AI Cradles: Mounting on Fore-Aft Supports, Not Left-Right?

Has anybody mounted their AI cradles on fore-aft supports instead of the side-to-side bar supports they seem designed for ?
viz: https://picasaweb.google.com/1081497986 ... 8849099266

I am running into a problem with spacing as the cradle does not want to lie flat on the 2x4 I am trying out for the support.
Instead, the space between 2x4 and cradle is subtley wedge-shaped.
viz: https://picasaweb.google.com/1081497986 ... 4102573378 - where you can see that it is wider on the right and narrower on the left by about 1/8".

Instead of trying to make up a wedge-shaped pad for that area, I am tempted to just drill the cradles at the nubbin that rests on the 2.4 and leave enough slop in the hole so that the cradle car rock back-and-forth to conform to the angle of the hull.

But that begs the question of whether said nubbins are strong enough to take the concentrated weight over time.

??

Tangentially, the instructions advise locating the fore cradle "at approx the drive well".

But, measuring center-to-center, the good fit I get is with the fore cradle almost 17" fore of the drive well.... and locating the rear cradle the recommended 67" aft of that gives a good fit for the rear cradle too. Placing the fore cradle *on* the drive well doesn't even come close to a fit: https://picasaweb.google.com/1081497986 ... 3940668194

Only reason I mention this is that I still wonder if I am doing something stupid here.

OTOH, the instructions ("#72020406 AI 2015 TRAILER CRADLES") seem carelessly-enough written (three obvious spelling errors) that I think *maybe* I've got it right....

The Bottom Line:

Has anybody mounted these cradles to supports that run fore-aft instead of port-starboard?

_________________
2015 AI in "Dune" - "The Grey Pig"
2017 Trailex 450 Trailer
Pre-September 2015 cradles
(anybody want to buy a slightly-used AI SpinKit?)
eMail: [email protected]

Seems you have an older set of cradles than what the current instructions describe (September 2015) when we decided to use one cradle for both fore and aft positions:

http://static.hobiecat.com/item_attachments/72020406_GhAShSo.pdf

The "nubbins" are not designed for load. There would also be too few contact points. The cradles are designed to contact the crossbars at 5 points.

Position for best fit on the hull as you have done. You must have "cross" bars to allow 5 points of contact to properly support the cradle/boat.

_________________
Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

Thanks for saving me from myself.

I will stop trying to fool Mother Nature and get with the program.... -)

I have to think that Hobie had a solid functional/structural reason for investing the time and money into that change.

How spun up should I get the retailer about their shipping me this obsolete set?

I am thinking wear-and-tear and/or damage to the akas as the boat/trailer bounce along over time.

_________________
2015 AI in "Dune" - "The Grey Pig"
2017 Trailex 450 Trailer
Pre-September 2015 cradles
(anybody want to buy a slightly-used AI SpinKit?)
eMail: [email protected]

Actually what you have is excellent. We just simplified the kits really.

_________________
Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

Thanks.

Now that I have the boat loaded on to my breadboard layout, I can see that the rear cradle supports the amas at exactly the ama balance point.

_________________
2015 AI in "Dune" - "The Grey Pig"
2017 Trailex 450 Trailer
Pre-September 2015 cradles
(anybody want to buy a slightly-used AI SpinKit?)
eMail: [email protected]

Here's a pic of the breadboard layout: https://picasaweb.google.com/1081497986 ... 9196368098

The raised areas on the two drilled parts limit the area upon which a cross member can bear - cutting it about in half:
https://picasaweb.google.com/1081497986 ... 7367493218

Doesn't feel right when I look at it:
https://picasaweb.google.com/1081497986 ... 4478847890
https://picasaweb.google.com/1081497986 ... 2711653522

I am considering use of a full 2x4 for the cross member, centering it on the cradles, and chiseling out receptales for the raised areas.

Or am I over-thinking this ?

_________________
2015 AI in "Dune" - "The Grey Pig"
2017 Trailex 450 Trailer
Pre-September 2015 cradles
(anybody want to buy a slightly-used AI SpinKit?)
eMail: [email protected]

Yeah... the front one should be raised to match.

_________________
Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

That went over my head. At first I thought you meant the front cradle because I had not yet set it on a cross-member like the rear one.... but then I realized that could not be seen in any of the pix.

"Front One" = "Front [what] ?

Or is it the cross member width thing? Full 2x4 with recesses chiseled out for the raised portions?
I am thinking maybe the Hobie trailer has some sort of semi-custom crossbar that accomplishes the same thing.... as it is it just looks too funky to me: https://picasaweb.google.com/1081497986 ... 4478847890

_________________
2015 AI in "Dune" - "The Grey Pig"
2017 Trailex 450 Trailer
Pre-September 2015 cradles
(anybody want to buy a slightly-used AI SpinKit?)
eMail: [email protected]

I am starting to wonder if maybe the retailer sent me a set of pre-2015 cradles.

