Peg Chair

July 2017   Bianchini-Love

Inspired by a chair found in an MIT machine shop, we built a peg chair, designed as a way to temporarily "sit" and take > 50% of the weight off your feet. The height is adjustable, and the seat is easily replaceable with any standard-mount bicycle seat. It's a quirky way to pseudo-sit-stand or an efficient way to produce another seat for more guests.

A redneck immersion for Henry

Bibit made her lamp (see the Lamp post) in the workshop of and using the expertise of Robert and Andi Moran, her northern Louisiana aunt and uncle.  The peg chair came out of a trip to give Henry a taste of what he was missing!

Henry and one of our furry friends went for a walk along the road.  Some serious redneck sights!

Inspiration

At the MIT Hobby Shop, we once spotted a peg chair by the welding station.  It had a tractor seat on top of a single peg:  not a proper chair, but an interesting way to alleviate some of the weight off your feet while working.  We liked the aesthetic and functional purpose, so we decided to make our own!  To suit both of us, however, it would need to be adjustable in height (to compensate for our 12" height difference).

Construction

We made the chair out of two steel tubes plus some additional hardware and repurposed parts:  a bike seat, a bike seat mount, and the rubber foot off an old set of crutches.  One steel tube fits inside the other and can telescope to provide height adjustability.  The tubes are locked at discrete intervals by inserting an oversized eyelet bolt through both tubes and threading it into a nut welded on the outside of the larger tube.

Bibit brushes the rust off a short piece of steel pipe.  This piece would become the interface between the top tube and the bike seat mount.

Henry gets started with brushing this piece.  You can see the difference between the brushed end and the unbrushed, rusty end.

To drill the series of holes on the smaller tube, we drilled each one through the larger tube's hole, which guaranteed proper alignment at each of the holes.  After this drilling, we welded a nut on one side of the larger tube's drilled hole so a threaded eyelet could pass through both tubes then lock into place.

The process took us a couple of days to design, find materials, fabricate, and assemble.

It passed each of our sitting tests!

Don't let the photos fool you -- the chair doesn't stand up (for long) on its own.  We took fast photos...

Etching graphics into the steel

The setup for etching a portion of the steel pipe.

Using a technique we developed ourselves, we etched our Bianchini-Love logo and "BIANCHINI-LOVE ENGINEERING" onto the peg.  First we used a vinyl cutter to make custom masks, leaving exposed only the parts which we wanted to etch away some of the thickness.  We applied the vinyl to the steel parts and used some additional vinyl to create walls for a "bath" around the etching area.  We filled this bath with salt water, then submerged some scrap aluminum pieces to hover above the pipe at a close distance (but it's important that they don't touch!).  The last step is to hook up a 9V battery across the two electrodes:  one side on the scrap aluminum and the other on the steel pipe.

You can see the etching process happening because of the bubbles that come off the salt water surface.

After unhooking the battery and removing the electrode, you can see some salty residues that built up in the salt bath (left).  Removing the vinyl leaves just what the mask didn't cover:  "BIANCHINI-LOVE ENGINEERING" up the whole tube (right).

To make the logo pop even more, after etching and before peeling off the vinyl sticker, we colored the etched surface with black sharpie (left).  After removing the sticker, we were left with a black BLE logo engraved into the tube (right).