Custom Chassis For a 4x10x4 1/2

[GreatPumpkin]

From my understanding of rubber, it only degrades:
1. When exposed to excess strain (too much weight, extreme impacts)
2. When exposed to sun (UV rays) for extended periods of time
3. In extreme heat / extreme low humidity

Really, as long as you stay well within the weight rating of the axle, your torsion axle should hold out for the life of your trailer. As they age, the axles will become less effective and may eventually need replaced. This is me speaking from logic though -- perhaps someone more knowledgeable than I can chime in and speak from experience...

Speaking from my experience with my Airstream, and the time spent on those forums (Airstream uses Dexter and/or Henschen Torsion Axles)...

Expected lifespan is 15-20 years. While some have held out for upwords of thirty, that is to the upper level. The biggest enemy of a torsion axle is sitting, unused. They can "set" from lack of use and the dead weight sitting on them. The rubber does experience degradation over time, but it won't be exposed to UV rays, or excess strain if you order the appropriate weight rating.

However, a Teardrop weighs nothing near the weight of an Airstream, so the weight isn't going to be an issue. Just make sure and use your trailer at least a couple times each year.

[angib]

Does anybody have cad or just plans for the flexiride?

Flexiride's technical page has got drawings - the only CAD model is of the 3500lb axle.

Andrew

[mikeschn]

I made a cad model of a 2000 # flexiride that I used on the Lil Diner.

It's just approximate, and doesn't include a lot of detail.

Mike...

[DMcCam]

My trailer is very similar to yours except that I don't have the center tongue extension. My trailer just has the 50-degree a-frame tongue. There is a benefit to your tongue design in that a longer tongue is easier to back.

I realize that your model doesn't go to this level of detail, but you may want to have 2x2x1/4" angle tabs welded to the side rails and/or crossmembers to give you a place to fasten the shell to the frame and a place to bolt rear stabilizers/levelers.

Tom

Hi Tom, thanks for the heads up on the tabs. I can't imagine how many TD's you'd have to build to finally get it right if this forum didn't exist. I was just going to drill and bolt through the 2x2 frame.

GreatPumpkin Speaking from my experience with my Airstream, and the time spent on those forums (Airstream uses Dexter and/or Henschen Torsion Axles)...

Expected lifespan is 15-20 years. While some have held out for upwords of thirty, that is to the upper level. The biggest enemy of a torsion axle is sitting, unused. They can "set" from lack of use and the dead weight sitting on them. The rubber does experience degradation over time, but it won't be exposed to UV rays, or excess strain if you order the appropriate weight rating.

However, a Teardrop weighs nothing near the weight of an Airstream, so the weight isn't going to be an issue. Just make sure and use your trailer at least a couple times each year.

Sounds like the Flexiride would be an elegant solution especially with a TD's weight. Thanks for the info!

Thank you Andrew sir, I found those guys just yesterday following Mike's breadcrumbs and downloaded the them for reference.

Hi Mike, Thank you for your kind offer sir. It will probably be simpler for me to just trace over the drawings in the same program I'm drawing in. Sometimes dxf's or dwg's come in a little wonky in Corel.

Once I do trace them I'll make sure they are available here for everyone.

Sooo... 2,000# or 3,500# for a 4x10x54" trailer?

Dave

[DMcCam]

Hey Tom, I've been looking for pictures of how members have attached their deck to the frame and have found very little. Would you have pictures of how you did it? This is one area that seems to be overlooked a bit. Any and all pictures of deck to frame attachments would be great to see.

Thanks in advance, Dave

[DMcCam]

Well guys, I've been working out the kinks in the design based on your input. Here's the plan so far for the custom trailer frame all drawn out for critique. I sure hope I got it close to correct.



Download large jpeg image here:
http://www.vulcaniavolunteers.com/TEARDROP/TFPLN_IPABIG.jpg

How do you derate an axle?

Thanks again, Dave

[Cliffmeister2000]

Dave, that's some amazing detail!

If you want to save some material and a bit of weight, eliminate the crossmember just in front of your axle. With a Flexiride, the axle acts as a crossmember, making that one redundant.

