Custom rackmount shelf, will this be strong enough?

R

Red Squirrel

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I'm thinking of buying a bunch of these:

http://www.monoprice.com/products/p...=10516&cs_id=1051602&p_id=8629&seq=1&format=2

To make 1 shelf I would have one at each end of a a 4 post rack and have a piece of plywood spanning both. I would add a 2x4 at the end of the plywood on both shelves so the weight is concentrated at the front of each shelf reducing leverage. My intention is for this shelf to hold several big lead acid batteries, basically car batteries. I never weighed one of those batteries but they're quite heavy, if I had to guess, about 50 pounds. Even though these shelves are only rated at 50 pounds do you think they'll be able to handle more in my planned configuration? Idealy I want this as dense as possible, so probably like 4 batteries per shelf. (I only have 2 right now but future planing)

I got a free server rack, so I will dedicate it towards power backup. It has side panels, doors and all.
 
I wouldn't even bother with those shelves. Cut some 2x4s or 2x6s and bolt them into the front of the rack. Then another at the back of the rack. Lay down like three long 2x4s between those two. Lay down a sheet of plywood on top of that. Toss the batteries on top and see how it holds. If it flexes, put down some more 2x4s and recover with the plywood.

house_attached_patio_roof_diagram.gif


Like the top of this patio roof, just, inside your server rack.
 
I was thinking of fully custom but how do I attach it to the threaded holes? I don't want to actually make holes in the rack for big bolts as there's always the potential I want to move stuff around or use it for something else so I don't want it dedicated for this purpose.

Do they make very long rack screws? I could make the shelf do a L with a 2x4 and have it go through that. The screw holes also seem smaller, so not sure what kind of screws those are. I recall buying a bag of screws from monoprice and they were too small, so maybe those will fit, but they would not be long enough to go through wood deep enough so those are out, anyway.

Also this rack is threaded, and the threads seem smaller than any rack screw I've seen... wondering if I should just drill out the holes bigger and unthreaded, I can still use it with normal rack stuff that way right?
 
Weird that the rack is already threaded. I'm use to racks with square holes. Then you put in a bracket that has the threads (usually a bracket with a square nut).

As for rack bolts, just take the bolts you have now and roll to Home Depot or Lowes. They'll have a random block that you can thread the bolts into. This will tell you what size/thread they are. Then just dig away in the bolt bins until you find the size/thread and length you want. Now if you don't have any bolts at all, you are a bit SOL. Guess you can just measure the threaded hole and then buy a few different bolts at Home Depot or Lowes. Unless you can remove that portion of the rack and take it with you.

You could just forgo bolting it to the rack altogether. If the bottom of the rack can support weight, just build a 2x4 cube and place it inside the rack. Zip tie it to the rack so it doesn't move, then build upon that.
 
Yeah there's a few bolts on it already, and I did buy some bolts a while back from monoprice and they turned out to be too small for the cage nuts of my normal square hole rack so maybe they fit too. I think there's two standards for racks so this is the smaller one.

I'll check HD to see what they got, never even thought the bolts could happen to be standard and be found there.

Worse case scenario I can also do as you suggested and build something separate and sit it inside. The bottom of the rack will be flush with the ground so weight capacity is not an issue.
 
Ya, I find just about everything now is standard. Cheaper than trying to create some odd size/thread size.
 
Why not just buy a rack mount shelf? They are not that pricey. Should be able to get one for less than $50. After buying wood,hardware, gas to get to store, and time for your ghetto shelf I can not see you saving that much money.

Only thing is since your rack does not have square holes just make sure the shelf you get can work with threaded rack rails. Should not be too hard to find one that would work.
 
x2 on just buying a proper 4-post shelf.
Or DIY the whole thing if you're going to crap it up with plywood anyway.

We have a few things sitting on 2-post shelves like your link, they are not very strong. The most we have on one is a couple of basic mid-towers, probably 40lbs total, and that seems like it's pushing it.
 
m1abram said:
Why not just buy a rack mount shelf? They are not that pricey. Should be able to get one for less than $50. After buying wood,hardware, gas to get to store, and time for your ghetto shelf I can not see you saving that much money.

Only thing is since your rack does not have square holes just make sure the shelf you get can work with threaded rack rails. Should not be too hard to find one that would work.
Click to expand...

The issue is the shipping. I was looking on ebay and everybody wants like 100 bucks for shipping. It would end up costing like a grand for the 5 shelves I want when all is said and done since there's also customs which is usually another couple hundred bucks. That racksolutions site looks nice though, I'll have to keep it in mind when I need stuff. I just can't justify paying 200 bucks for a shelf though. Really if I could get some L brackets that I can then attach the wood to that could work as well. I'll have to check HD for bolts though if I can find really long ones then I ca just have a 2x4 spanning behind the vertical and have a couple bolts go through then a nut on the other side, then just build the rest of the shelf on top, I'll size it exactly for that rack. Should be fairly easy to do and I already have some wood here.
 
