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damtrees420
07-18-2011, 10:07 PM
so i got a 428 gallon 84x42x28 and my buddy is making a stand out of 1 1/4 square tubing going to have 6 legs so it will be 3.5 ft to each leg with 1 inch plywood on top is it going to be enough to hold the 4000 pounds or so only going 28 inch tall so it can fit in a door with out having to come apart made like all the rest of the stands with a top and bottom with 6 legs going up

sphelps
07-18-2011, 11:33 PM
what size wall will the tubing have?

damtrees420
07-18-2011, 11:40 PM
3 1/16

The Grizz
07-18-2011, 11:45 PM
I would use at least 1 1/2" x 1 1/2" x 3/16 (.188) HSS if not 2 " x 2".

Skimmerking
07-18-2011, 11:52 PM
I would use at least 1 1/2" x 1 1/2" x 3/16 (.188) HSS if not 2 " x 2".


yup and This guy would know

sphelps
07-19-2011, 12:37 AM
Without going into too much detail I ran half the frame with half the weight using A36 steel in the size you're planning and you barely get a safety factor of 2, typically for this application I like to see 5 or more. 2" with a .25 wall will give you close to 5 following the same stand design/layout.

HTH

http://i11.photobucket.com/albums/a174/sphelps/Part2.jpg

jorjef
07-19-2011, 01:12 AM
If you are using 2x2x.250w HSS the grade would either be a G40-21 350W or an A500 GR C . This would increase your safety factor and possibly enable him use a lighter wall thickness.

viperfish
07-19-2011, 01:18 AM
Without going into too much detail I ran half the frame with half the weight using A36 steel in the size you're planning and you barely get a safety factor of 2, typically for this application I like to see 5 or more. 2" with a .25 wall will give you close to 5 following the same stand design/layout.

HTH

http://i11.photobucket.com/albums/a174/sphelps/Part2.jpg

A36 HSS? Dude, where you gettin' steel from?

lastlight
07-19-2011, 02:26 AM
I ran some similarly technical tests and determined this would not work:

http://diyfamily.files.wordpress.com/2009/11/table.jpg

The Grizz
07-19-2011, 02:30 AM
A36 is the most common and readily available steel grade used in structural fabrication.

If it is possible go with 2 mid supports splitting the tank length into 3rds.

The Grizz
07-19-2011, 02:31 AM
I ran some similarly technical tests and determined this would not work:

http://diyfamily.files.wordpress.com/2009/11/table.jpg

ROTFLMAO!! That is priceless Brett.

jorjef
07-19-2011, 02:47 AM
A36 is the most common and readily available steel grade used in structural fabrication.


In the states for the most part. A36 yield and tensile strengths (36K) are no where near what Canada uses or at least Saskatchewan. Tubing and beam are most often called with a 50K yield and bars with 44K.

Lance
07-19-2011, 03:02 AM
I ran some similarly technical tests and determined this would not work:

http://diyfamily.files.wordpress.com/2009/11/table.jpg



You ate all your kids popsicles to make that, didn't you?

sphelps
07-19-2011, 03:31 AM
In the states for the most part. A36 yield and tensile strengths (36K) are no where near what Canada uses or at least Saskatchewan. Tubing and beam are most often called with a 50K yield and bars with 44K.
Yes there is stronger steel out there but A36 is pretty common even here in Canada and you'll also have a hard time finding 1-1/4 in anything cold rolled, likely it will be hot rolled and at best A-36. Plus $20 says they have no idea what steel it is so for me to assume it's the strongest available would be pretty foolish. Anything you get from a local hardware store isn't anything special. Like I said before, without getting into too much detail that's what I came up with, take it for what it's worth to you.