[Cliffmeister2000]

How do you derate an axle?

With a standard axle, you change the spring configuration. With a Flexiride or any torsion axle, I believe you get what you buy. If you want a lighter axle, you will have to buy a lighter axle, as near as I can tell.

[angib]

Assorted thoughts:

3500lb axle is way overkill - this will mean you have virtually no suspension and so the teardrop will get hammered over every bump.

A 2000lb Flexiride axle can be ordered with any capacity (well, in 50lb increments, I think) from 1400 to 2000lb. A 3500lb can be rated at 2500-3500lb. The axle rating is set when the axle is ordered and cannot be changed thereafter.

Your drawing office instructor may be in his/her grave, but they will be gently rotating at the sight of the second cross-member that doesn't reach as far as either side rail......

The triple tongue arrangement would pass the Australian trailer rules for a 1250lb utility trailer if all the tubes are 2"x2"x1/8", so that's good for about a 2500lb teardrop. So overkill again, but the extra strength will do no harm and it doesn't look like light weight is your target.

Andrew

[Cliffmeister2000]

Your drawing office instructor may be in his/her grave, but they will be gently rotating at the sight of the second cross-member that doesn't reach as far as either side rail......
Andrew

I'm betting the second cross member is just in the wrong layer, and the A frame goes under it. (Andrew, I'm betting you saw this as the probable issue, also) I make that mistake all the time, but I only know how to draw in Visio, and to nowhere near this level of detail.

[DMcCam]

Excellent feedback gentlemen. You are both right about the plan. I did forget to change the line to dotted and move it to the right layer. And my father the architect would not be pleased that I missed such a obvious error.

I am going for a lighter build so removing the center brace and the long center tongue support would be helpful. Do I then center the two cross braces in the remaining space on both sides of the axle?

The weight I'm going for is around 1,000 lbs or a bit less if possible. If I change to a 2,000 lb Flexiride axle, I'll need to figure out the gross weight for derating it?

Oh, I did reload the plan with the glaring error fixed.

In Gratitude, Dave

[aggie79]

David,

I just thought of something you may want to consider. I have a reciever at the back of my teardrop so I can use my bike rack. Others have receives on the back or sides for side tables and other things.

By the way, I saw your section on another thread that showed the tabs. That is how I wished I did my trailer (another story for another time.)

Tom

[DMcCam]

Hi Tom, first of all, I really like how you are building your TD. The 'skeletonized' plywood walls seem a whole lot easier to work with than all the stick framing.

I've thought about the receiver mounts...just haven't figured out how they fit our camping style yet. I've only got a week or so before I'll have to pony up the plans for the trailer to me fabricator buddy. That's why I'm spending all the time to get the TD's foundation right in my first rodeo.

Thanks again for your help, Dave

[angib]

An A-frame tongue instead of the triple-tongue would be OK up to 800lb for a utility trailer, so I reckon that's 1600lb for a teardrop. The angle of the A-frame isn't right for a 50-deg coupler, so join the two A-frame tubes onto a short coupler mount tube - just what you've drawn but with 90% of the centre tongue tube missing.

With an A-frame tongue, the cross-members are only there to hold up the floor and serve no other structural purpose. They can be left out entirely if you wish (and you make the floor strong enough to hold itself up) or could be swapped for 2x2x1/8 angle which would provide easy bolting and save some weight. Put the cross-members wherever suits you.

Andrew

[DMcCam]

Thank you again Andrew Sir. So after all this, Rigsby's design is right on the mark! Just keep the 2x2x1/8 A-frame tubes and shorten the center one. Do you think I should extend the A-frame back close to the axle too? I do plan on a pretty wide tongue box so I do need support ahead of the TD.

Over here in England, the tendancy is to build your own frame rather than use a bought item, As i have now built over 20 cargo trailers of varying designs, i would personaly extend the two outer pieces of the tongue to nearer the axle. This way it will give more strength to the build and reduce any flexing, which is a potentional point of paint, varnish or even wood cracking
Similar to the way i built the chassis for my first tear

Dave