I am thinking through the bench build for a LowRider that has a cutting capacity of 4’x8’. According to the calculator, I need a table that is ~60" wide.
I want this bench to be dual purpose. Good for hand tools, normal woodworking running my CNC. This will need to stand up to being hit with a mallet, hold my vice and fit in my garage. With that said, I am not sure an MDF table will hold up to the use of a normal woodshop, in a garage that is not heated or cooled. So, I thought about using 2-by Kiln Dried (KD), Southern Yellow Pine (SYP) lumber from Lowes. This would be heavier (A plus), be able to withstand a beating, and last. With that idea, I evaluated the cost of all lumber sizes and found that 2"x12"x10’ KD SYP lumber is cheaper than even MDF, by far. (See table below). So I designed a table around those dimensions.
My thought is I could cut off the round overs on the 2x12’s, cut it in half long ways and still be have boards that are at least 1.5x5.25", actual dimensions. Below you will find images around the 5.25" board sizes. The lower shelf is based around 3.5" board widths because I wanted more space for a small cabinet or something. The lower shelf board dimensions may change because I will use scraps I have laying around to build it.
Here is where I would like your thoughts.
What are your general overall thoughts of the design. I am very open to opinions, experience and constructive criticism.
I tried to make this simple by having most of the lumber the same thickness and width, but I am having trouble thinking through some options for the top layer of pine boards. I really don’t want to resaw a 1.5" thick board down to .75" thick to match the thickness of the MDF.
Something else that is very annoying is, the top layer of pine boards are 6" wide. With a 2x12 boarding actually being 1.5x11.25 (Insert Conspiracy Here!) and cutting off the round overs, I won’t be able to get 2 boards by cutting the 2x12 down the middle.
Are you also planning on having a replaceable MDF spoilboard? Your design looks great! Some day I may try to organize my garage to that level of detail… My big LR4 table is an excellent assembly workbench, but not beefy enough for heavy woodworking. The Y rail may be an annoyance if you don’t plan ahead (either have it on the opposite side of the bench where you stand and work, or on a removable “plate” perhaps.)
From experience (using 2x4 construction), flatness may be an issue over time. With an almost 5’ span and no center supports, it is likely that the joists will twist, warp and swell over time. Kiln Dried will help a lot. For simple through cuts on sheet goods, you may be able to compensate by cutting a bit deeper, but on my table (not kiln dried, 10’ 2x4 cut to 5’ lengths for the joists, full length for the end beams), I ended up with a whopping 4mm difference between the highest and lowest spot. Surfacing helped a lot. Things like carving and engraving require very flat surfaces.
Note that a multi-purpose bench may be subjected to things like oil, water, etc. which are very incompatible with an MDF spoil board. Also be careful when mounting of other tools (like the vice shown above) so they do not interfere with the full movement of the LR4.
Yes, I have a 1/2 spoil board that will sit on top of the 3/4 table top.
Ya, that is why I put it on the end without the table saw. I will need to use the bench for a bit to determine if it is still useable or not. I may just have 2 pole options, 1 6ft and one 9ft. By default I will leave the 6ft on, thus leaving 2ft by the vice I can use without interruption. When I need to I can just install the 9ft pole and cut full sheets of ply.
This makes complete sense. I know a torsion box has many cross braces, but I couldn’t figure out a need for them. Now, I am pretty sure I am going to add 2 short cross braces to each gap to prevent twisting.
Great thought. I had the same one. These vices typically sits below the surface, then wooden jaw faces are added that make it level with the surface. So, it shouldn’t be a problem. See pics below for how I have my vise currently setup.
Any thoughts on what to do about the top boarder Pieces? I had another thought recently. I could just use standard 2x12’s and double up the MDF, but that would be another $48. Since 2x12’s are actually 1.5 inches thick and and each MDF panel is .75 inches thick, it should be on the same plane.
Also, what do you guys think about finishing the MDF to protect it from moisture? Maybe something like shellac?
This is somewhat off topic but, are there LR4 mods available that let you make taller x-y plates? I think that’d be good for application like this, a taller x-y plate on the rail side would allow you to drop the y-rail so that it’s level with or slightly below the surface of the bench. And that would let you rip long stock on the table saw with the y-rail getting in the way.
Thicker cuts is not the only reason one might want taller plates. In this case, I’m suggesting it might be nice to have a taller plate, let’s say about 35mm taller, only on the rail side, and a standard plate the other side thus allowing the rail to be dropped below the top surface of the bench. This would make the bench much more user friendly for non-cnc uses.
What are your thoughts on maximum spacing between 2x5 beams if I have two MDF boards stacked on top of each other? I think I might have too many horizontal cross beams in this build.
16" stud centers will support a crapload of projects. 2 person lift projects, up to “bring a case of beer for the guys” lifts. 24" centers is a pretty solid workbench and assembly table. It should hold anything that is a reasonable 1 person lift weight without issues.
32" centers is more than adequate for CNC table use, and close to what I’d go with. The downside here is that it loses some of the flatness constraint, however, MDF being what it is, it should still be reasonable.
I think it looks plenty strong enough, to my eyes, but perhaps a bit overbuilt in the number of cross braces.
My approach is to consider the smallest space supported by the uprights, which is half the table. Then look at just that as a section. The bend in the short axis of the table is well supported by 4 cross beams while the bend in the long axis of the table is supported by the 2 on the outside.
Based on that and ‘gut feel’, I would probably go with 5 cross beams down the length. That puts one in line with each leg and then an extra in the middle.
With a table this beefy, you can always go back and add to it later if needed, but I would tend to start off simpler and easier.
I have a smaller workbench that I made similar to this and it has a noticeable wobble to it due to the uprights racking side to side. In the end I put a sheet of thick plywood on one end which gave me a place to hang some tools and also made it stiff enough to not bother me anymore. The other alternative would be diagonals but again, all that can be added once you’re using it and have an idea what is important etc.
In the next couple of days I will redesign the bench build. I don’t want it to be unnecessarily expensive, but I do want it to be strong and stay flat. This will be my bench for the next 3-5 years at least.
Well I completed the redesign, bought the lumber and have already started the build. By my calculations, what I have built already is around 183 pounds, very flat and very square. Relative to my last bench. Next will be the legs and bottom shelf. Not sure which one I will do next.
Ya, I had a light weight bench before. I MAAAAAYYYYYY be over compensating. LOL
I also don’t want to be building a new bench every year. This design will allow me to pull out the MDF panels with relative ease. I don’t even think I am going to screw down the MDF panels.
