Looking to make a 6' wide teardrop camper with an expected overall weight of about #1500. I will use a Torflex 2.2K torsion axle. I have read that these axles place a higher stress on the frame just behind the trailing arm as compared to leaf spring axles. My thought is to use 2x3x.125 rectangular tubing for the axle mount frame members which run the length of the trailer which will be about 12' long. Knowing that the camper body and cargo in front of it will weigh <#1000, do you think the 2x3x .125 tubing is sufficient? Overkill? Maybe I could go with 2x2? If you need more information to answer the question, please let me know. I'm comfortable with my fabrication skills, but I'm no engineer or draftsman (see crappy pic attached. Each block = 4". Thanks.
Trailer frame using torsion axle
- Thread starter Bwinks
- Start date
mike93lx
ALLIANCE MEMBER
That would be built a lot better than all the teardrops rolling around on HF trailers that don't have any problems.
Box tubing often rusts from the inside out as water doesn't have a great way out. A piece of (small) channel running from the coupler, down the sides and all the way to the rear would be temping for me. Angle iron for cross members and to frame your extensions.
That said, the next trailer I build will be my first, so take it for what it's worth.
Box tubing often rusts from the inside out as water doesn't have a great way out. A piece of (small) channel running from the coupler, down the sides and all the way to the rear would be temping for me. Angle iron for cross members and to frame your extensions.
That said, the next trailer I build will be my first, so take it for what it's worth.
billconner
Well-known member
I think you'll be fine with 2x3, and many seem to get away with 2x2. You can find a lot of experience at tntt.com - a bulletin board for tear drops and tiny trailers. Nothing like hearing from someone who has built a bunch of them.
Hi Mike- Ha! I know what you mean. Those HF trailers are scary looking but they appear to get the job done (at least some of the time). Anything leaving my garage will be build on something more stout. I've read the same about tubing rusting out. It seems that with good design (no open tubing ends), and quality welds with venting holes on the upper sides of the tubing, preventing water and salt intrusion should be very easy.
Thanks Bill- I will check out that site.
mike93lx
ALLIANCE MEMBER
Tnttt is a great resource. I was on a teardrop kick for a while and spent a bunch of time there.
Lots of folks building on HF and NT kits.
Good luck. We'd love to see a build thread if/when this jumps off paper
Lots of folks building on HF and NT kits.
Good luck. We'd love to see a build thread if/when this jumps off paper
billconner
Well-known member
Lots of people scratch building their frames too at tntt.com. Not great bb software like here but workable.
whateg01
Well-known member
It's not just water and salt intrusion. It's when the water gets and can't get out. Vent holes in the top of the tube is a great way for water to get in. Weep holes let water out. Don't ever plan to keep water out. Every time you add a light to the frame, there's a hole. If you have to mount a bracket, there's a hole. Attaching the wooden frame, there's a hole. In fact, a tube with open ends is the easiest way to keep water from accumulating in a trailer frame but still get most of the torsional advantages of using tube.
Is the camper's overall length going to be 12'? Or is that the body of it? It seems like it's going to tough to keep that much trailer under 1500#, but maybe it's doable with the right material selection. But a cooler of ice and beers can add #50. So, it would be really easy to get too much weight on it.
mike93lx
ALLIANCE MEMBER
Weight savings through whiskey consumption!
Hi Mike- I agree with all of your points and had previously considered most of them. Very good food for thought. I appreciate it.
kerrynzl
Well-known member
2" x 2" x .125" is sufficient for a teardrop [I would even be comfortable with angle]
With a teardrop , the body side panels become a stressed member.
Don't fall into the trap of Bigger/Heavier is better.
With engineering "SHAPE IS MORE IMPORTANT THAN SIZE"
If I ever built a teardrop , I wouldn't even bother with a conventional frame. The torsion axle would be attached to an "A" frame tongue [cut back parallel] and the actual Teardrop camper made from 1" x 1" furniture tubing with glued panels as a stressed member.
I think a 2200 lb torsion is overkill, you are better off matching the torsion axle to the gross weight. [1500 lbs]
Here is an example of "SHAPE" This trailer pictured weighed 480 kg [1056 lbs] GVW was 2500kg [5500 lbs] It hauled around a C4 Corvette race car.
It had no frame except 3x 2 crossmembers, and the 4 x 2 "A" frame tongue
The actual deck runners were the frame made from 2mm [80"] galvanised sheet steel pressed into shape
The weakest point was the centre of the wheelbase because the payload straddled each side [front and rear] So the Fender backs became a stressed member by adding height.
Here is the frame rails
"SHAPE IS MORE IMPORTANT THAN SIZE"
Thank you for all of the information! I appreciate your response because I have a tendency to overbuild as I have no engineering background. Trying to figure it out using online physics calculators is beyond me. I wish I could order a 1500# axle. 2.2K was the lightest they could offer.2" x 2" x .125" is sufficient for a teardrop [I would even be comfortable with angle]
With a teardrop , the body side panels become a stressed member.
Don't fall into the trap of Bigger/Heavier is better.
With engineering "SHAPE IS MORE IMPORTANT THAN SIZE"
If I ever built a teardrop , I wouldn't even bother with a conventional frame. The torsion axle would be attached to an "A" frame tongue [cut back parallel] and the actual Teardrop camper made from 1" x 1" furniture tubing with glued panels as a stressed member.
I think a 2200 lb torsion is overkill, you are better off matching the torsion axle to the gross weight. [1500 lbs]
Here is an example of "SHAPE" This trailer pictured weighed 480 kg [1056 lbs] GVW was 2500kg [5500 lbs] It hauled around a C4 Corvette race car.
