Chassis for the Ultralight

[angib]

Someone has reminded me that I did these plans some time ago, but then forgot to put them in the Design Library.

These are plans for a simple, basic chassis to suit the Ultralight or any other lightweight small trailer. They are limited on trailer weight and size, and they do require a decently-built body as it has to be self-supporting.





Plans are available to suit 4ft and 5ft wide bodies and as well as normal welded construction, there are versions which are only bolted together, which will suit quite a few forum members.

Access the plans via the Design Library link above or directly here: Ultralight Chassis

Andrew

[tinksdad]

That's most interesting. I just ran the numbers real quick and it should come in about 120lb/54kg lighter than an equivalent HF trailer. That's not a bad weight savings right from the start. Price wise it should be real close as well and you have a torsion axle rather than leaf springs.

[KevinS]

Thanks!

Has this design actually been built?

[Arne]

I like the V tongue better than the straight tongue, and the fact it goes back to the axle. It might add a bit of weight, but much stronger.

[Rock]

Andrew,

Did you (or anyone else) determine the stripped HF trailer set-up in the Ultralight PDF to be insufficient?

I'm raising my hand and offering to give it a real world test as that's the way I'm going (the original HF trailer stripped down design.) The tongue will not be connected to the axle.

Eric

[tinksdad]

Andrew,

Did you (or anyone else) determine the stripped HF trailer set-up in the Ultralight PDF to be insufficient?

I'm raising my hand and offering to give it a real world test as that's the way I'm going (the original HF trailer stripped down design.) The tongue will not be connected to the axle.

Eric

Cool!! I'll be watching your progress. I want to do an ultralight; but I don't want to be first!! I know there is a frameless woody in the Hall of Fame; not sure if that one falls into the ultralight category though.

[angib]

Did you (or anyone else) determine the stripped HF trailer set-up in the Ultralight PDF to be insufficient?

Nope, and I think it is probably strong enough. My concern is not with the strength of the tongue itself, but with the strength of the floor it's bolted to.

I just prefer the A-frame type, for structural reasons.

Andrew

[tinksdad]

Since Andrew was kind enough to send his PDF's for a tear baggage hauler, it's not like I don't have enough projects!!!

But..... teardrop building is addictive!!

I'm looking at this axle for an ultralight....
http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200323651_200323651 I have a discount coupon, and if I can get it shipped to the store for pickup rather than to the house, it could very well fall into a price range I'm comfortable with.

It falls between 4 wide and 5 wide so the plans would need a little tweaking. My concern is whether a 30 degree drop would change the floor height significantly. Any comments or opinions?

If I keep buying trailer frames/parts I'm going to need to move to bigger quarters soon!!

[dwgriff1]

I know there is a frameless woody in the Hall of Fame; not sure if that one falls into the ultralight category though.[/quote]

I followed these plans, except for the frame, pretty close. It could be lighter, but it is 5' wide and everything is insulated. Weighs 580 dry.

What is an ultra light?

dave

[tinksdad]

Yours was the one in the Hall Of Fame that I was referring to. I've looked at the pics in your album many times before I started my first tear trying to glean ideas that I could emulate with my limited abilities and working space. I probably just never paid attention to the weight.

I don't know if there is an actual definition of an ultralight. In the Ultralight.pdf, the stated goal was a 4x8 trailer weighing 500 pounds with a tongue weight of 75 pounds. At 5 wide and 580 pounds, I would definitely believe yours qualifies as an ultralight.


I don't know if I have the confidence in my skills yet to go frameless, that's why I like the V-frame torsion axle setup.

[bobhenry]

I woke up this past weekend with the idea of a 1/4" steel plate 2'x4' to accept the torsion axle then a straight tongue welded and double bolted to the plate in the center. and "V" diagionals to stabilize the straight tongue and transfer the side pressure that developes in turns from the front of the center tube back to the plate.

I have in the past built torsion box floors that are extremely strong and impossible to rack. Sides screw or bolt to the floor only. This should make an excellent foundation for a middle weight teardrop trailer.

[angib]

I'm looking at this axle for an ultralight....

It says 57 inch frame width (usually measured to outside of brackets), so that would probably suit a 60" body if you used, say, 4"x4" angle under the body sides instead of the 2"x2" shown in those plans.

The height of this axle should be OK, though not ideal - it's got a 30 deg down start angle and it says the brackets are 1 inch above the tube (though they look a lot more than that in the photo).

Based on the Reliable web site for this axle (http://www.reliabletool.com/products/r1000lb.htm) it will be around 4" from the spindle up to the top of the axle bracket under load. So with a 14" wheel (about 12.5" static radius), that will be around 16-17" from the ground to the top of the axle bracket which is quite workable.

One feature of this ultralight chassis is that it only has the thickness of the side angle (1/8") between the axle bracket and the body, where most trailers have a 2" tube between the two, so the ultralight rides lower than most chassis.

Andrew

[tinksdad]

Well..... I'm committed now. Went to Northern Tool and they had one in stock on sale. With my 15% off coupon, it came to $155 with tax.

The 57" inch width will work just fine for me. It leaves me plenty of room to get a 54" full mattress in (not quite a queen; but still 19" more than I have now). I didn't get hubs yet because I'm going to look at some wheels in different sizes before if I decide on 4on 4 or 5 on 4 1/2.

I tweaked the design a little to work with the 6 foot lengths of angle I can find locally and to fit the 57" width. I think this should work, although I will have to find a way to disguise the additional 12" I will have to add to the axle mount pieces. If I can find a supplier of longer lengths, I will revert to the shorter side mounts and longer tongue pieces. Either way I think I will add a piece of flat stock across the top of the tongue under the front edge of the tear to compensate for the thickness of the angle walls.



The axle, steel, hubs and wheels should come in right about 150 pounds. It should handle the 500 pounds of tear that I will build on it.

[angib]

That looks good.

One issue is that the plans I drew showed 40" from the back of the body to the axle tube, but that was using a Dexter #8 axle that has 4" long trailing arms.

The 2000lb Reliable has 6" long trailing arms, so that will put the wheels 2" further back, if the axle tube is kept in the same place. 2" is pretty close to "don't matter" but if you wanted to keep the wheels in the same place, and hence the same trailer balance, the Reliable axle needs to be mounted 2" further forward.

Andrew

[Billy Onions]

Since Andrew was kind enough to send his PDF's for a tear baggage hauler, it's not like I don't have enough projects!!!

But..... teardrop building is addictive!!

I'm looking at this axle for an ultralight....
http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200323651_200323651 I have a discount coupon, and if I can get it shipped to the store for pickup rather than to the house, it could very well fall into a price range I'm comfortable with.

It falls between 4 wide and 5 wide so the plans would need a little tweaking. My concern is whether a 30 degree drop would change the floor height significantly. Any comments or opinions?

If I keep buying trailer frames/parts I'm going to need to move to bigger quarters soon!!

Just looked on Andy's site for this no joy. Any idea where I can find the plans for this, it sounds like something my brother has asked me to help him with.