Assembley table dilemma and ideas

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  • poolhound
    Veteran Member
    • Mar 2006
    • 3195
    • Phoenix, AZ
    • BT3100

    Assembley table dilemma and ideas

    First, sorry for the long post. Its mainly a brain dump on my current dilemma, it helps to write it down.

    Building some picture frames last week brought back into focus how NOT having a good assembley table is a real PITA. I have 3 main surfaces I use but none are perfectly flat or big enough for larger projects. As most of you know my shop has to do double duty as a functioning garage so I cant have a heavy permanent table or bench in the middle where it needs to be

    My main bench is the biggest (6' x 32") and flatest (not perfect) but it is fixed in the corner of the shop and I cant get around all sides. My small bench (normally has my CMS station on it) is on wheels and has levelers so moves out when needed but its only 5' x 22". The main surface I tend to use is and old hollow core door edged with solid wood which sits on saw horses (5' x 32") - youve probably seen it in many of my pics. When I have needed a wider surface I bring the small bench and saw horse top together but requires all sorts of shims to get them vaguly the same height and then still nowhere near perfectley level or FLAT!

    I have re-read all the assy table threads and most relate to some kick A$$ fixtures that I am jealous of but just dont have the room for. First I was wondering what size everybodies assembly tables are? I know from experience that 32" is too small for many projects 4' would seem ideal and of course match the width of sheet goods.

    I am trying to figure out how to solve the issue and get a workable solution. Here are options that I am currently considering.

    1. Rebuild a new top on my small bench or build a completely new bench. As it must live on the edge of the garage (even though it moves) the top would still be limited to about 25" - 30" wide.
    2. Build a new torsion box top to sit on the saw horses 4'x5' min. As most designs I see are made from a combination of 1/2" and 3/4" MDF 3" thick this is going to be really heavy to move about on a regular basis.
    3. try a multi beam construction (used with saw horses) as was outlined in a recent FWW article. It uses two torsion box beams approx 9" wide. You can use them on their own, or set them together (18") or apart up to the width of your saw horses. This still requires some tricky leveling issues when they are used together, the article doesnt mention it but it would seem to require a nice level/flat floor to work - my garage floor isnt either. If you can access FWW online here is the article.

    Comprised of five divisions — Collectibles, Home Arts, Home Building, Marine, and Writer’s Digest — Active Interest Media (AIM) produces leading consumer and trade events, websites, magazines and films/TV shows.


    Some questions I am considering:

    1. How heavy is a 4'x5' 3" thick MDF torsion box? How would I move it?
    2. How thin could I make it and still maintain the needed flatness?
    3. Other material or construction options

    In summary all ideas and suggestions the "collective" may have would be very much appreciated.
    Jon

    Phoenix AZ - It's a dry heat
    ________________________________

    We all make mistakes and I should know I've made enough of them
    techzibits.com
  • pelligrini
    Veteran Member
    • Apr 2007
    • 4217
    • Fort Worth, TX
    • Craftsman 21829

    #2
    I've got a 48x40 top that I lay over a couple sawhorses. It's pretty easy to move around. I used a piece of 3/8" plywood with a 1x4 frame. The ply overhangs the frame an inch on all the sides for some handy clamping. The frame is open on the bottom and consists of 4 sides and two more braces creating an x going from the corners.
    Erik

    Comment

    • LarryG
      The Full Monte
      • May 2004
      • 6693
      • Off The Back
      • Powermatic PM2000, BT3100-1

      #3
      My torsion box assembly table is 42" x 60" x 4" thick, built to the David Marks design shown on WoodWorks. The dimensions were sized to my previous shop space, which was about 40% of what I have now. The 42" x 60" size is okay for most purposes, but 48" x 72" would be a lot better and am considering building one of that size (about as large as I can go in my current shop).

      I've never weighed it but I'd guess it must be somewhere around 150 lbs, if not more. I've only moved it while getting it off and on its base, and it's a real handful -- mainly because there's no way to get a solid grip. But even if there was, it is not something I'd want to wrestle around often. Way too heavy for that.

      The 4" thickness is probably about the practical minimum to ensure the thing stays flat. Considerable weight could be saved by reducing the rib thickness to 1/4", but the problem with that will be fastening them together. If you're handy at metalwork, you might build the internal structure out of aluminum sheet, with riveted connections, literally like an airplane wing. But then you'd have to figure out how to attach the skins ...

      I understand your space constraints, but will urge you to build the thing as big as you possibly can. You know those old-time rolling chalkboards that can be flipped over, so you can write on both sides? I was once considering something like that, in order to have as big an assembly surface as I could get while somehow minimizing the storage footprint. You might give some thought to some sort of similar rolling, pivoting arrangement.

