khalid January 5, 2011 Share January 5, 2011 Ok so I was fine with my build until now that I have the 180 filled and salt is mixing. Please take a look and tell me if I am freaking out for no reason. I started off and built the stand with 2X4's then added additional 2X6 frame supports on the front and back as well as a sheet of 3/4 plywood on top which the tank sits on. Please take a look at the pictures and tell me what you think. http://picasaweb.google.com/KAlghussain/180StandInProgress# I also am planning to add additional 2X6 supports on the sides along with 3/4 plywood on the sides for additional safety of mind. Please let me know if you guys think the stand looks fine the way it is without the additional support. Thanks! PS. Sorry I couldn't post the pictures for some reason I keep getting and error when I try to do it. Link to comment Share on other sites More sharing options...
Origami January 5, 2011 Share January 5, 2011 Why would you be freaking out? That stand is so overbuilt, it should hold the load without problem! My 180 sits on a stand made of 3/4 inch plywood - not a frame of 2x4's or 2x6's. Now, were you planning on putting a sump in the stand? If so, will you be able to get the sump in and out of the stand through the openings that you've left? Link to comment Share on other sites More sharing options...
Chad January 5, 2011 Share January 5, 2011 You are freaking out for no reason. If you send me actual dimensions for everything, I will send run some 2d calculations and show you that you are overbuilt. I think you could park a car on it. Link to comment Share on other sites More sharing options...
Origami January 5, 2011 Share January 5, 2011 ...I think you could park a car on it. (Or a tank. Not the fish kind, but the big, metal, turret-wielding kind.) Disclaimer: Do not try this at home. Link to comment Share on other sites More sharing options...
Chad January 5, 2011 Share January 5, 2011 ^haha, I was thinking one of those bouncing hot rods with all the hydraulics you see in movies sometimes If you can try that at home... I want to see the you tube video! Link to comment Share on other sites More sharing options...
flowerseller January 5, 2011 Share January 5, 2011 I think it looks great and the workmanship is excellent. Much better to be over built than under built. Link to comment Share on other sites More sharing options...
Origami January 5, 2011 Share January 5, 2011 All kidding aside, the stand is strong. You should have no worries. I saw shims in one picture. Is the tank now level all the way around? That's important. Link to comment Share on other sites More sharing options...
khalid January 5, 2011 Author Share January 5, 2011 Why would you be freaking out? That stand is so overbuilt, it should hold the load without problem! My 180 sits on a stand made of 3/4 inch plywood - not a frame of 2x4's or 2x6's. Now, were you planning on putting a sump in the stand? If so, will you be able to get the sump in and out of the stand through the openings that you've left? Great thanks, I am not sure why I was freaking out I guess just got paranoid today after reading a few posts on reefcenral. I have a sump/fuge waiting to get drilled for the return pump and put in. It will fit in there easily along with the external skimmer and the remainder of equipment. Link to comment Share on other sites More sharing options...
khalid January 5, 2011 Author Share January 5, 2011 You are freaking out for no reason. If you send me actual dimensions for everything, I will send run some 2d calculations and show you that you are overbuilt. I think you could park a car on it. The whole stand is 35"+3/4" plywood High X 27W X 73L The 2x4 frame alone is 35H x 24W x 73L Thank you very much for the input! Link to comment Share on other sites More sharing options...
khalid January 5, 2011 Author Share January 5, 2011 (Or a tank. Not the fish kind, but the big, metal, turret-wielding kind.) Disclaimer: Do not try this at home. Lol! That's good to know Link to comment Share on other sites More sharing options...
khalid January 5, 2011 Author Share January 5, 2011 I think it looks great and the workmanship is excellent. Much better to be over built than under built. Thank you very much Chip that makes me feel a lot better! Link to comment Share on other sites More sharing options...
Chad January 5, 2011 Share January 5, 2011 Khalid, Some quick calcs for you to further bolster your confidence: Based on 6 2x6's carrying the load of your 180 gallon tank (180 gallons x 10 lbs/gallon x 1.25 misc factor) which is double conservative over actual weight) which will weigh around 2250 lbs. The 6 2x6's can carry around 90,000 lbs of load, so from a compression point of view you have a safety factor of around 40. Now, that isnt the whole story since there is a potential of some bending in the horizontal members, so I used the maximum bending formula out of the machinery handbook to figure out maximum deflection. Rocket Engineer over at RC and I had a conversation a while back where he convinced me that 0.125 inch of deflection is a good number to use as a limit for maximum OK deflection of a horizontal support member. For yours, the maximum unsupported horizontal distance is 28.5" by my best guess. The maximum deflection (based on the tank creating a point load in the center of the unsupported distance) is 0.01 inch. You are WELL beloew this limit. OK, bring on the Howitzer!!! Link to comment Share on other sites More sharing options...
Coral Hind January 5, 2011 Share January 5, 2011 I agree it is well built! I would pass on the extra 2x6's and go with a thinner plywood as 3/4" is much to thick. Link to comment Share on other sites More sharing options...
