This looks to be massively over built leading to excessive cost for what amounts to a work bench for electronics.
Hi all,
I'm working on replacing my dual rectangular white IKEA desks with a custom design that has a higher work surface and made out of 4545L extruded aluminum with T-slots. I fumbled my way around the Bosch Rexroth MTpro design software until I figured out how to put together a basic design, and now have something that I think should work. It's about 10.5 feet (3.2m) across, and 32 inches (0.8m) deep. I've included a set of photos that show the structure as I have it now. The main surface will be two 3/4" thick cuts of melamine, and the three shelves on the right will be the same material, just smaller cuts.
For straight electronics work you don't need more than one layer of hardwood plywood. Place Formica on both sides to keep it stable.
By the way you mention 3 different brands of extrusions in this post. Stick with one as they are not all compatible and sometimes in ways that create gotchas. I don't which is better is hard to say as we probably have a dozen different brands at work, thus how I know about compatibility. Personally I have a couple of Bosch tools I made up to make using that brand easier. If you make a few drilling guide blocks your construction job becomes 100% easier.
The longest unsupported spans are the two in the front, which are slightly under 63 inches (1.6m) each. My goal is to have a rock-solid bench that doesn't wobble or flex--hence all the diagonal cross braces.
That is all well and good but it makes little sense to go overboard. For example the top, once bolted in place will add structurally. Gussets are required in my mind so I'm not going to dismiss them but the diagonal braces are a waste. to be perfectly honest I would mot make the bench any longer than the length of the plywood that would make up the top can be had. If that is 8 ft then design for an 8 foot long bench with no center support legs as they just get in the way. Frankly the longer span would better justify the 45x90 extrusion.
I used 45x90 oriented vertically for the main support beams, and 45x45 for the verticals and the anti-flex braces. I don't have a lot of heavy equipment, e.g. what goes on the shelves on the right will not weigh more than 50-60 lbs at most (22-27 kg). Anything slightly heavy will be positioned near stronger supports and not on the hanging edges, or the front middle of the 1.6m spans of the main work surface.
The big open space on the left above the main surface fits around a large TV that I use for a monitor + viewport for an HDMI inspection camera, in case anyone is wondering why I did the shelving the way I did. I would otherwise have extended the shelves all the way across with vertical supports at the three obvious points.
Now, the fun part: I'm looking at the 45x45L/45x90L profile from tnutz.com, here:
Note my comment about using one brand and sticking with it.
All else being equal, I'd go for the non-lite profile just to be safe. But Tnutz has a significant sale on that particular profile right now, making it significantly cheaper than anything else. It is for this reason that I used the over-braced + 45x90-vertical arrangement shown in the photos. On the 80/20 website that has a calculator for estimated flexing of any given design, it looks like the 45x90L profile with a max 1.6m span supported on both ends has basically zero flex, as in a tiny fraction of an inch at worst if you put a 50kg object right in the middle. This seems sturdy enough to me; it's just an electronics workbench, not intended for massive industrial equipment.
It might actually be too stiff. By the way if you want to add a vice or other metal working equipment, of size, you will be better off having a second heavy duty bench. Backing up a bit, the legs at the front are the weak areas on benches like these, it is advisable to use gussets to better support those legs but that does move your usable sitting space in on each side. This is another reason to get rid of the center leg. Also a foot rest type runner can help support the legs better.
In any event back to the idea that another bench might make sense, that is build two different benches. The Problem with electronics work benches is that you need more depth than a common desk. Obviously this depends upon your interests but if you take some wild ass number, lets say 18 inches, for the front to back length of many common bench instruments, you end up having the work area on a 36 inch deep work bench. An 18" deep work area is not ideal for many interests. In other words an electronics work bench takes up a lot of space in a given room, I wouldn't make it any wider than required, at the same time I'm not convinced that a depth of 32 inches is enough.
Put your other tools and so forths on benches or counter tops that are not so deep. The savings in floor space will pay off down the road. I actually like kitchen cabinets (assuming better quality here) as they are designed to support a counter top, and create instant storage beneath.
Now kitchen cabinets can be seen as permanent but there are no rules against mounting them on a frame and wheels. I only mention them because being prefabed there is not a lot of custom wood working involved. In any event the idea here is to suggest alternatives.
Does this design look reasonable to all of you? Or, more appropriately, *unreasonable* to any of you?
Thanks!
Well it is over built in some ways. Is it unreasonable, that isn't for me to say. However I've pointed out what MIGHT be issues for you. The bench is very long for example but at the same time I'm not sure it is deep enough. How deep is very very dependent upon what your interests are. If you want to work on rack mounted equipment and have common bench electronics it probably will be tight. If the goal is to work on Raspberry PI's it is likely fine. I would not however make it much wider than 8 feet. There are lots of reasons behind managing size one is simply the effort required to move the bench.
This brings up one other really important item - wheels. Wheels can really make your life much easier, especially as you get older. Even if they are only used once every 5 years. So make sure you design in wheels or an easy way to put casters under the bench when you need to move it. You can buy temporary casters and jack a bench like this up and do so easily if you plan ahead. The obvious need is for a place to put the jack. The fact is this will be a heavy bench and you may not believe you will need to move it but crap happens.
By the way there is another option for a supplemental bench to the main electronics bench. That is to go to your local home center and buy the lower half of a roll around tool box. Put a layer or two of plywood on top and you have an instant roll around bench with oodles of storage. Considering how much aluminum costs these days that might actually be cheaper and you will not knock the storage. If you can make sure that the heights end up compatible. these are great for mounting a small drill press, CNC or a bench grinder.
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