Calculating Sign weight

[Big Rice Field]

Hw do I calcuolate sign weight in a design that is on paper and not built yet? Is there a formula for channel letters and cabinet signs? like pounds per square foot?

 

[Rick]

DISCLAIMER: I don't know if I'm supposed to run all my posts through the new self proclaimed moderator or if this answer is "professional" enough but I'll run the risk of giving what is hopefully helpful information prior to asking permission from any forum member(s) - who most likely needs some combination of a hug, viagra, psychotropic medication(s), drink or glucose tablet... who knows, next we will all be told we're wiping our a$ses incorrectly, that is more stress that I care to put myself through...

I use CadTools in Illustrator, or you can use the "GET AREA" macro in Corel or Corel Designer or Auto-Cad, which can calculate "area" and "perimeter". Using those calculations, along with my Ryerson Steel Reference Book, I can get the weight of metal sheet and tubing of whatever thickness I am calling out and estimate the weight with that. I also have square foot weights for acrylic and lexan. I have collected quite a few Ryerson handbooks over the years but you can get that information from their website, I still prefer flipping through the analog book.

Over time, I have developed an estimated sq. ft. weight for various width channel letters, reverse channel and dual lit, as well as wall cabinets into a spreadsheet. Then add internal/illumination components but I almost always have to calculate per job because most projects I work on are not standard channel letter/cabinet signs.

The unknown internal components are estimated, but always higher in case engineering and safety issues are a concern.

 

[Johnny Best]

"who knows, next we will all be told we're wiping our a$ses incorrectly, that is more stress that I care to put myself through..."

For girls, you wipe front to back. Guys anyway is good enough. Fancy Nancy prefers a bidet!

 

[Big Rice Field]

I do not need super engineering accuracy on weight estimation, just "ballpark" figures. There must be a simple formula.

 

[shoresigns]

I do not need super engineering accuracy on weight estimation, just "ballpark" figures. There must be a simple formula.

The simple formula is length × width × depth × density = mass. For example, if you have an empty lightbox cabinet made from .080" aluminum that measures 10'x2'x8", you just add up the 5 sides of the box using that formula:

Rear: 120" × 24" × .08" = 230.4 in³
L/R sides: 8" × 24" × .08" × 2 sides = 30.72 in³
Top/Bottom: 120" × 8" × .08" x 2 sides = 153.6 in³
_______________________________________
Total: 230.4 + 30.72 + 153.6 = 414.72 in³

Now I can swap length × width × depth for the total volume of aluminum I just calculated, and multiply it by density.

414.72 in³ × 0.1 lb/in³ = 41.5 lb total cabinet weight.

Obviously that's just the aluminum cabinet, not including the sign face, frame extrusions, ballasts, etc., but it gives you a good starting point. You can easily make a spreadsheet to automate this.

 

[Rick]

"who knows, next we will all be told we're wiping our a$ses incorrectly, that is more stress that I care to put myself through..."

For girls, you wipe front to back. Guys anyway is good enough. Fancy Nancy prefers a bidet!

Great, now you started a conversation over here in the office about the bidet... like, pre-wipe and post-wipe. Only one person here has used one and she's not talkin'... and to stay on topic, I brought my Ryerson Reference book in the restroom with me...

So yeah, you want a simple formula on a complex question like what is the depth, letter type, illumination type... there is a simple formula, take time to get the information on whatever basic channel letter you need and cabinets, stick it in a spreadsheet and done...

 

[Johnny Best]

Or be like Archimedes and put the channel letter in the toilet, probably to big an object, use the bathtub, and see how much water was displaced.

 

[Big Rice Field]

The simple formula is length × width × depth × density = mass. For example, if you have an empty lightbox cabinet made from .080" aluminum that measures 10'x2'x8", you just add up the 5 sides of the box using that formula:

Rear: 120" × 24" × .08" = 230.4 in³
L/R sides: 8" × 24" × .08" × 2 sides = 30.72 in³
Top/Bottom: 120" × 8" × .08" x 2 sides = 153.6 in³
_______________________________________
Total: 230.4 + 30.72 + 153.6 = 414.72 in³

Now I can swap length × width × depth for the total volume of aluminum I just calculated, and multiply it by density.

414.72 in³ × 0.1 lb/in³ = 41.5 lb total cabinet weight.

Obviously that's just the aluminum cabinet, not including the sign face, frame extrusions, ballasts, etc., but it gives you a good starting point. You can easily make a spreadsheet to automate this.

Thank you very much shoresign. That is exactly what I needed. Usually this type of stuff is done by engineering. But I just needed a ballpark figure to meet the requirements of a particularly difficult client.