Tuesday, August 15, 2017

2x4 Roubo Style Workbench Lathe Stand (part 1)

About two years ago, I bought a small wood lathe. I had always wanted one. When I was setting it up, there happened to be, just floating around the workshop, a small metal cabinet on casters that seemed just perfect to set the new lathe on. So, that's where I put it, and that's where it has been since it was unboxed.

Shortly after starting with wood turning, I started getting interested in woodworking in general. I watched a lot of YouTube videos about woodworking and wood turning. A LOT of videos. One of the first wood working projects I got interested in building for myself was a Roubo style workbench. Andre Jacob Roubo was an 18th century French craftsman who, literally, wrote the book on woodworking in his time (actually, it was a five volume set). However, before I got started on the epic workbench build, my mother passed along to me her grandfather's workbench, which was Roubo-esque and had an antique metal-jaw vise already on it. So, I didn't really need to build a workbench after all.

But recently, I got a new lathe. A much larger one, which will allow me to turn larger items.

One of the problems I have been having with my small lathe, and also my ShopSmith when used as a lathe, is excessive vibration when turning a blank that is out of balance. One thing that will help to stop this vibration is to have the lathe firmly bolted down to a heavy stand. My midi lathe is not bolted down to the metal cabinet it is on. It just sits there. And although the ShopSmith looks big, it is not really that heavy. I even have a problem with it wanting to scoot across the concrete floor while I am turning, just from the pressure I apply with the chisels.

As you can see from the picture, my new large lathe has its own metal stand, but the stand is not very heavy or sturdy. I expect that if I were to put an unbalanced bowl blank on this lathe, it would vibrate like crazy. This brings me back to my desire to build a Roubo style workbench. The one thing that really defines a Roubo style workbench is that it is heavy. It's heavy and solid and stable, exactly what is needed for woodworking and exactly what I need from a lathe stand. So, the Great Roubo Build is back on!

 Now, I don't have much money to spare at the moment, partly because I have been buying a bunch of tools on Craig's List lately. So, The Roubo workbench/lathe stand will have to be made on the cheap. Luckily, I have been watching a few videos on just how to accomplish this. I have a stash of 2x4s that have been sitting in the basement of my store for the past 20 years. They were part of a dividing wall that I took down when I moved into the building. They were nice and straight, so I kept them. I just never got around to using them because they are full of nails and screws. They've been sucking up space, cluttering up my basement ever since. It's time they had a new life, as a workbench!

I needed to know if I was going to have to buy materials for this project, so before I started building anything, I started mocking up a design in SketchUp. SketchUp is a great little program. I am ashamed to say that I have never really taken the time to learn how to use it. So, I had to watch a few tutorial videos before I got started. This was really my first time using the software, or really in making a 3D model for something. I don't usually even draw up plans for my projects, unless they are particularly complex or there are critical measurements, and then I usually just sketch something crudely and make some measurement notations.

As you can see from this screen shot, I am planning on making the workbench wide enough to mount both lathes to it. I figure, the more weight, the merrier. Fortunately, there are a community of people who make SketchUp models and upload them for others to use, so there were already models of both of my Harbor Freight lathes in the repository for me to download. This helped me figure out the spacing and how large my stand needed to be in order to fit both lathes comfortably. All I had to draw was the workbench itself. As soon as I can figure out how to upload it, I will link to the SketchUp model I made for this workbench, so that you can see it in more detail, or build one for yourself.

I wanted this workbench to be strong and heavy as hell, so I designed it with triple thick 2x4 legs, a 28"x60" laminated 2x4 solid wood top (with a 3/4" plywood replaceable surface), a lower shelf (so I can have storage, or add more weight), and laminated mortise and tenon style joinery. I briefly toyed with the idea of making the legs removable, but with all the vibration this thing is going to experience, I decided I would rather just have it be as solid as possible, so all the joints are glued. The lower shelf frame is integrated into the legs with mortise and tenon. The legs are integrated into the table top with double mortise and tenon, and with the exception of the plywood being screwed down (because I wanted it to be replaceable), everything is held together with wood glue. There are no screws or nails anywhere in the joinery.

I say mortise and tenon, but I didn't cut any mortises or tenons in the traditional sense. It was all done with the the way the 2x4s are overlapped as they are laminated together. It's sort of like a double mortise and tenon, and sort of like a double lap joint. Maybe more like a bridal joint. I don't really know what it should be properly called, so I'll just call it a mortise and tenon.

So, here is how it was done.

I drug all the 2x4s up from the basement of the store and hauled them over to the woodworking shop (my dad's old workshop). Then, I went about the laborious task of pulling out all the nails and screws so I could re-use the wood. There were a lot of nails and screws. A lot.

 I managed to reclaim quite a bit of good wood. I am hoping to buy as little materials for this project as possible, and if my calculations are correct, I should have just enough reclaimed wood to finish it, minus the plywood for the shelf and table top, which I already have on hand (though it's not reclaimed).