Hmm seems the Canadian Amazon has those too so I may be in luck. I never usually bother looking on Amazon since half the time the items are US only. And looks like shipping is free! That's usually the biggest killer when ordering anything online. I might just go with these. The capacity is 250lbs too, so it will handle the batteries just fine.

Just noticed too, the Canadian version only runs on Windows? :D
http://www.amazon.ca/APC-AR8122BLK-...sr=8-9&keywords=rack+shelves&tag=hardfocom-20
 
As an Amazon Associate, HardForum may earn from qualifying purchases.
If you are using lead-acid batteries, you may want to use anti-corrosion matts and battery post covers to protect against accidental short-circuiting. Batteries will also need to be vented properly as charging batteries discharges hydrogen gas.
Sealed batteries typically mitigate the corrosion and venting issue, it is best to check the battery mfg's instructions.
Put the batteries as low-down in the rack as possible to prevent tipping and corrosion damage to items below.
 
Red Squirrel said:
I'm thinking of buying a bunch of these:

http://www.monoprice.com/products/p...=10516&cs_id=1051602&p_id=8629&seq=1&format=2

To make 1 shelf I would have one at each end of a a 4 post rack and have a piece of plywood spanning both. I would add a 2x4 at the end of the plywood on both shelves so the weight is concentrated at the front of each shelf reducing leverage. My intention is for this shelf to hold several big lead acid batteries, basically car batteries. I never weighed one of those batteries but they're quite heavy, if I had to guess, about 50 pounds. Even though these shelves are only rated at 50 pounds do you think they'll be able to handle more in my planned configuration? Idealy I want this as dense as possible, so probably like 4 batteries per shelf. (I only have 2 right now but future planing)

I got a free server rack, so I will dedicate it towards power backup. It has side panels, doors and all.
Click to expand...

I have those shelves, they work awesome..
 
RocketTech said:
If you are using lead-acid batteries, you may want to use anti-corrosion matts and battery post covers to protect against accidental short-circuiting. Batteries will also need to be vented properly as charging batteries discharges hydrogen gas.
Sealed batteries typically mitigate the corrosion and venting issue, it is best to check the battery mfg's instructions.
Put the batteries as low-down in the rack as possible to prevent tipping and corrosion damage to items below.
Click to expand...

Yeah they will probably be kept in the existing plastic containers, which provide a secondary barrier. I will also be installing a hydrogen sensor in the server room, and definitely venting the rack properly. The batteries are on a standby system so they don't charge as much as if they were on a telco style system. I wanted a telco style system but there are too many variables to worry about such as proper float voltage, etc... and I have a feeling using cheap $100 marine batteries would not last very long in said configuration. The down side with standby systems is I have to depend on the relay switching fast enough. There could be a number of variables that change this such as age and temperature.

And yeah I will start from bottom up, and the rack will be bolted to the concrete floor.

I also had an idea on a custom solution, how about this?



Sorry for the bad pic, I'm still new to all the Linux graphic programs and trying to figure out which one works best for me. Basically I would use 2 L brackets and just lay the lumber across and do the same on the other side then link them with more 2x4's then plywood. Really I can probably even get away with 2x2's especially if I add a few cross members. The trick is finding L brackets where the holes will align with at least 2 rack holes. If I can go custom like this it will be the cheapest way. Think that will be strong enough? More concerned about having that much weight on only 8 small screws, since essentially those are what will be doing all the lifting. Then again same idea with a store bought shelf and if some are rated at like 200 lbs guess I should be fine.

Failing that though the shelves on amazon.ca I linked to seem like they'd be my best bet.

I do have some of those Monoprice shelves already too and they're petty decent for small stuff. Though now that I think of it if I'm going to spend money may as well do it right, or not spend money at all and go full custom. I already have the lumber to work with. Another good thing with the custom idea is I can always drop the plastic container idea and perhaps add spacers to hold the batteries in place better instead of just laying them there. I probably don't have to worry about a leak, it's not like these will be subjected to abuse, and they are designed to be in a boat or RV and possibly bounce around a bit.
 
Actually I'd like to learn eventually but I don't have a proper place to do it right now. I eventually want to finish my garage though. Insulation, more power, heat and A/C, etc...

Think my bracket idea will be ok though? I can't see why not though as long as I can find a bracket that 2 screws will align properly with the rack. Some brackets have oval holes that give some play, so I'll try to find these. Then I can just bolt it from the inside with the proper threaded screws.
 
