Here is an attempt to catelogue the various TAZ upgrades and modifications that currently exist. I have elected to leave Taz 1 and 2 specific modifications off the list as they are not compatable with 3 and Up machines for the most part. If you have a Taz 1 or 2 please consider upgrading it to 3 specifications at least.
If I missed your project, or you would like to see something added to the list, please feel free to post it in this thread and I’ll add it to the list.
Axis Retrofit
X axis Openrail Retrofit: https://forum.lulzbot.com/t/adding-an-openbuilds-openrail-x-axis-to-a-lulzbot-taz-4-5/1854/1
By: Piercet | Compatable with: TAZ 4, 5 | Status: Completed - pending directions writeup
Y axis Openrail Retrofit: https://forum.lulzbot.com/viewtopic.php?f=16&t=2426
By: Piercet | Compatable with: TAZ 3, 4, 5 | Status: Completed - pending directions writeup
Z axis Openrail Retrofit: https://forum.lulzbot.com/viewtopic.php?f=16&t=2524
By: Piercet | Compatable with: TAZ 3, 4, 5 | Status: Completed
Anti Wobble Z nut: http://www.thingiverse.com/thing:1089626
By: Piercet | Compatable with: TAZ 4, 5 | Status: Completed
Another anti Z wobble device: https://forum.lulzbot.com/viewtopic.php?f=16&t=2897
By: Sebastian | Compatable with: TAZ 4, 5 | Status: In Progress
Endstop Targets
Micrometer Endstp for Stock Taz 4/5: http://www.thingiverse.com/thing:1282759
By: Piercet | Compatable with: TAZ 4, 5 | Status: Completed - NEW 
Fans and Fan Ducts
Dual Duct Halo Taz 4: https://forum.lulzbot.com/t/dual-duct-halo-taz-4/1929/1
By: Open Edge Design | Compatable with: TAZ 3, 4 | Status: in progress
Improved TAZ Fan Duct: https://forum.lulzbot.com/t/improved-taz-fan-duct/658/1
By: American 3D Printing | Compatable with: TAZ 3, 4, 5 | Status: Completed
30/40mm Heat Sink Fan for Taz + Hexagon: https://forum.lulzbot.com/t/30-40mm-heat-sink-fan-for-taz-hexagon/1630/1
By: Wolfie | Compatable with: TAZ 5 | Status: Completed
dual extruder fan mount: https://forum.lulzbot.com/t/lulzbot-taz-dual-extruder-fan-mount/1027/1
By: 3dprintdaddy (Lulzbot Staff) | Compatable with: TAZ 3, 4, 5 | Status: Completed
TAZ Fan Duct Mk2: http://www.thingiverse.com/thing:147966
By: devzero | Compatable with: TAZ 3, 4, 5 | Status: in progress
Offical Lulzbot Extruder fan: http://devel.lulzbot.com/TAZ/accessories/extrusion_fan/
Lulzbot official upgrade | Compatable with: TAZ 3, 4, 5 | Status: Complete
Dual Extruder Dual Fan: http://devel.lulzbot.com/TAZ/accessories/icefish/
Lulzbot official upgrade | Compatable with: TAZ 3, 4, 5 | Status: In Progress
Lulzbot dual extruder double fan mount: http://www.thingiverse.com/thing:919415
By: jmillerid | Compatable with: TAZ 3, 4, 5 | Status: Completed
TAZ 5 Hexagon Left Side Fan Duct for dual fan ducts: http://www.thingiverse.com/thing:716002
By: jwantmys2000 | Compatable with: TAZ 4, 5 | Status: Completed
Belt Tensioners
X and Y Axis Belt Mounts with Adjustable Tension: https://forum.lulzbot.com/t/x-and-y-axis-belt-mounts-with-adjustable-tension/410/1
By: dt911 | Compatable with: TAZ 1 (partial) 2 (partial), 3, 4, 5 | Status: Completed
Taz X belt Tensioner Bolt On Retrofit: http://www.thingiverse.com/thing:438318
By: Piercet | Compatable with: TAZ 3, 4, 5 | Status: Completed
Fillament path
Fillament guide tube mount: https://forum.lulzbot.com/t/filament-guide-tube-restrainer-clip/1382/1
By: filipto | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Completed
fillament spool: https://forum.lulzbot.com/t/custom-filament-reel/1048/1
By: 3dprintdaddy (Lulzbot Staff) | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Completed
Filament Mount for Lulzbot TAZ: http://www.thingiverse.com/thing:804728
By: maker3121 | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Completed
