picture didn't make it

 

Can you see the picture now?

 

I agree with your concern of stability. Two ideas come to mind. 1. Lower the center of gravity as much as possible. The drawers at the bottom should help with that but consider what else you can add as low as you can. 2. Spread the casters as far as you can. Is there a way to make them retractable?
Good luck. Sometimes takes telling your customer what your concern is. Maybe they have an idea once you explain it to them.

 

I would go with option 2. As long as the bulk of the weight is at the bottom you should be alright for stability, (let the customer know this). Start off with a good solid base, as for the height, I would bring it down a few inches (a standard door is 80" high).

What do you plan on building this out of, if you use cabinet grade plywood I would use dados glued and nailed for strength, then add a face frame to finish the front. If you are building from solid wood, I would use rails and styles with thin panels, like a chest of drawers built (what I call old school).

 

Would attaching it to a wall once in place be possible? Does the cabinet get moved frequently?

 

Option 2, make the bottom drawer the largest drawer, and hopfully they will put the heaviest stuff in it.

 

Your instincts are valid. If there are small children in the house, I would warn them that this cabinet is a bad idea. Kids tend to climb when they cannot reach something and having this thing fall on top of a kid could be fatal. The castors make it even more unstable. Even if they do not climb, pulling all 3 drawers out at once could cause it to tip over if there is anything but light weight clothing in them and even then could cause it to tip over. A company making this would provide a means to connect it to the wall to prevent tipping and would not design it to be mobile. Even bookshelves without drawers or swing out doors come with wall anchor straps to avoid catastrophic accidents. If they insist on this design, I would would walk away from the project. I would worry that you could be sued if such an accident occurs.

 

100% agree. This is potential disaster.

The only way I see this working as drawn is if the casters could be designed on some kind of pull-out or fold-out outriggers. In addition, Some sort of un-latchable wall anchor needs to be incorporated into the design. These could be as simple as screen door hooks. These devices would, at least, put the onus on the owner to keep it safe and hopefully protect the designer/builder from liability.

If space allows, the best solution would be to rotate the design onto its side so that the whole unit has a low center of gravity. Even then, the drawers need to be designed so that only one can be opened at a time.

 

The design of this cabinet cannot be planned without some consideration of expected loads. Whether it's books or bricks, the stability depends on the contents. Some have mentioned "keeping the center of gravity low," but the design does not assure that. What would happen if the cabinet contains 500 lbs of "stuff" and the 3" casters encounter a 1" barrier? Collapse!

 

I bought an interesting wooden toolbox a few years back that is somewhat relevant to this discussion. Its similarities and differences may help you with your design.

It was originally built by/for a set designer for a traveling theatre company, so from the get-go it was designed to pack up and roll around as well as to fit conveniently in the moving truck. That ability to pack neatly in the truck heavily affected its design. It is actually two boxes, both about 24" square when closed up. The Bottom box is 36" high + wheels and the top is about 24" high, making it a cube.

Since I don't use it as intended, I have made some minor "adjustments" to make it better fit my needs. Firstly, I slipped a thin piece of plywood between the upper and lower boxes, and then screwed the top down to the bottom. That allowed the doors to open and close freely despite some wear and abuse that warped the top and bottom pieces before I got the box. I have found the 24"-deep hinged lid on top of the 60" of box and ~6" of wheel/castor height to be problematic when I used it in the basement, but not so much in the shop with the 9-foot ceilings or, presumably, in a theatre setting. I usually leave it propped up, but the top bin is pretty difficult to access so it is pretty much a waste of space.

Having two separate boxes has made moving this box much simpler and easier, and I highly recommend that you consider doing that as well.

As you can see, the 24"-deep base extends 6" more than the depth of the cabinet. This protects the doors when moving and aids in locking the box, but it also GREATLY increases its stability when rolling the box around, something that was no doubt an important design criterion in the theatre business. As for wheels, it had two large fixed wheels recessed into the back of the base cabinet and two swivel castors at the front. The rear wheels were obviously an issue, so they were modified like this before I got it. This new configuration makes it easy to maneuver while somewhat preventing random sideways motion on less-than-perfect floors.

In your case, since you will have a wider, shallower, and taller cabinet, pushing it around will make it less stable than this one. Changing the orientation of the fixed wheels 90 degrees to align them left-to-right would help make it more stable when moving but would also make it tricky or impossible to slide it in a tight space. The configuration that I have is ideal for that case.
All the drawers and shelves that my cabinet has are 18" (outside measurements from the back of the box to the front of the drawer). There are times when I feel that these are too deep. About 1/3 of the space behind the things on the shelves cannot be accessed without moving everything in front. The additional 6" of the bases has never interfered with access to the contents EXCEPT when I use it as a convenient place to set something down until I find a home for it.

Since you will not be having the doors (I hope! They are too shallow AND waste a lot of space compared to a cabinet), perhaps you could do three cabinets wide (12", 12" & 18") mounted between some top and bottom pieces similar to my cabinet with an additional cabinet stacked on top? This would be a similar configuration to modern mechanics' toolboxes.
I hope that this helps somehow. Please let us know what you and the customer decide upon.

