Would you assemble your own trailer if you had a kit? (1 Viewer)

[stevezero]

Great concept!

I should be seeing Dick V. at OSH in a couple weeks at Airventure. Should I ask him if Vans would want a neat little side business project? I honestly doubt he would want to take that on....makes far too much more doin the airplanes.

I looked at building a trailer for many years, different designs, configurations, etc. Since I was pressed for time and lacked some of the tools and space (not to mention the welding ability), I opted to have one built. www.rustictrailteardrops.com built me one of their Grizzly Bear models. Not a perfect solution, but their product line has quite a niche, so I know I can get my money back out of it. We had a bunch of conversations at the shop (they are about an hour away), and working on them building a composite trailer model. I wanted to go that route, but I didnt have enough time to spare on my build.

The only downside I could see with regards to an alum rivet/bolt trailer would be for those hitting a bunch of washboard roads. Concern would be the joints loosening up over time, or a failure that you wouldnt have with steel. Could be mitigated with some structural adhesive along with the rivets and bolts.

 

[Chris Wilcox]

As someone who has helped build six(6) vans aircraft (the first one was just plans), built an FJ40 including narrowing axles and stretching the frame and designed a rivited aluminum trailer for the US military K-Band satellite program, I would say that the market for your proposal is extremely limited. The airplane and the typical steel trailer are totally different animals construction and tooling wise. People that are invested in the offroad or expedition hobby won't have many tools that are required for the airplane type construction. Another factor is repair from trail damage. Steel is more forgiving and easier to spot repair. All airplanes I've had to repair are by removal of the whole sheet and replacement with new. This ranges from mild to a float plane inverted in a lake. My thoughts only. If it goes ahead and is successful I'll be watching with interest but keeping my M101CDN.

 

[cme4lyt]

I've been involved in assembling and rebuilding an RV4 and a RV6. What I loved about the process is that I was essentially just supplying the 'dumb' labor; Vans had done all the hard work and heavy lifting ! Pretty much anyone who can swing a wrench can do this.

So, your idea has merit and I would certainly be interested in 'slamming' a new trailer together over a weekend with my buddies after it arrived in a simple flat pack crate.

I personally don't have the time/space/effort/inclination to spend a gazzilion $'s on special tools and equipment I'd need for my custom one-off trailer I'm building, I'd rather you supply me 90% of what I need and I'll finish/customize/personalize the rest myself.

Following along with interest...........

Regards, Jonathan

 

[NMBruce]

I think you have a good idea, cost would be a big factor. You need to make sure the frame and suspension (with kit or recommended) will hold up to off road abuse. Dinoot has done well, but the people who build off the Harbor Frieght frame can have problems, don't know if Dinoot makes a steel frames for their kits.
Here is a forum where people talk about the trailers they build JeepForum.com - Jeep & Off-Road Discussion Community
And you can read how they have reinforced the HF type frames.
The vibration off road, like on wash board roads will tear things apart. For joins, if using rivets or bolts, I would look at a glue also to reinforce/secure the joint.
I got lucky and had a friend weld me a frame, but with 30k miles on it, I have broke a couple of springs and trailing arms.

Good luck

 

[NMBruce]

Home-Built Camping Trailer Welded Frame Kits

 

[ntsqd]

Lots of room for improvement on that frame!

 

[AeroAggie]

Home-Built Camping Trailer Welded Frame Kits

Now that's a nice looking little trailer. There's no way I would recommend anything from Harbor Freight if I'm going to put my name on it. I don't mind disposable hand tools, but I'm not interested in disposable trailers.

I've been involved in assembling and rebuilding an RV4 and a RV6. What I loved about the process is that I was essentially just supplying the 'dumb' labor; Vans had done all the hard work and heavy lifting ! Pretty much anyone who can swing a wrench can do this.
I personally don't have the time/space/effort/inclination to spend a gazzilion $'s on special tools and equipment I'd need for my custom one-off trailer I'm building, I'd rather you supply me 90% of what I need and I'll finish/customize/personalize the rest myself.

Exactly my point. Any one of you out there can assemble a trailer (or an airplane, for that matter) with the right design and the right tools. There are a lot of expensive aircraft specialty tools that make things easier, but I wouldn't design around those. Maybe a compressor and a rivet gun for the bulk of the work.

The airplane and the typical steel trailer are totally different animals construction and tooling wise. People that are invested in the offroad or expedition hobby won't have many tools that are required for the airplane type construction. Another factor is repair from trail damage. Steel is more forgiving and easier to spot repair. All airplanes I've had to repair are by removal of the whole sheet and replacement with new. This ranges from mild to a float plane inverted in a lake. My thoughts only. If it goes ahead and is successful I'll be watching with interest but keeping my M101CDN.

