Martyn
Supporting Sponsor, Overland Certified OC0018
Remember the cantilever effect. If you add weight away from the pivot point it has the multiplier of the distance from the pivot point.
As pointed out the torsion bar is rated to make the opening and closing of the roof section easy. Increasing the spring rate to accommodate extra weight on the roof would then become an small engineering problem for each case. How much does the item weigh? where will it be mounted? how long is the item? is the weight evenly distributed along it's length ?
What happens if the weight on the roof changes or you decide to add more weight than intended? How do we warranty a product like this when we have no real control over the extra weight added to the roof? Not impossible but complex.
Lance does have a good idea of the solar panel being hinged at the front so that when the lid is open the panel can swing down and be positioned to catch the sun. The new issue now is that the solar panel would have to be mounted all the way to the front of the roof (when open) to allow it to pivot away from the roof. Rather than keeping the weigh close to the pivot point it's putting it out to the furthers point, maximizing the multiplying effect of the distance from the pivot point.
More issues are:
Torsion bars are not inexpensive, they are custom made in batches not off the shelf items. If we were to produce torsion bars at three different ratings we would have to stock three times the inventory, and store three times the inventory. Would increasing the price of the Habitat from $6000.00 to $6500.00 be justified?
Does the increased load on the torsion bar negatively effect the anchor arms that are embedded in the roof and shell of the Habitat? Should that be modeled in Solid Works and the expense passed along to the consumer?
So as you can see a simple question never has a simple answer when you think it through as a manufacturer.
As pointed out the torsion bar is rated to make the opening and closing of the roof section easy. Increasing the spring rate to accommodate extra weight on the roof would then become an small engineering problem for each case. How much does the item weigh? where will it be mounted? how long is the item? is the weight evenly distributed along it's length ?
What happens if the weight on the roof changes or you decide to add more weight than intended? How do we warranty a product like this when we have no real control over the extra weight added to the roof? Not impossible but complex.
Lance does have a good idea of the solar panel being hinged at the front so that when the lid is open the panel can swing down and be positioned to catch the sun. The new issue now is that the solar panel would have to be mounted all the way to the front of the roof (when open) to allow it to pivot away from the roof. Rather than keeping the weigh close to the pivot point it's putting it out to the furthers point, maximizing the multiplying effect of the distance from the pivot point.
More issues are:
Torsion bars are not inexpensive, they are custom made in batches not off the shelf items. If we were to produce torsion bars at three different ratings we would have to stock three times the inventory, and store three times the inventory. Would increasing the price of the Habitat from $6000.00 to $6500.00 be justified?
Does the increased load on the torsion bar negatively effect the anchor arms that are embedded in the roof and shell of the Habitat? Should that be modeled in Solid Works and the expense passed along to the consumer?
So as you can see a simple question never has a simple answer when you think it through as a manufacturer.
