DIY Stands Template and Calculator

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I've said it before and I'll say it again...I don't understand why so many folks on here choose to build a 2x4 frame then wrap it in thin plywood. Why not save yourself the time, weight, and money and just use thicker plywood to begin with and no "frame"?

StandOptions.jpg~original
 
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<a href=showthread.php?s=&postid=14048425#post14048425 target=_blank>Originally posted</a> by RocketEngineer
benihana,

The sway is caused by not having enough stiffness in the corners. This can be caused by not clamping the legs to the rails while assembling or by not adding glue. I would disassemble the stand, glue and clamp the legs onto the bottom frame and then once the glue has had a day to set do the same for the top frame. The key here is the clamps. You want the glue to contact as much surface as possible.

Instead of skinning the entire stand, think about adding plywood triangles across the outside of the corners, the more the better. I would use 6-12" squares cut on the diagonal at the top and bottom to give the corners some added support. This way you get the benefits of the skin without covering the entire area of the tank.

HTH.

Thanks, it does help... I will dissasemble the stand and then glue.
 
<a href=showthread.php?s=&postid=14046381#post14046381 target=_blank>Originally posted</a> by kgross
When you skin the stand it will stop the swaying.

Kim
I'm not familiar with that term Kim, what does it mean to "skin the stand"?

Thank you ---
Chris
 
Skinning the stand, is covering the framework with some type of a "skin" like plywood so it looks better and you can't see inside the frame. It will hold the legs in place and parallel so the stand can not sway. It is amazing how much a piece of 1/4 inch plywood covering even just the ends of the stand stiffens it up.

Kim
 
My 20 gallon long stand

My 20 gallon long stand

Just built mine today in 45 minutes, although I forgot to ask for UNTREATED 2x4x12s I bought 4 of them at 4.38 a piece. I followed they original plans in thread to the T LOL and I think its overkill for my 20 gallon long. But hey its an awesome design and my stand would hold a 12ft tall tank if they made one LOL. heres a pic. It also has about 100 2 1/2 inch drywall screws keeping it nice and tight, there no wobble or sway or anything. Im thinking of putting bead board around mine and making the side panels removeable




>
 
Warped 2x4

Warped 2x4

<a href=showthread.php?s=&postid=10434116#post10434116 target=_blank>Originally posted</a> by RocketEngineer
Ok, Siffy. Being a student, here is the original source of information I used and continue to use when looking at lumber in a stand setting.

Full Document portal:
http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr113/fplgtr113.htm

Specifically, Chapter 4: Mechanical Properties of Wood
http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr113/ch04.pdf

For those with the background, the number I typically employ within my beam bending calculator is 4000 psi. A piece of Douglas Fir has a rupture strenght of ~7000 psi when GREEN! This "Strength of Rupture" is determined experimentally and considered the working value for lumber under bending loads.

As to what deflection is acceptable, personally I work for 1/8th inch and this is typically more restrictive then the strength of the beam.

Should anyone have any questions, let me know. I will be happy to post the equations I use for those interested.
Hello RocketEngineer --- I have an issue that one piece of 2x4, at the base is warped, causing one corner to elevate off of the floor about 1/2 an inch. Should I be concerned? Will it level out once my tank of 180g sits on top of it? Or what would you suggest I do? Please let me know.
Thank you
 
I'm not Rocket, but if the problem is just that the warp is holding up the stand, the weight of the tank should bend it down. But if you have the tools, shaving the bottom of the warp off will make sure it sets level.

Depending on where the warp in would determine what I would do. If it is a gentile warp over the length of the whole board, I would not worry about it. If it is a bad warp near the end, I would trim it down.

Kim
 
<a href=showthread.php?s=&postid=14063097#post14063097 target=_blank>Originally posted</a> by kgross
I'm not Rocket, but if the problem is just that the warp is holding up the stand, the weight of the tank should bend it down. But if you have the tools, shaving the bottom of the warp off will make sure it sets level.

Depending on where the warp in would determine what I would do. If it is a gentile warp over the length of the whole board, I would not worry about it. If it is a bad warp near the end, I would trim it down.

Kim
Thank you Kgross for the quick reply.

I will give you a brief description of the problem --- If you are facing the stand, the left rear corner sticks up. If you stand on it then the right front corner comes up. If 2 people stand on both corners at the same time then everything stays flat. Thats why I feel the weight of the system should hold it down fine. I used wood screws and wood glue during the assembly.

I think that the problem is due to the front 2x4 in the base. It actually looks like the right side at the end of this 2x4 is twisting outward. I hope that makes sense to you. I don't know if shaving is going to fix it.

Thanks ---
Chris
 
Careful Yankee. If the stand doesn't create a flat plane for the tank to sit on when its full, then you may create a lot of stress on the tanks seams.

Make sure its not a hump or bubble in the floor the stand is sitting on.
 
<a href=showthread.php?s=&postid=14063436#post14063436 target=_blank>Originally posted</a> by marinebarn
Careful Yankee. If the stand doesn't create a flat plane for the tank to sit on when its full, then you may create a lot of stress on the tanks seams.

