Tool fot Automatic Calculation of the Weight

[Marcelo Bernardo]

Hey guys 
Is it possible to automatically calculate the total weight of a truss with Light Instruments and cables? 
Example:
I have a Truss line of 10 meters with 5 Varilites Spot 3000 and cables. I put on that truss two hoist. Is there any tool that gives me the automatic calculation of the weight of this set?
Thanks a lot. 
And sorry for my bad English 

[michaelk]

Not really.  VW doesn't have a unit of weight.  So it doesn't know that a kilogram is 1000 grams or how that's related to our antiquated pounds.

 

So the weight information that is stored in all of the instruments is actually just text.

 

But you can make your own record format that attaches to everything with a weight field in the same units as a real number instead of text and use that.

 

Let me know if that doesn't make sense.  I have an example here somewhere I can dig up and clean up.

 

 

[Marcelo Bernardo]

17 hours ago, michaelk said:

Not really.  VW doesn't have a unit of weight.  So it doesn't know that a kilogram is 1000 grams or how that's related to our antiquated pounds.

 

So the weight information that is stored in all of the instruments is actually just text.

 

But you can make your own record format that attaches to everything with a weight field in the same units as a real number instead of text and use that.

 

Let me know if that doesn't make sense.  I have an example here somewhere I can dig up and clean up.

 

 

I understand...
If I create this record is it possible to calculate the total through Vwctorworks?
In my example it is easy to do in hand, however I am involved in a priojeto where this will become an inconvenience.
If possible which way? Thank you in advance! 

[michaelk]

Yes, it's very possible and pretty easy.

 

I'll see if I can find an example to post.

[Claes Lundstrom]

On 2017-08-10 at 11:30 PM, michaelk said:

Not really.  VW doesn't have a unit of weight.  So it doesn't know that a kilogram is 1000 grams or how that's related to our antiquated pounds.

 

So the weight information that is stored in all of the instruments is actually just text.

 

But you can make your own record format that attaches to everything with a weight field in the same units as a real number instead of text and use that.

 

Let me know if that doesn't make sense.  I have an example here somewhere I can dig up and clean up.

 

 

I disagree. It can be calculated using the surface area of the tubes included. Sorry for bing a bit metric here, but let's say that the  truss consists of for example aluminum tubes having a wall thickness of say 2 mm. The denstiny of aluminum is 2.7 kilos per liter, and one liter spread out over 1 square meter has a thickness of 1 mm. From that follows that a material thickness of 1 mm and a surface area of one square meter has a weigh of 2.7 kilos. 2 mm = 5.4 kilos and so on. So, you basically only need to multiply the density of the material with the wall thickness and surface area in square meters to get the weight. If the truss consists of materials having different material densities and wall thicknesses, you can create a database where one field simply has the density multiplied by the wall thickness, and then multiply that by the surface areas of the respective in a database spreadsheet. This can be elaborated even further by also calculating the center of gravity in three directions, or simply adding a given point weight for a given element, for example a fitting element instead of using the surface area method. I use all these methods extensively and find them very handy. 

[bcd]

Not sure I would take this approach, for a couple or reasons:

1) that's a lot of calculating and there is no way to reliably invigilate that all tubes/plates/welds/reinforcement/alloy etc or even materials are uniquely and completely accounted for. Especially if you don't have control of how the symbol was drawn & saved. 

2) Truss objects are typically specified and certified by the manufacturer- I would rely on their certified weight that -as above- can be listed in a prescribed field of the record format for each truss symbol.

 

in cases where you are responsible for the design & spec of the truss itself then I do see value in the automatic weight derivation you describe. But I would be wary of promoting it broadly.