Origami January 5, 2011 Share January 5, 2011 Khalid, Some quick calcs for you to further bolster your confidence: Based on 6 2x6's carrying the load of your 180 gallon tank (180 gallons x 10 lbs/gallon x 1.25 misc factor) which is double conservative over actual weight) which will weigh around 2250 lbs. The 6 2x6's can carry around 90,000 lbs of load, so from a compression point of view you have a safety factor of around 40. Now, that isnt the whole story since there is a potential of some bending in the horizontal members, so I used the maximum bending formula out of the machinery handbook to figure out maximum deflection. Rocket Engineer over at RC and I had a conversation a while back where he convinced me that 0.125 inch of deflection is a good number to use as a limit for maximum OK deflection of a horizontal support member. For yours, the maximum unsupported horizontal distance is 28.5" by my best guess. The maximum deflection (based on the tank creating a point load in the center of the unsupported distance) is 0.01 inch. You are WELL beloew this limit. OK, bring on the Howitzer!!! Howitzer, nothing. Let's bring on an M4 Sherman tank weighing in at 66,800 pounds! We've got that with a safety factor of nearly 50%! Impressive analysis, Chad! Link to comment Share on other sites More sharing options...
khalid January 6, 2011 Author Share January 6, 2011 Khalid, Some quick calcs for you to further bolster your confidence: Based on 6 2x6's carrying the load of your 180 gallon tank (180 gallons x 10 lbs/gallon x 1.25 misc factor) which is double conservative over actual weight) which will weigh around 2250 lbs. The 6 2x6's can carry around 90,000 lbs of load, so from a compression point of view you have a safety factor of around 40. Now, that isnt the whole story since there is a potential of some bending in the horizontal members, so I used the maximum bending formula out of the machinery handbook to figure out maximum deflection. Rocket Engineer over at RC and I had a conversation a while back where he convinced me that 0.125 inch of deflection is a good number to use as a limit for maximum OK deflection of a horizontal support member. For yours, the maximum unsupported horizontal distance is 28.5" by my best guess. The maximum deflection (based on the tank creating a point load in the center of the unsupported distance) is 0.01 inch. You are WELL beloew this limit. OK, bring on the Howitzer!!! Nice!!! Thank you very much I really appreciate it. Maybe I'll have to build another one and we can have a WAMAS event where we can load it up and see what happens. Just for my future reference where can I get the formula you used for the calculations? Thanks Link to comment Share on other sites More sharing options...
khalid January 6, 2011 Author Share January 6, 2011 I agree it is well built! I would pass on the extra 2x6's and go with a thinner plywood as 3/4" is much to thick. Thanks, since i have some thinner plywood laying around so I might just use that. Link to comment Share on other sites More sharing options...
Chad January 6, 2011 Share January 6, 2011 (edited) I knew off the top of my head that a 2x4 can take around 10,000 lbs force in compression and the relationship to area is linear... so I extrapolated for the first part to 6 2x6s. If needed, I could dig up a source for the equations, though. For the second part I used the equation for bending (point load center of beam or really conservative) out of the Machinery Handbook (several good sources for this, but since I had this one on my desk, it is the one I used) and a PDF I saved from a while back that has a ton of constants for various types of structural wood... I think I used the lowest strength number for a structural lumber which I think was 1100 ksi. I have an excell document somewhere that I baked a bunch of these equations into that I could dig up if you want to play with it. It isnt a bad thing to overbuild a stand since lumber is cheap and piece of mind is priceless. But most aquarium stands are super structurally sound and honestly nothing to worry about. Edited January 6, 2011 by Chad Link to comment Share on other sites More sharing options...
khalid January 6, 2011 Author Share January 6, 2011 Thanks Chad no worries about digging it up i was just curious. Got the dry rock and seed rock in today and started the cycling process. This weekend I'll get the rest of the equipment and plumbing done. Link to comment Share on other sites More sharing options...
Swimboy123 January 6, 2011 Share January 6, 2011 Khalid, Some quick calcs for you to further bolster your confidence: Based on 6 2x6's carrying the load of your 180 gallon tank (180 gallons x 10 lbs/gallon x 1.25 misc factor) which is double conservative over actual weight) which will weigh around 2250 lbs. The 6 2x6's can carry around 90,000 lbs of load, so from a compression point of view you have a safety factor of around 40. Now, that isnt the whole story since there is a potential of some bending in the horizontal members, so I used the maximum bending formula out of the machinery handbook to figure out maximum deflection. Rocket Engineer over at RC and I had a conversation a while back where he convinced me that 0.125 inch of deflection is a good number to use as a limit for maximum OK deflection of a horizontal support member. For yours, the maximum unsupported horizontal distance is 28.5" by my best guess. The maximum deflection (based on the tank creating a point load in the center of the unsupported distance) is 0.01 inch. You are WELL beloew this limit. OK, bring on the Howitzer!!! Chad, the next time I build something I'm having you over for beer and pizza! Link to comment Share on other sites More sharing options...
slimeemoss January 6, 2011 Share January 6, 2011 Wow......guess it will hold a tank with ease....sherman or 180gal...lol Link to comment Share on other sites More sharing options...
Chad January 6, 2011 Share January 6, 2011 Here is that spreadsheet that I put together a few months back when I was playing with ideas for my next system. I guess I didnt add the compression piece... but it is not an issue in most of our stands. Using a distributed load is more accurate for actual conditions on an acrylic tank. Little to no bending of the horitontal members will occur on a glass tank since glass flexes less than wood... in a glass case the actual capability of the stand is probably limited by rigidity (a skin or tension wires are more than adequate to compensate). However, using acrylic calcs on a glass tank is bounding and conservative. Did someone say beer? beam calc.xls Link to comment Share on other sites More sharing options...
Coral Hind January 6, 2011 Share January 6, 2011 Just something to remember when doing these calcs is there is more to a stand then just the amount of weight the wood can support. Making it stable and rigid enough to resist any side to side movement is also important. Without proper bracing and fastening of corners and joints an unsheathed stand could fold like a house a cards if bumped on the side. Link to comment Share on other sites More sharing options...
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