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-- Short Term Goals --
- replace all STLs with OpenSCAD files
-- Medium Term Goals --
- improve parameterization
- move all defined constants into mendel.conf
- consolidate modules in
- re-use constants and modules wherever possible
- create commented pre-defined configurations of the mendel in mendel.conf for easy selection of a few major variants
-- Long Term Goals --
- improve servicability
- re-design parts to allow any individual part to be removed without requiring significant disassembly
- modify parts for easy tool access after installation
-- Individual Items --
- fix vik's fudging of various hole diameters
- unify z leadscrew base, z motor bracket, and z tensioner bracket files - optionally render as individual or combined parts
- parameterize foot height on frame vertex, and make middle three holes optional
- merge x carriage upper and lower with modified bfb versions
- thin the X vert drive side plate 180 a bit, to reduce X axis guide rod bending
- add nut trap void to x vert side plate 180, eliminate nut trap jig part.
- de-couple the Z drive trapped nut a bit, to dampen drive rod wobble
-- Additions from fen for mini-mendel --
z axis rod clamp is not the same spacing as other 6mm clamp arch thingies
clamp arch thingies should accept 20mm m3 shcs
clamp arch thingies are too small for 6mm rods
clamp arch thingies should work with 20mm m3's, and have hexagon nut holders
90 degree thingies should only need 1 clamp screw each
y front clamp thingy screws interfere with nema 17 motor
enlarge 22mm holes in motor connector interfaces to accomodate larger pulley hubs + set screws sticking out
reduce number of 30mm m3's to <50 qty
eliminate 12mm m3's
z axis 180 should be 1 piece.. shouldnt need washers to offset the bearings
move z 180 side leadscrew closer to smooth z rod, to increase x travel
space for washer on z 360 piece. reengineer z 360 assy to not need threaded rod
add holes for nema17 on x y z
z nut traps only need 4 screws, two on the outside, and front and back of the screw
get rid of nut traps on y chassis
fix misaligned counterbore on x carriage
get rid of counterbores on x carriage, switch to hexagons
x-carriage hexagon should be symmetrical (two less holes? what are they for?)
x carriage triangular lumps may interfere with bearing next to it
x carriage triangular lumps need nut bearing surface on opposite side
x carriage needs a little more stiffness (thickness at thinnest part)
x carriage diagonal 30mm m3's interfere with vertical 20mm's (barely)
x carriage should be symmetrical distance from rods or belt will rub on backside
x carriage only needs one vertical 360 bearing and should have outer diagonals on ends (wider wheelbase = more rigidity against racking forces)
speaking of racking forces, belt clamp should be more central (offset motor, huge redesign of x axis)
belt clamp should have same spacing as arch thingies
y 360 sliders are too wide for 30mm m3+two nuts + lock washer (barely) (+two washers would be nice)
only need 2 y 180's, not 4
true kinematic design would use less bearings
lower y axis somehow, it's too much clearance between bottom of y and bottom of machine, i.e. switch z tension rods+frame rods
purge plate gets really close to y motor bracket
wtf is purge plate for??
need more 623 bearings in BOM
should have adjustable (spring?) tension idlers for x and y belts
y idler washers overlap < 1mm
z has way too many idler pulleys (should have like one tensioner and that's it)
z leadscrew blocks are too tall for 30mm to comfortably fit idlers
use timing pulley for y idler instead of smooth?
nophead pulley needs counterbore for m3 shcs head, or switch to clamp configuration instead of set screw
y motor bracket doesn't clear nophead pulley base
brackets shouldn't have full circle holes, should be slots for easy removal, or clamps
something's fucked up with the y axis belt - the top half of the loop makes a triangle instead of a line, this causes tension changes (oops my frog was on upside down, this could be clearer in the docs)
y (and x?) belt clamp don't work with m12's (maybe this is ok)
you really do need to use lock nuts on the frame pieces <- hmm. maybe not
#12 SAE lock washers don't fit on M6 threaded rod, FYI
some measurements:
x travel: 126mm
y travel: 154mm <- more like 145mm because of some belt tension weirdness at the motor end
10 washers on each idler pulley; could be reduced with 20mm's and jamb nuts instead
x idler pulley to bar: 8mm
x carriage clamp face to bar: 17mm
x carriage opposite face to bar: 20mm
x blunt plate:
width: 54mm
height: 24mm
thickness: 4mm
horizontal hole spacing: 46.5mm
vertical hole spacing: 14mm
hardware used: (first count)
m3x30: 39
m3x20: 70
m3x12: 18? 24?
m6 nut: 88
m6 washer: 74?
m3 fender washer:
m3 washer:
m3 lock washer:
existing stepper hookup:
sync sync enable max min dir step gnd