You're right, they are different. And you're right that most people won't have the tools, but that doesn't mean they can't acquire them. Let's say you're after a Turtleback type of trailer - Loaded with with features and a $30k price tag to match. Building something like that from scratch could take months or even years, depending on your situation. But let's say you could buy the kit for 1/3 the cost of the finished product and complete it as a summer project. Don't you think spending a couple hundred dollars for tools would be worth it? And like the kit plane builders, you can turn around and sell those tools to the next guy and get 75% of your money back. Forum based communities such as this one and the many airplane builders out there make for a great secondary market for passing around tools to other builders.

The only downside I could see with regards to an alum rivet/bolt trailer would be for those hitting a bunch of washboard roads. Concern would be the joints loosening up over time, or a failure that you wouldnt have with steel. Could be mitigated with some structural adhesive along with the rivets and bolts.View attachment 1496370

While you're at OSH, ask Dick how much adhesive he uses. There's zero need for adhesive in riveted structure.

 

[ntsqd]

I have worked on exotics, particularly Italian, that had riveted fuel tanks. I've seen those leak, but only because of rot or accident or mishandling.

This car has/had such a riveted fuel tank, I *think* it now has a Fuel Safe fuel cell, but I haven't worked on it in 15+ years so it may have been changed out back to original.

That said, bonding & riveting has an appeal to me. Perhaps its detrimental to the seam, perhaps it's simply not necessary, but it appeals from a structural perspective.

 

[AeroAggie]

Perhaps its detrimental to the seam, perhaps it's simply not necessary, but it appeals from a structural perspective.

Fuel tank sealant and structural bond are completely different animals.

It absolutely could be detrimental to the structural joint if not engineered properly. No aluminum commercial aircraft skins are bonded and riveted, and they see a tremendous amount of fatigue loading for decades in a very harsh environment. There is a sealant along some joints at pressure boundaries, but it is not structural in any way. In fact, it's effectively a kind of fuel tank sealant.

This is not the thread for the technical discussion of the details because they simply don't exist yet for this application. You have a particular experience with a thing, and I have a different experience with a completely different thing. Feel free to build your things however you wish, and I'll do the same.

 

[NMBruce]

Home-Built Camping Trailer Welded Frame Kits

Read that's the same company that owns Dinoot

 

[ntsqd]

I was sort of making your point while acknowledging the appeal for a bonding agent. If a fuel tank can be riveted together in the early 1950's without any sort of sealant or bonding agent and still hold fuel in the early 2000's then it says something about the structural integrity of rivets only. The common fear is that the rivets will work loose over time resulting in a sloppy and loose joint, yet here is an example of a riveted joint that is liquid tight roughly 50 years after the joint was assembled. That particular car was literally rolled into a ball of aluminum sheet metal and completely rebuilt (at a cost that would buy several completed RV-7's), yet the fuel tank still holds fuel.

FWIW the Lola T-8990 that I worked on had some sort of agent in the riveted joints of it's aluminum sheet metal monocoque. I won't call it a bonding agent because I've no idea what it's purpose was, but it was very visible and was present in every joint. My guess is that it did bond the joint together.
Aircraft assemblies are built for maximum fatigue life. Race cars are built for maximum torsional rigidity. Design goals are totally different and the path taken probably reflects that. Assuming that my guess is correct that tells me that a bonded joint is appropriate depending on the design goal. Clearly the bonding agent needs to be well chosen for the joints to work correctly. You aren't going to just add J-B Weld to a riveted joint design and expect a good joint without a lot of testing first to determine that it adds rather than subtracts from the structure.

IMHO the Dinoot trailer frame has all of the common errors made by home builders already included, no extra charge. Springs are too short, angle of the dampers makes them pointless and with those short springs they aren't going to be needed to do much anyway, tongue and diagonals should be under the main part of the frame not butted onto the front of the first cross member, and a good idea though not necessary is to then tie the diagonals into the front spring mounts. The info to design a good frame is easily available, why these errors continue to be made is frustrating.

 

[AeroAggie]

I guess I misunderstood your fuel tank analogy. Thanks for clarifying!

Fastened joints begin fail for one of two reasons: Static shear strength of the fastener, or bearing strength of the joint materials. What most people in this thread think of when they say riveted joints "loosen up" is actually bearing failure (often confused with Fatigue which is a different form of failure). The joint material deforms and the hole gets bigger, allowing the fastener to move. Once the fastener is loose in the hole, you add a third form of failure - fastener bending - then your joint is doomed. Both the fastener material and the base material are pushed beyond the linear elastic part of the stress-strain curve, into the nonlinear plastic region. Failure is imminent.