Lulzbot Taz 5 Spool Arm: http://www.thingiverse.com/thing:855587
By: pvtkirsch | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Completed
Lulzbot Taz overhead spoolholder: http://www.thingiverse.com/thing:762831
By: grizzlyadams | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Completed
Dual Extruder Fillament Guide: https://forum.lulzbot.com/viewtopic.php?f=36&t=3319
By: KelVarnson | Compatable with: TAZ 4, 5 DUAL EXTRUDER ONLY | Status: Completed - NEW
Tools and Miscelaneous
X end counterweight: https://forum.lulzbot.com/t/more-apparently-level-bed-counter-weights/1722/1
By: Uptime | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Complete
Pen Plotter: https://forum.lulzbot.com/t/2d-printing-its-cooler-than-it-sounds/881/1
By: bam (Lulzbot staff) | Compatable with: TAZ 3, 4, 5 | Status: Completed
Pen Plotter #2: http://www.thingiverse.com/thing:637670
By: unclouded | Compatable with: TAZ 3, 4, 5 | Status: Complete
Paste Extruder: https://0x7d.com/2014/10/3d-printed-precision-paste-dispenser/
By: Kevin | Compatable with: TAZ 3, 4, 5 | Status: Complete
Etched glass build plate: https://forum.lulzbot.com/t/taz-4-stuff-projects/1028/1
By: printeverything | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Complete
Laser cutter conversion: https://forum.lulzbot.com/t/adding-laser-to-taz-5/1491/1
By: jtechphotonics | Compatable with: TAZ 3, 4, 5 | Status: Completed
Ninjaflex and PVA Spool Spacers for the TAZ Spool Arms: https://forum.lulzbot.com/viewtopic.php?f=36&t=2416
By: American 3D Printing | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Completed
Lulzbot TAZ Dial Indicator Mount: https://www.thingiverse.com/thing:551366
By: prstein | Compatable with: TAZ 3, 4, 5 | Status: Completed
Taz Bed level for short rear mount level gauges: http://www.thingiverse.com/thing:950610
By: Piercet | Compatable with: TAZ 3, 4, 5 | Status: Completed
TAZ Printer SD Card Holder: http://www.thingiverse.com/thing:898163
By: south2012 | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Completed
Taz Tool Caddy : http://www.thingiverse.com/thing:1080504
By: dbush | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Completed - NEW
Taz Bed Camera Mount : http://www.thingiverse.com/thing:1204616
By: dboitnot | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Completed - NEW
c270 camera arm : http://www.thingiverse.com/thing:1195929
By: hitnrun74 | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Completed - NEW
Lulzbot Filament Idler Tension Jig for TAZ and Mini : http://www.thingiverse.com/thing:1171976
By: ITWorks | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Completed - NEW
Taz top Spool Holder : http://www.thingiverse.com/thing:1099267
By: dbush | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Completed - NEW
Cable Pathing and Routing
Cable Carriers: https://forum.lulzbot.com/t/upgraded-taz-w-lulzbot-mini-parts-cable-carrier-chains/1186/1
By: Techsavvy34 | Compatable with: TAZ 3, 4, 5 | Status: Complete
Taz Y axis Cable Chain: http://www.thingiverse.com/thing:1145951
By: Piercet | Compatable with: TAZ 1,2, 3, 4, 5 | Status: Completed
Openbuilds X and Z Cable chains for Taz : http://www.thingiverse.com/thing:1277441
By: Piercet | Compatable with: TAZ Openbuilds X axis modification only | Status: Completed - NEW
Enclosures
HOT BOX 3DP ENCLOSURE SYSTEM (For Taz): https://forum.lulzbot.com/t/hot-box-3dp-enclosure-system-for-taz/1283/1
By: JonathanB | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Complete
Custom TAZ enclosure: https://forum.lulzbot.com/t/custom-taz-enclosure/172/1
By: benfarmer | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Complete
Lulzbot Catguard 9000: http://devel.lulzbot.com/TAZ/cat_guard/
Lulzbot official upgrade | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Catpleted
