Remixed to mount to the front where the blower fan goes, or right on top of the blower fan. I don't need a pen or scraper mount very often (just for PCB prototyping), so removing the blower fan when I need to install this is not inconvenient. YouTube videos still to come.
##Why:##
I've been using the LaserPrinter PCB etching method for a while now, and it works well. But, I figured since I have a new Anet A8, I should be able to use it to "Draw" out my PCBs. Now, I can use a pen/marker to draw an etch mask over my traces. Or use a piece of hardened steel to scrape off a PCB Board covered with mask to expose an "Isolation" route.
Components
- Base: Bolts to the front of the extruder fan.
- Carriage: Holds the pen or scraper
- Brace: added strength to the A8 carriage bracket.
##Parts:##
- 2 x Traxxas T/E Max A-Arm screws. 3mmx70mm (Part #5161).
- 2 x springs from retractable pen
- 2 x 20mmx3mm screw -> Pen Holder
- 2 x 3mm nut -> Pen Holder
- 2 x 20mmx3mm -> Base to Printer Carriage & blower Fan
- 2 x small 12-13mm OD washer -> between base and fan
##Assembly:##
- 20mm screw -> Base -> 12mm washer -> Blower Fan -> Printer Carriage
Brace
- The brace is just a simple 55x20x5 block. It gets wedged above the extruder motor to add a little stability to the flex of the metal carriage bracket. (see photo). It actually seemed to do the trick.
##Print:##
- 25% infill
- 3 walls
- 0.1 layer height
##Tips:##
- The guides on the carriage were a nice fit on the pins, but a little too snug for a smooth glide. To improve the movement of the carriage on the pins, I used my electric drill to spin the pins inside the carriage for about a minute. The friction of the pin spinning in the carriage hole helped aligned the bore better, and increased the hole size a tiny amount for a little better play.
- For scraping the copper with the drill bit, the pen spring was still enough to provide a nice scraping force. Very precise Z Control was necessary to push down enough on the bit to use the full force of the spring.
- Large washers between the fan and pen base were very necessary and helped reduce any warping of the base. This warping was affecting the up-down smooth travel of the carriage. If you're getting binding on the slide pins, be sure to try washers here.
- Mounting the base to the front of the fan is convenient, but it does induce a little flex which can cause the carriage to bind a small bit. Removing the fan, and mounting the pen base directly to the metal bracket is by far the most stable and smooth.
##Problems:##
- The only real problem so far is that with the stock A8 220x220 bed, the position of the pen relative to the extruder tip means I lose about 60mm of Y axis depth. I easily fixed this by moving the piece of glass on my build plate down the Y axis and re attaching it with the binder clips on the sides (skipping the 1 clip closest to the HOME position).
##Plans:##
- Another base design to mount to back of carriage for better stability.
##Videos:##
https://youtu.be/C9f2XlPntug (Short clip of PCB Traces). I need to work on my FlatCAM knowledge to get this drawing just right.
https://youtu.be/ek8bC_pFCbA (Short cip of PCB Isolation Routing).
July 14 2018: Added small hole recesses to base for more common 20mm length screws.
ShaneAPowell
