Minimalist Torsion Axle Frame

[alaska teardrop]

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[Juneaudave]

I've only got one Alaska criteria...if you build it, would you haul it down McCarthy Road to Kennecott? McCarthy Road

Of course, your destination would be the Kennecott Mine in the Wrangle St.Elias Nat. Park...Cool place

I'm a thinking that if you can haul the McCarthy Road....your gold for the Tok, the Dalton, or potholed Anchorage streets!!!

 

[madjack]

I like it Fred...functionally light...are you envisioning a solid ply floor or a sandwich floor..............................

 

[angib]

Fred,

Looks good - that's exactly the amount of connection to/support of the body that I also think is needed.

Here is some more weight estimating data for you:

Wheel and tire (source: Northern Tool)
205/70x15, D range - 1710lb capacity, each 44lb
205/70x14, D range - 1710lb capacity, each 37lb
175/70x13, C range - 1360lb capacity, each 32lb
175/70x13, B range - 1100lb capacity, each 29lb
5.30x12, C range - 1045lb capacity, each 24lb
4.80x12, B range - 780lb capacity, each 20lb
4.80x8, C range - 745lb capacity, each 12lb
Note: capacities and weights are PER WHEEL/TIRE

Axles (incl hubs)
Rubber torsion axle, #8, no brakes, 1100lb capacity, 60" over hubfaces: 53lb
Rubber torsion axle, #8, electric brakes, 1100lb capacity, 60" over hubfaces: 75lb
Rubber torsion axle, #9, no brakes, 2200lb capacity, 60" over hubfaces: 68lb
Rubber torsion axle, #9, electric brakes, 2200lb capacity, 60" over hubfaces: 89lb
Leaf sprung tube axle, no brakes, 2000lb capacity, 60" track, complete: 65lb
Note: thanks to Dexter who provided weight data for the examples above

Andrew

 

[subtearanean]

What would need to be done to the floor at the bolt through area to strengthen the connection? I would think that enough bouncing around just with normal highway use would start to undermine the plywood floor?

 

[alaska teardrop]

I've only got one Alaska criteria...if you build it, would you haul it down McCarthy Road to Kennecott? McCarthy Road

Of course, your destination would be the Kennecott Mine in the Wrangle St.Elias Nat. Park...Cool place

I'm a thinking that if you can haul the McCarthy Road....your gold for the Tok, the Dalton, or potholed Anchorage streets!!!

• Gotta admit that a trip to McCarthy would be a true "shake-down" cruise. Broke a rear control arm on the old Volvo last trip. But, Dave, didn't you fix that road since then?

• http://tnttt.com/viewtopic.php?t=10200

• I heard that the foot bridge was washed out in last months' flood. Another road to no bridge to nowhere! Back to pulling ourselves across the Chitina on that cable contraption. At least you'll never run out of work making & fixing Alaska roads.

• Madjack, I should explain. Mike's 'Ultra-Light' discussion lead me to adapt my Northern Lite frame design to a minimal towbar, but with a torsion axle, in order to contribute to the idea.

• http://tnttt.com/viewtopic.php?t=11522

• In Alaska reality, as Dave points out, support extended full length with a bumper & spare tire would be more practical. What I have in mind (and need to finish the drawings), is a floor with no wood, steel or perimeter frame, as such.

• Andrew, Thanks for the compliment, the additional information and, again, your explanation of the Australian rules. Your info points to the variety of choices available with a torsion axle. Weights, wheel size, ride height, ect.

• Sub, I made a stronger attachment change in the cabin mount example. But that choice would really be dependent on the type of cabin construction. Guess, there would be several choices.

• Sunshine & 17*

 

[alaska teardrop]

• After some major life's changes, I've finally been able to implement this chassis concept.

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  • • The design allows for different widths, cabin length and tongue length. The torsion axle is the main chassis crossmember. It assumes a cabin with torsional integrity. The #3 tie together parts are 1/8" flat bar. The #2 parts are 1/8"x2" square tubes for the coupler and axle mounting. The weight and tongue length of the trailer determine the #1 main rails. With a 36" tongue for example, the gross capacity would be 980# using 1/8"x2"x1" rectangular tube. 1341# using 1/8"x2"x1-1/2" rect. tube. 1701# using 1/8"x2"x2" square tube.
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    • This chassis is for a 4'x7' cabin, 39" tongue, 905# gross weight and #8 - 900# Dexter axle. For simplicity, instead of bolting on the all aluminum body, it has a perimeter and two crossmembers of 16 gage (1/16") 1" square tube welded to the chassis in order to integrate the floor and walls to the chassis using VHB tape and rivets. Total steel weight of 81#
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    • The axle location and balance can be adjusted when the trailer is finished, but before the fenders are installed.
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    • 
    • The four axle mounting bolts are offered up at the open ends of the 2" sq. tube and through the bottom of the tube.
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    • Jack, chains and coupler mount.
    • Fred

• Guess you have to click on gallery for full size pictures.

