A Frame Fixings

LURCHER · 02 March 2005, 16:23

Yet another problem that I know you guys will have the answer to .
I am having a new A frame made which we hope to have a tow point fixed up high for wakeboarding . Given the extra loads generated by this high point how do we fix the front legs to the deck , there is of course no access under the deck where the front feet would be positioned . The origional horrible galvanised steel A frame was fixed by two M10 stainless lengths of studding with a type of rawlbolt style fixing which has of course dropped off and is now in the void below.
Tubes are being made as we speak by Ribraff (Ed you shouldn't be reading this you should be busy glueing etc ! ) will post pics as soon as I get it back .

Nick Hearne · 02 March 2005, 16:35

Why don't you get Ed to glass in 2 plates in the floor with bolts sticking up so you can then bolt the A frame to the glassed in plates!
Just like that!

LURCHER · 02 March 2005, 16:42

As yet the A frame has not been made and I am picking boat up from ED on Wed I hope!

Scary Des · 02 March 2005, 16:47

How about popping a couple of small inspection hatches in the deck that way you could bolt through and add backing plates

Des

swginn · 02 March 2005, 17:29

If you want a really strong fixing, forget the deck and go straight through the hull!! Mine is bolted through the hull and has two stainless plates on the outside of the hull. This also strengthens the transom-hull join as the back legs are bolted through the transom.

Rogue Wave · 02 March 2005, 17:41

I prefer the last two methods for fixing, but having said that I wouldn't tow of an a frame I was most surprised when I snapped the A frame on a Ribcraft!

Swifty · 02 March 2005, 21:25

How high up are you hoping to put the tow point. Reason I ask is that even Ribs can tip over. Just ask Daniel TD5!

Tim.

Simon B · 03 March 2005, 08:40

Will post a picture of some gravity toggles I made in stainless, oh my their ugliness! but practical, inspection hatches were an option allowing to bolt through deck, however, if I had to a similar job I'd use the hull/plate solution.

A friend of mine had his A frame shear off, bear in mind the expense of replacing all your masthead kit if it gets ripped off, samsom post??

Squirrel · 03 March 2005, 09:38

Just had my A-frame braced for wakeboarding. The guys at Pro-sport added a couple of eyes to the backs of the rear seat pods. These allow for a cable to go from the back of the seats through to the tow-line connection at the top of the A-frame. This means that the load is shared between teh A-frame and the seats. Just hope my seat pods are strong enough now.....

And before you ask, we put the eyes in the back of the seats rather than the floor because it gave a better angle and doesn't interfere with the bikini clad passengers (that's my job

)

It's being serviced at the mo', but I'll try and get pictures if you're interested.

smokie · 03 March 2005, 12:53

Does anyone know if rib manufacturers will install deck plates on the underside of the deck when the hull is being made for such loads if you ask them?

Rogue Wave · 03 March 2005, 13:18

Squireel are your seats held in with self tappers or Bolts.

Bikini Clad passengers Lucky guy I have only ever had one Bikini Clad passenger on my boat and I have to say that yellow Polka dots is definitely not gArfies colour at all!

Seaharrier · 03 March 2005, 13:33

Quote:

Originally Posted by smokie

Does anyone know if rib manufacturers will install deck plates on the underside of the deck when the hull is being made for such loads if you ask them?

Mine did. On our rib we installed a twin bolster. Problem was fixing that bolster to the deck. Normally they fix it in the factory. But in our case it was not possible (big delivery delay for those bolsters + distance between console and bolster should be set at our length). So they put a big metal plate on the underside of the deck. Now we are able to drill a hole through the deck and metal plate to fix those bolsters.

Squirrel · 03 March 2005, 13:38

Quote:

Originally Posted by Rogue Wave

Squireel are your seats held in with self tappers or Bolts.

Dunno, I'll check, might be tricky as I think they are glassed into the deck. Jason at Prosport assures me its fine....

Its all very well having bikini clad passengers, but they do tend to scream above 30 kts and complain at going round and round at 20 kts with a boarder. Can't win.

Simon B · 03 March 2005, 22:19

Here's the homemade version of some gravity toggle type fasteners, in catering stainless and stainless boiler tubing. Studding left long and then cut off after nuts tightened

Rogue Wave · 03 March 2005, 23:23

clever guy that would definitely make a good fixing and the aperture to fit them wouldn't compromise the decks integrity as much as an inspection plate.

Scary Des · 04 March 2005, 08:50

One issue with this type of bolt is drilling blind into a closed void

you never know what you are going to find

if your hole lands on top of a stringer or rib, you end up having to drill again

Des

Simon B · 04 March 2005, 09:43

A very valid point, I was lucky in that we were re-fixing and existing but poor fastener. Delta did offer to supply us with the relevant drawing had we needed it.

jwalker · 04 March 2005, 12:07

Quote:

Originally Posted by Scary Des

One issue with this type of bolt is drilling blind into a closed void

you never know what you are going to find

if your hole lands on top of a stringer or rib, you end up having to drill again

Des

Tap the deck gently with the handle of a screwdriver, you'll hear the solid bits.

Scary, parcel is on it's way.

Scary Des · 04 March 2005, 13:12

Quote:

Originally Posted by jwalker

Tap the deck gently with the handle of a screwdriver, you'll hear the solid bits.

True, but still a point to consider

I suppose another issue is the vertical height of these fixings, they need to pass through a long way before the horizontal bar falls into position, now that would be OK on my boat because there is loads of room, but on some boats this might not be the case, especially working close to the side of the boat where the hull comes up to meet the deck. Still they would be a lot simpler than fitting a couple of small inspection holes

Quote:

Originally Posted by jwalker

Scary, parcel is on it's way.

Brilliant thanks very much

Des

Simon B · 04 March 2005, 16:20

Sacry,

Designed ours to drop in 40mm or deeper. They are limited as have to remember to tie fisshing line or other retrieval method on to keep hold of them if you wish to make any changes after sawing off the excess. I did wonder if there were any stainless versions currently being made but couldnt find any hence the heath robison eddifice.