Lulzbot Taz 4 or 5 enclosure remix: Lulzbot Taz 4 or 5 enclosure remix
By: billyd | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Complete
Extruder Modifications
Bowden and E3Dv6: https://forum.lulzbot.com/t/bowden-version-of-e3d-v6-for-use-with-taz4/1777/1
By: sstantz | Compatable with: TAZ 3, 4, 5 | Status: In Progress
E3D Volcano mount: https://forum.lulzbot.com/t/e3d-valcano-hotend-toolhead-print-w-bigger-layers/1138/1
By: Techsavvy34 | Compatable with: TAZ 3, 4, 5 | Status: In Progressv
TAZ 5 Strengthened Hexagon Extruder Body: http://www.thingiverse.com/thing:755184
By: wantmys2000 | Compatable with: TAZ 5 | Status: Completed
Heavy duty herringbone gears for Taz: https://forum.lulzbot.com/t/heavy-duty-herringbone-gears-for-taz/870/1
By: mar363636 | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Completed
Toolhead for 1.75mm filament: http://devel.lulzbot.com/TAZ/accessories/fangtooth_guppy/
Lulzbot official upgrade | Compatable with: TAZ 5 | Status: Unknown
Flexystruder: http://devel.lulzbot.com/TAZ/accessories/flexystruder/
Lulzbot official upgrade | Compatable with: TAZ 1, 2, 3, 4 | Status: Completed
E3D V6 1.75mm mount: https://forum.lulzbot.com/viewtopic.php?f=36&t=2384
By: caenan | Compatable with: TAZ 3, 4, 5 | Status: Completed
Strengthened Extruder for Mangrove Mount: http://www.thingiverse.com/thing:1149597
By: discojohn | Compatable with: TAZ 4, 5 | Status: Completed
Flexystruder V2: http://devel.lulzbot.com/TAZ/accessories/kanyu/
Lulzbot official upgrade | Compatable with: TAZ 5 | Status: Completed
An Improved Flexible Filliment Extruder: http://www.thingiverse.com/thing:1201229
By: Piercet | Compatable with: TAZ 5 | Status: Completed
Extruder Carriage Modifications
Reinforced and Altered Taz extruder mount: http://www.thingiverse.com/thing:1113697
By: Piercet | Compatable with: TAZ 4, 5 | Status: Completed
Multi Extruder Modifications
Paralell printing: https://forum.lulzbot.com/t/taz-parallel-printing/402/1
By: bam (Lulzbot staff) | Compatable with: TAZ 3, 4, 5 | Status: Completed
Dual Extruder: https://ohai-kit.alephobjects.com/project/taz4_dual_extruder/
Lulzbot official upgrade | Compatable with: TAZ 3, 4, 5 | Status: Completed
Unischnozzle (I think it’s a dual extruder head: http://devel.lulzbot.com/TAZ/accessories/mako/
Lulzbot official upgrade | Compatable with: TAZ 3, 4, 5 | Status: Who knows?
Taz Kracken Mount: http://www.thingiverse.com/thing:243927
By: mfuqua | Compatable with: TAZ 3, 4, 5 | Status: In Progress
Double E3D v6 mount for TAZ : http://www.thingiverse.com/thing:1248309
By: rvasilchenko | Compatable with: TAZ 4, 5 | Status: Completed - NEW
Bed and Bed Leveling
Mini style resistive leveling: https://forum.lulzbot.com/t/upgraded-taz-w-lulzbot-mini-parts-cable-carrier-chains/1186/1 / https://forum.lulzbot.com/t/update-video-of-taz-auto-bed-leveling-mod-based-on-taz-mini/1063/1
By: Techsavvy34 | Compatable with: TAZ 3, 4, 5 | Status: Completed
Capacitive Auto leveling: https://forum.lulzbot.com/t/capacitive-auto-leveling-on-taz-5/1730/1
By: vitormhenrique | Compatable with: TAZ 3, 4, 5 | Status: Completed
Manual wingnut modification: https://forum.lulzbot.com/t/a-little-mod-to-make-bed-leveling-easier/1610/1
By: gghouck | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Completed
LULZBOT TAZ-4 3D PRINTER platfrom leveling screws: http://www.thingiverse.com/thing:627331
By: margok | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Completed
Ninja Plate Riser Kit for Lulzbot TAZ: http://www.thingiverse.com/thing:444860
By: truncie | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Completed
LulzBot Taz precision Z Optical endstop: http://www.thingiverse.com/thing:506359
