Deep (42") drawers under pallet rack

[jloehlein]

So, I have a section of 42" deep pallet rack in my shop. I'd like to be able to store things under the first tier, which is ~30" off the ground, more efficiently. Stuff like jack stands, extra boxes of shop towels, safety glasses, etc. I'd like a couple drawers underneath it so I can utilize the full depth.

I briefly looked for pre-built things that could meet my needs, but didn't really find anything that deep. I then started looking at drawer slides to build something and they are way too expensive. At that point, I drafted up a system that I think would work in SketchUp. Would love feedback on it.

Here's how it works:
The base is basically a couple pieces of angle iron supported by 1" square tube legs that would be bolted to the ground. There are bearings attached to the base that support the drawer at the front. The drawer is an angle iron frame that I could put plywood sides/bottom in. There are sets of bearings supporting that back of the drawer that the angle iron rides between. Here are some pictures of what I mean and a link to the SketchUp file.

The few thoughts I've had:
1) Capacity: I'd want to limit drawer travel so ~6" stayed on the rails - then I've got ~36" past the front bearings and ~6" behind them when opened making a 6:1 lever. I think (8) 608 bearings (rated @300lbs each) could easily support most things in the top drawer (even 100lbs all the way at the front of the drawer would only exert 600lbs of force when fully opened...am I thinking about that right?)
2) Side-to-side play: I'd leave 1/16"-1/8" between the drawer sides and the rails. I'm not too worried about these being precise feeling, so I think this would be fine? Maybe if it was I could throw in some UHMW to limit side to side movement.

I think I could build these, including a drawer on wheels on the bottom that just rolled on the floor, for like $50-$60, which isn't too bad. Please poke holes in this design before I cut up a bunch of metal and spend time building it!

 

[ard]

Unless you are at the load limit, Id hang it from the shelf- so the space under the drawers are unmolested.

Run a 'ring' around the drawer box, have the runner be on the TOP of the drawer. Two rollers at the back of the drawer, two at the front of the fixed part.

4 legs should do it, chose the tubing appropriately. (Unless you are doing 500+ lbs of stuff)

 

[tjdux]

This is almost exacly the same design concept used for 6-8ft long extension truck bed storage boxes.

Here is 1 example. http://www.sunnyskyz.com/blog/494/W...t-And-Going-To-Make-Truck-Owners-Very-Jealous

Do a google search "diy truck bed drawers" and you can see many more ideas like that.

Now i didn't bring that up to belittle your plan and in fact your steel idea looks great and should work well.

It may be worth a look at those guys ideas anyways and see if there's any tips worth taking before you begin. Ive only ever looked at the pictures as i have no plans to build anything like what they (or you) are doing but its cool so I store it in the old mind palace. Both theirs and yours.

Also between the 2 i can forsee me needing something like what your planning so i am requesting finished results photos please and thanks.

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[tjdux]

Also agree with ard abount not needing legs at all but with legs they are eaiser to relocate or make into a workbench if ever you no longer have the pallet racking.

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[jloehlein]

Thanks, guys. Good thought about hanging it. I like the idea of keeping the space below more open. Have to think about that tradeoff some more.

I did take some inspiration from the truck bed drawers. I saw a lot of them that had all the bearings fixed to the base, like the one linked above. Or just had a set of rollers in c-channel. Those looked like the tailgate helped support the drawer when it was open though. I think this setup makes more effective use of the bearings. I'm no engineer though, so one specific question I had as I as thinking about this some more is if I'm thinking about the lever effect when the drawer is fully open the right way. Let's say I do have 36" past the front bearings and 6" behind them to the rear bearings. If there is 100lbs in the front of the drawer, does that put 600lbs of force on both the front and rear bearings, or does 600lbs get split across the front and rear bearings?

 

[cheechi]

My first thought when I read the title was a 'box' (think of a bed frame with drawers under the box spring) that would attach to the sides of the pallet rack, and slide flush or the front be just proud of the rack legs. It wouldn't be portable or self-supported it would hook into your pallet legs' support holes. I envision building it out of pallet wood or similar plank & sheet wood.

I am visualizing something like this but with common pulleys, so you don't have to buy a $300 kit you can use say clothesline pulleys, some bar stock, etc. as the slide mechanism. You could also weld tabs to make a hard stop anywhere you wanted.

Your design is probably better in being more versatile, and the height is good if you put a top on it and wheel it out as an extra flat surface. Either way I'd like to see the end result and a progress thread on this kind of build. I have shelves, not pallet racks, but I may want to steal some ideas from you as you get this going.

 

[cvairwerks]

Build a standard type cabinet carcass and put it on wheels...much easier and you can use standard drawer slides, if you make it a back to back carcass.... ie various sized drawers on either end. BTW, with my racks, I used the bottom section for heavy stuff that needed to be palletized to move. All the light stuff went on the upper shelves, with a shelf spacing to take a two stack of bankers boxes.

 

[Radix2]

Just to answer your bearing load question.

If you have 100lbs at one end of a 6:1 lever.
Then you will have 600lbs pushing down from the opposite end of that lever.
The middle bearing will have to support both forces, so in your case 700lbs.

Think about it as a balance. 200 each end, 400 in the middle...

 

[Trey T]

My only concern is the deflection. What angle steel (mild steel?) are you using? Hopefully, steel structural guy can help you verify the capacity vs deflection.

 

[ard]

Thanks, guys. Good thought about hanging it. I like the idea of keeping the space below more open. Have to think about that tradeoff some more.