 

I see what you're talking about. And I agree deep shelves are not optimal. They will be storing hats and shirts in this cabinet so I was thinking pull-out drawers would be best, but I don't think that will help stabilize the unit when they are pulled out. Maybe I will make 2-inch high pull-out drawers that function like a shelf but you don't have to get on your knees to see the shirt or hat size. I think all the feedback here has been great and I will be mocking up some options in Sketchup now. I am going to for sure start with a base that is 20-22 inches deep vs the suggested 18.

 

I see an issue being if it is placed on an uneven surface and all three drawers slide forward at the same time and the cabinet falls over. I have a file cabinet that you can only open one drawer at a time but I'm not sure how the mechanics work. I built two cabinets almost exactly the same dimensions as the one you are contemplating for my church and I refused to put drawers in them for safety reasons. I placed shelves in the lower section that held trays and baskets that could be slid in and out. The person who requested the cabinets understood my concern and agreed since different volunteers would be using the cabinets each week, most likely untrained. The upper section held a flat screen television and the doors held literature racks.

 

I think that the liability issues are very large and would not make it.

 

IF - a big "if," you decide to build it, I would ask the owner to sign a release of liability that explains the issues. That should help protect you, but it should also make the reconsider the dimensions. .

 

Hi Matt,

Option 1 - clearly... and I think the dimensions at 20" deep are quite workable. Remember you're building a display cabinet not a bureau of drawers as in Option 2. Clean lines are better since the focus should be on the display area above and not drawers below. Which leads to...

• Drawers??? I would just offer them adjustable shelves (4 shelves, 2 on each side of a center support) inside the lower portion. That plus the bottom gives them 6 shelving areas in lower portion. You could even make the 4 upper shelves with back stops pull out a few inches for easier access to back. Problem solved.
• When I first started doing commissions it was easy to be swayed by what people wanted despite them not having the foggiest idea how things go together. You have to set parameters based on your experience, knowledge, best practices, etc and roughly design within those boundaries.
• Have you tried using Sketchup? If you plan to present designs to clients, Sketchup is the way to go and makes it easy to present several different versions and views. It also allows you to dial in the proportions and move around the piece in 3D.
• There are several higher end castors out there (preferably locking) that are better than standard utility castors.

 

These are good points and I appreciate the feedback. And your advice regarding designing within boundaries based on my experience/knowledge vs the customer's hair brain ideas is a good one. This is kind of one of those that I have to go back to and recommend options for scale to help with stability. Also, I am a longtime user of Sketchup and use it for everything I do. I have some good casters that lock and glide very well - not ones you find at Ace Hardware or Home Depot.

 

Would it be too crazy to slant the front of the cabinet back at the top? This makes it narrower at top, thicker front to rear on the base, giving a bit more stability. Somewhere around 7° to 15° would help, and may give it a 'lighter' feel. (a 'step' inset would do the same thing)

 

I would think that since it is mobile, slanting the front won't mitigate issues with instability while moving it. It could just as easily get pushed over backwards as you roll it over a floor transition strip for example.

 

When we made carts for equipment where I used to work, seismic stability was a concern. We'd put enough weight in the bottom of the cart so that they wouldn't tip over in an earthquake. This added weight could be upwards of 1000 pounds. Sounds like overkill, right? I have only 60 pounds added to the base of my Dust Deputy/shopvac stack for stability, but I'm the only one who moves it. Given the high moment of inertia of this high of a cabinet, I'd be looking for a bit of weight in the base. You'll have to consider what is in it, but I'd personally add as much weight as possible to the base so that someone who knows nothing about safely moving tall objects gets hurt. In my case it was up to $25M worth of hardware. In your case it may be children? Consider the liability.

 

I totally agree, I was thinking of adding weight to the base somehow to stabilize the cabinet while it's being moved. You are right, this is going into a community area so using error and injuries, as a result, are top of mine for me.

 

I would also suggest weighting the cabinet to lower the center of gravity. Ideally the added extra weight would go below the cabinet proper, which is to say between the wheels. Ground clearance would be reduced but the cabinet is going on a hard floor I would think. Probably look better with less space between the cabinet and the floor.

Consider what’s being displayed. If it’s art work or other thin items, then the upper sides do not need to be so deep. 20” deep sides will hide the artwork from off-angle viewing. From a visual point of view, the tall deep sides makes the piece seem rather like a tool cabinet and not a display cabinet.

Art display can be brought forward, too. So the vertical panel to which the art is attached would not be aligned with the back, but 4-8” towards the front. This will help stabilize the cabinet as well as make a better display.

 

Thanks all for your feedback. These are all good points to use in my next design iteration. I also wanted to say it's great to be back on LumberJocks; the new design is excellent. However, I haven't figured out how to reply to someone's comment, so it doesn't include your original post. Maybe I will do some playing around to figure that out.

 

Someone mentioned to obtain a lability release. That could backfire on you in a court of law. I read of a case where the judge told the builder, "a release does not give you protection to do something that could be hazardous". Not exact words, but you get the idea.

I read that on the woodweb cabinet makers forum.
I would not build it of a paying coustomer.

 

Someone mentioned to obtain a lability release. That could backfire on you in a court of law. I read of a case where the judge told the builder, "a release does not give you protection to do something that could be hazardous". Not exact words, but you get the idea.

Yes, THIS.

 

Today it's holding shirts and hats. Next month it will be used to store reams of paper, books, and batteries. It doesn't make any difference what the intended purpose is today, it's what they could put in those drawers in the future that's what I would be concerned about.