ever seen a 8x3x3 2 tier?

[Squirtle919]

Hey MFK

So I will be getting a 8.5x3x3 pretty soon and planning on building a 2 tier stand just wondering if anyone has seen one before? any pictures?

Plan is to weld up a frame as per normally done for a 6ft tier, no legs in front of the bottom tank also which has caused a 1% doubt in my mind due to the span of the tank.

I am planning on using 70-100mm steel so in theory everything should be fine but its an awful lot of weight.

If you have any pictures or links would be great!

I am very excited about this !!

 

[wednesday13]

Yup ive made one before to hold 4 8' 100 gals (2 per tier). Only used 1" box tube 1/16" thickness. You should b fine, just keep a couple legs in the back of the stand. For more support in the front i threw in some larger than normal 45's to support the open span. Ill try to dig up pics but i sold this rack almost 2 yrs agp. Another idea is to just make a bolt on leg for the open span after the bottom tank is put in. I have a 125 stacker like this and if u dont mind a bar in front of your tank it will add that much more suport and peace of mind.

Sent from my SAMSUNG-SGH-I747 using MonsterAquariaNetwork App

 

[David R]

8' is a hell of a long span to be unsupported, especially with a 3' tall tank. The 1100mm spans on my stand are made from 100x50x5mm steel to avoid sag, and I think you'd want something even more rigid than that with a 3' tall tank. Glass has zero ability to flex, so if the steel sags by even 0.25mm it's going to be transferring the weight to the glass. TBH if you're going to go for an 8' unsupported span I'd use some seriously rigid steel and/or go with a much lower water level for the top tank so the span doesn't have to support so much weight. Having two 3' tall tanks stacked one on top of the other will put the top one so far out of reach it will be damn awkward, so having a lower tank on top will be easier to work on too.

 

[Squirtle919]

Thanks guys we almost finished all the drawings for it and hopefully will start to order the steel soon =D

Yes we understand it cant flex at all, I have gone without a center leg we are just going to use a thicker metal with a thick inner wall. off our calculations the stand is going to weight 750kg alone which is going to be lovely to move so we have tried to come up with a few nice ideas to make it come apart but the idea of having it as one seems a bit more safe to me. other option was to use ali for the metal to reduce weight but the cost is too much.

As for size yes it will be a pain to clean, I already have 3ft tall tanks on 2 tier stands ones salt water also to make it even more fun =) I have quite long arms so its not too bad for me but it is annoying hitting my head on the roof but I love big tanks and 2 stacked means I can have 2 big tanks! 2 more big tanks... its not too bad but my fish room is quite tall almost 3m roof height, the pain is more trying to jump into a 3ft tank from a ladder lol

The exact tank size is 8.5 FT x 3 FT x 2.6 FT tall so 500G ruffly. we the thickness planned there should be very little sag, it has been designed by engineers so lets hope they know whats going on! lol on awesome perk of work free advise on anything!

Plan is pretty much as you have described wednesday13 but thicker steel and have a leg every 2ft across the back connected to the top tier. the bottom tier will have legs on the front and in the middle of the stand connecting directly to the cement flooring, this will hopefully take some stress/pressure of the side legs. so in theory it will be supported from sides and back. from memory the plan is 75x75MM 5-7mm thick I could be wrong here though.

Anyways I will take some pictures as soon as its started and keep everyone up to date!! this is going to be the first major thing I have welded so theres another risk factor =D after this one I am planning a 10x3x3 or 10x2.5x2.5 2 tier stand but I will need a center leg on that one! I should have taken a picture of one of the tanks, its 300kg of glass all my friends are already telling me to make sure the stand is not too high otherwise its going to be another nightmare at my house.

 

[David R]

When I was doing some research for my steel stand I came across a massive thread on reefcentral about steel stands. One of the posters on there seems fairly knowledgeable on the subject, and had this to say about uneven vertical supports;

Here's another issue I left off my list that most definitely should've been included. Non-symmetry of uprights. Notice six uprights along the back and only 4 in the front.

Any non-symmetry of the verticals is going to cause the top of the stand to deform non-uniformly. This results in a twisted top causing complex forces that have to be resolved by the tank's structure, which is busy enough trying to keep the water in. Try to avoid this at all costs. When they get bad enough or the tank is not particularly stout you will have results like you see with SantaMonica's pictures. His stand deformed enough that the tank couldn't resolve the forces.

You can have weird non-symmetric stands you just have to go extraordinary measures to limit the distortions. When things start going crazy just reach for rectangular tubing as it covers a world of issues.

post: http://www.reefcentral.com/forums/showpost.php?p=21145322&postcount=1718

What thickness steel are you going for to support the 8' span? I'd be inclined to do the same front and rear unless it is going to add hugely to the cost.

 

[Squirtle919]

Hey david, I cant say as of yet work was busy today and crazy so I had little time BUT my 8x4x3 sits on a stand with no center leg and was running for a year plus with no issues, it also had a 8x4x20 on top. from memory its 70x70mm 4-5mm thickness I can double check tomorrow, I have got some center legs for it but I dont know if they are required or not and unsure if I will be using them but I do have some cut up.

 

[Squirtle919]

ok so its going to be 75 x 50 mm steel no clue on the thickness. This is a bit larger then dexion pallet racking which supports 2 tons on a 8ft span so we should be fine.

also going to build a pulley type system onto the stand that can be removed to get the tanks up to the tier height. the tank is going to be a pain to lift so this will hopefully make it a breeze.

The bays that hold the actual tanks will be removable and adjustable so I can change the height if need be and it will make moving the actual stand a lot easier. Also going to wack some adjustable legs on it always wanted some, no more metal plates to level stands yay.



Anyways heres one picture of god knows what lol I think they used the density of the metal to figure out the avg weight based of the length of the metal beams etc but I honestly have no clue it just looks crazy so I figured i would share it lol.