 I started cutting all my pieces to length on the chop saw, starting with the short pieces. I have pretty much exactly the right number of long pieces I will need to make the table top, so I need to make as much use of the shorter pieces as I can, for the legs. Aside from helping to finalize the design details, figuring out how many of what sized pieces was one thing that the SketchUp model was really helpful with.

 I wasn't originally planning to, but I thought it would be a good idea to run the pieces through my new planer. Having smooth flat sides will help with the glue-up, and although it's not that important for the table top, the leg assemblies need their pieces to be exactly the same thickness in order for everything to come together correctly. In hind sight, I should have planed them first, then cut them to length.

.Because the joinery is being accomplished by overlapping the pieces as they are laminated together, the entire workbench can be made from straight 2x4s cut to specific lengths, with the exception of one notch that needs to be cut into four of the leg pieces to accept the leg stretcher. I cut this notch by taking multiple passes on the table saw and then cleaning it up with a chisel. I should have taken this opportunity to try out my new dado blade stack, but I was too lazy to change the table saw blade. If there were more notches to cut, it would have been worth it, but with just four... meh. This method works fine. At least I got out the table saw sled instead of just free-handing it (which can cause dangerous kick-back).

 Next came the dry fit assembly of the legs. My plan is, to make the two leg assemblies (one pair of legs and a stretcher each) and then sandwich the planks for the table top in between them. Almost all of the joinery will happen in the leg assemblies.

 By the way, that's my Great Grandfather's Roubo style workbench that I am using as an assembly table. It is also made of 2x4s and plywood, though the 2x4s are oak and its top is made from laminated sheets of plywood and then topped with 1-by dimensional lumber, where as my top will be made from laminated 2x4s, with a plywood topper, and its legs are attached with large bolts, where as my legs will be glued joints. I had to give the legs a bit of a tightening when I first got it, and the top needed smoothed out with a hand plane and refinished with some boiled linseed oil, but it has held up nicely for being over 60 years old.

 OK, back to the build.
 Satisfied with the dry fit, I made sure the legs were square to the top planks before gluing everything together. Those white pieces of MDF with the two holes cut in them are my corner square jigs. The holes are for clamping through.

 I originally thought I was going to glue up all three layers of the leg assembly at the same time, and then clamp it all together in a big multi layered 2x4 sandwich and wait for it to dry. But trying to get everything positioned correctly was difficult enough doing it one layer at a time. I ended up doing about one and a half layers at a time, clamping it and waiting for it to dry, before coming back and continuing with the next layer. It took about two days (and most of my clamps) to glue up each leg assembly.

The leg assembly is technically three layers thick, but as I was gluing them up, I decided to add one of the planks of the table top to the top of the stack to finish off the mortise and tenon joint. So, the top side of the leg assembly is four layers thick.
 Those notches are where a short stretcher that will connect the two leg assemblies will go.

And here are the two assemblies together. Just imagine more 2x4s stacked side by side across the top, and a couple of smaller stretchers connecting the legs at the bottom, and you are almost there.

 Since I ran just the two wide faces through the thickness planer, the short faces were not perfectly straight, so after the leg assemblies were dry, I used a hand plane to smooth them out nice and flat. Well, flat enough for government work anyway.

Here, you can see a nice close up of how that mortise and tenon joint fits the leg to the table top.

 OK, time to glue up the table top. The only thing I have that will clamp the table top for glue up are those cheap pipe clamps from Harbor Freight. The plan was to turn the leg assemblies upside down, lay them on top of those pipe clamps and stack the 60" 2x4s in between them (with glue). Before gluing, I cut my 60" table top planks to rough length, leaving them a little long so that lining them up perfectly would not be critical. I will trim them to the correct length later. I also ran each of them through the thickness planer so that they had nice smooth flat sides for good glue adhesion.

I had to rest my pipe clamps on 2x4 scraps because they were not all the same brand, and so they didn't rest on the floor at the same height. So, I rested the pipe itself (which is a standard size) on the 2x4 scraps so that each pipe clamp would be level with the floor.  I strapped a level to the side of the leg to help keep the legs in square, and used a ratchet strap to pull the legs together as needed (I ran out of pipe clamps).

 Here, I have cut and added the 22" 2x4 stretchers to the bottom of the legs. They fit like a glove;  another way I could tell that everything was reasonably square.

You will note that there are pipe clamps positioned on the top and bottom of the table top. This is to help ensure even pressure. If you only put your clamps on one side of a glue up like this, you will get uneven pressure on the top side and the bottom side, which will result in cupping. This is also true for gluing up panels. 

Although not in the original plan, and probably unnecessary, I decided to add a couple of stretchers to help brace the bottom shelf, just in case I decide to put something heavy on it for more stability.