Make sure its not a hump or bubble in the floor the stand is sitting on.
Thanks Marinebarn, I appreciate the concern.
No its definitely in the front 2x4 of the base. I have moved the stand around to see if it was something in the floor and its not. The front 2x4 has a slight twist on one end. When I put even weight on the entire base everything flats out.

Thanks again ---
Chris
 
Yankee... the same thing happened with the stand I build. I have one bottom piece that is slightly warped, causing one end to stick up about 3/8". This is over 106". I haven't put the tank on it, (370 gal w/ 30"x94" footprint) but I'm confident everything will settle out.
 
Haffts09 ---
Thanks, I think I will be fine as well. I was just looking for other opinions and answers before I set the tank on it.
 
Yankee, if you are going to skin the stand, don't, unless you can put weight on it to bring it staight first. I would try to put weight on it, bring it flat, then if you glue and nail plywood on the sides it should stay, (I would also leave the weight on until the glue has time to set. I was a carpenter for 13 years and have done things similar to this lots of times. Of course if it takes "alot" of weight to bring it down, then you will need to cut it or replace the board. Good luck, I hope this helps! :thumbsup:
 
4jlong ---

I appreciate your advice very much. I don't plan on skinning the entire stand, only the back of it. When I do I will make sure to have plenty of weight on both the L/R, as well as the R/F of the stand before I skin.

I built the stand for a new 180 gallon tank that I'm getting. Maybe I should use the weight of the tank, then skin it. That should be heavy enough.

By the way, I noticed that you are starting a 150. My current tank is a 150 and I have some equipment you might be interested in. Let me know.

Thanks again ---
Chris
 
you got PM :D

by the way, i would put the tank on the stand and try to "wobble" it-push down on each corner and be sure it doesn't rock at all. if it lays flat with the weight of the empty tank you'll be fine.
 
<a href=showthread.php?s=&postid=14048656#post14048656 target=_blank>Originally posted</a> by RedEDGE2k1
I've said it before and I'll say it again...I don't understand why so many folks on here choose to build a 2x4 frame then wrap it in thin plywood. Why not save yourself the time, weight, and money and just use thicker plywood to begin with and no "frame"?

StandOptions.jpg~original

I agree. Using 3/4 plywood with cleats glued and nailed to the panels, the entire panel transfers the load, not just the vertical members. I still use some vertical supporting members, but they are typically 2x2s
 
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RedEDGE2k1,

Stronger: The mechanical properties of standard sheathing grade plywood and douglas fir are approximately the same at ~4000 PSI tensile and compressive strength. That being the case, a .75" thick piece of plywood 3.5" wide has the same characteristics as half of one "2X4" of the same length. SO, your contention that the stand would be stronger only fits as long as there are no holes cut into the panels. Now, I don't know about you but I need access to my sump. Therefore people will need to be careful about the size of the openings in the stand to ensure they are strong enough. In fact, while a 2X4 top span can easily support a 75g tank, you would need the plywood under the top to be at least 4.5" wide to have the same strength. So therefore the perception that plywood is stronger then the solid wood stand is conditional.

Faster: That depends on what tools and help one has available to them. For one, how do you hold the side panels upright so you can pre-drill the holes? My original design allows for clamping pieces together or to a carpenters square for easy pre-drilling and tight assembly. Also, how do you cut out the holes in your panels? A drill for a pilot hole and jig saw with guide is one way. A router and guide is another. For mine, a pilot hole and then a counter top edging bit in the router uses the frame as a guide and gives you openings as big as the legs. I would say they are even in time of build.

Easier: In terms of figuring out sizing to get strength I would say the solid wood is easier to size as its in known steps. Overall, I would like to hear why you think your plan is easier? Fewer pieces surely but the panels seem harder to assemble to me.

Lighter: Absolutely. I won't argue there.

Cheaper: That depends on the quality of materials. Thinner plywood is less expensive and 2X material is easy to come by where as quality A face plywood can run a pretty penny. If you screw up the plywood you may have to buy a whole new piece where as mine can be faced in strips as several folks on RC have shown. It all depends on the final look.

schristi69, the whole panel transfers the load only when it is left intact. If the sump is located under the tank, an opening of some kind is need and this will degrade the strength of the stand.

To all those who wish to pursue the panel stand concept, please go for it and keep us posted. It is my opinion that all ideas are worth a good look.
 
Thanks RocketEngineer great thread.

After a lot of reading, I decided to go with your idea about the stand, but I`ll need your opinion if it will work. Tank is 215gal (72x24x29) but the stand I made is 73x20x36.5
So here's what's been happening so far:

My framing guys made a stand for me, but after that I decided to finish the room with tiling so I took apart almost everything, just left the top part which is connected to the wall. It looks like this:

89895IMG_2064.JPG


I covered the wall part with wonderboard, and finished with tiling (I want to have a waterproof room)

89895IMG_2079.JPG


Two platforms

89895IMG_2219.JPG


Stand ready after 40min work

89895IMG_2221.JPG


Deckmate screws

89895IMG_2225.JPG


Stand ready, I squeezed the new stand under the plywood

89895IMG_2227.JPG


done after 2 hours

89895IMG_2235.JPG
 
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