Welcome to Montana ... Please!

[jim_manley]

Howdy Everyone,

Me: "Hi, I'm Jim and I'm a TearDropaholic ... "

Fellow and Fellowette TDaholics: "Hi, Jim!"

And so it begins ... yet-another "hobby" that is already a long-seated obsession going back quite a while, that I'm finally forced to act upon by that most motivating factor (well, short of a hanging in the morning), and that's economics. I finally have an opportunity to attend AirVenture Oshkosh, Wisconsin, the last week of July, where 12,000+ aircraft and 600,000+ aviation nuts are gathered each year to ogle and salivate over the past, present, and future of aviation. I can't afford to prep my self-built aircraft to fly there this year due to the lousy pay for pre-tenured teachers, so I will have to camp at the venue (a hotel would be even more expensive than prepping and flying my aircraft and I'd have to drive at least an hour each way for a week, plus pay parking). I'll be driving from just East of Glacier National Park in Northwest Montana to Oshkosh, via Tennessee and Ohio, and then back to Montana

So, Plan A is to just sleep in the back of my Grand Caravan ... and that would actually be more roomy than most TDs, but what fun is that? It also turns out that I need to pick up items left in storage near Nashville where I worked last year and it will need to go in a trailer if I'm going to sleep in the van. Well, if I'm going to go through the trouble of hauling a small trailer full of household goods that far (including lots of computer equipment for computing educational events I host evenings and weekends), I might as well just stow the goods in the van and enjoy the TD life! OK, so, you may have looked at the calendar and said to yourself, "Self, there's only a bit over four weeks between now and the start of AirVenture the last week of July - how in the world can anyone build a TD to any level of completion in that amount of time?"

I have a few aces up my sleeve - first, I'm a teacher, so I'm off for the Summer, so I have some time - not a lot, but more than none. Second, I've built three aircraft (a seaplane, a helicopter, and an autogyro) that I fly. Third, I've built an 8 x 8 x 24 foot (H x W x L) trailer based on Northern Tool axles and Harbor Freight frame parts and wheels, and it's survived cross-country trips quite nicely. Fourth, I'm an engineer ... OK, so three out of four ain't bad, right? Fortunately, I'm an engineer who designs and builds robots for fun (as well as profit, occasionally), and I can do pretty much any assembly and repair work on aircraft and vehicle power plants and frames/bodies. I'm also a computing geek with about 45 years of experience (including a couple of decades in Silicon Valley), so wiring a trailer for lighting, power, sound, and networking is something I can do in my sleep (and given some of my work done under extreme schedule pressure, it can look like it! ).

Now, despite all of that, I'm one of those people who's smart enough to still be learning (and yes, crazy) after all these years. I could probably bang out a basic TD trailer without even making a sketch by starting with a 1,195 or 1,720 pound rated HF folding trailer kit (they're on sale for $40 off at the moment). However, it would certainly require fixes and rework if I didn't look at what others have done here and discuss some finer points. The first issue that I'd spend a lot of time on is making sure that the giant gash in the roof called the hinge is made absolutely leak-proof both at highway speeds and in a downpour at a campsite. I'm guessing that something like a vinyl strip would work that has a T-shaped cross-section of at least an inch of width in each of the flanges across the top of the T as well as the vertical stem. The stem would be placed along the back of the hinge with sealant and fasteners into the cross frame part that supports the forward flange of the hinge

Being an aircraft builder and sailboat racer, I'm a big fan of monocoque design and smooth curves that minimize aerodynamic drag while maximizing internal volume and structural strength. Hence my deep interest in building a TD trailer that will also keep the load down as much as possible on my vehicle (it has about 96,000 miles on its 11 year-old 3.8 liter engine and automatic transmission). I have used thin fiber-reinforced plastic (FRP) sheets available at Home Depot that are meant for bathroom and kitchen backsplashes and walls for exterior surfaces on my 8 x 8 x 24 foot trailer because they are very flexible, strong, light, and waterproof. I think they would make an outstanding outer surface on a TDT as they would require no maintenance and should clean up with just hosing off, as they're optimized to repel dirt, soap scum, hard water mineral deposits, etc. These sheets would be used as the outer layer of a foam-core sandwich (another favorite used extensively in self-built aircraft), and might also be used on the interior surfaces of foam panels in kitchen and bath areas

As noted in the photo in my siggy below, the creme de la creme design I'd love to mimic is the Alto commercially-built TDT, including the full-roof pop-up section that is hinged at the leading edge of the shell. The latter is important because I'm 6'3" and becoming a curmudgeon about small things like putting on socks and other tasks that require traveling through an airline hub to reach my most remote extremities. As you may have heard, Montana's Summers last only days some years - they're still plowing snow off the famed Going to the Sun Road through Glacier National Park here and have well over a dozen miles left to clear of avalanche debris, aka upslope forests that didn't stay there during this past Winter's heavier-than-normal snows. My foam panels may be at least two inches thick, which results in at least an R-10 insulating factor. I may not use permanent adhesives to hold the inner surfaces on the panels until I'm sure how many foam layers will be needed on various internal surfaces. Those in the bedding/seating area will also likely have some sort of fireproof padded fabric to eliminate appendage bumps against hard surfaces, as well as increase insulation values there

I'll obviously be building this TDT from the outside, in, and I'll likely not get all of the interior details completed before the July trip to Oshkosh. That will mostly be things like storage, but that can be ameliorated by using plastic bins and soft-side clothing and equipment bags. Lighting will likely be low-voltage, so I can temporarily route wiring with minimal protection, keeping it as high in the TDT as possible to keep it from being snagged by my size 13 clodhoppers and items moved around inside the TDT. If there is a need for 120VAC, it will likely initially be routed temporarily via heavy-gauge extension cords also routed up well off the floor. Internet access will be via wireless connections, so that will reduce the total amount of wiring needed

One of the challenges here is that the closest Home Depot, Lowe's, Harbor Freight, Tractor Supply Company, West Marine, Walmart, etc., are at least 100 miles away, and they often don't have every product in stock that I'm used to being able to pick up in such stores in metropolitan areas the rest of my entire life. I have to be very disciplined about typing up shopping lists when going to look for things only available in brick-and-mortar stores, after using free shipping wherever possible from on-line and click-and-mortar retail stores. Despite improving abilities to see inventory in stores such as Walmart, where everything has been wired for decades, most stores don't have accurate inventory tracking, especially when stocked quantities are small. There's nothing worse than getting home from a shopping excursion with a pile of hardware and tools, only to find that I'd missed picking up a critical part needed to complete a fabrication or assembly step that's in the critical path to completion on schedule. Having to go get something I missed means tacking at least $20 for gas on top of the cost of a bolt, nut, or washer

