Curving Genoa Track

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co256

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I have two 1.2 metre lengths of 20mm Barton T track to curve.

The max deflection is 60mm.

I've got them clamped in place along a length of heavy timber and screwed it down.

Anyone have any idea how long it will take to "set" ?
 
co256 said:
I have two 1.2 metre lengths of 20mm Barton T track to curve.

The max deflection is 60mm.

I've got them clamped in place along a length of heavy timber and screwed it down.

Anyone have any idea how long it will take to "set" ?
Click to expand...

Whats it made of?

If its aluminium you will be able to bend it to the shape you want but make sur the cars will still run along it easily

If its plastic it will probably take years to be permanently set
 
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co256 said:
Thank you,

Any idea what it's elastic limit might be?

And how long I will need to leave it screwed to the timber??
Click to expand...

You'd have to subject it to more bending than you actually need in order to get it to keep a bend. But this is tricky. However, if it bends sufficiently when screwed to a piece of wood, it'll surely bend sufficiently when bolted to the boat. Can't you bend it gradually whilst bolting it down?
 
It will not "set" over time, plastic distortion is immediate. As VicS says, you will have to deform it by over-bending to achieve your 60mm. Progressive trial and error will be needed.
You may well find that it will bend preferentially at pre-drilled holes and also the anodising might crack, spoiling the finish somewhat.
 
I would rather encourage it to hold the curve I need than do it all at the "bolting down stage".

It took quite a lot of slow, progressive clamping to get it to the curve I need, so I wouldn't fancy doing all that at the fitting stage, I did it that way on my previous boat and it was quite "stressful" you might say!

I have avoided putting any direct pressure on the pre drilled holes and spread the load with soft wood blocks on either side of the T track, the curve appears smooth and considerably less than the maximum recommended by Barton.

earlybird: are you suggesting that leaving it clamped up for a few days will not induce any more bend than a few minutes?

DSCN0458.jpg
 
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It is not that much of a curve. I did mine in situ without any problems. I don't know how you could reliably achieve the perfect bend beforehand because, as others have said you would need to over bend and then allow it to relax back. If you bolt one end to the boat and then get someone to use the other end as a lever you can progressively bolt it down to the exact curve.
 
I'd rather have some bend in the right direction than non at all.

What you have suggested is exactly what I did before and I would prefer not to do it that way again.

My previous boat had the tracks mounted to the toe rail, which was substantial, and could easily take the strain of progressive bending.

But my current boat has tracks through bolted to the side decks and as I have said I would rather not do the bending in situ.
 
co256 said:
I'd rather have some bend in the right direction than non at all.

I would rather not do the bending in situ.
Click to expand...

OK then
Release the track from your rig.

Measure the amount of permanent bend if any you have induced ........ you may decide it's enough ........ if not estimate the amount you will have to overbend to achieve the result you desire. Adjust your rig accordingly then bend the track to this new curve. Release it and it will spring back to the curve you need.
 
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Thank you VicS,

Sounds like a plan...

I would have expected that an element of time held in the curved position would have had some bearing on it's permanence?!

I guess I'll just have to wait and see?
 
OK...

Having spent two hours clamped and screwed down in position, I have removed the screws, released the clamps and...

...created no more than 2mm of deflection at the mid point of the curve!
 
co256 said:
OK...

Having spent two hours clamped and screwed down in position, I have removed the screws, released the clamps and...

...created no more than 2mm of deflection at the mid point of the curve!
Click to expand...

OK so you got 2mm , 58mm less than you wanted.

adjust your rig to 118 mm of bend and you should get what you want. Y u may have to do it in stages.
 
co256 said:
earlybird: are you suggesting that leaving it clamped up for a few days will not induce any more bend than a few minutes?
Click to expand...

At temperatures >>100 deg C and high stress, timescales of several tens of thousands of hours just might have some small effect.
Metal is different from wood!
 
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