Some tube stuff...............

[Blackjack]

Anybody got any use for this?

You can't distribute it and you can't post it on any websites. Cause it's mine and I said so.

It doesn't really explain what it does right now, but basically it lets you compare different sizes of tube for weight, bending stiffness, and tensile strength (that being a function of the cross sectional area).

Moment of inertia is the bending stiffness, higher the number, stiffer the tube.

There's a more complex version which is easier to understand in progress (does that make sense???) which is why I don't want this version cropping up all over the place. However some feedback on the usefullness or lack of it would be useful at this stage, so I'm posting this version as Brits will quite happily tell you when something is crap.

It's a HTML page so once you unzip it you just open it with your internet browser.

[Doro]

it's good, useful, easy to use, my only comment would be can we have the choice of metric and imperial? Maybe some asterix to show any required fields? You can tell I fill in a lot of electronic forms!

hmmm, will use this when I build my teardrop trailer..!! ha ha

[Sir Ewok]

As above, took a few moments to realise that wall thicknes was a decimal input rather than a fraction ie. .25 instead of 1/4. Could be useful to frame and trike builders alike. Cheers!

[dracken1]

very usefull blackjack.
but i would echo doro's comment.
personally i would rather work in metric

[Blackjack]

So,

Weight in kg per metre? A metric/ imperial button.

All that really needs is the metric/imperial button to alter the weight per length answer and the units for the cross sectional area. If you poke in mm the answer will be in mm but the equation that gives the weight/length is obviously different, but that should be doable with a constant, lbs per foot over 2.2 (ish) gives kg per foot, divide that by 12 multiply by 39 (ish) gives kg per metre. Something like times 1.47727. Put the units in a window, have the text change when you click the metric/imperial button and assign a value of either 1 or 1.47727 (ish) to a variable to multiply the weight/length answer.

Seems the easiest way. Probably. I'll have a think.