So, that's my insane "plan", most of which currently resides on the inner side of the posterior of my jeans. We'll see whether I can make something decent in the compressed timeline I'm pursuing. The first thing I need to find soon is a HF frame - I'm already going to be in a city with a HF store next week, but they don't currently show any of the trailers I'm considering in stock. They did just get a truckload delivered from the warehouse Thursday night, so we'll see if they received what I'm looking for after it's sorted by Friday morning Otherwise, I may have to drive as much as six hours ... each way ... to get to an alternative store that does have suitable trailer parts in stock

I'm pretty bad at taking photos but I'll try to document the progress I make, especially the more unusual steps unique to an Alto style build, which is a variation on a Kampmaster/Wild Goose design. More to Come, So Stay Tuned, as they used to say on the late night talk shows ...

All the Best,
Jim

P.S.: I tend to wax eloquently ... or at least verbosely ... and nounosely ... and adjectivosely ... those with ADD need to beware of ... squirrels!!!

[tony.latham]

That's quite the introduction.

The first issue that I'd spend a lot of time on is making sure that the giant gash in the roof called the hinge is made absolutely leak-proof both at highway speeds and in a downpour at a campsite.

Not a drop of a leak with my hurricane hinge. Properly installed, they work great and stay dry. Now that Grant's retired, I'd probably get one from Vintage.

I live three hours from the nearest Home-Depot-like store. (The same ones you do BTW). What I've found with my three builds is that hardware needed for a teardrop is somewhat specialized and it's not always found in a box store. I relied on Amazon for stainless screws and 12V electrical stuff. Cheap and fast with Prime. Building a teardrop is kinda like shooting ducks. You've got to lead it. Get the stuff before you need it.

I buy most of my trim in Victor, Montana: http://teardropparts.com/index.html You can buzz down there (but make an appointment) and pick it up.

Good luck (with this quick build) and enjoy your EAA adventure. Amazing event.

Tony

[jim_manley]

That's quite the introduction.
Not a drop of a leak with my hurricane hinge. Properly installed, they work great and stay dry. Now that Grant's retired, I'd probably get one from Vintage.

I live three hours from the nearest Home-Depot-like store. (The same ones you do BTW). What I've found with my three builds is that hardware needed for a teardrop is somewhat specialized and it's not always found in a box store. I relied on Amazon for stainless screws and 12V electrical stuff. Cheap and fast with Prime. Building a teardrop is kinda like shooting ducks. You've got to lead it. Get the stuff before you need it.

I buy most of my trim in Victor, Montana: http://teardropparts.com/index.html You can buzz down there (but make an appointment) and pick it up.

Good luck (with this quick build) and enjoy your EAA adventure. Amazing event.

Tony

Hey Tony!

Great to hear from another denizen on The Edge of Forever - like Sarah Palin, I can't actually see Russia from here, it just seems like it. I can't complain too much though, having a National Park for my back yard (well, across a dirt street, US-12, and the BNSF Hi-Line double mainline). I spent six months that seemed like a lifetime at the Navy nuclear prototype facility at the National Energy Lab in Atomic City, where we had to be bused in from Pocatello or Idaho Falls for 12-hour shifts. It was frustrating being so close to Sun Valley, but we didn't get any time off beyond the 12-hour shift downtimes - we had a Cold War to win and there was no time to waste. It's funny watching the Russians pretend that they're still a superpower when their economy is smaller than Italy's, now - the aircraft they're flying off Alaska and ships they're deploying off the coast of Syria are probably the only ones left that can actually fly or get under way.

Thanks for the tip about the hinge and I did notice that Teardrop Parts was in MT, but I didn't realize it was in Victor. I may have reasons to visit Corvallis, which is less than 10 miles South of VIctor, so that's a nice coincidence. Yeah, it's no surprise that TDT parts aren't always available via The Usual Suspects - like self-built aviation parts, you can try to chintz and make do with something generic, but there are just some situations where the right part/tool makes life bearable, let alone enjoyable, when it comes to fabrication and assembly. Sure, you can build your own pitot tube and airspeed indicator, but do you really want to bet your life that you're actually about to drop below stall speed when your Rube Goldberg lash-up says, "No problem, you're still 20 knots above stall!"?

I found a video of a tour of an Alto TDT at https://www.youtube.com/watch?v=YWHZqhfLTTs, so now I have yet-another source of motivation/shame to guide me as I attempt this folly of a project. If I get the exterior done in time for AirVenture, I'll be ahead of the game. I have to have a trailer to haul my stuff from Nashville anyway, and it will be cheaper to buy the HF trailer than to rent a U-Haul, so that's part of what got my butt in gear to actually start the build. It will be forever before I could have anything even remotely approaching an Alto in terms of shiny niceness, but that's a ~$37,000 TDT that the waiting list was 18 months for as of March 2016, and they've gone up by about $10,000 since then

Thanks again for the info and maybe we can wind up in the same part of Nowhere once I've got my TDT rolling ... and water "resistant"

All the Best,
Jim

[pchast]

Welcome..... theory and drawings are great but they don't prove out with
all real life experiences. As you look around and read the forum and builds,
you see it often recommended.... get some cardboard and make the volume.
Paint it white and take a nap in it. I found that I didn't like or want the larger
height.

[jim_manley]

Welcome..... theory and drawings are great but they don't prove out with
all real life experiences. As you look around and read the forum and builds,
you see it often recommended.... get some cardboard and make the volume.
Paint it white and take a nap in it. I found that I didn't like or want the larger
height.

Hi Pete!

Thanks for the most welcome advice. As I first said, my TDT obsession goes waaaaay back, and I've already done a lot of prep work, including mockups, which I agree are absolutely required before deciding anything (I've done the same thing when designing the aircraft I've built). One of the advantages of a TDT for me is that I tend to be a packrat, and I will fill any volume in which I'm enclosed. So, if the volume is minimal, I won't be so tempted to fill it with stuff (it's all "valuable" stuff, of course! ). The ability to temporarily expand my operating space by literally raising the roof will accommodate my other need to be able to stretch my bones no matter what it's doing outside.