      However you do it, of whatever size, do build one. I guarantee it will become one of the most used and most valuable "tools" in your shop.
      Last edited by LarryG; 01-07-2009, 12:07 PM.
      Larry

      Comment

      • MikeMcCoy
        Senior Member
        • Nov 2004
        • 790
        • Moncks Corner, SC, USA.
        • Delta Contractor Saw

        #4
        I'm cramped like a lot of us but I have several pieces of various size MDF that I place on cheapy Harbor Freight saw horses. I just got home and I'm trying to finish a set of bunk beds I started two months ago and this one will take 4 saw horses and two pieces of
        24" x 48" MDF butted side by side. If I need more room than that, I just start moving tools out of the way and use my floor.

        Comment

        • drillman88
          Senior Member
          • Dec 2007
          • 572
          • Southeast
          • Delta Platinum Edition Contractor Saw

          #5
          I am planning to build an outfeed/assmbly table similar to this once I add on to my shop.You could build the top as a torsion box for stiffness.It will wheel over tablesaw using virtually no space when not needed.I think fww did a similar one as well but I'm not certain.

          Space-Saving Double-Duty Tablesaw Workbench , Woodworking Plans, Workshop & Jigs, Tool Bases & Stands, WOOD Issue 178, September 2007, 2007, Intermediate
          I think therefore I .....awwww where is that remote.

          Comment

          • RmeDad
            Established Member
            • Jan 2006
            • 231
            • Scottsdale, AZ
            • BT3100-1

            #6
            My table

            Here's what I did. Found 6 small bathroom vanities at HD on clearance for $10 each. Mounted two groups of three side-by-side with screws and blind nuts. Mounted them back-to-back with pegboard between. Two tops of MDF and a covering of hardboard. One sheet of PLY underneath. Mounted six heavy duty swiveling casters with brakes. Works great, plenty big for assembly, right height, lots of storage space underneath, pegboard works great for hanging misc. stuff. Hope this picture works.

            Click image for larger version

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            Jack

            Throughout my racing career I was constantly reminded of this: "Keep the pointy end forward and the shiny side up!"

            Comment

            • poolhound
              Veteran Member
              • Mar 2006
              • 3195
              • Phoenix, AZ
              • BT3100

              #7
              Originally posted by pelligrini
              I've got a 48x40 top that I lay over a couple sawhorses. It's pretty easy to move around. I used a piece of 3/8" plywood with a 1x4 frame. The ply overhangs the frame an inch on all the sides for some handy clamping. The frame is open on the bottom and consists of 4 sides and two more braces creating an x going from the corners.
              I have been considering alternative constructions. The key for me is finally getting a surface I can be sure is true, flat and stays that way.

              Do you find this construction remains perfectly flat with zero twist?
              Jon

              Phoenix AZ - It's a dry heat
              ________________________________

              We all make mistakes and I should know I've made enough of them
              techzibits.com

              Comment

              • poolhound
                Veteran Member
                • Mar 2006
                • 3195
                • Phoenix, AZ
                • BT3100

                #8
                Originally posted by LarryG
                The 4" thickness is probably about the practical minimum to ensure the thing stays flat.

                I understand your space constraints, but will urge you to build the thing as big as you possibly can. You know those old-time rolling chalkboards that can be flipped over, so you can write on both sides? I was once considering something like that, in order to have as big an assembly surface as I could get while somehow minimizing the storage footprint. You might give some thought to some sort of similar rolling, pivoting arrangement.

                However you do it, of whatever size, do build one. I guarantee it will become one of the most used and most valuable "tools" in your shop.
                I was afraid the thickness issue may start to make the project moot if I try make it thinner. I was hoping that I could get away with only a couple of inches but I guess that may start to introuduce twist.

                Hmm, flip over rotating supports, interesting idea. With 150lbs of weight that may make for an interesting base.

                I agree about its value. I have plenty of worksurfaces right now but it bugs the heck out of me that none are true/flat. I can create large surfaces but not consistently flat ones without introudcing lots of weight. I guess you cant make an omelette without breaking eggs
                Jon

                Phoenix AZ - It's a dry heat
                ________________________________

                We all make mistakes and I should know I've made enough of them
                techzibits.com

                Comment

                • ejs1097
                  Established Member
                  • Mar 2005
                  • 486
                  • Pittsburgh, PA, USA.

                  #9
                  I was joking myself at first, but then on second thought...

                  can you build a hoist and hover the table top over head (with proper hardware for the weight of course)? Use a removeable base that can be folded/stored out of the way when the garage is in use?

                  I have no problem with the mechanism I use to hoist my canoe with all my hunting gear stored (about 100#) into the rafters by myself.
                  Eric
                  Be Kind Online

                  Comment

                  • shoottx
                    Veteran Member
                    • May 2008
                    • 1240
                    • Plano, Texas
                    • BT3000

                    #10
                    Just addressing the storage issue think about some thing like this


                    Garage Overhead Storage

                    Often in error - Never in doubt

                    Mike

                    Comment

                    • pelligrini
                      Veteran Member
                      • Apr 2007
                      • 4217
                      • Fort Worth, TX
                      • Craftsman 21829

                      #11
                      Don't know about perfectly flat all the time. Depending on what the tolerances are perfect can be a pretty tall order.

