|
08/04/2007, 11:01 PM | #26 |
Registered Member
Join Date: Jul 2007
Location: Pembroke Pines
Posts: 895
|
Rocket I got a few questions.... First, I will be building a stand for a 90gallon, 48"L x 18" w x 30"h. For this everything according to this design will be 2x4s. The green pieces should be one inch off the ground and one inch from the top right?? The top frame and the bottom frame, how are they attached to the purple legs?? Is everything just screwed down to the green 2x4s or really long screws from the top and bottom frame to the purple pieces or both?? Everything is bolted down with just wood screws right, no brackets?? Would adding one more leg to the back middle do any harm? What size wood screws do you use?? Sorry for all the questions .
__________________
Leo Click on my red house to see my 90g RR tank :) Tons of pictures, tons... Click!!! Current Tank Info: 90g AGA Reef Ready, 6x54w T5s w/ SLRs, 29g Sump/fuge, OR 2500 Return, Octopus NW150, 2 x TLF Phosban Reactor, Koralia #1, #4, MJ Modded |
08/05/2007, 12:06 AM | #27 |
Registered Member
Join Date: Mar 2005
Location: AL
Posts: 1,047
|
Yep, everything is just screwed into the green strips. 2 1/2" to 3" screws will work. They are, in a sense, brackets. They could be cut to a few inches in length and still hold things in place until you attach plywood to the whole thing. Adding another leg won't do harm, but it's not necessary at all. The only harm would be getting in the way at some point.
__________________
"When I get sad, I stop being sad and be awesome instead. True Story." Current Tank Info: 29g Mixed Reef with Metal Halide |
08/05/2007, 12:36 AM | #28 |
Registered Member
Join Date: Jul 2007
Location: Pembroke Pines
Posts: 895
|
ok so no need to put like 5inch screws from the top of the top frame to the legs, thank you
__________________
Leo Click on my red house to see my 90g RR tank :) Tons of pictures, tons... Click!!! Current Tank Info: 90g AGA Reef Ready, 6x54w T5s w/ SLRs, 29g Sump/fuge, OR 2500 Return, Octopus NW150, 2 x TLF Phosban Reactor, Koralia #1, #4, MJ Modded |
08/05/2007, 01:51 AM | #29 |
Registered Member
Join Date: Mar 2005
Location: AL
Posts: 1,047
|
You shouldn't. Unless the laws of physics suddenly change. The weight of the tank will hold in that direction.
__________________
"When I get sad, I stop being sad and be awesome instead. True Story." Current Tank Info: 29g Mixed Reef with Metal Halide |
08/05/2007, 08:42 AM | #30 |
Registered Member
Join Date: May 2007
Posts: 19
|
RocketEngineer -
Why aren't the green fastening strips the same height as the stand? I understand they aren't load bearing, but having them run the full height of the stand makes assembly easier since you can square them up on a flat surface and against the box frames. |
08/05/2007, 08:49 AM | #31 |
Registered Member
Join Date: Sep 2006
Location: St.Petersburg,Florida
Posts: 7,368
|
great post rocket engineer.i used this same basic layout for my 150g stand and its very rigid and strong.
__________________
Deep Blue 28g rimless, AI Prime LED,Vortech MP-10,SCA-301 skimmer, Tunze 1073.04 return pump,Tunze nano osmolator, 10g glass sump,Ehiem 100w heater,RK Lite. SPS dominant reef |
08/05/2007, 10:14 AM | #32 |
Space is big.
Join Date: Feb 2007
Location: Maryland Eastern Shore
Posts: 3,226
|
slevesque - depends on whether you are looking at it sitting down or standing up. I don't have exact numbers but others on RC may have some suggestions. For a tank that short though, you may be able to reduce the lumber sizes a little. What size tank is it?
flyguy7150 - I think Siffy answered all you questions. Siffy - Thanks for answering all of flyguy7150's questions. Charlutz - The reason the screw strips are shorter is that it prevents them from being part of the load bearing structure. Because they sit above the bottom frame you are assured its the frame sitting on the floor, not the screw strips. They are below the top surface to ensure that plywood or the tank frame sits directly on the upper box, rather then on the screw strips. checkinhawk - Thanks for the support.
__________________
-RocketEngineer "Knowledge is what you get when you read the directions, experience is what you get when you don't." - Unknown Current Tank Info: None Currently |
08/05/2007, 10:26 AM | #33 |
Registered Member
Join Date: Jan 2006
Location: Montreal
Posts: 377
|
My new tank is a 33L AGA: 48 x 12.5 x 12H
My 55G stand is 28" high and I find it a bit too low. I might go for 30-31" this time. I sit down for watching the tank, so many stuff to look at
__________________
Stephane Levesque The Shrimp Guy! Current Tank Info: 55 + 20L |
08/05/2007, 11:15 AM | #34 | |
Registered Member
Join Date: May 2007
Posts: 19
|
Quote:
|
|
08/05/2007, 04:42 PM | #35 |
Registered Member
Join Date: Mar 2005
Location: AL
Posts: 1,047
|
Yep, you just don't want them (the screw strips/green pieces) touching the floor when the tank weight is on them. A small piece of 3/4" plywood or 1xwhatever will shim/hold them up while screwing into them and fall off once the stand is picked up. I might suggest cutting the screw strips an inch longer if you're only able to shim them 1/2" off the floor instead of a full inch so there is plenty of material to screw the top frame into place.