If you didn't get my (too?) subtle joke about being able to reach my extremities, I need room to sit up and stand, for circulation and other reasons. The outside conditions are also an issue where I typically like to camp - I'm starting from over 4,000 feet in elevation and within a few miles of me, it gets to 9,000 feet-plus in almost every direction. They don't call it Glacier National Park because of the warm beaches - the glaciers have actually been melting for about 8,000 years, which has nothing to do with humans. It's been just _barely_ above freezing long enough during the Summers over that period for the melting to continue, but being nippy is what a broiling afternoon is like around here. Plus, there will always be two of us inside, we're both tall, and we both prefer not sharing a log with a bear and a bunny for whom poop doesn't stick to its fur, much to the bear's delight

So, the Safari Condo Alto R17xx is a nice combination of the TDT concept and room to stretch when needed. It should be noted that you can still easily access all of the facilities in an Alto when the top is all the way down, including the kitchen, which is something even a traditional TDT can't provide - the kitchen isn't open unless the back hatch is pretty much fully open. Now, the floorplan of an Alto is about 6 x 13 feet and it's about five feet high with the top lowered (it's about 7.5 feet at the peak with the top popped), so it's definitely not a 4 x 4 x 8 (H x W x L), or smaller, Tiny TDT. However, Safari Garden has maintained in the Alto the proportions of the early TDTs that were designed foremost for economy (after safety, of course). I'm currently experimenting with the scale of what my TDT should be between 4 x 4 x 8 and 5 x 6 x 13 (top down), so appliance boxes from stores in the area are trembling at the sight of my box cutter!

There's another reason around here for wanting the pop top and the possibility of openings or windows along the edge of the raised top. The only light pollution around here, once you get over the first ridge from the park gates, is from the Moon and stars that are so bright that it can make it difficult to pick out fainter stars. I will never forget the first time I actually saw the Milky Way at around 12 years old after growing up 20 miles West of New Yawk City (I lived in Joisey, not far from the places you see in the "Sopranos"). Now, I can see them any night that the clouds allow, which is a lot of the time, including the dead of Winter, when it often gets down to single digits - without a wind chill effect. So, it will be nice to be able to raise the top and watch the light show from 8,000+ feet while all snuggly in bed ... with heat.

Thanks again and All the Best,
Jim

[jim_manley]

OK, so I've perused a sampling of the introductory topics and I've looked at all of the classic designs I've found so far to incorporate into my thinking the time-honored shapes, dimensions, and ... "aesthetics" (well, OK, I'll use the "C" word just this once - the "cuteness" factor - ugh! ).

I'm not complaining at all, as a lot of work has been done to create the reference topic posts, but one observation is that there are a _lot_ of broken links. However, that's not surprising, since many of the introductory posts here for newbies were made around 2005 - 2006. In Internet years, that puts them back around the Cretaceous Period, when herbivorous dinosaurs roamed the Earth with "cute" TDTs in tow Fortunately, some content has been resurrected in later posts, but it's hit-or-miss as to whether all of the dead links in an original post have been updated or removed.

Most people posting info meant to be referential don't realize how many thousands of hours are later wasted by many people (upwards of tens of thousands, from what I've been able to determine by looking at the number of post views) when, not if, they wind up pursuing dead links. There are on-line utilities that can automate the process, so there's really no excuse for this situation. At least some posters are aware of Archive.org and have updated some links to point the appropriate pages there. There are nearly a trillion archived pages there now, so if you encounter a dead link on any web page, copy and paste them into the Wayback Machine field to see if they've been saved for "posteriority"

Anyway, here's what I'm drifting toward in the way of design goals. I'm going to minimize weight wherever possible, so I may have so little wood in my TDT to the point where the only cellulose on my TDT may be some quality veneers in special interior accents with gobs of urethane varnish applied in bunches of coats (I believe the artsy-fartsy term is "glassy"). In place of the wood, I'm considering fabricating every possible structural element from foam-core with waterproof surface materials, such as the FRP panels I mentioned in a previous post:
Since foam and FRP suffer no effects from water and make it easy to achieve a waterproof (let alone airtight) enclosure, a lot of problems associated with wood-and-metal shells, such as rotting and corrosion, are eliminated. Weight is also vastly reduced through both use of these materials as well as inherently strong structural techniques such as monocoque construction that dominates aircraft production.

Here's what an Alto looks like with the roof popped up and dropped down - note that when down, the Alto is 5 feet high measured from the bottom of the frame, which is about 20% more than a more traditional TDT:

Here are some interior shots - notice how striking the light and views through the glass windows are:


All of the photos were taken from just inside the door, except those of the toilet and shower (one model has an indoor shower with the toilet).

My goal for Oshkosh in 29 days, 17 hours, 32 minutes, and 24 seconds (but, who's counting?) is to get at least the exterior shell completed, plus enough of the interior done that sleeping will be safe and comfortable. Plastic interlocking storage containers of various sizes can stand in until I can fabricate proper cabinets. Oshkosh has wonderful infrastructure for the tens of thousands of pilots, passengers, and visitors who camp there, including buildings along the grass areas adjacent to runways where planes are parked and tents are pitched that provide showers, sinks, toilets, power for charging mobile devices, and WiFi access. So, I don't need a toilet or power in the TDT for now (and few TDTs ever have them), and I can use 12-volts available via my van or my backup vehicle starter if I don't want to make the trek to the nearest bath house just for that.

I don't even need to have the pop-top working for The Big Trip, which will take a lot of pressure off my schedule. Another design goal is to make it possible to disassemble the TDT shell by building modular panel sections that bolt together. It's apparent that many builds rely on cabinets and shelves to provide rigidity, which allows use of fewer structural members, but they're generally screwed-and-glued (a situation I often find myself in, otherwise in life! ) to the floor, walls, and often, the overhead (Navy talk for the inside of the roof, aka a ceiling, if finished to female sensibility levels ). If I do this right, the entire frame and all of the TDT panels should fit inside my Grand Caravan when disassembled (the frame may need to fold, at least the tongue).

