Heatbed design for mini kossels. It is slightly elevated above the base extrusions in order to keep the motors underneath as cool as possible. For the same reason, there's a 3mm cork mat sandwiched between the heater and base aluminum plate. Quick and dirty steady-state thermal simulations have shown that the bottom alu plate will be about 60°C with a bed heated to 110°C.
- It works very well in general, heatup times are below 1 minute
- 1 mm aluminum is on the lower end in terms of stiffness. If I redid this, I'd increase the metal to a least 2 mm
- Fits kossel mini
- Solid construction using lasered 1mm aluminum sheets
- thermal isolation towards the frame using ptfe tubing and PE washers for minimized heat loss and faster heatup times.
- Cork isolation under the heater to protect motors underneath
- Cut
alu_base
,alu_fixture
,alu_ring
from 1 mm aluminum sheet - cork, circular, diameter around 180mm
- kapton bed heater, 160mm diameter
- 3 pieces of ptfe tubing 6mm od, ideally 3mm id, 6mm long
- 3x M3x20 and nuts to fix the whole thing to your kossel, as well as three compression springs, approx. 6-9mm in height.
- Your choice of build platform, i.e. boro, regular glass, carbon. Diameter 170 mm
Check the exploded view and the pics to get a better idea.
- Align
alu_fixture
andalu_ring
, mark the cutout ofalu_ring
on the fixture. It helps to stackalu_fixture
andalu_ring
using M6 screws in the holes while doing this. - Glue your kapton heater on the marked alu_fixture
- Resolder the wires on the heater so that they point towards the heater's center. This way they'll go out nicely in the center hole of
alu_base
- Prepare cork circle, cut out a hole big enough to get the cables of the heater and thermistor through
- Prepare the screws and ptfe-tubing (see pics for washer detail), put everything together.
alu_fixture
with glued-on kapton heateralu_ring
- cork circle
alu_base
- Screw setup from top to bottom:
- M3 washer
- Plastic washer
- Into ptfe tube and through heatbed sandwich
- Plastic washer
- Spring
- Plastic washer
- Nut in extrusion