc brakes may seem like overkill to some but I believe that properly modulated, you can never have too much braking power. Disc brakes have a huge advantage over drum in stopping the trailer in a straight line. Disk brakes never need adjustment while a frequent precise brake adjustment would be necessary with drum brakes. Precision adjustment would be necessary as there would be no tow vehicle to keep the trailer going straight if the adjustment caused one side to grab more on one side than the other. You would have a much better chance of keeping the trailer straight with disc brakes as the pad are always at the optimum distance from the rotor.

IMHO, Low wind resistance + low rolling resistance + brake overkill = Little need for overkill tow vehicle.

But, what the hell, I'll probably overkill that, too.

[Guest]

My guess, is that your trailer brakes will lock up every time you brake unless you set your controller to zero amps.

You might even disconnect four wheels, you have to tell me if I was right. (empty or not)

Sway in the breeze, all trailer do it, reguardless of weight. the rig passing you at 75mph grabs the back and pulls the front.

Tracking, with three sets of wheels four will be hoping around every corner turned.

You need the Weight to horse power ratio:

The rated weight of your trailer + the weight of the car divide by the car rated horse power.

So,

my trailer: (3800 lbs.+5,500 lbs.)/325hp = 28.6 lbs per hp.

20 lbs/hp to 30 lbs/hp . = hot rod.

30 lbs/hp to 40 lbs/hp = normal performance.

50 lbs/hp to 60 lbs/hp = high end over load. Danager on wet roads.

This is all out of my 1964 Airstream manual.

The hoot is these cars pulled them in the 50's.

This web link will help you out:

http://www.vintageairstream.com/FAQ/FAQ_index.html

[Barry Wolk]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I'm no trailer expert</div></div>

Please bother someone else. I'm asking nicely.

[Guest]

Barry,

I lied.......

"a teacher will be provide when the mind is open."

I would like to see the unit in action, were are you located? ,Farmington Hills MI is to far away to drop by, but the tincans are going to rally in your state:

NINTH ANNUAL GATHERING ? May 18-21, 2006 - Nifty Fifties (1950-1959) Camp Dearborn in Milford Michigan

FEATURED TRAILERS (All makes and models) Cars from the 50?s will be on display, also.

Registration ($130) if submitted by May 1 - Late registration will be $155.00) includes each member?s annual TCT dues, three nights camping (electric only), dinner, morning coffee and continental breakfast, rally plaque, window sign, and much more. Water & Electric sites or Full Hook-up sites are available for an additional charge. Contact Forrest at f23bone@earthlink.net We have reserved the entire park. There are 65 Electric Only

sites available; 54 Water and Electric sites; and 42 Full Hookup sites.

Registration form:

We have other topics like converts, and inverters, to cover when you get to that point.

[Barry Wolk]

So now you're a liar and a pest. Go away!

I'm sure you know more than Dexter's engineers. Give me a break.

[Guest]

Say what you want about me, but leave "Checkers" alone.

[Barry Wolk]

Goodyear's got it all wrong too? The RST tire is trailer specific. It is designed to be used in multiple axle configurations. Its qualifications are an operating pressure of 110 lbs leaving very little contact patch. The tires have virtually no pattern other than grooves, like an airplane tire. The rest of the tire surface is smooth. They don't need turning traction as the tires are not steered. The tire is designed to lose its lateral grip in turns. No grip, no tire hop. As you can see, the outer edge is solid rubber for slip.

I don't understand your rant about the brakes. Your trailer is 3800 lbs and mine is 11,000 lbs.

Maybe I could tolerate you if you asked questions instead of making statements for me to refute. I'd gladly answer your questions to the best of my knowledge. Can we make this more of a discussion? I can be convinced with a well laid out arguement rather than an attack on my decision making progress.

BTW, you missed a spot.

[Guest]

Barry,

I seen from your other web pages, that you come from the automotive holyland, from your photo you are bigger then me, and you have better techincal and mechincal skill... so how do I get my airstream into your shop?

I really don't know much about pulling that kind of weights, and only pass on the trailer people web sights as a point of interest. I think that crowd would like to see the trailer more then the car.

the comments are "yuck-yucks", nothing more.

I will be intrested in how the brake control handles the load.

My last post on the subject.

[Barry Wolk]

That is a sweet setup. Beautiful combination. Have you ever stabbed the front of the trailer with those fins? I'd love to have a cool tow vehicle but I'll probably end up with something new. Damn.

Now, imagine putting your car inside your trailer. I'm sure the Caddy is comparable in size, if not bigger. The Mark II is 5300 lbs, 18 ft 2 1/2 in long and 6 ft 5 1/2" wide and 4'8" tall.

I'll be testing the systems after the salt is washed off our roads. I'll report my findings. Your "question" about my brakes made me think of a solution if there is a problem. Should 1600 lbs of pressure be too much a simple pressure regulator on the brake actuator output would allow me to fine tune the brakes.