I did take some inspiration from the truck bed drawers. I saw a lot of them that had all the bearings fixed to the base, like the one linked above. Or just had a set of rollers in c-channel. Those looked like the tailgate helped support the drawer when it was open though. I think this setup makes more effective use of the bearings. I'm no engineer though, so one specific question I had as I as thinking about this some more is if I'm thinking about the lever effect when the drawer is fully open the right way. Let's say I do have 36" past the front bearings and 6" behind them to the rear bearings. If there is 100lbs in the front of the drawer, does that put 600lbs of force on both the front and rear bearings, or does 600lbs get split across the front and rear bearings?

I was going to mention this. You need to stop the draw from full extension, if it is a simple slide (i.e. One glide, one set of rollers)

Full-extension' drawer slides have a 'floating' component that serves to distribute this leverage from the open drawer back to the support. IMO that kind of design here will be tough to execute.

Two ways to accomplish this- make the draw box a bit 'shallolwer' than the fill 42" depth (but still have the 'glide' portion extending back ..AND install a stopper to prevent full opening. And or a combination of both.

 

[jloehlein]

Just to answer your bearing load question.

If you have 100lbs at one end of a 6:1 lever.
Then you will have 600lbs pushing down from the opposite end of that lever.
The middle bearing will have to support both forces, so in your case 700lbs.

Think about it as a balance. 200 each end, 400 in the middle...

Ah, thanks.

I like the idea of having the floor space open and not needing legs. I mocked up another version where I could bolt the side supports to my pallet rack beams, and the drawer has the bearings at the top. I like this a lot more. Here is the SketchUp file.

I plan on using 1" or 1.5" angle iron, likely 1/8" thick but I'll go for whatever the steel supplier has for cheap. I'll think through exactly what I'm putting in the drawers and see how much they'll weigh. At least with the rear bearing in the middle of the angle iron (drawer half open), most of the weight will actually be supported by the front bearing, so I don't think the angle needs to be that large.

Here is how I can configure the supports. The plates get bolted to the rack beams.

And the drawer with the bearings at the top now with angle iron to ride on the front bearings.

Together, under the rack

Drawer open

I'll definitely build a stop so the drawer doesn't extend too far (leaving ~6" between the two bearings). I'm not too worried that the drawer won't fully open - having 36" open and 6" covered in a ~42" deep drawer seems fine to me. I don't think I'll have too much trouble getting something out of the back of the cabinet.

I really like this design - I'll rummage around my steel pile and see what I've got to order. Will likely get around to building it in a couple weeks when I'm off of work. I'll definitely take pics. In the meantime, keep the feedback coming!

 

[ard]

Thinking about it, there will be a lot of load at one spot on the angle/rail... just keep that in mind

Also, consider a cross member (or two) to solidly fix the position of the two rails (ie not relying in bolt holes and possible slop/twist in the mounts)

 

[SarcasticDwarf]

Keep in mind that you will be significantly derating and weakening the beams by drilling into them (and hanging a load from them).

 

[jloehlein]

Thinking about it, there will be a lot of load at one spot on the angle/rail... just keep that in mind

Also, consider a cross member (or two) to solidly fix the position of the two rails (ie not relying in bolt holes and possible slop/twist in the mounts)

Makes sense - I'll definitely tie the two rails together at the back. That's easy. I went through what I'll be putting in the drawers and don't think it'll be more than 100lbs total, so I should be fine. The other nice thing about this design is that if I need to make the rails out of bigger angle or even just square tube, I can do that easily.

Keep in mind that you will be significantly derating and weakening the beams by drilling into them (and hanging a load from them).

Good point. Thankfully, the beams I have are rated to 5500lbs and that first shelf is just workbench!

 

[jloehlein]

Alright, I finished the drawer. Got a few pictures of the process. The main changes I made were using skateboard wheels to help the drawer roll more smoothly and I moved the bolts to the bottom of the pallet rack beams, rather than the side.

Here are the mounts and the rails for the drawer to run on. The visible holes aren't used, I drilled a new set on the bottom.

And the drawer itself. The rails are 1.5" angle iron and the rest is 1".

I painted up the drawer and mounted the skateboard wheels.

Here is everything mounted up. I spent a bunch of time making sure the rails were parallel and spaced ~1/8" wider than the drawer itself. I also made a matching cart underneath so I could use the full depth and still get to everything without crawling under the pallet rack.

I just used a washer on the front to keep it from over closing and a couple pieces of wood as a stop to keep it from opening too far. I left 10" between the center of the wheels. I could sit on the front of the drawer at that distance. I'm ~180lbs and it was definitely a little sketchy - the angle iron wanted to twist, but that's a pretty extreme load, so I felt good opening the drawer that far.

Here is a video of the drawer closing. I am really happy with how smoothly it rolls. I probably only have 30lbs of stuff in it now, so I didn't feel the need to brace anything. I might try convincing a friend to get in it so I can really test it out.

 

[ducksface]

I think 36inch long full length, full open, cabinet slides cost 250 bucks a pair.
But they hold 300lbs wide open.
Rocklers.

But:
Attach that floor piece to your top piece and you can slide it all out instead of just the drawer, and you have 360 degree access. Nothing lost space wise, and 360 access and mobility added.

And it won't put 600lbs of stress on your shelving mounts.

 

[jloehlein]

I think 36inch long full length, full open, cabinet slides cost 250 bucks a pair.
But they hold 300lbs wide open.
Rocklers.

But:
Attach that floor piece to your top piece and you can slide it all out instead of just the drawer, and you have 360 degree access. Nothing lost space wise, and 360 access and mobility added.

And it won't put 600lbs of stress on your shelving mounts.

Yeah - long drawer slides are way too expensive. I've got like $60 in the whole setup (top and bottom pieces: $25 of wheels, $25 of steel, $10 sheet of plywood). I prefer to have the top and bottom separate here, but like the cart idea. That may work really well for jack stands and stuff. I've got a bunch of spare casters from broken floor jacks, maybe I'll make a cart next.

 

[Trey T]

Looks good