Wednesday, April 30, 2014

20140429 (Tu) Upcycled 3D Printer

Part of my job is drafting.  I enjoy using the computer for drawing not only technical things but recreation.  In 2009 I even drew a comic using a USB drawing pad.  There is still something about holding actual pens and making imperfect lines on a piece of flimsy graph paper.

A drafted image is much cleaner and other people with the same program can edit and improve it.  But a piece of paper with a hand-drawn sketch is unique, almost an artifact.  I’m waxing romantic here but parents hang crayon drawings on the fridge because they are precious in the same way.

Enough background.
Parts and a design were gathered to mount the glue gun nozzle.  The design was hand-drawn on graph paper with colored pens.

Hand-drawn sketch of what to make

The long bolt in the nozzle was replaced with a short #8 bolt.

 Short bolt in the glue nozzle

The aluminum bar mount for the mounting the nozzle was shortened and made the same length from the center of the large nozzle hole.  The ends were cut with a horizontal band saw then cleaned up with a belt sander.  Positions were marked 1 ½” from the center of the nozzle hole by making divots with a center punch.  The bar was clamped in place on the plastic piece.  The threaded shafts had to be removed for this.  The aluminum bar and plastic piece were propped on wooden slats and drilled with pilot holes.  The plastic was drilled to 5/32” and the aluminum was drilled to 3/16”.  The underside of the plastic had the mounting holes countersunk.  The central hole for the glue gun nozzle was given a pilot hole then the countersinking bit (1/2”) was used to drill to the bottom to give a V-shaped hole for the glue nozzle.

Position of bar

 Bar clamped to plastic

Underside countersunk holes

Hole drilled for glue nozzle

The aluminum bar had the small nozzle mounting hole redrilled so it could mount straight.  Nuts were put on the short bolt and tightened to secure the nozzle in place

 Remounted glue nozzle

Remounted glue nozzle from side

Long #8 countersunk bolts were inserted into the plastic from below and the aluminum bar with nozzle was fixed in place by putting nuts on either side of the aluminum bar and tightened.

 Mounted glue nozzle

Mounted glue nozzle from side
While the shafts were removed they were sat next to each other and the nuts were adjusted to assure they were all the same.
Identical shafts
A saw blade was degreased by using dish detergent available at the hack space’s kitchen unit.  The clean blade was put over the end of a servo and a servo horn was put over that.  The two were held together tightly and hot glue was applied.  It was allowed to cool in place then removed and stored in a plastic container for safety.

 Hack space degreaser

Servo in place 1
Servo in place 2
Blade glued to servo horn HOT
Blade glued to servo horn cooled
Blade and servo horn safely stored in plastic container
The schematics were updated to use different color lines for power, 0V, and signals.  The debugging hardware was cordoned off to show it was modular. 

Updated schematics

To do:
  • Mount glue servo 
  • Design and build proto board circuit 
  • Install in mint tin enclosure 
  • Test + Debug 
  • Revise documentation

Journal page 1

 Journal page 2

Tuesday, April 29, 2014

20140428 (M) Upcycled 3D Printer

Service Vs hammer

Today was unnecessarily expensive for two reasons.  The first reason is that I decided to buy a bicycle chain tool so I have it available for future projects.  The chain tool cost $9 at Bicycle Chain.  I could have used a hammer and nail to drive a link (pin) from the chain but this is a tool that should have already been in my tool box.  The second reason someone else could have done it cheaper is that I'm sure the guys at the bike store would have modified the piece of chain for me without any fuss.

Modifying the chain doesn't have to be expensive.  The store sold me a scrap for $1 and to show my gratitude I bought the chain tool from the same place.  Seems like a good exercise of consumer loyalty.

Enough background.

A chain tool was purchased from Bicycle Chain on Lexington in Roseville, MN.  The employee confirmed the tool could be used on any link of a bicycle chain.  The tool was $8.99 plus tax.

At the hack space the previously marked link (pin) was put in the chain tool and extracted.  The metal link was lost on the floor.  A second joint was separated to obtain another link.

 Chain in the chain tool

Chain tool has extracted a link
Second link pin between chain loop
The link was reinserted by using an alligator clip to position the link over the hole [of the chain joint] while in the chain tool.  Keeping the link straight proved difficult.  A hammer was used to drive the link most of the way and probably could have done all the work.  The chain tool was used to make the link flush with the chain again.

 Alligator clip positioning link pin

Chain tool working the pin into place
Another angle of the chain tool
Use a hammer to drive the pin into place

 Making the pin flush with the chain

The continuous chain fits loosely on all the sprockets.  A tensioner will be necessary and probably a rubber band and rag.

A loose fitting chain

The hole for the glue gun nozzle was widened slightly.  The nozzle now fits well.

The nozzle is now snug

To do:

  • Mount aluminum bar to plastic with countersunk bolts from below 
  • Design stripboard circuit, drill and wire 
  • Clean saw blade and glue to servo 
  • Mount glueServo 
  • Install in mint tin enclosure 
  • Test + debug 
  • Revise documentation
Journal page