PDA

View Full Version : Roof vibrating a bit



ovakil
19-07-2008, 06:25 PM
I made an alloy hardtop for boat.When driving boat with front clears open the roof vibrates or shakes side ways.Was thinking of putting some extra bracing on the front.Will try to explain,Have a bar that runs from roof to deck either side,another bar run along windscreen to join them,another bar from each side windscreen height on a 45' angle to center of deck.
I saw similar bar work on a haines hunter 680 patriot.
I hope I made sense
Any idea's welcome.

Roughasguts
19-07-2008, 07:43 PM
Okay front open, is the back open or closed ???

Cause if the back is closed off yep I recKon it will shake around a bit, it's the air pressure building up trying to stabilize and it can't.

You need a vent on the roof to let the pressure escape, if the back is closed off.

Think of it as a wind sock, to keep it stable it needs a hole in the end, close the end off and the wind sock is all over the place.

ovakil
20-07-2008, 08:17 AM
Back is open.
When I built it I thought the centre stainless bar work would steady it.I can with a bit of force shake the roof a bit.It doesn't move that much but it's annoying.

gofishin
20-07-2008, 09:21 AM
I would start by adding bracing at the main support as shown. Make sure you tie-in adjacent to existing stanchions (to better disperse stresses).

I don't feel that this would be enough, as the front has no lateral bracing at all. You could use the same here, but better a diagonal down to the screen frame (deck would be better still , but your canopy doesn't go far enough forward to come down from the front corners, unless they were at a dicky angle).
my 2c
cheers

ovakil
20-07-2008, 03:07 PM
I was going to get bars bent to suit angle of windscreen & clears,as when i push & pull the roof top section moves as one.That stainless center bars only moves down bottom where it's bolted to the hull.It is solid up top.Thanks anyhow.Some pictures of haines where I got idea's

Roughasguts
20-07-2008, 03:54 PM
I think your going to need bracing that you can pull up tight.
Eg on the right side a wire cable and turn buckle, from your floor (or something Solid and remote from your canopy), to come up and over your rocket launchers and hold half way on the top of that.

So when you do up the turn buckle it pull up sideways on your canopy and hold it down and to the side, the turn buckle is on.

Then of course do the same for the other side, that should stop the sideways flex provided you can get it tight enough with out ripping your floor up.

Try it first with a rubber occy strap, or ratchet tie down, and play with that at various positions if it doesn't work over the top of the rod holders.

A rubber occy strap just on one side may act as a shock absorber, you could try that, put that on as above see what happens.