My Giant Teardrop (updated 04/21/10)

[Ivar the Red]

Posted: Mon May 05, 2008 5:34 am

Ok, after almost a year of posting with no tear, and shopping for the perfect starting point, I think I'm finally ready to start my build!

I "over bought" as far as the length, but too much is better than not enough.


I've got plenty of "chopping room"



I should be able to move the axles after the chop, kind of want to keep the tandems for a different look. Thoughts any one?




What do you guys think I should do about these brakes, and I wonder how hard it will be to replace these wheels?



Well, there it is. My stimulus check actually stayed in America for my part cause $300 of it went to this guy for the trailer, some more went to the Bass Pro Shop in Oklahoma City, a fair chuck went to Joe's Crab Shack, and some more will go to McCoy's Lumber Yard today after work.

[Ivar the Red]

Posted: Mon May 05, 2008 9:27 am

Johnny,

Hope you got something big to pull that thing!!

What length will it be when you are done cutting?? Do you have a sketch of the camper you are putting on it??

Don't know yet...I'm not much of a "plans" guy. I see something in my head and cut, hammer, and glue until it gets there. But....with this being as big as it is, I think I'll swipe some cardboard from work, and at least try to make a template.


The Durango pulled it just fine...so far.

[Ivar the Red]

Posted: Mon May 05, 2008 6:41 am

I'm picturing a pimped out teardrop limo.

Posted: Mon May 05, 2008 10:05 am

Hey Lisa.

Yeah, something like that!

[Ivar the Red]

Posted: Mon May 05, 2008 12:38 pm

Thinking something like this for a floor plan, been wondering what to do for my daughter's sleeping arangement, but with the extra room I think the problem is solved.


Looking at it now, if I do that, I may add another door for the other bed.

[Ivar the Red]

Posted: Wed May 07, 2008 6:56 am

[Ivar the Red]

Posted: Thu May 08, 2008 8:48 pm

Ok here's a little preview
no...the Mustang is the neighbor's

the blank area in front is for the deck

this set-up is exactly 40 foot long

[Ivar the Red]

Posted: Fri May 09, 2008 2:35 am

Ivar,

Just a quick thought - with the cardboard profile as it is in your picture, the weight of the trailer is too much to the back without the toy at the front. So, if you will ALWAYS tow the trailer with the toy at the front, the overall tongue weight will be okay. But if you ever tow the trailer without the extra weight of the toy in front, you will definitely have some serious problems with fishtailing (because the heavier galley is at the back). And fishtailing on a highway is really no joke!

My suggestion is that you put the profile slightly forward. This will add slightly to your tongue weight, but if you have a tow car to match that monstrosity of a trailer, I think the added weight will be okay.

The placement of the axle with these toy haulers are always problematic. That's why so many people consider moveable axles on toy haulers (although very few have them)!

Anyway, good luck with the build. It certainly will be an interesting one!

[Ivar the Red]

Fri May 09, 2008 5:07 am

Ivar,

Just a quick thought - with the cardboard profile as it is in your picture, the weight of the trailer is too much to the back without the toy at the front. So, if you will ALWAYS tow the trailer with the toy at the front, the overall tongue weight will be okay. But if you ever tow the trailer without the extra weight of the toy in front, you will definitely have some serious problems with fishtailing (because the heavier galley is at the back). And fishtailing on a highway is really no joke!

My suggestion is that you put the profile slightly forward. This will add slightly to your tongue weight, but if you have a tow car to match that monstrosity of a trailer, I think the added weight will be okay.

The placement of the axle with these toy haulers are always problematic. That's why so many people consider moveable axles on toy haulers (although very few have them)!

Anyway, good luck with the build. It certainly will be an interesting one!

I would disagree with this. It is a large heavy trailer with dual axles and the addition of the box (camper portion) on top is going to be very minimal weight. Add to that the fact that all of the storage is in the front of the camper area and will add most of the weight to the front when traveling, unless you do not have anything in there. Even then, I doubt that the weight will be shifted back that much. Just be sure and carry all of your cast iron stuff in the forward storage area.

Just my opinion, I am by far NOT an expert on this.

According to Ivar's own plans (seen below) the trailer has a regular galley. That means that the galley is usually the heaviest portion of the trailer, and that is also why most teardrop trailer's wheels are further backward than 'regular' trailers.

I understand about the storage at the front. I suppose the question remains whether the galley will be heavier than the front storage, or vice versa. If the galley is heavier, then the profile needs to be moved forward. If the storage compartment up at the front is the heavier of the two, then I suppose toypusher's sugestion would be the better option.

My 2c worth....

[Ivar the Red]

Posted: Fri May 09, 2008 5:46 am

Whoa!!!!!!!!!!!!!!!!!!!!!!!!!!!!Slow down everybody. The general rule of thumb is 10% of Total bodyweight as the ideal tongue weight. I predict this will make his ideal tongue weight around the 400 pounds plus, if he continues along these lines. If Ivar is serious about building this, the Mother of all Td's, his main aim is to balance his build around that centre tandem axle. Then he can adjust his frontal loading and build to give a nominal tongue weight that his tow vehicle can handle.
Andrew can probably confirm, or destroy this, but I think you'll find that you are all barking in wrong direction.

Cheers
Paul
PS slightly different rules apply when you start using tandem axle trailers.

[Ivar the Red]

Posted: Fri May 09, 2008 3:54 pm

It seems to me the first thing to do is to haul that trailer down a weighbridge and find out what it weighs, as it is now - it looks heavy, but then there's quite a few bits, like the cross-members, that are just flanged sheet and could be quite light.

If they'll let you, weighing it complete standing on its prop stand and then weighing just the axles with the prop stand off the weighbridge would be useful as that would tell you what the hitch weight is now.