I'm curious how the various TDT side profile curves were derived. I've played with ellipses of differing semi-major axis lengths joined at the peak, Cassini and Cartesian ellipses, and even egg profiles along the longitudinal axis. I was particularly interested in this because I need to calculate how much material will be needed for the roof. Sure, I could build cardboard models, measure them, and scale them up (or even measuring a 1:1 cardboard mockup), but that's just too darned easy. As my favorite (and only) Danish philosopher, Piet Hein, has said, "Problems worthy of attack prove their worth by fighting back." So far, I've calculated that a 4 foot high, 8 foot long TDT would require around 14 feet of foam and FRP or other material on each side (the length varies about six inches, depending on what kind of curve is used).

Another decision I have to make is the size of the floor plan, as well as the height. I'm tending toward a 4 x 8 foot footprint because that's the nominal size of foam and FRP sheets that are readily available for reasonable prices. The cost of foam, FRP, fasteners, and adhesives for a 4 x 4 x 8 foot (H x W x L) TDT would be about $350, plus a HF trailer for $260 ~ $400 (1,195 ~ 1,720 pound), and around $200 for trim. The only other thing I will need in time for Oshkosh is door hardware, which starts under $25 for something without high-security reinforcement (a metal frame for the door and the panel in which it's mounted). A typical vinyl-framed sliding window with a screen would cost upwards of $100, but that's probably going to be a bit further down the line. A ceiling vent will be a must, so that would be about $30+ and, as many others have noted, low side/floor vents to allow C02 and humidity to vent, or fresh air to be drawn in, are required. My initial cost should be well under $1,000 with some basic bedding foam and a couple of windows, but not much in the way of internal cabinets, kitchen and bathroom amenities, heating and A/C, or any other foofy stuff not needed for warm Summer camping in a site with well-equipped infrastructure, including readily-available, prepared, delicious food nearby.

This is doable over the three weeks I have available, plus a week in transit from Montana to Nashville, then Cincinnati for a couple of days, and ultimately arriving in Oshkosh, but I'm going to be busy every day for full days over those three weeks. I'll have my trailer frame and van hitch by next Wednesday when I have to travel to Helena for an overnight trip. The frame will take about a day to assemble (I've put together half-a-dozen of those over the years), and I've installed hitches in less than a couple of hours, including the wiring, assuming Dodge hasn't done anything ... dare I say it ... dodgy electrically in the Grand Caravan!

I'm officially across the starting line, having picked up a very nice Ryobi ONE+ 18-Volt Lithium-Ion Cordless Super Combo Kit with a 5-1/4-inch circular saw, a variable-speed reversible 1/2-inch drill, a reciprocating saw with a six-inch blade, a work light, two batteries, a charger, and a nylon carrying bag for the bargain price of $129:

I also just acquired a Worx Pegasus folding/tiltable table with integrated removable bar clamps, stops, magnetic parts/tool storage trays, etc., on sale for $99:

I have some honey-do projects to complete while I'm waiting to pick up the foam, FRP, etc., so I can break in my new toys on those, and then continue filling in more of the details for my plans. I'll be in full fabrication and assembly mode the week before the Independence Day weekend, but this 22-year Navy veteran will be taking off the 4th to celebrate with family and friends our freedoms for which so many have fought, been severely injured, and died.

All the Best,
Jim

[jim_manley]

I've been working out the wacky idea of modular panels that can be reconfigured to accommodate various shell sizes for different travel needs. I'm thinking of starting with a 4 x 4 x 8 foot (H x W x L) minimal configuration and having options for expanding the width, height, and length by connecting additional panels together, or perhaps even enabling them to interlock and slide among each other. The 4 x 8 foot standard dimensions of materials is particularly annoying in the vertical direction, which is one reason why I'm attracted to the Alto concept, where the entire roof panel rotates up around a hinge at the forward end of the shell to create a very fancy version of a popup camper. The aerodynamics and reduced weight of a TDT are highly desirable, but sometimes an expanded capacity is needed, so that's why I'm taking the time to consider this option. Besides, I'm never satisfied with anything I start building, but when is anything we build not like that?

The fixed connect-together concept would be the easiest to implement and it doesn't necessarily obviate the interlocking-and-sliding variant, but the latter will probably require more time than I have if anything goes wrong (and it will, as Murphy insists). The most direct method of connecting the panels would be to bolt them together by overlapping edges by about four inches (i.e., lap joints). The fancy way of doing it would be to carve halfway through each edge with a rectangular profile one inch wide and four inches deep along the edges of 2-inch foam panels so that the panels would overlap in a flush manner. That would require a lot of extra time and work that would be aesthetically pleasing, but I would also need to fabricate some jigs to get the curved edges right.

Here's some drawing views of the Safari Condo Alto to scale, where the floor plan is about 6 x 13 x 5 feet W x L x H (roof lowered), and 6 x 13 x 7 feet (roof raised).



One option would be to just scale it down to fit into a 4 x 8 foot floor plan on a HF trailer frame, which would result in a 42-inch high shell. Obviously, it wouldn't need to be that low, and the more typical 48-inch height would be more comfortable, not to mention providing more storage and facilities volume, if less aesthetically true to the classical TDT profile. Naturally, most of the amenities in an Alto wouldn't be possible to include in such a small shell without the roof being raised to a much higher angle, but, I could provide an option to access the kitchenette from the back as well as the inside. I don't need to worry about that for now, since I won't be buying the foam and FRP until probably the first weekend of July, but I'll be pontificating the possibilities in my subconscious. I'll also have the time to do that when I can't do anything more productive than tend to biological imperatives which, ironically, require the use of a kitchen(ette) and a bathroom. The intervening five days will be an eternity since I'm off for the Summer, and the cardboard is shuddering in fright as I begin mocking up my version of the follow-on to the Apollo spacecraft living space volumes, and I'll be assembling the trailer frame on Friday.

Before I acquire the foam, I need to poke around and figure out what the spacing and depth needs to be between kerfs for various curve radii. I've already been wandering around the forum and looking at the samples in some books on Amazon, seeing what others have learned concerning the finer points of TDT construction, along with materials and techniques generally used in trailer fabrication that have been developed since the last time I built a trailer about ten years ago. So much fun, so little time

[alchemist77]

Have you checked out the winter warrior? Might be an option. Is the Alto a patented design? Don't want to step on any toes. I'm reminded of a unit that used sliding panels, interlocking as each slid in.

Sent from my Lenovo TAB 2 A10-70F using Tapatalk

[jim_manley]

Have you checked out the winter warrior? Might be an option. Is the Alto a patented design? Don't want to step on any toes. I'm reminded of a unit that used sliding panels, interlocking as each slid in.