It was tempting to use screws to affix these stretchers, but I was kind of amused by the idea that up until now, I had not used any metal fasteners in this build. So, I decided to use butt joints with glue between the long stretchers. However, a butt joint, especially one made with end grain, is inherently weak, so once that was dry, I reinforced that weak butt joint with oak dowels pegged through from the outside. 

 I started off using 1/2 inch oak dowel (which was overkill), but I didn't have enough of it to do two pegs per joint, so each one got one 1/2" and one 3/8" peg. Once the glue was dry, I cut and sanded the rough dowel ends flush. I retroactively added the additional stretchers to the SketchUp model, but I didn't think it was worth the effort to add the dowel pegs.

 Before turning the table over, I took a moment to smooth out the bottom of each leg, and add a chamfer, with the belt sander (which I also did not add to the SketchUp model). I should have made the chamfer a little bit smaller. I hope it doesn't interfere with putting on the casters.

Once the pipe clamps were removed, I could flip the table over and get a good look at my handy work.

 As I mentioned, the table top planks were cut long intentionally. Now all I have to do is strike a line across the end with a straight edge, and trim the table top flush with the legs using the circular saw.

 But the circular saw won't cut all the way through a 2x4 tipped up on its end, so I have to finish the cut with a hand saw. I always hated using hand saws, until I discovered Japanese style hand saws. Don't get me wrong, hand saws still suck, it's just that Japanese hand saws suck on the pull stroke instead of the push stroke. Much easier.

 The table top actually came out about as good as I hoped it would, but of course there was always going to be some unevenness, because the 2x4s weren't planed on their short edges. So, I started smoothing out the top with a hand plane.Then I moved to the belt sander, and then I finished up with a little more hand planing. Wow, what a difference.

 We're almost done! Time to add the plywood top and shelf. I cut the 3/4" plywood for the top with the circular saw and a straight edge. I cut it about a half inch larger on each side, than the laminated table top, because I wanted to cut the plywood square, and I figured the laminated top would probably be a little off (it was, but not by much). Having the plywood slightly bigger, would make positioning it easier.

I did not glue the plywood to the laminated top, because I want to be able to replace it if necessary. So, for the first time in this build, I used deck screws to attach it- pre-drilling and countersinking each one.

 I gave the plywood top a quick sanding with the belt sander, mostly to take off any splinters and round over the top corners. Then I gave it, and the legs, a quick coat of shellac. I don't plan to paint or polyurethane this workbench, but I wanted to give it a modicum of protection. I can always paint or finish the bench later, if I think it is necessary.
I was a bit unhappy that the table top needed to be more than 24" wide, meaning that I could not get both the topper and the lower shelf out of one sheet of plywood. It killed me to think I would have to cut up a second $35 sheet of 3/4" plywood for the lower shelf. But, as luck would have it, I found a scrap of 3/8" plywood in my sheet goods rack from when I did a recent bathroom remodeling project for my mother. It was almost a perfect fit. I had to trim off about four inches from one end, and about a half inch along the side. Huzzah! Then I needed to cut out notches for the leg posts.

 The lower shelf wouldn't fit into place from the front, and only barely fit in from the side. I hadn't really thought getting it in there was going to be a problem. I got lucky. I mean, it just fit in there. Once in place, it was screwed down with decking screws.

OK, so that's actually the end of the build process for the main workbench. The workbench is technically done at this point. But that's not quite the end of the project. We still need to mount the lathes and I think I might do something a little fancier with that bottom shelf, maybe some drawers or cabinet doors. At the very least, I need to transfer my chisel racks from the old metal cabinet. I also need to add some casters so this thing can be moved around. Unloaded, I estimate that the workbench itself weighs somewhere between 150 and 200 pounds. Once the machines are mounted, and especially if I do any drawers or cabinets on the bottom, this thing will end up weighing over 400 pounds.

I was originally going to make this all one post, but it is getting really long already, and in the past couple of days I have had several idea for improvements, like adding drawers to the bottom, maybe a lifting mechanism for the casters, not really sure what all I might do yet, so I think I will just let the basic workbench stand alone as a post, and then add my equipment and upgrades in another post.

BTW, the real world workbench did end up differing from the 3D model just slightly. Because of planing the sides of the 2x4s, they ended up losing a little width, so I ended up with one more 2x4 in the real table top than is in the model. This made the real table top end up a little over 28 inches wide, compared to the 27 inches of the model.  No big deal. I didn't cut my stretchers or bottom panel ahead of time, and I measured the real workbench to get those measurements instead of relying on the model for them, so it wasn't a problem. If you download the SketchUp model, juts be aware of this, and just use the model as a guide, not an exact technical drawing.

Until next time...

See Also:

2x4 Roubo Style Workbench Lathe Stand (part 2)

1 comment:

  1. Wow, that's a monster build - I like it!
    And should you need more weight, you can always screw another sheet of plywood below the stretchers and fill the space between the two bottom sheets with sand. That will make it heavy enough that you'd need an elephant to move it ;-)
    And still you can remove the sand easily if the need arises.