At first sight the weight layout of what you're adding doesn't look too good - the weight of the body is centred maybe a little behind the last axle - however if you are looking to carry much on that deck, the deck itself is going to weigh quite a lot. It would be easy to make the deck both indestructible and heavy, which would kill two birds with one stone.

If I just assume the deck weighs the same per foot of length as the body behind it, the centre of the weight you're adding falls somewhere around 10% forward of the equalisers (between the axles) which is about as near perfect as you could want.

If you want to carry much on the deck, you should note that about 60% of the cargo weight will end up on the hitch and only about 40% on the trailer's axles. But it looks like a Durango can carry so much weight on its hitch that you'd be hard pressed to get anything heavy enough onto the deck to overload the hitch.

So it looks good, but finding out the trailer weight before you start could avoid tears later.....

Andrew

[Ivar the Red]

Posted: Fri May 09, 2008 5:26 pm

Thank you very much Andrew. I'll make that my weekend challenge; to find a scale. I hope I don't have to pull it all the way to Lawton, it's quite bouncy as it sits now.

I think there is some miss-conception about the deck on front. This is not a toy hauler like those Lil Guy 6 Wides.(for one thing, I have no toys) It is just a deck, like to sit on and watch the sunset and maybe have a cold one(or 6). If the extra weight is needed up front, I think I could come up with railings, or bench seats, or whatnot.

Now, out back. I'm not planning any kind of luxury galley or something like that, it will be bare-bones. The main cabin will be double walled, with the bead board on the outside, foam board insulation, then polly some kind of paneling. Once I get to the galley I think I could go with just the single wall.

[Ivar the Red]

Posted: Fri May 09, 2008 6:00 pm

I agree that front/rear distribution is a problem, because the amount of stuff in the front is so variable. The Trailer Balance Worksheet is definitely called for here.

For this situation of forward-located cargo (in the compartment, I realize there's none on the deck), one approach is to balance for just adequate tongue weight without cargo, and know that with cargo it will only go higher. Then work out the worst case of full cargo, and ensure that the tug is adequate.

Even when the front/rear balance is settled, and tongue weight seems okay, this will be a poor configuration for stability, because the masses are at the ends (the middle has just a bed and lots of air space). This is the "high polar moment of inertia" situation which has been discussed before - the trailer acts like a flywheel, so once it starts rotating (yawing or swaying in direction), it wants to keep going.

I think the traditional rear-heavy teardrop layout is great for stability if the axle is well placed, but does not lend itself well to a forward cargo load.

With the deck weighing very little, it does look like the axles need to move back, at a guess.

It might be cool if the front corners of the deck folded over, so the deck could run very close to the tug in use, but fold out of the way for towing to allow good turning angles.

[Ivar the Red]

Posted: Fri May 09, 2008 6:13 pm

It seems to me the first thing to do is to haul that trailer down a weighbridge and find out what it weighs, as it is now - it looks heavy, but then there's quite a few bits, like the cross-members, that are just flanged sheet and could be quite light.

If they'll let you, weighing it complete standing on its prop stand and then weighing just the axles with the prop stand off the weighbridge would be useful as that would tell you what the hitch weight is now...

I vote for getting some real weight data, too.

The "prop stand" (a.k.a. tongue jack) is mounted well back from the coupler, so it will carry more load than the hitch will. It's relatively easy to calculate a correction if you use that jack rather than a stand under the coupler, if the coupler-to-axle (middle of the two) and coupler-to-jack distances are known. Distances (from coupler to axles at least) are needed for the balance worksheet anyway; the layout from back on Tuesday had dimensions, and if the earlier tape measure shot was from the rear of the trailer, I guess we have the tongue length as well, so we only need the jack position.

The height of the tongue always matters when weighing, but especially with tandem axles. If it is too high, for instance, the tongue jack will be lifting load off the front axle and transferring it to itself and the rear axle. The trailer should be set up level, so the axle load is equalized, both for towing and for this measurement.

[Ivar the Red]

Posted: Fri May 09, 2008 6:16 pm

..........It might be cool if the front corners of the deck folded over, so the deck could run very close to the tug in use, but fold out of the way for towing to allow good turning angles.

That is a cool idea. Allows for a much bigger deck and you could build in some foldup steps too. All that would also help add some more weight up front.

I still don't understand why everone seems to think that the galley weight will be a problem. When camping, it will have stuff in it, but so will the front storage area. When not camping, it should not have any more weight than the sleeping area does. JMO

Edit: Just wanted to add that my galley is only heavy due to the fact that there is a 7gal water tank directly under it. When the tank is empty, the galley is very light indeed compared to the rest of the tear. Cabinetry in the galley is not much more than the interior and the upper cabinets are over the axle location, whereas the interior cabinets are forward of the axle placement. And I have a tongue box.

[Ivar the Red]

Posted: Sat May 10, 2008 2:55 pm

...I still don't understand why everone seems to think that the galley weight will be a problem. When camping, it will have stuff in it, but so will the front storage area. When not camping, it should not have any more weight than the sleeping area does. JMO

When not camping, with everything not built-in removed from the trailer, I can see the galley being not much heavier than a bed area... but does it matter?

When camping, the galley would normally have a stove (maybe with fuel), sink, cooler or refrigerator, all of the food, pot & pans (including cast iron for many T&TTT members), dishes & cutlery... almost everything carried in the trailer other than clothing.

The front storage area is the big unknown... will it carry some light and bulky stuff (not enough to balance the galley) or a ton of equipment?

A while ago there was a commercially-made stand-up trailer with outside rear galley discussed here, and I commented that in the specs it had an unreasonably high tongue weight. The designer responded that by the time the galley is loaded, the balance would be right... because the galley area gets so heavy.

In some individual cases, the galley might not be such a concentrated load.