Hi David!

Thanks for the reference to the Winter Warrior. I was aware of it and have looked at some of the builds here based on that design, which are very nice.

As a patent awardee, I'm very familiar with what it takes to get one awarded. Beyond the paperchase, it's not actually that hard to get one, other than maintaining your sanity for the four years it takes, on average, for the US Patent and Trademark Office to get its butt in gear. The hard part is defending it in court against the inevitable challenges, and if successful (always even more years than the review and award period), countersuing, negotiating licensing, and suing those who just keep flaunting your achievements because they have much deeper pockets and can wait out small fry. The record gestation period is something like 30 years for the intermittent windshield wiper, IIRC, that some poor schmuck in his garage had to battle for against all of the lawyers for all of the vehicle manufacturers in the world, but ultimately won. When the guy finally prevailed, he was in his 70s and said that his grandkids might eventually get to enjoy the damages and licensing fees after all of the lawyers were paid off

I did look at U.S. Patent # 7,488,030 awarded to what appears to be a holding company that owns Safari Condo, and I'm surprised that I didn't find any challenges to the patent. Their primary claim is to an aerodynamic travel trailer with flat sides (sound familiar?) and a roof that can be raised when parked for habitation, by pivoting on a hinge at the leading edge of the body. That's despite citing prior art in patents going all the way back to 1936 for what are essentially early teardrop trailers, not to mention every pop-up trailer ever built. I don't see how they can successfully claim the aerodynamic shape as being unique, for starters

The key claim appears to be the hinge at the leading edge, so if a challenger placed the hinge even an inch above or below the leading edge, or there is no leading edge because the front wall drops straight down to the base without forming a leading edge, there would be no infringement. I'm actually considering putting my hinge along the bottom of the front wall, which wouldn't infringe or change the movement of the roof very much fore-and-aft or vertically in achieving coverage of the interior as well as providing sufficient headroom. It would also solve the hurricane hinge challenge as the low hinge would be below the shell base (so no moisture could drain into the interior) and behind the air dam known as the tow vehicle, vastly reducing tow wind velocity and air pressure that could cause moisture infiltration

They recently announced the shipment of Alto Number 1,000, and I don't know how many of their fixed-roof F-series trailers and vertical pop-top RV van conversions they've sold, but the revenue from the Altos is somewhere North of $30,000,000. Given a very generous profit estimate of, say, 30%, that's less than $10,000,000, but it's spread over the past 10 years that they've been in business, starting with 2 - 3 sales per week, and now doing around 3 - 4 sales a day. Their investors have to be profit-taking now, as the price of the Alto has gone from about $27,000 in March 2016 to $37,000 now, with 18-month lead times due to limited production capacity (they're based in Quebec - their logo/mascot is a snail/escargot, of course ).

As long as I don't infringe on their leading-edge hinge and a few other very specific features that I'm not going to replicate, I won't have any problem (and good luck finding any assets to misappropriate if they were so silly as to sue me and somehow prevail through buying a judge and jury ). In Montana, people routinely leave the keys in their unlocked vehicles because by the time a stolen vehicle makes it to the state line, the Highway Patrol will have made their way through an entire box of glazed baked goods. Stealing a vehicle here still comes under the law for stealing a man's horse, aka his means of making a living, which is punishable by death! A French-speaking lawyer headed in my direction wouldn't get very far into the state after an All Points Bulletin was issued if I were being served with a cease-and-desist order, especially given that I'm a decorated war veteran - we're treated _very_ respectfully here

Besides, if I were cited as infringing, the only thing they would be able to find as evidence would be a HF trailer and a pile of modular FRP/veneer-laminated foam-core panels that could be configured in a large number of geometric permutations, very few, if any, of which any reasonable person would say resembled an RV, let alone an Alto! Besides, good luck finding a reasonable person these days, much less a dozen of them from a jury pool ... especially if they're my peers!

Thanks again for your post and All the Best,
Jim

[jim_manley]

I'lll be starting a thread on my build soon, but I'm on the road for a very minor medical procedure ... guys of a certain age are very familiar with the ol' Silver Stallion . The worst part of it for me is the prep because I can't eat anything solid for two days in advance, and I have a 5,000 calories-a-day metabolism. I've never been so aware of commercials, billboards, and eateries on every street hawking food - no wonder so many people are weight-challenged.

The great news is that the trip to the VA hospital closest to me, also put me within 10 blocks of the closest Harbor Freight to me (both about 200 miles away), and I got to go shopping Wednesday afternoon. Yes, I am now the proud owner of about 250 pounds of steel, copper, chrome, rubber, plastic, and paint, aka a HaulMaster 1720-pound capacity 48 in. x 96 in. Super Duty Folding Trailer! Unassembled, of course ... After recovery Thursday and the drive home (with stops at every pizza, sandwich, and other purveyor of nutrition on the way ), I'm going to start the clock and see what kind of record I can set for building a TDT from self-built foam-core panels laminated with FRP sheets (and possibly wood veneer on interior surfaces). The trailer frame should be assembled by the time I go to bed Friday, modulo not mounting the fenders and the lighting and wiring, as I've built half a dozen of these and they're all still in service after taking some preventive measures to prevent corrosion and paint deterioration.

I'm still considering options as to what size my shell will be, but the 4 x 4 x 8 foot (H x W x L) design would be really, really tight for two adults well over six feet in height. In the mockup, I was surprised that I can sit upright in a chair with an 18-inch seat height, very comfortably under the five-foot interior height when the roof is rotated into the raised position. The width is definitely challenging, and makes it obvious why there are so many five-foot-plus-wide TDTs. The towing drag on a full-size Safari Condo Alto lookalike with 5 x 6 x 13 foot dimensions would be an order of magnitude greater than that of the version scaled down to 4 x 4 x 8 feet.

Here's what the 4 x 4 x 8 foot version would look like:


I will probably go buy my foam, FRP, and veneer sheets during the weekend after running the numbers in terms of both cost and time. I was thinking about buying the 1,085-pound HF trailer, but the three they had in their weekly shipment last Thursday were gone by last weekend. They will only hold items for 24 hours, you can't buy on-line and then pickup at a store, and shipping a trailer to my home would cost nearly half the price of the trailer. So, buying the 1,720-pound trailer for $120 more ate the equivalent of about six sheets of FRP or four sheets of 2-inch foam, which is a big chunk of my limited budget for the trailer and shell phases of this TDT build.

