Pls audit this steel stand design

[picker]

This design lets one use a sump the same width as as the display tank and wets the area behind the display tank facilitating plumbing without elbows for fast full siphon formation.

http://rob.com/lancair/2012.11/tankfront.png

http://rob.com/lancair/2012.11/tankside.png

1) Is 1.5" tubing acceptable for a 36" span? 48"?
2) Is it better to mirror the anti-racking braces, or should I flip the longer arm for the rear legs?

[kcress]

Everything should be as symmetric as possible. Racking should be on both the top and the bottom.

Have you looked at the BIG steel stand thread?

[r-balljunkie]

im not going to say it wont work, however its not a "sound" design.

ideally the top and bottom would be the same. your vertical support legs would be welded on top of the bottom piece, and not welded 1" off the bottom. if you want to raise the tank off the floor, use threaded levels to do so.

1 1/2" is fine. no need to use flat bar for the gussets..use the same square stock.

you can achieve the same intent (sump extend further out the back) using symmetrical tops and bottoms.

you should really check out the steel stand thread, like suggested above. you'll get better ideas/tips/tricks.

here's a 36" tank using 1 1/2" square tubing.

48" would be pushing it..at the very least would want to go with larger rectangular tubing across the top.

what are the holes in the back for? they seem very low and big.

the sump shown is largish...you might want to opt for something a bit shorter to get equipment in and out.


http://i143.photobucket.com/albums/r158/cchavis/36cubeforsale04.jpg


http://i143.photobucket.com/albums/r158/cchavis/DSC05910.jpg


http://i143.photobucket.com/albums/r158/cchavis/IMG_1268.jpg


http://i143.photobucket.com/albums/r158/cchavis/IMG_1272.jpg


http://i143.photobucket.com/albums/r158/cchavis/IMG_1280.jpg


http://i143.photobucket.com/albums/r158/cchavis/IMG_1289.jpg

[amond003]

Looks good. I have always liked steel stands

[picker]

> Racking should be on both the top and the bottom.

We can easily add lower side to side anti racking, but not lower back to back.

So should I add the tiny lower anti side to side keeping all 4 longer upper back to back rather than breaking upper symmetry moving a pair of the longer back to back to anti side to side?

> use threaded levels to do so.

why are threaded levels safer than shimmed feet?

[r-balljunkie]

dude,

it just aint a sound design. go find the steel stand thread and get some ideas to improve upon your initial concept.

ive been a mechanical engineer for 15 years now, put a bunch of structural steel thru fab shops....you need to change directions a bit, but you are on the right track.

you should always be in static compression, you have members in tension, and you are relying on weld integrity. if a weld fails on your design, you are toast.

little tweaking, thats all.

C

[picker]

so remove the 45 at the top of the legs so they are in static compression (and put plastic end caps on) and drop the sump support to the ground, probably bolting rather than welding it to the legs?

[picker]

How about removing the 45 and dropping the bottom to the floor, that should put more of the design in static compression. Then the questions are:

1) is 1" aluminum going to hold a 20g tank?
2) is there a way to reduce the cost of the "two tanks the same size" design?

http://rob.com/lancair/2017.05/1.jpg
http://rob.com/lancair/2017.05/2.jpg

http://rob.com/lancair/2017.05/FishTank.skp

[BlueRoofTang]

I would not use 1" aluminum on even a 20g. Take a piece the length of the tank, put one end on a brick, the other on the floor. Step on it and you will see how much it bends. I would use steel, or larger aluminum.

As for the rest of the stuff....its a stand, not rocket surgery. If you are worried about the weld strength, dont weld it. A good weld is stronger than the base material. Having gussets on the top is fine. No need for them on the bottom unless you are a bit on the paranoid side. I have built metal frames for about 20+yrs and have seen much less hold much more.

[ratherbeflyen]

I used 6" aluminum channel for a 215 gallon tank. I didn't elevate the sump though. I use a 75 gallon tank for a sump and wanted it as low as possible to fit equipment and be able to work under the stand.

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