Pivoting Canopy Lid - Help!

[coralreefer]

I am building a pivoting canopy lid due to space restrictions above my tank. I am trying to copy those canopies in the LFS that have an outside case that pivots on a base (base sits on the aquarium rim). They all have a ~2.5 - 3" plywood disc that they pivot on.

My question is: why are their discs so large? What is the mechanical advantage of having a larger disc to pivot on rather that a 1-2" disc?

The difference in my design will make a difference on the clearance between the back if the canopy and the wall. I just can't wrap my brain around all the physics involved with rotational motion this morning.

 

[mikebow16]

If you could get a picture that would help a lot. Just off the top of my head I would assume that they use a thicker disk to reduce the amount of defection when they move it. But just a guess I have not seen one of these setups.

 

[coralreefer]

I have made my decisions on dimensions. I am in the process of mocking it up. I will post pics when I am done.

 

[Saltpro]

Yes, i have seen some like that at DNA. Im not sure maybe its a strength issue or it's the bigger disk makes it move easier...less force needed to move it....just a guess

 

[coralreefer]

@Saltpro wrote:

Yes i do believe the larger the disc the less force to move it for sure. If the disc was made too small, it could easily become a strength issue.

I decided to go with a disc the size of a doorknob hole - since that is what size hole saw I already have.

 

[Saltpro]

Lmk how it turns out for you