Want to add a new feature to a cheap 3d printer like the wanhao i3? Why not add the ability for the printer to clean the print nozzle before every print. This thing was made to give that feature in a cheap easy to do way. Using Velcro with a sticky back adhesive allows one to easily remove and replace old and worn wiper pads.
This is merely how I did this and can easily be changed. All you really need to do is just stick Some velcro onto the bed and go from there. I use the wiper plate as it means I replace pads in the right place every time.Allowing me to never have to change my start gcode. The only problem is the plate will interfere with some coolers like the diii and ciii. If you are using those coolers I recommend just slapping the Velcro on the bed without the plate. Just try to keep up with the pads location if you can, maybe outline it on the bed if possible. Just too ensure you replace a pad in the right location. See it in action here https://www.youtube.com/watch?v=ydbMzVH3A2E
This thing does need a small bit of hardware to get going. You will need
Velcro I used the fabric like side
1 M3 countersunk screw around 20mm (10mm should work if not using a glass bed)
1 to 3 M3 nuts (will need more nuts if you are using a glass bed.
Optional 1 M3 locknut to replace normal nut for tighter fit
How to install
To see if you can do this mod you need to check the back of the heat bed for a hole. The stock build tak surface will cover that hole so the best thing to do is look at the underside of the heat bed for that hole. I know my wanhao i3 v2 has it and I hear that printers like the maker select v2.1 have the hole as well.
Next you cut the Velcro to size around 10mm by 50mm, of course each print will possibly be off so just cut it till it fits with in the indent on the print.
Now that you have it placed on the print we can put the wiper onto the printer. If you have glass you will need to add nuts onto the screw so it offsets the print to lay on the glass bed. I used 2 nuts for this function
If you are using something like the build tak simply make a hole in it where the screw hole in the heated bed is. You will not need height nut as the print will lay on the build surface as is.
Now simply take the normal nut or locknut and tighten the wiper to the heated bed.
Now you have the wiper installed on the printer. We need to tell the printer to use the wiper.
All you custom start gcode users may not need this section. Since you can just create gcode to use this upgrade.
Now I actually upgraded my Gcode after we filmed the video above. My Gcode works for my printer, however you may need to edit it for the best performance on your printer. I simply suggest manually moving the printer x,y, and z to the right postion and writing down the positions, then editing the code below
G21 ;metric values
G90 ;absolute positioning
M82 ;set extruder to absolute mode
M107 ;start with the fan off
G28 X0 Y0 ;move X/Y to min endstops
G28 Z0 ;move Z to min endstops
G1 Z4 ;Moves Z up so its not on glass
G1 X100 Y192 ;Moves X and y into middle of nozzle scruber
G1 X79 ;Moves x to left side of velcro wipe
G1 Z2 ;Lower nozzle inro scruber
G1 X125 ;Moves X to Right side of Velcro Wipe
G1 X79 ;Moves X to left side of velcro wipe again
G1 Z7 ;Moves Z above velcro wipe
G28 X0 Y0 ;Move X and Y to home
G28 Z0 ;Move Z to home
G1 Z1 ; Move z off of build plate 1mm
G92 E0 ;zero the extruded length
G1 X50.0 F500 E35.0 ;Start purge line and extrude 35mm
G92 E0 ;zero the extruded length again
G1 Z2 ;Move Z up 2mm
;Put printing message on LCD screen
Edit:11/13/17 added an edits section
Edit:3/20/17 Okay added some new pictures of a used nozzle scrub pad that I removed from the printer.
Edit:2/14/17 Well I have been doing some tests with other cooling shrouds and I have some mixed news. So I have been using a diii cooler remix with the scrubber pad (printed part) for some time. It cuts off some of the bed and overall was really limiting what the machine could do. So I tested two more coolers that connect on the back side of the printer. I tested both the cobra cooler and the ciii cooler. The ciii cooler had the same problem as the diii only since its on the back it limited bed usage even more. So I would overall simply call it incompatible with the Printed Part included here. I was not using the short version I tested at a .2 layer height. The cobra cooler however looks promising as it did not run into the scrubber pad right off the bat. The was at .2 layer height. I am currently thinking that it may be a good choice if you plan to use this mods printed wiper plate and I plan to start using it.
Edit:1/30/17 Hindsight is 20/20 here, I think i might be a smart idea to put something like a insulating washer on before tightening down the scrub pad. I don't know if the nut could scrub off the protective layer on the bottom of the bed.