Well, it's almost 1 AM Thursday and I have to start drinking the second half of the prep solution at 3:45 AM to be ready for my appointment at 7:45 AM. I hope they knock me out to at least twilight level so that the time will pass without me knowing. That way, I'll only have to wait during the few hours when I'll be awake between now and when I can finally start eating solid food again around lunchtime Thursday ... MMMMmmmm ...

[jim_manley]

Good news all around on Throwback Thursday - I not only woke up from twilight sedation while they had their way with me during my minor procedure (one step above a general anesthesia - Better Living Through Chemistry ), but no pre-cancerous polyps were found for the third time in six years. That means no more two-day starvation diet and downing disgusting electrolyte prep formula (and the resulting uncomfortable "cleanse") for another five years (the formula feels slippery like antifreeze, but tastes worse - don't ask me how I know how antifreeze tastes ). It also means I need to pay more attention to wayward buses passing in my vicinity ). I got home safely with my HF HaulMaster Super-Duty trailer kit in the back of the van after leaving a trail of devastated food emporia between the VA hospital and my humble commode ... I mean abode. I didn't get much sleep Wednesday night due to numerous trips to preside on the porcelain throne, so when I got home Thursday evening, a significant nap was in order.

I'm starting to unpack and misassemble the trailer, but the lion's share of the progress will occur Friday. As an additional bonus, the Going to the Sun Road in Glacier National Park was opened Wednesday following months of snow plowing and avalanche debris removal due to the heavier-than-average snow fall this past Winter. So, I'm going to pass through the park on the way to picking up my foam, FRP, and sundry other hardware, adhesives, etc., needed to fabricate the panels for my shell. That additionally means that, once I've got my TDT on the road, I'll have some phenomenal opportunities to tow and test out camping in the Corto (the project name, unless I come up with something more spiffy - alto means tall in Español, and corto means short ) before The Big Trip to Nashville, Cincinnati, Airventure Oshkosh, and back home. My million-plus-acre back yard has over 175 named mountains, 762 lakes, 563 streams, 200+ named waterfalls, 25 named glaciers, and more than 745 miles of maintained hiking trails (aka Glacier National Park). That doesn't even count the 124,800 acres in the immediately-adjacent Waterton Lakes National Park, and the nearby Banff National Park in Canada, among many other national/state/provincial parks, forests, monuments, etc., Out Here in the Intermountain Region.

I happened to get an e-mail response back from Safari Condo on Wednesday about current lead times for their Alto RV trailers, and it's 16 months, about two months less than it was in March 2016. Saving about $35,000 that I could never afford on my non-tenured teaching pittance, and that much waiting, are even more motivation for me to get my Corto on the road sooner, rather than later. Despite the good news on the health front Thursday, I'm not getting any younger, and doing things like hauling 250 pounds of trailer frame parts to my home isn't something I'll be able to do forever. That's yet-another reason why the featherweight attribute of foam trailer shell components is so attractive to me, along with the insulation advantage that's a big deal here. While the glaciers have been on the wane here for upwards of 8,000 years, as the recent late clearing of the Going to the Sun Road demonstrates, it's still quite chilly (the latest it's been opened since the Park was established in 1933 was July 13th ... 2011 - so much for global warming - we're within 1,000 years of the decline toward the beginning of the next ice age, BTW).

Well, time to get my butt in gear and start the clock on my build - with any luck (like that of my healthy prognosis), I should have the Corto frame and modular shell on the road within a couple of weeks!

[jim_manley]

I forgot to mention that during my trip to and from the VA hospital, I saw at least half-a-dozen TDTs, all of which I'm pretty sure were commercially-built. That's based on what I could see of their construction and materials as they whizzed by going the other way and passing me (I'm a very safe driver ... yeah ... sometimes, Dad let me drive the car in the driveway ... yeah ... ). One was an R.pod, apparently one of the early models that looks very much like a T@B 320, sorta like this R.pod:

The current Forest River R.pods are all full-size/feature models now, many of which have friggin' slide-outs! They start around 2,400 pounds dry and go up in mass quickly through 3,000 pounds and well beyond, which is way heavier than my 4 x 4 x 8 foot option, that should tip the scales at around 900 pounds (a third of which will be the HF Super Duty trailer). Even my roughly 5 x 6 x 12 foot maximal Alto-inspired design should be under 1,500 dry pounds, including the HF trailer.

While I was luxuriating in the wonderfulness of a breakfast of Graham Crackers in milk for breakfast Friday morning to help my digestive system recover from Thursday's activity, I perused the online sites for the Usual Suspect home improvement emporiums. While looking for wood veneer options for my Corto's interior, I was delighted to find 5mm x 4 x 8 foot poplar five-ply panels for $14.98 each, which are already sanded and cleaned for finishing:

These are a very pleasing light color that's absolutely necessary for the small interior surface area of a TDT, unless you're really into Goth style (not that there's anything wrong with that ). I really hate painting and varnishing because of the mess, cleanup, and smell, and the poplar will require urethane varnish, but at least my modular laminated foam sandwich panel idea will allow the panels to be aired out between initial fitting and final assembly on the HF trailer. However, the 25% lower cost for the poplar vs. PolyWall will take some of the sting out of the bother to have to do the varnishing.

Speaking of my modular panel concept, I think I've got it pretty well nailed down, or at least bolted together, subject to testing that will be done once I have some scrap foam, plywood, and plastic sheets available. I'm considering bolting my panels together, where plastic sheets or plywood pieces about 2 x 6 inches are drilled to allow the bolts (probably 1/4 or 3/8-inch diameter) to pass through and be threaded into tee nuts inserted into the drilled holes. The plastic or plywood pieces would be inserted into six-inch wide slots sawn into the foam panels about two inches in from the edges of the panels, and 18 - 24 inches apart along the edges, thusly:

The 45-degree hashing (going up to the right) is a two-inch thick foam sandwich panel (oriented in the plane of the computer display) in which the slots are being sawn and the plastic/plywood parts are being inserted. The 135-degree hashing (going up to the left) is a two-inch thick foam sandwich panel (perpendicular to the computer display's surface) through which bolts are inserted through drilled holes that extend into the edges of the foam of the first panel. The tee nut is inserted through the plastic/plywood part (the 50% dotted pattern) through a hole aligned with that drilled through the foam, so the prongs of the tee nut penetrate into the plastic/plywood as the bolt is tightened. The solid black lines are the FRP/plastic sheets glued to the edges of the foam sandwich panels. The dotted line between the solid black lines is a thin, compressible foam/rubber/plastic gasket that seals the panel corners against air, water, and moisture intrusion, even at highway towing speeds.

