Wednesday, 12 June 2019

Workshop Upgrade: Building a folding center bench.

3/4" hardwood plywood 
    Past month has been busy, had a couple of family projects to do, one of which resulted in a large stack of leftover plywood looking for a project. After tripping over the old plywood on sawhorses bench one more time, I decided it was time to replace it with something better suited to the job.


Workbench hardware, green brackets are thing:1259505
    Sorting through the stack revealed a pair of panels that combined to form a 30" by 84" worktop, a nice size for working on large projects but a bit cumbersome for my workspace all the time, so I needed to find some way of fixing that. Looking through my hardware bin turned up a 30" piano hinge, so I decided to make one side of the bench permanent and the other a folding extension that could be collapsed when not needed. More digging through the rafters turned up a couple lengths of 2" squares stock that could be cut down into legs and I was starting to get a feel for what my options were, so I fired up Fusion 360 to do some rough planning.


Rough design in Fusion 360
   Measuring the available materials fixed the workbench total height at 35" tall, so the design in F360 was useful for figuring out what length to cut the legs, along with providing a solid framework for the basic form. The old diagonal bracing angle iron from the Mega Kossel's previous frame proved to be exactly the right length for the long side bracing and shelf supports, so it got bolted onto the legs to help stiffen things. Bracing for the short sides is a couple lengths of 1/4" plywood that were in the stack, these also double as mounts for the 2.5" caster wheels.


Workbench assembled and folded
    Once the bulk of the assembly work was finished, it was time to give some thought to what type of finish to give the top, something hard-wearing and durable was needed, so I ultimately went with some semi-gloss Varathane that was leftover from another project. it's got 1 coat on all sides so far. Seems to be holding up fairly well, and I've got plenty more if it needs another coat later after some use.

Unfolded with first coat of Varathane drying
Folding Section Leg
    For supporting the fold-out section of the work-top, I was playing with a bunch of different ideas, but ultimately I decided to create a bolt-on leg that will clip to the underside of the worktop when not in use. This meant that I needed something light but strong, some leftover aluminum tubing from the Mega Kossel 2.0 fit the bill perfectly. The longest section that I had on hand was slightly short but I just modified the design for the mounting bracket and foot to account for that.

3D printed foot for folding section support
Folding support leg mounting bracket
    I'm fairly happy with how the leg came together, the printed parts were intended to have M5 bolts used to secure them but the fit as printed turned out to be nice and snug with friction alone, so the entire leg can be broken down without tools if needed or if something breaks at some point. There's a bit of a teaser for a future post in the mounting bracket for the leg, those are the former bed levelling knobs off my Ender 3 being used as wing-nuts to hold things in place, but more on that next time.

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