Geeetech G2s Upgrades v2 by LuckyPants

Last crawled date: 3 years, 1 month ago

This is version 2 of my upgraded G2s (version 1 http://www.thingiverse.com/thing:2020086) - basically a full overhaul of everything but the top/bottom plates and the linear rods. It is a continuation of trying to make my G2s the best it can be (not really a G2s anymore at this point i guess!).
Quick summary of upgrades:
Custom Carriages.
Magnetic Arms.
Custom Effector.
E3D Cyclops 2in-1out Hotend - or - E3D v6
Part Cooling Fan.
Greg’s Wade Geared Extruders.
Optical Endstops.
Duet Wifi electronics.
7” PanelDue interface.
Increased usable print diameter and height (Ø200mm x 210mm height).
Issues with the G2s:

Motion slop
a. Delta arms have play and design limits ability to accurately calibrate length.
b. 2 bearing carriages have excessive play and torque from the arms causes them to pitch up, having significant influence on the end effector.
c. Design of the stock end effector has the effector center of mass below the rod link locations, which will cause effector tilt and unwanted movement during acceleration/jerk moves.


Hotend performance
a. Stock hotend is difficult to level and reduces usable bed size.
b. Dual nozzle configuration suffers when effector tilt occurs.
c. No part cooling fan included.


Extruder performance
a. The direct drive extruder is ok, but the hobbing on the drive gear is a bit shallow, and the force on the filament could be a bit stronger to handle higher print and retraction speeds. It is likely ok for stock setup, but will not be sufficient once other components are upgraded.


Probing performance
a. Microswitch probe must be manually deployed, sometimes binds in bore causing unrepeatable measures.


Electronics
a. GT2560 board is not capable of driving the axes past ~80mm/sec. Studdering occurs at higher speeds. Interpolation is broken into segments that are too large for higher speed movement.
b. Included limit switches are acceptable, but not repeatable enough to make probing and really dialing in the delta parameters worth it, as each G28 throws it off here or there.

Lighting
a. None!
My solutions to those issues:

Motion slop
a. Haydn’s magnetic arms (http://www.blueeaglelabs.com/products/haydns-carbon-fiber-arms-with-cnc-precision-machined-delrin-sockets). Mine came accurate in length to .01mm.
b. Complete redesign of carriages to accept 4 LMU-N10 bearings (https://us.misumi-ec.com/vona2/detail/110300026540/?HissuCode=LMU-N10) and the mag arms. Carriages work with stock microswitch endstops or optical endstop upgrade.
c. Rather that adapt the stock effector to fit the mag arms, I designed a new one. This effector design is much more modular and makes creating addons easy.
d. With below hotend, center of mass is aligned to mag arm spheres to resist effector tilt.


Hotend performance
a. 2in-1out hotend (http://e3d-online.com/Cyclops), retain dual extrusion ability but without the loss of bed area or difficulty in levelling. Also available with E3D v6 configuration.
b. Influence of effector tilt is greatly reduced with a single nozzle centered on the effector.
c. Integrated part cooling fan into hotend mount.


Extruder performance
a. I ordered 2 of the Greg's Wade Extruder hardware kit at (https://www.ultibots.com/gregs-wade-extruder-hardware-kit/), and printed 2 sets of the extruder parts - 1 regular and 1 mirrored (http://www.thingiverse.com/thing:18379). In order to fit in the location of the original, you need to mirror one of the extruders. In doing so you need to reverse the hobbed bolt - to get the hobbed portion of the bolt aligned with the feeder tube, you'll need the included spacer. In addition, the attached gear has a deeper relief to accept the bolt in the mirrored extruder. Any questions on this let me know.


Probing performance
a. Force Sensitive Resistor (FSR) probing system (https://www.ultibots.com/fsr-kit/).
b. FSR’s live under the bed and probing is done directly when the nozzle contacts the bed. They are not affected by choice of bed (glass/non-conductive/etc).


Electronics
a. Duet Wifi (https://duet3d.com/DuetWifi). Tons of processing HP to deal with the calculations needed to drive a delta bot. Firmware configuration is very easy and powerful. Program transfer and machine control via WiFi through the web interface is awesome. Interpolating at 300mm/s with no issues.
b. PanelDue (https://miscsolutions.wordpress.com/paneldue/). 7” touchscreen that allows easy control of the bot, plus a nice menu to execute custom macros for filament loading/probing/etc.
c. Optical endstops (http://www.ebay.ca/itm/282247383661). Plenty on eBay if you search “RAMPS 1.4 Optical Endstop”. Enstops are shielded from sunlight interference in a protective housing.

Lighting
a. Enclosure mounted LED’s for overall interior lighting.
b. Effector mounted LED’s for part lighting.
c. LED brightness controllable by M code.