The answer is more fasteners or larger fasteners to reduce the bearing stress at each fastener. Adding a bond to this joint may temporarily postpone these failures, but not prevent it. Bonding metal to metal is not as easy you'd think to make a structurally sound joint, and some of the chemistry and processing involved is beyond the capabilities of the average car guy. The only example I can think of in the big airplane world is hot-bonded doublers around cutouts (doors, windows, etc) for fatigue reasons, not static strength. This is not something you can generally do at home.

I don't do race cars, so I don't know what design limitations they had for your particular example but I can assure you it wasn't because bonding was stronger. My guess is it was to save weight. Weight is far more important in racing than durability because they can rebuild after every race. Offroad racers do have to consider durability, but even then, they really only need to get to the finish line. But these examples are vastly different than just building a trailer.

 

[NyNomad]

Smittybilt has an offroad/overlanding trailer that you have to assemble. yes, I would if I had the $$, tools and space

 

[half k cruiser]

@AeroAggie I've been following this thread with some interest. First because I assume you are down in Wichita, which is only an hour and a half from me. Second because I like the concept. Third because I'm in the design process of building an overland trailer and I like to see other peoples ideas. I can see why trailers could be a hard sell on here though. Lots of guys on this forum and the other off road forums have the skills to build their own setup for probably less than a $1k. What a lot of them don't have is access to CNC cut panels. Its all going to be cost driven regardless. If you offered a steel trailer kit ( weld it yourself ) with precision cut panels and joints, maybe some locking hardware, for less than $2000 I could see that being a relatively easy sell. Whether or not its feasible for you is a different story.

Now, back to your idea of an aluminum trailer that gets riveted together. I really like the idea for the fact that I don't own a TIG or a CNC plasma table to make those precision cut side panels. I would be curious about the following....

1) Will there be an actual weight savings ? Our aerial platform ladder truck at work has an all aluminum 3 segment ladder. I believe the engineer told us its actually 900lbs heavier than the equivalent strength steel ladder. So no weight savings there, but it hasn't rusted yet !

2) How would it hold up to the type of shock loading it would receive off road ? Obviously airplanes have some pretty unique loads happening on their structures. I'm sure the g loads on the wings and airframe, as well as turbulence, are significant. However, I'm assuming because you have a laminar flow over the airframe, that these loads are not exactly comparable to the sharp impact style loads you might see when driving a trailer over rough stretches of roads ?

3) Not much of a question, but a summary of what I think would make your idea sellable. Weight savings would be number one on my list. Can I tow this thing behind my already overloaded 80 series without it dragging me down ? If so then that is a huge benefit in my book. Second would be having something that is very precisely cut and can be assembled by me, in my shop, at significant savings over buying a pre-fabbed unit from the usual vendors. Whether or not the joints would hold up in the real world is something that can be discovered with some long term testing.

 

[Steve83]

Like bringing anything else to market, I see this as your biggest hurdle:

My biggest problem is that my target market is ME. What do I want?

are there more of me or the next guy? if you offer my ideal will the next guy compromise? if you offer his ideal will i compromise?

You're saying it's not a question of the product yet - just the business concept. But they're inseparable. If you have a perfect business model selling unmarketable products, the business will fail. If you build a better mouse trap, but you sell them short, it'll fail.

So until you have a design that you think will appeal to a market segment with corresponding disposable income, the questions of materials & production techniques is moot. Or: it has already been answered. Yes, there are MANY successful businesses using CNC to sell unassembled products. But there are many MORE that failed. And if there are so few operating in the trailer market, there has to be a reason. It's certainly NOT that no one has had the idea...

Did you build plastic models of cars as a kid? Same idea.

Not exactly... I built MANY plastic models. But probably less than 4 cars. Most were airplanes & tanks, and that's my point. If you don't have a product that appeals to enough of the market, producing something that doesn't will be a losing proposition.

I've made several short-run products with VERY limited appeal, but they were all ridiculously-simple to design & produce. So I always knew how to keep my costs down so I could afford to sell what I made. A trailer like you're considering is MUCH more complicated, which makes the economics equally more-complicated; especially when you don't have a design to test-market.

There's zero need for adhesive in riveted structure.

That strikes me as an overly-sweeping statement... And somewhat biased. It could even be interpreted as a tautology. What would you say about the need for rivets in an adhered structure?

