Mingda D2/D3 Service Bulletin #1 by Pops668

Last crawled date: 2 years, 10 months ago

Mingda D2/D3 Field Expedient Repair/modification kit #1.
Contents:
Ah-Tenshunn!™ belt adjustment tool
Body, Indicator, M4/M4 adator, 3x M3 washers, 1x 3mm brass rod, 1x M3 'acorn' nut, 4x harvested Springs
Fair-Trade, Cage-Free Filament Runout Sensor mounting system (not certified Organic)
Pylon, Wheel, Arm, M4 screw, M3 screw, washers and 'acorn' nut, 608 'skate bearing'
Air-shovel™ parts cooling duct with mounting bracket
Duct, Bracket, M3 screws, washers, nuts
Silent Partner™ Y-axis idler brace, internal
Brace, M5 screws and washers
Lamp hanger brackets to delver the Faithful from darkness...
Left and right hangers...your risk is yours to enjoy...I used 110v 'shop-light', 24V DC LED strip might be a better bet?
Hot-end and parts cooler fan spinners, optional?
30mm Spinner is slip-on over M3 screw-heads, 5015 Spinner uses M3 screws, washes and nuts for mounting.
Whine-be-Gone™ stepper gaskets and Washers
Gaskets and washers. Simple as a pimple.
Hobs-Knobs™ strain reliefe whozits for flopsie cable orifices.
Large (Z gantry cable) or small segments (print bed cable), three segments per knob!
(Almost) All parts printed at 0.2 mm layer height, using ColorFabb Dutch Orange or Blue PLA.
Whine-be-Gone™ and Hobs-Kobs™ are printed using ColorFabb VarioShore foaming TPU; 0.25 layers, 30 mm/sec, 245C, 70% flow, no retraction
Printing/ assembly Notes:
Ah-Tenshunn™ gauge:
1) Indicator has two little internal hooks that line up with coils on the spring. Have to fiddle with it to make it fit right.
Tiny notches on the outside of the Indicator are for pigment/ink/radium glow-paint.
Indicator is PETG, as it is subject to lots of stress and is low-key a safety device.
2) Springs for Ah-Tenshunn!™ tool are harvested from the printing bed.
Don't need springs there, so why not use them for a gauge?
The adjustment knobs support the print-bed on screws, nuts under the Y-axis carrier lock the adjustment in place.
Set and forget.
3) Speaking of accuracy, calibrating the tool uses measured weights.
Your Newton reading is as accurate as your scale and your math...
510 grams = 5 Newtons, 1020 grams = 10 Newtons.
Y-axis brace:
1) Double check spacing of Y-axis idler brace! The curved end must fit snug-close to the inner curve of the chassis and the stepped end clears the cross-brace!
Shims if it short, cut it if it is long.
This part was measured and fitted for a Mingda Rock 3 Pro, likely D2 and D3 use the same cabinet and idler parts...cannot verify it will fit!
Ideal fitment: Y-axis Idler prevents panel from acting as loud-speaker and is fully supported and does not deflect with changes in Y-blyet tenshunn.
Excuse me, Y-belt tension.
Hobs-Knobs™:
1) Print these at 0.6 lines, 0.3 layers, 2 walls, 25% Gyroid infill, 240C @ 70% flow, no retraction. This stuff drools terribly!
Three segments per festering gob to be plugged.
2) Slip each sections 'toe' into the gaping chasm, the last one is a snug 'wiggle fit'.
3) Position the cable to the perfect pose, then secure with ty-rap.
4) Check position after a few prints, the material has an initial 'creep' that you might need to adjust for.
5) These are intended to be snug enough to prevent slipping and rotation!
6) The smaller one is for Heated-bed cable, the larger for Z-gantry cabling.
Whine-be-Gone™ washers and gaskets:
1) Same print setting as the Hobs-Knobs™, except no top or bottom layers, 10% Lines infill, 0.6 line width and 1.8mm walls.
Infill will print 'fluffy' as it is not constrained by neighboring lines and can fully expand.
Walls around holes will print somewhat more densely.
2) You may need to use longer screw to hold the steppers if you use thicker gaskets. Set gasket depth in the slicer by setting a small negative Z displacement!
0.6-0.9mm gaskets are OK for most use, the model uses 1.2mm
3) Washers have a 'bump' on one side; this side goes toward the panel.
Ideally, the panel hole is a little over-sized (3.5-4mm for a 3mm screw) and has a slight chamfer...the TPU squishes into the gap, centering the screw in the hole.
Done right, there should be no eletrical continuity between stepper body and panel. This indicates no metal-to-metal contact to transmit vibration.
Tighten the screws a little at a time to prevent tilting/binding.
Fan Spinners:
OK, these are for fun, but there is one important detail!
1) Hot-end fan is reversed to pull air through heat-sink, rather than blow air at it!
2) Slinging the fan and Spinner down-wind of the Parts Cooler adds to the cooling Mojo.
3) Inlet Spinner for 5015 fan does lower the RPM a bit, this demonstrates less intake turbulance, more air being delivered.
Air-Shovel™:
OK, you got me, t's an air-knife, but that name might be trademarked or something.
1) This part is NOT in final form.
Consider making the outlet ports a little 'taller'.
2) Air delivery is Laser-straight and goes exactly where pointed.
The 'fins' on the top surface are an induction-pump.
Air moving through the ports pulls air between the fins, moving much more air than what comes out the ports!
Bracket holes are a bit over-sized to allow for adjustment.
Air-shovel™ duct is glued onto 5015 fan using E6000
With the Cooler running, air all around printing-plate starts moving from right to left!
It makes its own prevaling winds!
3) 40mm width and spacing from nozzle covers diagonal 'fill' or 'skin' printing.
4) Miniatures are actually over-cooled (PLA printing matte instead of glossy), if that is a thing.
5) Brass nozzle is NOT being actively cooled...did I mention the air-flow was directional like a Laser?
6) Hot-end temps are more stable, not having to fight the Cooling fan.
Full print with 4x4x4 walls/top/bottom and 38% infil came to about 48g in weight.
Glue in lettering and spade. Star may need minor sanding but should push fit into the space tightly and not need anything else to secure it.