It had no frame except 3x 2 crossmembers, and the 4 x 2 "A" frame tongue
The actual deck runners were the frame made from 2mm [80"] galvanised sheet steel pressed into shape
The weakest point was the centre of the wheelbase because the payload straddled each side [front and rear] So the Fender backs became a stressed member by adding height.
Here is the frame rails
"SHAPE IS MORE IMPORTANT THAN SIZE"
kerrynzl
Well-known member
I can show you a few more examples if needed.
Just for simplicity ...... A cardboard box is stronger than a cardboard tube
Here is an Al-Ko Caravan Frame [Travel trailer] , there are literally millions of these all over Europe / UK / Australia / NZ
If you removed the frame it is quite flimsy BUT when it is tied together with the body it is strong
These Al-Ko frames are usually supporting a "stick and tin" body
I built a high sided folded sheet steel [.80"] utility trailer that had a plywood floor.
The floor was supported by 2" x .80" angle cross members, and the trailer was used to cart around a small excavator to construction sites
My biggest concern was the tyres not the frame
billconner
Well-known member
Look at a harbor freight or northern tools trailer and just consider they have lasted for years in many years drops. I'm not saying use them, only look as a guide.
I believe few years drops are built with a steel frame. They rely on the skins - ply of fibreglass - and foam to separate the inner and outer skins. If you really want light weight consider that. Best approach, think airplane, not house.
I believe few years drops are built with a steel frame. They rely on the skins - ply of fibreglass - and foam to separate the inner and outer skins. If you really want light weight consider that. Best approach, think airplane, not house.
Save your Overkill for the tires, that is where you will get the best ROI.
kerrynzl
Well-known member
This won't be applicable to a treardrop.
But many years ago , I built a 1" tube framed enclosed trailer that had glued [1 piece] aluminium sides as a stressed member.
The Aluminium was so drum tight and people thought it was composite .
2 problems with it.. ..It was so light that it was unstable in the wind when empty [when loaded it was a dream to haul]
And it was irrepairable
Nowadays I would use pre-finished "sign-boards" [alloy/composite sandwich] and **** join them.
If one got damaged you can still cut out the panel and replace it.
billconner
Well-known member
Personally I favor foam core with plywood adhered to it both sides - probably 1/4 if flat or 1/8 if curved - and then fibreglass it.
kerrynzl
Well-known member
I was commenting about the 1- piece type construction.
I once tendered in on this German Caravan that was 1 year old and written off by the insurance company.
This was the damage [the insurance company couldn't repair it to an acceptable standard
I like composites , but the design needs to be considered [for the nature of the beast]
gahrajmahal
Well-known member
When I was a lad of 16 I needed a trailer for my dirt bike and a few of my friends. I found a VW pan, with front end and transaxle. The transaxle went into a bug and I had the H-beam front end leftover. We found a neighbor with a Lincoln tombstone welder to make our trailer. We welded a 10 ft piece of black iron to the top beam. We added angle iron braces from the pipe to the outer shock towers. For the bike mounts we added lengths of 4” wide channel iron. We usually had three bikes on this trailer and sometimes had a fourth mini bike mounted sideways.
The reason for this long description is to say this was the best riding and tracking trailer I have ever towed. The 15” tires and torsion bar suspension was very smooth. Gas cans and coolers strapped to this rig never got tossed or bounced around much.
I look forward to seeing what you come up with!
The reason for this long description is to say this was the best riding and tracking trailer I have ever towed. The 15” tires and torsion bar suspension was very smooth. Gas cans and coolers strapped to this rig never got tossed or bounced around much.
I look forward to seeing what you come up with!
I can't write in public what I really think of Dexter Torflex axles (I have 2 trailers using them with extremely poor results). They are compact, simple, easy to mount - but the OP is right to realize the rear mount bolt are is extremely stressed - easy to fix with a welded on doubler/angle to spread that load. For OP's use, though, extremely stiff/short travel that will beat the trailer up pretty badly. Being some kind of a trailer guy, I recommend Timbren stuff for those who want far better ride and construction quality.
IF you can keep it light: https://timbren.com/products/asr1200s02-axle-less
If you are going to pork out: https://timbren.com/products/asr2khds02-axle-less
Prices are MSRP in Cannuckistan Loonies, not real money. You can do a lot better with Greenbacks.
Personally, I HATE single axle trailer suspension. The only one I have ever done was in independent on air to get payload and ride in small space. You can make MUCH better ride/suspension using walking beams on tandems (will probably convert one of my 2 x 3500 Torflex trailers to torflex on walking beam since it is a trailer used by many people who don't seem to listen when I tell them it needs to be LEVEL. My other Torflex trailer is 3 x 8k on its 3rd set of axles over last 24 years. Trailer was literally designed around the axles to maximize space and brake surface (discs) so not going to convert, just retired it. Oh: you CAN pull triples but only with air on the tractor (has to be kept dead level).
IF you can keep it light: https://timbren.com/products/asr1200s02-axle-less
If you are going to pork out: https://timbren.com/products/asr2khds02-axle-less
Prices are MSRP in Cannuckistan Loonies, not real money. You can do a lot better with Greenbacks.
Personally, I HATE single axle trailer suspension. The only one I have ever done was in independent on air to get payload and ride in small space. You can make MUCH better ride/suspension using walking beams on tandems (will probably convert one of my 2 x 3500 Torflex trailers to torflex on walking beam since it is a trailer used by many people who don't seem to listen when I tell them it needs to be LEVEL. My other Torflex trailer is 3 x 8k on its 3rd set of axles over last 24 years. Trailer was literally designed around the axles to maximize space and brake surface (discs) so not going to convert, just retired it. Oh: you CAN pull triples but only with air on the tractor (has to be kept dead level).