__________________
"When I get sad, I stop being sad and be awesome instead. True Story." Current Tank Info: 29g Mixed Reef with Metal Halide |
08/05/2007, 08:41 PM | #36 | |
Registered Member
Join Date: Jun 2005
Location: Kansas City, MO
Posts: 586
|
Quote:
And for those that are concerned about deflection you don't need to worry about a thing as all of the weight from your tank will be sitting at the corners. Think of it this way, in order for that top box to deflect, you would have to be putting load on it in the middle somewhere. And in order for that to happen, the glass (including the sides) from your tank would have to deflect to apply that load to the wood. The sides of your tank are not going to deflect. Looking at the side piece of a standard 75g tank, 21"x48"x3/8 with a load of 10 lbs/ in (that would be a total load on the tank of 960 lbs which would be a conservative estimate) (and assumeing a Youngs modulus of 72GPa http://www.roymech.co.uk/Useful_Tabl...ter/Glass.html) you would get a deflection of 0.00123" barely over a thousandth of an inch, not enough to load that wooden beam. You would have have to apply a load of 125 lbs/in (a total tank load of 12000 lbs) to get it to deflect 1/64 of an inch, and this load also corresponds to the point that that side piece would break in flexure (and the bottom would have gone way before that, but I'm trying to make a point). Even at 1/64 of an inch you would bairly begin to load that wood beam. So, in summary, the wooden beam at the top does verturally nothing; it holds the 4 columns at the corners in place providing a little bit of stability. And how high can you make your stand... if you are worried about tipping it over try this: It would be very difficult for a single person to push or pull 100 lbs without actually sliding on the carpet or wood or whatever first. With that assumption, use this equation as to how high the mid hight of your tank can be: W= Weight of tank (use a conservative value of 9 lbs/ gallon which would include the weight of the tank itself and your rock and sand) b = the width of your stand from front to back h = hight to the middle of your tank Equation: h = (1/100)*W*(b/2) So using that 75 gallon tank example: W= 75*9 = 675 h = (1/100)*675*(18"/2)=60.75" Moral of this story, you can build your stand just about however high you want without worries. |
|
08/05/2007, 08:57 PM | #37 |
Registered Member
Join Date: Jan 2006
Location: Montreal
Posts: 377
|
Well, your formula got me worried
In my case I got a 33L, so W= 33*9=297 h= (1/100)*297*(13"/2)=19.3" Since the tank is 12" high this means I'm allowed to have a 13.3" high stand!!! I hope I got that wrong
__________________
Stephane Levesque The Shrimp Guy! Current Tank Info: 55 + 20L |
08/06/2007, 05:26 AM | #38 | |||
Registered Member
Join Date: May 2007
Posts: 19
|
Quote:
I don't think it's the shear of the screw that is the main problem. It's the shear strength of the wood which is low. All of the pressure of the tank will be concentrated on the screw. My concern is that it would be enough to rip the wood. Quote:
Doesn't this depend somewhat on the height of the stand? If the stand is taller, the posts will lean in under weight. Quote:
Taller stands will rock more easily due to leverage. It's the same as using a prybar. It's much easier to move a tank on a tall stand. Add in the fact that it will be top heavy, making it that much easier. Not saying the tank needs to lie on the ground, but you do need to consider height in the build. |
|||
08/06/2007, 01:31 PM | #39 |
Space is big.
Join Date: Feb 2007
Location: Maryland Eastern Shore
Posts: 3,226
|
Mykayel, Thanks for you comments.
But I don't agree on some points. 1) Screws in wood are likely to tear out sideways due to the shear forces on them. As the screws are in single shear, the wood is likely to fail before the screw itself. I for one would never trust a screw to take shear loading and transfer it from one piece of wood to another but this is just me. 2) You made the assumption that the tank was glass and with some simple additions such as a plywood top, this design could be used for an acrylic tank. In this case deflection IS an issue and needs to be accounted for. 3) I would like to know what that formula pertains to and what all the variables that make up that 1/100 factor come from. I have never seen it before so would like more info on it. Thanks for the comments everyone.
