I love browsing the new submissions for Instructables.com. One thing on there that kind of chaps my bottom is when people base a project around a hard-to-find item. “I found this old pen plotter in the dump-“ That does me no good since the odds of me finding another 15 year old pen plotter is remote and I’m not going to spend a few hundred dollars to make another hammock rocker. That is not to say that some projects aren’t worth scrapping a valuable piece of machinery. My projects follow the philosophy of the scientific method in that I want people to be able to recreate my work. The parts in my projects tend to be very easy to get or so generic that they can be replaced by employing a little common sense.
In the 3D printer project I use a pie tin as one of the components. It doesn’t have to be a specific name brand with a particular size base, it doesn’t even really have to be a pie tin, anyone could use a non-stick cookie sheet and get the same results. The most unique part of that project is the aquarium which is pentagonal and meant to fit into a corner. There’s no reason someone else would have to use a pentagonal fish tank. In fact a circular Rubbermaid container or a rectangular Tupperware container would be better in some regards.
Sometimes I do pull apart things for their parts, video game controllers have vibrating motors and buttons inside but I try to use controllers that can be found easily. I’ve seen quadcopters which have a body made by laser cutting old desktop motherboards and I think that’s a brilliant use of scrap material. Now, if they had said you must use ASUS model XXXXX motherboard and align the RAM slots in your XXXXXXX model laser cutter I would not appreciate it.
Ceramic magnets were purchased on 2014-05-02 but not recorded since no other work was done on the printer that day. The magnets were roughly ½ the thickness of the plastic layer.
Magnets next to a piece of plastic to show thickness
Two magnets were glued to the bottom of the long wooden stand with a hot glue gun. The magnets were too short so the stand wobbled when in place.
Magnets glued to long wooden stand
A pair of small washers were put between the magnets but they interfered with the plastic layer so a single Fender washer was put between the magnets since it was thicker.
Application of washers and magnets
Large washer in place of two small washers
The stand now sits level and solid. The glue pusher will also rely on the rigidity [of the glue sticks going into the hot glue nozzle to keep it in place].
How the glueServo sits
A 5VDC coil relay was already stocked and chosen to control the air pump. The relay can control up to 0.5Amps at 120VAC or 60Watts. The pump only draws 1.9Watts. The hot wire was cut [on the pump line]. The hot wire corresponds to the smaller blade of a polarized plug. The ends were stripped and tinned. The other wire, which wasn’t cut, was bent over.
Air pump, wire and 5VDC relay
Air pump and relay specs
Cut made on air pump cord
The narrow blade is the hot wire
The tinned wires were soldered to the normally open (N.O.) terminals of the relay after putting shrink tubing over the stubs. Once soldered the shrink tubing was heated over the wires to keep them isolated and protected from touching.
Scrapped phone wire was used to wire the coil of the relay. The color of the wires is unimportant since this relay does not have an integrated diode. This also means that the relay is not polarity sensitive so the coil cannot be hooked up backwards. The wires were soldered and held together with shrink tubing for support.
Phone wire soldered to relay coil and held with shrink tube
All the wires were tightly bundled and a zip tie was tightened around them. The entire bundle was wrapped in electrical tape.
Bundled wires bound together
Relay and wires wrapped in electrical tape
The low voltage wires were given small pieces of shrink tubing to keep the wires from tangling. The ends were fitted with round header pins and soldered in place. Matching pins were soldered to the proto shield and connected to Digital I/O 5 and ground. To repeat, this is not a polarity sensitive connection so an unpolarized connector can be used.
Low voltage wires with shrink tube pieces
Round header pins on low voltage wires
Header pins on protoshield
Red wire from Digital I/O to header pin
- Install chain tensioner
- Devise debugging method
- Physically install Arduino + protoshield
- Test + Debug
- Revise documentation
Journal page 1
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