Lengthening the Lunette..how long???

[airlaird]

Guys I have an M416 trailer and a welder is going to lengthen my lunette. How long should I make it...any ideas. Is there a standard length..like maybe the length of a single Jet- Ski trailer tongue??
airlaird

[Exiled]

Originally Posted by airlaird

Guys I have an M416 trailer and a welder is going to lengthen my lunette. How long should I make it...any ideas. Is there a standard length..like maybe the length of a single Jet- Ski trailer tongue??
airlaird

Depends on what you're lengthening it for. At the very least, make sure that when the trailer is jacknifed against the Cruiser, the trailer's tub doesn't touch the corners of the truck.

[photogod]

Do you mean lengthing the lunette ring it's self or the trailer tongue? I don't think it is a good idea to go longer on the lunette casting but I could be really wrong. Isn't it rather hard to properly weld castings?

[airlaird]

Well it's done. I meant the tongue...sorry. I added 14 inches and it came out bad ass.
airlaird

[pint]

Originally Posted by airlaird

Well it's done. I meant the tongue...sorry. I added 14 inches and it came out bad ass.
airlaird

Where are the pics???

[airlaird]

Here ya go. He took off the lunette. Then added solid bar to it...and sleeved it. The bar wieghs about about 45 lbs.. Of course it's primered green.
airlaird

[pint]

Wow, that sucker is looong. Be interesting to see how it pulls. Thanks for the pics.

[KOWBOY]

I would highly recommend replacin' that with a stock lunnette and lengthenin' the trailer tongue instead.

Just my opinion Brother ... but I would not tow a trailer with that setup.

[pint]

Originally Posted by KOWBOY

I would highly recommend replacin' that with a stock lunnette and lengthenin' the trailer tongue instead.

Just my opinion Brother ... but I would not tow a trailer with that setup.

That's kinda what I was thinking. I hope it works out, but makes me nervous!

[cruzzer]

Ditto on the last two comments,, Don't know how well the welded casting will take the stresses of highway driving let alone off-road.. I would have lengthened the a-frame instead..
Good luck and be careful!

[photogod]

Not safe and your landing leg is in backwards.

[airlaird]

Ya'll sure?? he used duck tape and superglue...you don't think it'll hold huh ;-)....come on boys, this guy makes multi ton aircraft dolly's for a livin. It's tig welded and has 1/4 sleeves..it'll hold a rooftop tent ;-).
airlaird

[kcsmithson]

I towed mine a lot of miles with a similiar set up. Never an ounce of trouble. Of course YMMV.

Chad

[photogod]

I was thinking more along the lines of the triangulation of the wheels and the tip of the lunette. The added length without the stability of added width makes a pretty tippy trailer. Then add a RTT and the center of gravity adds to the stability problems. Just sayin'.

[KOWBOY]

Originally Posted by airlaird

... this guy makes multi ton aircraft dolly's for a livin. It's tig welded and has 1/4 sleeves ...

It ain't the weldin' that would worry me Steve. That hunk of metal that shaft sticks into was designed and built over a half a century ago based on forces created by the original design.

By lengthenin' that shaft you have greatly increased those forces.

It's the basic lever principle of physics.

None of my bid'ness though ... good luck with the build.

[kcsmithson]

I thought the design was to remove the force and friction. With it greased and operating properly, it will turn the trailer over with out putting undo force on the hitch right? Add the up and down and side to side travel of the lunette ring in the hitch and I don't see the issue. If it was welded solid to the trailer, I could see your point.

By the way Steve, I did upgrade my safety chains just in case.

[wearsabrowncoat]

I wouldn't be worried with that set up. I will be doing something similar. I like the mod that someone earlier used that allowed switching between the lunette and a normal ball setup. Also allowed you to remove them completely to deter theft.


Was 14 inches enough to clear the rear panel with a jackknifed trailer? If you get a chance, a picture would be awesome.

[airlaird]

Kowboy, I certainly respect your opinion on this and your concerns are respectfully noted. But I have to agree with Chad. The design of the lunette is to rotate....I don't see how making it 14" longer is going to counteract with the way thelunette is designed. IF the trailer rolls over...the lunette stays level...correct??
airlaird

[boctor12]

I think what Kowboy is trying to say is that by making the lunete longer, it creates a larger moment or (force). The lunete is fixed at the hitch, and the load is the tounge weight. The welds that you did by making the lunete longer will just provide a point of failure if the load is to great. If they were done properly and the load does not get too excessive, which may not ever happen, because of the thick sleeving you did, it will be fine. I want to lengthen my M-416 as well, but i would haver lengthened the frame of the trailer instead.

[Brian in Oregon]

One advantage of lengthening the lunette is that it would have less of a tendancy to contact the corners of the tow vehicle in a tight turn than a lengthened A frame.

I don't see a problem with the casting the lengthened lunette inserts into IF it is stripped and inspected for cracks, corrosion and damage. I would assume that airlaird did that prior to primering it.

As for the lengthened lunette itself, I would think it would bend at the socket end or in the middle long before it would break.

BTW, did you use the green Rodda Barrier paint?

[inkpot]

Originally Posted by boctor12

I think what Kowboy is trying to say is that by making the lunete longer, it creates a larger moment or (force). The lunete is fixed at the hitch, and the load is the tounge weight. The welds that you did by making the lunete longer will just provide a point of failure if the load is to great. If they were done properly and the load does not get too excessive, which may not ever happen, because of the thick sleeving you did, it will be fine. I want to lengthen my M-416 as well, but i would haver lengthened the frame of the trailer instead.

I think what Kowboy is referring to is the vertical and lateral stress on the little itsy bitsy V-shaped base that it goes into. Now the leverage of the Lunnete is 2 or 3 times greater on it. Looks like the weak link to me. John

[KOWBOY]

Originally Posted by inkpot

I think what Kowboy is referring to is the vertical and lateral stress on the little itsy bitsy V-shaped base that it goes into. Now the leverage of the Lunnete is 2 or 3 times greater on it.

BINGO!!

It's one of them force times distance thangs.

Ain't nothin' wrong with lenghtenin' the shaft ... as long as the base is beefed up to accomodate the extra forces.

Carry on.

[airlaird]

OK, well it's still a work in progress...maybe I'll add more later support to the lunette. Thankyou guys for the insight!
airlaird

[inkpot]

Originally Posted by airlaird

OK, well it's still a work in progress...maybe I'll add more later support to the lunette. Thankyou guys for the insight!
airlaird

Howdy! I did my setup just the opposite. Way overkill. I am building a trailer based on an 87 minitruck frame. The bed and the frame were free. I notched the frame just ahead of the crossmember and folded it in. Then I welded in a piece of 3" pipe from the crossmember thru the frame arms. Next i slid in a piece of 2.5" pipe with a plug welded in the end. My lunette ring bolts thru the plug and has an adjustable preload on it to allow it to swivel if the trailer rolls over. Also, the smaller tube can slide in and out of the larger one so it can be pinned in any of several lengths. The shortest position will work on my Piggy with a regular pintle on a 2" slide in receiver. I can pull it out if I need more length for manuvering, or if it is pulled behind a truck with a flatbed that extends out over the hitch. Oh, the pipes are both 1/4" thick wall, and free, so the price is right, and it will handle any extra tongue weight I might add later, like a spare on the front of the trailer bed, or storage, or whatever. John