The crux of the matter seems to be that the sides of the fore cradle are parallel, yet the only
place where it even comes close to fitting the hull is where the hull tapers.


To Wit:
Hull sitting on cradles so that the balance points of the amas are right over the aft cradle, which I assume is the intended position of the hull relative to the aft cradle. https://picasaweb.google.com/1081497986 ... 2667851474

This gives a nice-looking fit in the aft cradle:

Looking from the center: https://picasaweb.google.com/1081497986 ... 5426309890
Looking from the left: https://picasaweb.google.com/1081497986 ... 2894273090
Looking from the right: https://picasaweb.google.com/1081497986 ... 9689697906

But the fore cradle - spaced *exactly* the recommended 67" fore of the aft cradle does not seem to be a proper fit.
Specifically: at that point the hull curves inward - i.e. the sides of the hull are no longer parallel.

But the sides of the fore cradle *are* parallel: https://picasaweb.google.com/1081497986 ... 1327559218

Try sliding the hull forward to where the hull sides are closer to parallel; the hull becomes wider than the cradle and the fit is not even close: https://picasaweb.google.com/1081497986 ... 3916782546

Does any of this make sense to anybody?

Or am I doing something really stupid?

_________________
2015 AI in "Dune" - "The Grey Pig"
2017 Trailex 450 Trailer
Pre-September 2015 cradles
(anybody want to buy a slightly-used AI SpinKit?)
eMail: [email protected]

Your problems are similar to what I experienced with my TI and cradles. I found it wasn't sitting right, basically putting all the weight on just a couple points at each cradle - I realized this when I found divots in the sides of the hull. I could get ONE cradle to fit fine, but couldn't find a good location for the other one.

That's when I gave up and went with PVC bunks, which fit like a charm. I also found it was a *LOT* easier to slide the TI on/off the PVC than the cradles. (Almost TOO easy, in a way!)

I breadboarded up a set of bunks using 3" PVC, but I think the span on my trailer cross members was not right because when I put a straight-edge on the hull after overnite storage, it came up slightly deformed. i.e. the bunks were bending too much under load and point-loading the hull.

How long have you been using the bunks? What diameter? What length? How many support points (i.e. trailer crossmembers) What span between support points ?

If these cradles do not work out soon, I will try a few other bunk configs. One of them will be 2x4's rounded off to a 1.5" semicircle where they bear on the hull - with the expectation that they would be plenty stiff enough to avoid point-loading.
One thing that will have to be worked around is the cockpit venturi drain.... but as long as it holds up to being slid beck-and-forth over the bunk, chiseling out a dent to accomodate it at the hull's final resting point would seem to do the trick.

OTOH, it has just dawned on me that, with the center-of-gravity (hand holds) of the amas centered over the rear cradle, the cradle is bearing on the part of the hull with the scupper holes in it - which would seem to be the strongest area on the hull.

That leaves the mal-fitting fore cradle (parallel sides on a tapering hull)... but up there, I feel very little weight - so maybe the mal-fit is by design because it's just not that critical...... And I have both cradles working in the intended way.

_________________
2015 AI in "Dune" - "The Grey Pig"
2017 Trailex 450 Trailer
Pre-September 2015 cradles
(anybody want to buy a slightly-used AI SpinKit?)
eMail: [email protected]

I have three cross members, the front two are roughly where the cradles would have been and the third at the back end. Don't recall right off what diameter it is, 2 - 2.5" I think? Nothing huge. The PVC is held down only on the front and back cross member, and a bit loose at that, so when I slide the TI on it can flex / conform to the grooves in the bottom.

I've had the TI on the bunks since early last year. Here's my post about it:
viewtopic.php?f=73&t=54210

Looking at those instructions, I do not see anything about the fore-aft orientation of the rear cradle.

Is that no longer a consideration?

_________________
2015 AI in "Dune" - "The Grey Pig"
2017 Trailex 450 Trailer
Pre-September 2015 cradles
(anybody want to buy a slightly-used AI SpinKit?)
eMail: [email protected]

Yep.....

For the benefit of anybody else on this little journey: although the instruction sheet that comes with the cradles specifically points out that the aft cradle has a "Fore" and "Aft" side that needs tb properly oriented, it does not say anything about the fore cradle..... even so it actually does have a "Fore" and "Aft" side.

Somebody more perceptive than I probably sees this right away - but I did not and HogMan and KayakingBob had to point it out for me.

Thanks Hogman.

Thanks KayakingBob.

_________________
2015 AI in "Dune" - "The Grey Pig"
2017 Trailex 450 Trailer
Pre-September 2015 cradles
(anybody want to buy a slightly-used AI SpinKit?)
eMail: [email protected]