By: lucibrandus | Compatable with: TAZ 3, 4, 5 | Status: Completed
Larger Corners for Mounting 3/16" Aluminum Heated Bed: http://www.thingiverse.com/thing:1098784
By: Piercet | Compatable with: TAZ 3, 4, 5 | Status: Completed
Mini style Nozzle Wiper for Taz : http://www.thingiverse.com/thing:1261303
By: Piercet | Compatable with: TAZ 4, 5 (Hexagon or E3dV6 Hotend) | Status: Completed - NEW
Lulzbot Taz 4 or 5 Removable Build Bed Upgrade : http://www.thingiverse.com/thing:1021403
By: Billyd | Compatable with: TAZ 4, 5 | Status: Completed - NEW
Structure
Taz frame corners: https://forum.lulzbot.com/t/taz-frame-connectors/147/1
By: elgullitch | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Completed
Taz 3 and below Extra print height modification: https://forum.lulzbot.com/t/taz-12mm-extra-x-axis-travel-parts/150/1
By: 1013 | Compatable with: TAZ 1, 2, 3 | Status: Completed
Taz 4/5 stiffened plastic X end plates: https://forum.lulzbot.com/t/taz-3-1-4-0-stiffened-x-ends/784/1
By: chiphead | Compatable with: TAZ 4, 5 | Status: Completed
Taz Y-axis Raised Stepper Mount: http://www.thingiverse.com/thing:1178068
By: billyd | Compatable with: TAZ 3, 4, 5 | Status: Completed
Lighting and LED Status indicators
Color shift LED status indicator lights: https://forum.lulzbot.com/t/add-status-indicator-leds-to-your-taz/1741/1
By: Piercet | Compatable with: TAZ 3, 4, 5 | Status: Completed
Taz Lightbars: http://www.thingiverse.com/thing:1277735
By: Piercet | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Completed
USB Powered Printer Lighting for Lulzbot Mini (or others) Using Eveready LED Flashlight : http://www.thingiverse.com/thing:892007
By: hemocyanin | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Completed
Adding Filliment width and outage sensors to a TAZ: https://forum.lulzbot.com/viewtopic.php?f=16&t=2645
By: Piercet | Compatable with: TAZ 3, 4, 5 | Status: Just Starting
Remote Printer Control Modifications
Taz 4/5 Raspberry pie add on case: http://www.thingiverse.com/thing:685585
By: arachno7| Compatable with: TAZ 4, 5 | Status: Completed
Taz Pie Camera: http://www.thingiverse.com/thing:168581
By: devzero | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Completed
Taz Rambo Raspberry Pie retrofit: http://www.thingiverse.com/thing:161302
By: devzero | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Completed
TAZ5 - PIP Swivel Camera Mount (GoPro-style): https://www.thingiverse.com/thing:949219
By: kcchen_00 | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Completed
Raspberry Pi extension cover Remix: http://www.thingiverse.com/thing:709868
By: discojon | Compatable with: TAZ 1, 2, 3, 4, 5 | Status: Completed
Camera for Taz 4/5: https://forum.lulzbot.com/viewtopic.php?f=36&t=3086&p=19210#p19154
By: Menissalt | Compatable with: TAZ 4, 5 | Status: Completed
Enclosure Temperature / Fan / Light Control - Octoprint Plugin: https://forum.lulzbot.com/viewtopic.php?f=16&t=2925
By: vitormhenrique | Compatable with: TAZ 4, 5 | Status: Completed
Lulzbot Taz LCD + Raspberry Pi Case: http://www.thingiverse.com/thing:1215279
By: Scuttlebot | Compatable with: TAZ 2, 3, 4, 5 | Status: Completed
General Upgrade and Information
Upgrading a Taz 3 to a 4/5: https://forum.lulzbot.com/t/ground-up-restoration-taz3-to-taz5/1900/1
Thread by: CWAVE6K
Marlin 1.1 Firmware upgrades for Taz 5: https://forum.lulzbot.com/viewtopic.php?f=18&t=2136&p=17555#p17555
Thread by: Sebastian
Projects coming soon or in planning
Taz 6 - Project nutmeg: devel.lulzbot.com/TAZ/nutmeg
Lulzbot official project - Please note, this replaces Project Kauri. Pictures of the previous prototype, which should be similar are in the mangrove folder.
If any of you also have projects in the works, please let me know so I can include them here as well