As far as my skills go, I count myself part of the split-knuckle club. I painted my shop floor the color of dried blood, on purpose. I don't claim to be master of all trades so I post this type of thread to have hundreds of eyes looking at the same problem at the same time. I appreciate everyone's input.

Yes, I am a big person. Please don't hold that against me. Being 6'5" is such a challenge. Try and find a 38" sleeve on a dress shirt. Size 14 shoes aren't too hard to find but finding a vehicle with headroom has always been a challenge. That's probably why I like Continental convertibles.

[Guest South_paw]

Hi Barry, I was looking at the sketch drawing of the trailer and the car. It looks as the car will sit mostly behind the axles. Your elaborate suspension will allow you to "level off" but do you think there will be enough suspension left to properly handle whatever the road throws at you? I can't help thinking that there will be a great deal of negative tongue weight while driving over bumps and uneven surfaces(kinda like a fat kid on one end of a see saw).

[Barry Wolk]

Actually, the drawing is just a bit off. The garage space increased to about 22 feet so I have room to make it a balanced payload simply by where I put the 18' 2 1/2" car in the 22 foot space. The object is to balance the load with no air in the suspension. That way, if I loose air pressure in the air bags the torsion suspension (that's the flex part of the Airflex system) takes over and still gives me a bumpy, but level ride. I may not have made it clear that the primary suspension is self supporting.

I don't know if you have ever seen a torque-flex system. They use two steel tubes. The smaller one is small enough to fit into the larger square on a 45° angle. The remaining triangular spaces are filled with rubber. The outer square is fixed and the inner attaches to the axle spindle. Any movement of the inner square compresses rubber and deflects motion.

The air bags allow me to give a very soft ride to the cargo. They also allow me to weight shift, fore or aft, to attain a tongue weight ideal for the tow vehicle. Each axle can be the fulcrum in the "teeter-totter" depending on which vehicle I have inside.

I've talked to several drivers that use this system and it's reported to be as smooth as glass. I'll know soon.

[Shop Rat]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> Being 6'5" is such a challenge. Try and find a 38" sleeve on a dress shirt. Size 14 shoes aren't too hard to find...</div></div>

Barry, My seventeen-year-old grandson Kit is not far behind you. 6'3" and still growing. He's in size 14 shoes right now. From the time he understood what height meant he said he wanted to be 6' 4". I think he is going to make it.

[Barry Wolk]

Your grandson is lucky that his growth spurt is happening at this stage in his life. Mine happened much earlier. I was 5'8" at 13 and 6'1" six months later. I pretty much stopped growing at 16. I think I cried for six months as I could feel my legs growing. What a painful experience. My father is 6'6" so at least I knew what I was in for.

Tell your grandson that being tall is one of the best assets he has. Couple that with self-assuredness and he will go a long way in life. It may not be fair but tall people have better job opportunities and are inherently listened to. Being tall as an awkward teenager is tough because every move you make is scrutinized by other teens and teenage torture makes Abu Grahbi pale by comparison.

Someone told me I look normal size next to the Mark II. My wife said, "No, you don't" You be the judge.

[Barry Wolk]

Update 2-12-2006

I wanted to complete the clearance and marker lights so that I could finish the wiring within the trailer in preparation for spray foam installation. I ended up polishing almost the whole side and discovered the only holes in this 55 year-old beauty. It looks like there must have been an awning bracket installed here at one time. No amount of polishing made the holes go away. The hole are down near the bottom and were simply too big to install fake rivets.

I backed the holes up with metal duct tape after cleaning away the tar in the area.

I used Lab Metal as a filler. The sample I saw looked just like aluminum, and it does, until you hit it with a buffer.

The aluminum oxide seems to embed itself in the pores of the Lab Metal and turn it a dull gray.

Did a bunch of mock-ups on the spacing of the clearance lights and settled on 8" spacing.

The marker lights make attactive clearance lights too. There are 20 of these in amber and red.

The curvature of the Indian Motorcycle replica fender light didn't fit the curvature of the trailer exactly so I fabricated a spacer out of black acrylic and heat bent it to fill the space between the trailer and the light base.

It's hard to tell that it's even there.

Front lighting just about complete.

Carpenter showed up for a few hours today. Took apart everything I did at the rear opening and started over. Said I used three times as many screws as necessary and no glue.

I explained my logic as not wanting to make anything permanent as I've had to take things apart so many times that I couldn't bring myself to gluing anything permanently. I am allowing him to glue his work together.

[Barry Wolk]

I was asked to start a new thread as opening the first one was becoming cumbersome even with DSL due to all the pictures.

"Toybox" trailer project (2)

I have been encouraged in PM and in this thread to continue posting my progress reports as they are apparently generating some interest.

I want to encourage an open dialogue so that I can receive constructive criticism and answer anyone's questions. A lot of details are starting to come together in anticipation of a test flight , um, test tow, sometime in the spring.

Brakes are done, lighting's done, electrical's done, polishing is ongoing and lounge interior is imminent.

Next step is ramps and insulation. The lift mechanism jury is still out.