__________________
-RocketEngineer "Knowledge is what you get when you read the directions, experience is what you get when you don't." - Unknown Current Tank Info: None Currently |
08/06/2007, 01:48 PM | #40 | |||
Registered Member
Join Date: Mar 2005
Location: AL
Posts: 1,047
|
Quote:
Quote:
Quote:
__________________
"When I get sad, I stop being sad and be awesome instead. True Story." Current Tank Info: 29g Mixed Reef with Metal Halide |
|||
08/06/2007, 06:36 PM | #41 |
Registered Member
Join Date: Apr 2005
Location: Pembroke Pines, FL
Posts: 1,988
|
Subscribing to the thread so I can have it for future reference. Great info.
|
08/06/2007, 06:42 PM | #42 | |||
Registered Member
Join Date: Jun 2005
Location: Kansas City, MO
Posts: 586
|
Quote:
Quote:
Quote:
|
|||
08/07/2007, 06:50 AM | #43 |
Registered Member
Join Date: Jan 2006
Location: Montreal
Posts: 377
|
Instead of having a full pane of plywood to cover the back of the stand, would it be OK to use triangular shaped plywood in each corner, let's say 1' long?
__________________
Stephane Levesque The Shrimp Guy! Current Tank Info: 55 + 20L |
08/07/2007, 10:13 AM | #44 |
Registered Member
Join Date: Jun 2001
Location: Albuquerque, New Mexico
Posts: 207
|
slevesque,
That should work fine. The corner braces do not carry any of the weight of the tank. They only carry shear loads caused when someone leans up against the tank. Four one foot long triangles properly attached to the frame will be able to handle a lot of shear loads before you start breaking screws or tearing the wood.
__________________
--Roamer Current Tank Info: 150 gallon reef with sand bed |
08/09/2007, 09:49 AM | #45 |
Registered Member
Join Date: Nov 2006
Location: Central IA
Posts: 165
|
First of all, thanks for the thread. I know basically nothing about this stuff and it's been very helpful. I just have a question or two.
I want to build a stand like this for my 55g (48.25"x12.75"). The thing is I want to put a 29g (30.25"x12.50") inside the stand for a sump and in order to do that I would have to build the stand a little deeper than the 55g tank. I was thinking that I could make the inside of the stand 13" deep, leave off the screw strips and put a piece of plywood on top to set the 55g on. If I did this, would the plywood effectively distribute the weight of the 55g onto the 2x4s or would the it break under the weight? |
08/09/2007, 12:52 PM | #46 |
Space is big.
Join Date: Feb 2007
Location: Maryland Eastern Shore
Posts: 3,226
|
Jen D, First I need a little more information about the 55G. Is it glass or acrylic? If glass, does it have a plastic frame around the bottom?
If the tank is glass and has the plastic frame, you only need to support the perimeter of the tank. This means you could leave off the plywood top and just rest the tank on the 2X4s. You could use 2X2s screw strips and have the sump rest up against these. This would give you the space needed for the sump. Hope that helps
__________________
-RocketEngineer "Knowledge is what you get when you read the directions, experience is what you get when you don't." - Unknown Current Tank Info: None Currently |
08/09/2007, 02:30 PM | #47 |
Registered Member
Join Date: Nov 2006
Location: Central IA
Posts: 165
|
It's glass with plastic trim. I was going to use the plywood because the stand would be too deep to support the long sides of the tank if I make it with a 13" opening inside the stand. The tank would only rest on the 2x4s on the short sides.
I like the idea of the 2x2 screw strips. Now that I rethink it I could use the 2x4 screw strips, too. I had it in my head that the sump was going to be up against the short side of the stand, but it doesn't have to be... duh. |
08/10/2007, 03:16 AM | #48 |
Registered Member
Join Date: Dec 2004
Location: central ca
Posts: 1,831
|
thanks rocketengineer!!! I built my first ever stand tonight with the help of your plans...here are some pics!
one question i have is why not make the green boards or screw boards the run entire hieght of the stand? and how should I go about putting a floor and top on it?
__________________
The power of moonlight Current Tank Info: 90g rimless tank in the makes and a 15g nano Last edited by Misled; 03/27/2018 at 06:41 PM. |
08/10/2007, 03:25 AM | #49 | |
Registered Member
Join Date: Mar 2005
Location: AL
Posts: 1,047
|
Quote:
__________________
"When I get sad, I stop being sad and be awesome instead. True Story." Current Tank Info: 29g Mixed Reef with Metal Halide |
|
08/10/2007, 03:30 AM | #50 |
Registered Member
Join Date: Mar 2005
Location: AL
Posts: 1,047
|
As for a top and floor. If your tank has a glass bottom that's tempered a top isn't required. The tank can just sit on the 2x's. For a floor I'd just notch the corners out the size of the screw strips and install it through the opening at an angle it should fit. I'd make it the full width and length of the stand except at the corners.
__________________
"When I get sad, I stop being sad and be awesome instead. True Story." Current Tank Info: 29g Mixed Reef with Metal Halide |
Thread Tools | |
|
|