 

[AeroAggie]

@Steve83, I agree with pretty much all your comments. The business aspect is very complex. My wife started a service business from scratch. She spent probably 6 months just writing a business plan, and she has been very successful. As an engineer, I don't know how to start a business plan without a product, so I'm putting myself in the position of working the problem backwards, from product to plan. It's quite possible that will guarantee failure, so I'm not exactly ready to quit my day job and go all in.

That's why I'm using a forum like this just to kick ideas around and gauge the reception to the concept. Aside from a handful of folks, I'd say that reception was somewhat less than enthusiastic. I think it's difficult for people to get their head out of the construction details and think about concepts in more abstract terms. That's fine...it's not a criticism, it's just that my words aren't enough to fully convey the idea, so people naturally want to fill in the blanks with their own ideas.

That strikes me as an overly-sweeping statement... And somewhat biased. It could even be interpreted as a tautology. What would you say about the need for rivets in an adhered structure?

Sweeping? Sure. Biased? Definitely. Tautology? hmm...not sure what that one means. I'm just an aircraft structures engineer, but I'm pretty darn good at it. Bolts, rivets, and glue all have their uses. What I'm talking about does not require glue. Period. Come on down to Wichita and I'll take you through a factory that produces almost $6 Billion worth of riveted and bolted - but not glued - structure annually. We spend something like $175 million/year on fasteners alone. I know fastened structure. We also do composite structures (you know, strings and glue). We run more carbon fiber through autoclaves than just about anyone in the world, and are currently installing one of the largest autoclaves in the world. But I digress...

I think this thread has run its course for my original intent. I still think the concept has some merit (but maybe no market?) but this discussion is pointless without a physical prototype and some hands-on interaction. Thanks for all the feedback!

 

[Steve83]

A tautology is a theory that presupposes its own conclusion, or a redundant assertion. The word means "same meaning". What I meant was that your assertion about "no need" for a second method of fixing something that you described as a "structure" is redundant because the concept of "structure" presupposes that it's already sound. So that assertion could be made about ANY structure, and ANY second method of fixing it.

I would love to tour a factory like that - if I ever get out that direction, I might try to take you up on the offer. I'm an avid fan of the "How It's Made" TV series. Have you seen the episodes about travel trailers, motor homes, & expedition vehicles? I've been kicking around an idea for a drop-in camper for my Bronco, so I was particularly interested in those segments. The way wall panels are assembled by laminating sheet Aluminum to honeycomb cardboard, styrofoam, & FRPP by passing them through a simple roller made me think it was something I could do at home.

And I have some even-farther-fetched fantasies about building various ultralights, based on the A-10 Thunderbolt II & some modern miniature turbojets, the Ekranoplan/WIG concept, &/or an autogyro. But I'm not sure I'd have the guts to test-fly them. I have a local friend who's an avid ultralight pilot & mechanic, and he has a runway & hangars at his house where many others rent space from him. But I haven't gone up with him yet.

But back on-topic...
Most of the short-run products I've sold were things I actually wanted for myself. So I didn't have to worry with the economics or logistics of large production runs. But I did put a little thought into their design regarding mass-production, so that when a demand arose, I was ready to make a few. When demand dropped off, I had no investment to pay down. When demand reappeared, I made another run.

Here are some (as I said: ridiculously simple, and VERY small batches). Although I've ceased making the last one, its success & demand surprised even me: 2 runs of ~12 units each. (These links probably WON'T work from a phone app - use a browser on a fullsize monitor.)

. . . .

So that's my suggestion - don't really worry about "producing" a kit trailer yet. Design the trailer YOU want, as a produceable kit, and build it that way. Take LOTS of pics (like 10x as many as you think you might ever need). When it's done, revise the design with what you learned, and then file it away. Post a few of the assembly-process pics, and add pics of the trailer in-use so that people who might be interested can see you enjoying it, and contact you. If enough of them demand a copy, make a short run (maybe presold or with deposit) at a cost that justifies your effort. If THAT succeeds, and demand increases...

 

[AeroAggie]

I love the How It's Made shows too, and yes, I've seen those episodes. They're great.

Here's a video of our factory. It's not so much a How it's Made, but it gives you a fly through of most of our products in recognizable form.

 

[AeroAggie]

So that's my suggestion - don't really worry about "producing" a kit trailer yet. Design the trailer YOU want, as a produceable kit, and build it that way....

Agreed 100%, and that was my assumption right from the start. This thread was just about testing the waters. I don't think this community is quite ready to jump in with me yet, but I think if I were to build something and drag it to an event like Horizons Unlimited or one of the plethora of other vehicle shows, I might get a little more interest. Or maybe I just build something and mind my own damn business and be happy. I can't lose.

 

[ntsqd]

Guys, "Steve83" is pretty much a troll on another forum. Please don't feed him.