If it's not intuitively obvious to the most casual of observers, at least one layer of the panels can't be glued on until the foam slot is cut and the tee nuts and plastic/plywood pieces are inserted. The bolts can be inserted and tightened after the exterior and interior layers have been glued on and it's hardened, as well as applying varnish to the interior layer, if needed, as access will be unlimited before panel assembly. The precise longitudinal dimension of the plastic/plywood pieces and their depth into the foam from the edge will be determined empirically through pull tests on foam scraps. The length of the bolts will be limited by what's available, which is six inches for 1/4-inch bolts, and eight inches for 3/8-inch bolts, so the maximum depth from the edge of a panel will be about 7.5 inches. I'm guessing that four inches of depth will be way more than enough, so six-inch long, 1/4-inch bolts will reach through both the edge of the perpendicular panel and 3.5 inches into the edge of the panel containing the tee nut in the plastic/plywood parts.

Exterior/interior layers need to be glued on for the testing as they will strengthen the foam against compression from the plastic/plywood parts, up until the critical amount of stress has been exceeded. I haven't been through all six pages of rowerwet's amazing and wonderful utilitarian summary index, much less all 466 pages of The Big Foamie Saga, to see if someone else has already trodden the path I'm pursuing virtually via my mind's eye, while mindlessly inserting and tightening bolts and nuts in my HF Super Duty trailer. I hope it actually looks like a trailer when I'm done, as I'm easily distracted ... squirrel!

Well, back to the HF trailer assembly that will continue late into Friday night, as, once I'm in my groove, I like to bop until I drop. I just have to be careful not to drop any of those massive steel members onto my slipper-clad toes! Yes, I do have steel-toed boots within my line-of-sight right now, but what fun is that?

[Roly Nelson]

Well hello dreamer, what an impossible plan you have posted. There ain't no way that you can accomplish what you have listed in your lengthy epistle! Nevertheless, just keep on dreaming and posting the results. I feel you are really pulling our leg, but we'll wait and see what your camping rig looks like if it ever gets to the campground in Oskosh. Honestly, many of us have built TDs on a condensed schedule, but what you have so elequently discribed, is Impossible! If your home-built airplane is also the result of such a condensed time frame, I myself as a private pilot, would never consider venturing into the sky with you. Nevertheless, I suggest you concentrate more on actual building, and cut down on the lengthy epistles you have so far posted. So with tongue-in-cheek, I say good luck on your efforts. Keep us posted. At least, your rambling is entertaining. (this has gotta be a joke)
Roly, the li'l ol' woody teardrop builder in So Calif (anxious to see the time-crunched results)

[Vedette]

And I though I was delusional with my time frame attempts?
Oh yah, missed every schedule so far!
I am with Roly on this one.........and I have not read half of the post yet, as they are TOO long!
Good Morning Roll!
Happy Canada Day!
We are 150 years old.
Brian & Sandi

[jim_manley]

Hi Roly and Vedette!

Finally, some more people are starting to pay attention to this diatribe! Please tell all your family and friends to follow along for the entertainment value, if nothing else

Ordinarily, since I'm a dyed-in-the-wool engineer and pilot with 41 years of experience with Murphy, I would agree wholeheartedly with your entirely pessimistic assessments (or, as I like to call such prognostications, "pestimistic", reflective of the attitude of Those Who Can't or Won't). It's OK, I've dealt with that kind of thinking my entire life, and I have a pretty good track record of having done so much, with so little, for so long, that I can do anything, with nothing, forever. Anyone who has served in a part of the military that actually does anything that really matters (aka The Pointy Tip of the Spear) will recognize that phrase, along with the old recruiting ad motto, "We do more before 9 AM than most people do all day." I spent quite a full career in the Navy, as I served on subs, carriers, amphibs, and smaller surface skimmers/targets (so, you know I'm a submariner, first and foremost).

After I served as a nuclear engineer, pilot, software engineer, computer scientist, intelligence officer, and systems acquisition officer, I spent almost 20 years as a software engineer and leader in Sillycon Valley startup companies. 120 hour work-weeks are the norm in The Valley, and the compensation is excellent, you just have to wait a while to actually spend it on anything, like building three aircraft in my case. My typical workday has been 16 hours pretty much my entire adult life, and now I have 24 hours a day to do whatever I want for the next couple of months. I've flown into Oshkosh before, but because I need to pick up some educational computing equipment around the country during my trip to/from Airventure, I'll be constrained to ground operations this year (building the equivalent of a C-130 was just a bit beyond my budget and even my more-than-optimistic schedule estimates! )).

I spent a large chunk of my military and software career doing planning, so that's another reason for the voluminous verbiage here. "Those who fail to plan, plan to fail.", and "Plans always collapse upon contact with the enemy, but planning isn't the goal, it's a process that enables you to ferret out as many bad outcomes as possible, and avoid them.", as we professionals say. In software development, as with flying and aircraft maintenance, successful practitioners spend much more time planning than actually executing plans - only about 15% of the time expended on a typical software project is spent actually writing code that will wind up in the final product. Military aircraft maintenance typically requires 200 person-hours of flightline and operational hangar effort for every hour of flight, and that's not counting depot-level work for overhauls and major equipment replacement and upgrades.

I'm not approaching the Corto project from a dead stop as of a week ago - I've been thinking about this for many, many years, that included building an 8 x8 x 24 foot (H x W x L) aircraft transportation trailer (I built that in a couple of weeks using 2 x 2 framing and plywood/FRP-exterior sandwich panels - so, the Corto isn't my first whirl at the dance). I've also observed and discussed what others have done in RV builds (not just TDTs), incorporating a lot of what went into my commercially-built 7.5 x 8 x 24 foot (H x W x L) V-nose vehicle trailer, as well as what I've seen through my engineer's (and, just as importantly, fabricator's) eye at countless RV, boat, and aircraft shows and events. The materials and techniques we have available today are far beyond what was known even as recently as when this forum was started, much less what was possible going back to the 1930s, with literally baling wire (a structural material) and chewing gum (for sealing leaks). Chewing gum is actually quite a capable material when allowed to harden, as I can tell you from trying to remove it from the undersides of the seats in the movie theaters my parents managed when I was a kid (which required the nasty carcinogen carbon tetrachloride - they just leave it there, nowadays)!