For the actual shelf surface, Advantech flooring is great. We've used 8' sheets to span 7' gaps before (just to temporarily give us something to stand on). It would have no problem holding the load if you support it every 2' or even 4'.
 
mwarps said:
A couple hundred bucks worth of 80/20 and this problem is solved.
http://8020.net/
Click to expand...

That stuff looks pretty neat. I don't see a place to buy though. And one of the issues is most of this specialized stuff is hard to get in Canada without paying high shipping and customs.

Think I'll stick with my original plan of making it myself, since I already have the lumber on hand, I'll just have to get some L brackets. Looking at the way most shelves are made I think it will come up to the same if I use L brackets as long as there are at least 4 bolts per side. Of course it wont be adjustable, but I'll just build it to fit that rack.
 
Red Squirrel said:
That stuff looks pretty neat. I don't see a place to buy though. And one of the issues is most of this specialized stuff is hard to get in Canada without paying high shipping and customs.

Think I'll stick with my original plan of making it myself, since I already have the lumber on hand, I'll just have to get some L brackets. Looking at the way most shelves are made I think it will come up to the same if I use L brackets as long as there are at least 4 bolts per side. Of course it wont be adjustable, but I'll just build it to fit that rack.
Click to expand...

http://www.8020.net/PostalLookup.asp change pulldown to Canada, and put in your postal code.
 
Why not get a proper UPS used off ebay?... no shelf or ghetto modding needed.
 
Ockie said:
Why not get a proper UPS used off ebay?... no shelf or ghetto modding needed.
Click to expand...

Car batteries are cheap. An UPS that would be comparable to what he seems to want to make, would be a few thousand dollars, as opposed to a few hundred for ghetto setup.
 
krotch said:
Car batteries are cheap. An UPS that would be comparable to what he seems to want to make, would be a few thousand dollars, as opposed to a few hundred for ghetto setup.
Click to expand...

Yep exactly. I already have the inverter-charger and 2 batteries so this is just to set it up better given I got lucky enough to score this rack for free. Total cost was maybe 700-800 bucks, the inverter-charger was about 500. It's very expensive to ship a UPS from ebay, most sellers want 500+ bucks, it's actually kinda ridiculous. Was cheaper to buy the inverter-charger and it's designed to use these bigger batteries anyway.



Once it's setup better with shelving I'll put more batteries. I don't mind spending a couple hundred bucks when I know I'm getting tons of amp hours out of the money. I'll probably add 2 more batteries to it. Being a 12v system I can add any number I want, but I like to have an even number in case I go with a 24 or 48v system in the future.

It's nice to be able to ride through even big outages. We don't get them often, but we do get them, because of all the construction in my area.
 
Honestly I would not put those batteries in a rack. I would just make a stand of some sort just for them that is open. Wet cell batteries in a tight space is not usually a good idea, best to have them open and with good airflow.

Also having them in a rack will just make maintaining the water levels in the batteries a PITA.
 
That was actually my original plan but since I scored this rack for free figured I'd use it. In the future I could add a rackmount rectifier/inverter as well. I will be leaving enough spacing to maintain the batteries as well. It's something I have to read up on still as I'm not entirely sure how to determine if they need more distilled water. The guy at Canadian Tire told me I should never need to do any maintenance on it but I take that with a grain of salt, I'm sure any flooded lead acid battery needs maintenance if you want to make it last longer than their estimated life span.
 
Red Squirrel said:
That was actually my original plan but since I scored this rack for free figured I'd use it. In the future I could add a rackmount rectifier/inverter as well. I will be leaving enough spacing to maintain the batteries as well. It's something I have to read up on still as I'm not entirely sure how to determine if they need more distilled water. The guy at Canadian Tire told me I should never need to do any maintenance on it but I take that with a grain of salt, I'm sure any flooded lead acid battery needs maintenance if you want to make it last longer than their estimated life span.
Click to expand...

The amount of maintenance will depend on the charge/cycle rate they go through. They will need maintenance, the tire guy is an idiot or thinks you have sealed batteries.
 
Red Squirrel said:
I'm thinking of buying a bunch of these:

http://www.monoprice.com/products/p...=10516&cs_id=1051602&p_id=8629&seq=1&format=2

To make 1 shelf I would have one at each end of a a 4 post rack and have a piece of plywood spanning both. I would add a 2x4 at the end of the plywood on both shelves so the weight is concentrated at the front of each shelf reducing leverage. My intention is for this shelf to hold several big lead acid batteries, basically car batteries. I never weighed one of those batteries but they're quite heavy, if I had to guess, about 50 pounds. Even though these shelves are only rated at 50 pounds do you think they'll be able to handle more in my planned configuration? Idealy I want this as dense as possible, so probably like 4 batteries per shelf. (I only have 2 right now but future planing)

I got a free server rack, so I will dedicate it towards power backup. It has side panels, doors and all.
Click to expand...