 

[alaska teardrop]

• Well, this trailer is completed. 525# dry weight. 90# tongue weight. Pulls smooth & steady, even at 90 mph.

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• Fred

 

[KCStudly]

Nice!

 

[Lgboro]

Just awesome!!!... is your design a mini toy hauler?

Edit: Stupid question as upon further viewing I see the hinge for your galley, however, your design would be perfect for a mini toy hauler.

 

[48Rob]

6 year build?

You have way more patience than me

Looks nice!

Rob

 

[alaska teardrop]

• Thanks guys. The sketches laid on the drawing board until this spring when I was able to make detailed mechanical drawings and start building. It is designed to be a light weight traveler. It has a galley & sleeping interior.

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• I'll get a thread going on how it is constructed and then offer it for sale.

• Fred

• Link to design & construction thread: viewtopic.php?f=27&t=51991

 

[WesGrimes]

Looks great! Well done!

 

[alaska teardrop]

• Thanks Wes,

• Here's a link to this trailers' build: viewtopic.php?f=27&t=51991

• But to get back on track, this thread began as a light weight tow bar & torsion axle concept that could be adjusted for cabin length - width, tongue length, weight & axle location. A wood builder such as yourself could attach a well constructed cabin to just the tow bar & axle. Or add a light weight steel or aluminum perimeter floor frame to build from.

• This particular trailer has aluminum sheet attached to the perimeter floor frame & cross members. The continuous floor insulation is installed in the last stages of the build. This approach to the floor construction eliminates the need for insulating & undercoating the bottom side, heavy sandwiched floors with thermal bridges & potential wood rot, ect. The idea could also be applied to other chassis, including bolt together types.

• As an example of what I mean, imagine this trailer with aluminum floor & insulation built with wooden walls, roof, ect.

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• Fred

 

[alaska teardrop]

• This design & rendering of her new trailer is by Stacie Tamaki in San Jose, Ca.

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• It will have a 6' L x 4' W x 4.5' H aluminum cabin with the door at the rear - framing a combination of steel & aluminum tubing. The tongue is 48". The main rails are 2" x 1-1/2" x 11 gage (1/8") rectangular steel tubing, allowing for a GVW rating of 1005#. The frame weighs 83#.

• Topside

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• Underside

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• Tongue

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• Axle mount

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• Fred

 

[alaska teardrop]

• Dexter #8 - 1100# - 22 1/2* up start angle

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• Dexter #8 axle w/7" brakes

• Adjustable forward or back for final balance before fender installation

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• 195/70/14 Radial tires

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• Steel wheels w/moons

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• Edit:

• Weights: Frame & floor steel = 83#, Axle w/brakes = 82#, 2 Steel wheels/tires/caps = 70#, Jack w/o wheel = 7#, Chain/links/bolts & nuts/coupler = 7#

• Total chassis weight = 249#.

• Fred

 

[aggie79-HILO]

I love your trailer designs and am envious of your skills.

Could you answer a question for me please? For your adjustable axle mount, how do you get the bolts in (and have room for a wrench)?

 

[alaska teardrop]

• That's good of you to say. Thank you, Tom.

• I'll return the compliment & say that your classic & classy teardrop design is really cool!

• To answer your question, this picture probably shows the axle attachment the best.

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• The tubing is 2" & the bolts are 1-1/4". After the cabin is finished the axle is lifted in place. The bolts are dropped in place through the open ends of the tube with a long nose plier. The head of the bolt is held with a box wrench while the heavy washer & locking nut are secured with a socket wrench.

• Fred

 

[KCStudly]

Not exactly on topic, but interesting just the same: the trailer hitch kit that I got for my Ford Escape TV (with unit body) included a fine spring wire fish tool that had a cork screw like curl (a spiral wound end that gripped the treads of the bolts) on one end that was used to pull the bolts up through the channel in the unit body frame rail and out through the existing holes. I don't recall at the moment what kept the bolts from turning while securing the nuts, but it worked very well.

 

[angib]

I don't recall at the moment what kept the bolts from turning while securing the nuts, but it worked very well.

What I've seen elsewhere is using a carriage bolt and fitting a big square/rectangular washer under the head of the carriage bolt - a square hole for the bolt locks the bolt and washer together and if the washer is big enough, it can't turn inside the tube/chassis member.