Using FRP for the skin saves the months that others have spent stretching, gluing, and painting fabric, in addition to sealing a multitude of leaks and correcting misalignments due to non-square/non-straight edges. It's also immensely strong with minimal work/time, well beyond that possible with any wood and fabric construction, just as modern aircraft and boats are much more durable than their wooden and fabric forebears, without substantial maintenance. The weight and fabrication/assembly time advantages of FRP/foam/veneer-plywood over the beautiful all-wood carpentry that took upwards of years to complete is another reason why I'll be able to accomplish my self-admittedly insane build schedule. I'm almost certainly not going to be able to build my own door(s), let alone windows, before Oshkosh, so I'm considering whether used/new options will fit within my current budget (I'm in an extremely rural area, so local used opportunities are limited), but those may not be possible to get done before I leave in a few weeks anyway due to the time crunch.

The pop-top may not even be within the realm of reality, but if I can get that done, the windows and doors can be delayed until after my trip is over, as I can enter/exit via the rear (ala a Kampmaster). I could just hang lightweight bug netting around the edges of the pop-top, and dropping it nearly closed when, not if, the thunderstorms pass through. A freak 70-mph microcell passed right over Oshkosh back around Airventure 2008 that snapped the fiberglass poles in my substantial dome tent pitched next to my aircraft - it came and went within about five minutes. As I said, if all else fails, there will be plenty of room in the back of the van - that's my ultimate ace in the hole - I really don't need to finish much before I get on the road.

Regarding writing vs. doing, I've been slinging code pretty much my entire life (being a complete nerd from a very early age), so, I can type 200+ words per minute because it's a professional hazard (as well as a hard-earned "gift"), so this isn't taking nearly as much time as it would for "normal" people (whomever they are!). That's on top of my various other professional work, and building a seaplane, an autogyro, and a helicopter, but each of those took several years of part-time effort, so I'm not as much of a threat to fellow/fellowette pilots (not to mention innocents on the ground) as one might otherwise surmise . I'm not writing this so much for anyone else to read as I am to document my thinking, progress (or lack thereof), and personal events for myself, because the current generation's penchant for everything to be a video is simply worthless without about 100:1 time editing of source material down to a final product, and for that I don't have any time. However, you have at least picked up on my sharp wit, or weak attempts at humor, at best, perhaps, and that is a big part of my reason for writing. Plus, it's cathartic, so it allows me to vent my frustrations built up after an academic year with high school kids who mostly have no interest in learning anything, let alone STEM subjects (there are some outstanding exceptions, and they're the ones I'm there for the most).

As a three-star admiral once admonished me after my first, very dry, boring, technical briefing on Soviet naval and aerial operations, "That was a very nice, detailed briefing about things my staff and I don't understand the associated minutiae, so if you can't be informative, at least be entertaining!" The next day, I slipped substitute names for some of the ships (e.g., "Boris Badanov"), along with other subtle quips, into my briefing, and I could see the admiral's brow start to furrow as his subconscious processed what I was saying, after the fact. Suddenly, he said, "Wait, what did you say the name of that ship was?" I replied, "Boris Badanov, sir.", and he busted out in a big grin, saying, "As in the bad guy in 'Rocky and Bullwinkle' ... very good, that's exactly what I was talking about! Proceed." I got a Number 1 of 10 rating compared with my peers on my fitness report from him - Mission Accomplished, as they say.

Since you may not have read, let alone absorbed, everything I've blathered on about so far, I'll reiterate that my only goal for Oshkosh is to have a safely-towable utility trailer frame with an FRP/foam/plywood sandwich shell mounted on it that may, or may not, be camping-ready at Oshkosh. If the TDT isn't habitable, I can always snooze in the back of my Dodge Caravan, which can fit 4 x 8 foot sheets of material, at least four feet high, with the Stow 'n Go second and third row seats folded down, and the computing equipment can ride in the Corto, in that case. Airventure campground shower/toilet/IT support facilities are simply amazing, and I can remain overstuffed just feeding on tailgate BBQ offerings from complete strangers willing to listen to my ersatz (but, true) stories, so I don't need any bath or kitchen stuff in the trailer there, but it would be nice. Hotel reservations are already made along my route where camping isn't a good idea, to ensure comfortable and restful sleep during the long-distance sojourn. I have been known to drive all the way across the country in a few days, sleeping in my reclined vehicle driver's seat in rest areas just before I got too sleepy to make rational decisions - well, OK, less irrational decisions! ).

Charles Dickens didn't originally publish his magnum opuses (opi?) as books, they were serials in newspapers, and while I would never compare my writing to Dickens', think of these "posts" as a similar art form, only to be bound in a compendium upon sufficient demand (and after my death, like so many misunderstood raving lunatics who turned out to have at least a few good brain farts ). I have included some pictures for the less literature-intensive readers, and if someone is willing to pay for it, I'll produce a comic book version ... "Look, up in the sky ... it's a bird ... it's a plane ... [SPLAT!] ... no, it's a bird ..." "In all the confusion, I lost track ... was it five shots, or was it six? Do you feel lucky today, punk? Well, do ya? Go ahead, make my day!"

Happy Canadia Day back atcha! "Oh, Canada ... La-la-la-la-la-laaaa!" 150 years old ... man, you Great White Northerners must bury yourselves in snow banks to achieve suspended animation each Winter (September through June?) ... but, it must work, as you don't look a day over 149, Cryptkeepers!

As for ongoing progress, to quote a military FLA (Four-Letter Acronym, which is itself a TLA, a Three-Letter Acronym!), STFB, mo-foes! Film at 11 ... note that I didn't say AM, PM, or what day, week, month, or year, of course - I may be crazy, but I'm not stoopid!

And now, time to analyze some aerodynamic simulation calculations that have been running during my typing, while enjoying some delicious reheated pizza for lunch - Italian-style food is always better as leftovers since the carbs get to absorb the sauce ... as Homer Simpson would say, "MMMMMmmmmm ... Piiiii-zaaaahhhhh!!!"

All the Best,
Jim