Regarding that last sentence: Lead/acid batteries gas Hydrogen. In a relatively open space like the engine compartment of a car or your garage there is little risk of a dangerous gas buildup. Putting them into a cabinet with "side panels and doors" creates a risk. The risk is magnified if your UPS goes haywire and causes an overcharge or too fast of a charge. Its a small risk, to be sure, but if you get a buildup inside that cabinet you risk a pretty nasty explosion. Do be careful.

For those mounting them in the bottom of your server rack: Car batteries designs can also vent small amounts of gaseous acid. The solder on your PC boards does not really like acids (especially the more modern lead-free compounds). Its probably not a big deal, but you really should keep some space between the batteries and the equipment if you are not going to use batteries designed for use around electronics (sealed ones like the ones APC, et al, distribute).
 
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Threaded rack stuff is probably just going to be 10/32 threaded. See if you can get some 10/32 bolts, then just have a small piece of wood bolted into the rack. Do that on both sides, then attach a 1x2 or something between them. The idea is just to get a strip of wood bolted on, then you can screw whatever you need to that.

Also, 80/20 is the shit. No, seriously. I love innovative modular systems such as that and 80/20 is actually serious gear. Have seen it used in all sorts of mechanical awesome.
 
cymon said:
Threaded rack stuff is probably just going to be 10/32 threaded. See if you can get some 10/32 bolts, then just have a small piece of wood bolted into the rack. Do that on both sides, then attach a 1x2 or something between them. The idea is just to get a strip of wood bolted on, then you can screw whatever you need to that.

Also, 80/20 is the shit. No, seriously. I love innovative modular systems such as that and 80/20 is actually serious gear. Have seen it used in all sorts of mechanical awesome.
Click to expand...

Yeah was thinking I may just do that especially if I can find long version of those bolts and it can go right through the lumber and then thread in to secure it.

As for hydrogen I'm aware of the dangers and will mitigate it accordingly. I'll be installing some intake fans at the bottom of the rack and there will also be a hydrogen sensor. I don't really NEED the fans, since I'm thinking of doing a negative pressure "hot isle" but I will add them anyway. Did not know the batteries sometimes drain acid though. If that's the case I will be sure to leave them in a plastic container, as plastic is acid resistant. I guess it really depends on the type of plastic though but it's probably still better than wood.
 
Red Squirrel said:
Yeah was thinking I may just do that especially if I can find long version of those bolts and it can go right through the lumber and then thread in to secure it.

As for hydrogen I'm aware of the dangers and will mitigate it accordingly. I'll be installing some intake fans at the bottom of the rack and there will also be a hydrogen sensor. I don't really NEED the fans, since I'm thinking of doing a negative pressure "hot isle" but I will add them anyway. Did not know the batteries sometimes drain acid though. If that's the case I will be sure to leave them in a plastic container, as plastic is acid resistant. I guess it really depends on the type of plastic though but it's probably still better than wood.
Click to expand...

Its not that they drain acid - its that they allow gaseous acid fumes to escape. Even wonder why you get that nasty corrosion around the anode (positive terminal) in your car? Those are crystals that form when the gaseous acid is attracted to the positively charged terminal and then reacts with the metal. Guess what - your electronics has quite a few solder joints carrying a positive charge too...putting car batteries in the same cabinet - usually right below the electronics - is a really bad idea. As long as you keep them separated you are probably OK.
 
PigLover said:
Its not that they drain acid - its that they allow gaseous acid fumes to escape. Even wonder why you get that nasty corrosion around the anode (positive terminal) in your car? Those are crystals that form when the gaseous acid is attracted to the positively charged terminal and then reacts with the metal. Guess what - your electronics has quite a few solder joints carrying a positive charge too...putting car batteries in the same cabinet - usually right below the electronics - is a really bad idea. As long as you keep them separated you are probably OK.
Click to expand...

Ahh I see what you are saying. Did not realize it was in gas form. That is more serious, will it actually be bad enough to start corroding stuff in the room? I plan to make the room a closed system that will be water cooled. Anything I can add to the room to absorb any stray acid? Will it naturally want to bond with a certain element perhaps?
 
Red Squirrel said:
Ahh I see what you are saying. Did not realize it was in gas form. That is more serious, will it actually be bad enough to start corroding stuff in the room? I plan to make the room a closed system that will be water cooled. Anything I can add to the room to absorb any stray acid? Will it naturally want to bond with a certain element perhaps?
Click to expand...

I wouldn't use wet batteries in a room like that. Sealed cells cells are more expensive but applications like yours is why they exist. But hey - lots of "unwise" things get done every day with absolutely no ill effects...
 
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