                      Quite often the sawhorses will be set up in the yard and getting the pair of them level isn't easy. There might be some twisting with heavy loads under those conditions. When I first built it I climbed up on top and jumped on it.

                      The last time I put a level/straight edge on it was when it was set up in my little shop about a year ago. I was trying to figure out why my drill press cabinet was not assembling square. It was within 1/16" of an inch; flat enough for me. I found that my SMT was out of alignment. The table was already a couple years old by then too. It usually gets put up at the end of every shop session.
                      Erik

                      Comment

                      • Tom Miller
                        Veteran Member
                        • Mar 2003
                        • 2507
                        • Twin Cities, MN
                        • BT3000 - Cuttin' it old school

                        #12
                        (Hey, look at me -- I'm posting!)

                        IIRC, 3/4" mdf is ~100# for a 4x8 sheet. For a 4'x5' table, you'll use ~2 sheets including ribs, so 200#.

                        I think LarryG's idea could work well for you. The base doesn't need to be extraordinary; you can add outriggers or other extra support for when you go to flip it up.

                        Either way, you really should consider making your existing work surfaces flat. I think it would definitely be worth the effort, as these are the surfaces you're using to mill your parts in the first place. If they're not flat/true during milling, your assembly table isn't going to fix that.

                        Regards,
                        Tom

                        Comment

                        • poolhound
                          Veteran Member
                          • Mar 2006
                          • 3195
                          • Phoenix, AZ
                          • BT3100

                          #13
                          Originally posted by ejs1097
                          I was joking myself at first, but then on second thought...

                          can you build a hoist and hover the table top over head (with proper hardware for the weight of course)? Use a removeable base that can be folded/stored out of the way when the garage is in use?

                          I have no problem with the mechanism I use to hoist my canoe with all my hunting gear stored (about 100#) into the rafters by myself.
                          Its not such a crazy idea and I was just out there looking around for the millionth time and puzzling over where it could go and started to consider this very same idea.
                          Jon

                          Phoenix AZ - It's a dry heat
                          ________________________________

                          We all make mistakes and I should know I've made enough of them
                          techzibits.com

                          Comment

                          • LarryG
                            The Full Monte
                            • May 2004
                            • 6693
                            • Off The Back
                            • Powermatic PM2000, BT3100-1

                            #14
                            Originally posted by poolhound
                            I have plenty of worksurfaces right now but it bugs the heck out of me that none are true/flat.
                            As I think you already understand, that's the revelation one has when one builds a torsion box. It's not that you suddenly have all this big wonderful new acreage on which to build -- well, okay, it's that, too; that part is also great. But the main thing is that it's FLAT. It's a reference surface, that you can trust.

                            An arrangement like pelligrini's is just another version of a torsion box; I think the main difference between his and mine is that the trueness of its supporting base becomes fussier. With mine the base could be all out of kilter and the working surface would still remain flat, because the small-cell internal grid with skins on both sides is incredibly stiff. But, as we've discussed, it's also incredibly heavy.

                            +1 on Tom's suggestion to get your other surfaces trued up. I don't even like for a known-flat surface to be slightly out-of-level, because that can fool your eye as you're looking at whatever is sitting upon it.

                            I forgot to mention one point that may help with your space planning. In my previous shop, I had one of the short ends of my table all the way up against a wall. Well, actually, it was about 4" clear of the wall, to allow just enough space to hang clamps. Point is, I was able to walk around only three sides. In a perfect world access to all four sides is best, but I really didn't find not being able to get to the fourth side to be a significant hardship. (Even in my current shop I only have about a foot of walk space on one of the long sides, and that's not bad, either.)
                            Last edited by LarryG; 01-07-2009, 01:34 PM. Reason: additional thoughts
                            Larry

                            Comment

                            • poolhound
                              Veteran Member
                              • Mar 2006
                              • 3195
                              • Phoenix, AZ
                              • BT3100

                              #15
                              Originally posted by pelligrini
                              It was within 1/16" of an inch; flat enough for me.
                              Although I havent measured them lately I think my current surfaces are within a 1/16" but even that can cause all sorts of allignment problems. As you move a workpiece around during assembly that 1/16 can magnify and with potential twist in a large surface that could end up being as much as an 1/8 from corner to corner.

                              I am hoping to end up with something a lot flatter.
                              Jon

                              Phoenix AZ - It's a dry heat
                              ________________________________

                              We all make mistakes and I should know I've made enough of them
                              techzibits.com

                              Comment

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