Update on Stablebot!
Alright, time for another update!
I’ve been able to spend a few hours modeling, and have figured out most of the items for my first stablebot build.
Initial printable range is going to be a whopping 622x622x900mm! (~2’x2’ftx3’) This is including volume lost for extra-large hotends like a supervolcano, so real printable height for “standard” hotends will be closer to 1m.
The model is fully parametric, so once its ready for release I’ll be able to export BOM’s for many different sizes for customizing sizes based on needs.
Few more design choices I’ve worked through:
1) Z Axis
a. Triple Lead Screws+Motor
i. This is for triple-axis leveling as well as utter stability during printing – Z wobble be gone!
b. Kinematic Mounting (Ball Stud+Spring)
i. Simple, easy mounting!
c. 3 MGN12 Rails
d. 120V, 1500W heater
i. Redundant Thermistors
ii. Quick Heatup times
iii. PID Controlled with SSR
iv. Capable of 140C
v. Thermal cutoff fuse for safety
e. Bed Frame created by 20-2040 frame for rigidity, directly mounted and insulted by ½-1” of cork (Maybe, could go cork-less for enclosed printers, and use bed heater as enclosure-heated
f. No frigging compression springs
g. PEI+Spring Steel Sheet
a. Currently configured with the cable-driven toolchanger Jubilee head.
b. 2040 gantry member – Should be stiff enough for even driving in some subtractive loads/pressing inserts
i. Calculated deflection with a 1.5kg load in the center is ~.02mm (expected head weight is half that)
ii. Considerably heavy, so may not be able to achieve insane speeds, but without machining something custom, I believe that’s an acceptable compromise for such a large span.
iii. 6mm machined brackets to join the X axis to the linear rails.
iv. 10mm steel-core GT2 belts
a. 20-4040 for the Y-axis supports and Z-axis height
b. 20-2040 for connecting members
c. Z+Y Axis will be drilled+tapped for joints, with the cross members (running across X axis) joined with L-brackets. This is to give the most rigidity
d. Fully enclosable
i. Will use triple-wall polycarbonate sheets for insulation
ii. Will complete out frame with 2020 to cover top wiring and prevent warm air from escaping
iii. Top enclosure can include HEPA+Carbon filter as option
a. Back Panel will have all electronics, will be included on every printer
b. Front Panel will be 7” touchscreen hooked up to pi, running duet’s web interface
c. Will run Duet 3 with additional 3HC board for the tools.
i. This will give the capability of running up to nema23’s for the X+Y, to easily move the relatively heavy gantry.
1. Currently only planning nema 17’s for now, however.
d. 24v ATX power supply, controllable through power switch/pi
e. Independent power for Pi, to allow ATX control remotely.
f. 1-2 webcams for print monitoring
g. Physical End Stops
h. LED Lighting
As I creep my size (was originally shooting for 400x400x700) it got a touch more expensive. Known items in USD
Duet 3 - $230
Pi3b - $35
10m of 2040 - $100
~6m of 4040 - $165
1500w Sillicone heater - $260
Toolchanger - $260 for the jubilee
Tools - $120/ea from e3d
Power supply $55
Motion System Components from Zyltech-
· 3x MGN12, 1000mm Z-axis – $156
· 2x MGN12, ~770mm Y-axis - $124
· 1x MGN12 ~699mm X-axis - $62
· 3x T12 Leadscrew - $147
2020 Brackets $150
Aluminum+Machining/mechanical parts $200
Belts+Pulleys, Motors $80
Expansion board: $150
Yeah, oof. It will definitely get cheaper as I scale down, and if I stick to 300x300 or 400x400, it will as well as I can buy off-the-shelf heaters, smaller wiring, etc.
That’s all for this time! I’ve already recieved my Duet 3, and can’t wait to start ordering other parts.