reefwars
07-19-2011, 03:39 AM
I ran some similarly technical tests and determined this would not work:

http://diyfamily.files.wordpress.com/2009/11/table.jpg



its true brett it didnt there was a design flaw so they had to revamp the whole thing and after 3yrs of structural engineering they managed to come up with this :



http://t2.gstatic.com/images?q=tbn:ANd9GcT5DmgjddrUOzwUukExtM0LcYpMTraXd bu9C3uj03eHcqsFPDch

viperfish
07-19-2011, 03:49 AM
A36 is common in plate and bar stock but you'll be hard pressed to find it in HSS so no sense recommending it to a guy looking for HSS to build a tank stand. 44W (or the Canadian version 300W) is sometimes available and 50W (Canadian 350W) is also sold in HSS stock. I wish I had a dollar everytime an Engineer specified a material grade/shape combination that doesn't exist.

This technical jargen doesn't mean a roll of beans to our guy that's looking to build a stand. I think it's safe to say whatever grade he buys as long as it's plenty thick and sized right (Grizz had it right with the 1.5 or 2" x .188 HSS) and has it welded true and square by someone that is a decent welder, there will be no issues. I've seen so many stands that the welding looked like a bird crapped on it, and they held (God only knows how) so the key is not to Engineer it to the minimum, overbuild it so there's no chance of it falling apart.

sphelps
07-19-2011, 04:06 AM
Wasn't recommending anything, just trying to answer the question at hand, will it hold.... What material? You tell me.

viperfish
07-19-2011, 04:31 AM
Sorry, not trying to be an ass. You obviously know your material. We probably took the thread away from its original intent just a little.

I would say the easiest way to deal with the stand design dilemma is to find a good welder leave it up to him or her. Most capable structural welders know their stuff so there should be no need of getting too technical. It will probably be overbuilt but that's not a bad thing.

damtrees420
07-19-2011, 01:39 PM
Its getting built from a buddys welding shop so only cost 80$ so im not to conserned about the money as its already cheap i think ill tell him to go 1 1/2 if they have that in stock or add some supports thanks for the input i knew it was going to be close glad I checked before i had a tidle wave tank for a few min as the tank its self is a bit of a gamble made out of 1/2 glass but has been reinforced and has held water for over a week now in the garage

BMW Rider
07-19-2011, 02:13 PM
Part of the issue is going to be rigidity too. If the stand is able to rack even a little, the strength of the vertical members will drop drastically. I've no engineering experience, but my gut would have me adding in more coulums, probably a couple more on each side, and possibly a cross brace to keep it stable.

The Grizz
07-19-2011, 03:40 PM
Definitely go with 1 1/2 tube, have 2 vertical members to split length in 3rds and if they build it right it will hold. And by build it right I mean, build the front and back frames first with 45 degree corners and then join them with the horizontal members. Doing this makes your corners bullet proof. You could add a knee brace into the backside of the stand just to be really on the safe side.

sphelps
07-19-2011, 04:45 PM
Personally I would still suggest going 2" for the amount of weight. If you do use 1-1/2 then be sure it is actually HSS (structural steel, cold forged). If it's just hot rolled square tubing 1-1/2 is going to be pretty sketchy. As others have suggested extra columns is a good idea as well as adding angled supports at all corners to reduce the load on the joints and keep things square.

jorjef
07-19-2011, 05:26 PM
Personally I would still suggest going 2" for the amount of weight. If you do use 1-1/2 then be sure it is actually HSS (structural steel, cold forged). If it's just hot rolled square tubing 1-1/2 is going to be pretty sketchy. As others have suggested extra columns is a good idea as well as adding angled supports at all corners to reduce the load on the joints and keep things square.

Good point almost all tubing 1.5 or smaller isn't tested for yield and tensile with the exception Griz mentioned 188 wall. Personally I would worry more about the guy doing the fabricating. You could get the best materials but if the guy doing the work doesn't know what he's doing it could be a disaster

claymax
07-19-2011, 11:29 PM
Are those popsicle grade or fudgsicle grade sticks? You might need some cross bracing in there, esp if you're gonna use a wavemaker