This modification adds Openrail extrusions in place of the existing Lulzbot Taz 4 or 5 smooth Z rod. I will post a parts list soon. It basically just needs 8 of the mini wheels, with 4 mini wheel eccentrics and 4 6mm spacers. Extrusions are 20mm x 20mm openrail 500mm extrusions, stock. You will also need some T slot nuts (m5, I recommend the Dropin ones for this) 4 spacers and longer M5 bolts to move the control box out fromt he frame to clear the wheels, and several longer M3 bolts. THis project also has an option to replace the existing stock heat set insert based Z endstop with a full on Micrometer body, which I highly recommend.
Edit: Uploaded a new version of the bearing carriage. This version has sufficient clearance to work with my new Anti wobble nut project. If you dio not intend to fit that project, the older version is fine. The anti wobble Z nut mount project may be found here: http://www.thingiverse.com/thing:1089626
Edit 2: wobble clearance block with passthrough slot for the Z endstop cable now uploaded.
Edit 3: Cabel routing top cover option now uploaded. The sum difference of that part and prior versions is the cable chase segment on the side for routing front to back. This is mainly useful for adding lightbars or sensors on top of the gantry.
printed with 0.50mm nozzle
You want a pretty dense infil for these as they will be structural. I would not recommend PLA for this application. The Z motor brackets and top plates are quite large and cannot be printed on a mini.
It appears Thingiverse ate my origional instructions section. Will need to rebuild it later. For now here's the Bill of materials
Z axis Bill of Materials
6 M5 heat set inserts http://www.mcmaster.com/#94180a361/=zhts4o
4 3/16" 1 and 3/4" long steel shafts (locally sourced from Ace Hardware)
8 Igus 2MTRI MYI-03-03 Flanged Bearing, 3/16" IDx 3/16" L (ebay)
8 1/4" threaded nylon spacers, at least 1/2" length
8 bolts that will fit the threaded nylon spacers
Openbuilds Z axis:
8 Xtreme Mini V Wheel™ Kit http://openbuildspartstore.com/xtreme-mini-v-wheel-kit/
8 30mm Low profile head M5 bolts http://openbuildspartstore.com/low-profile-screws-m5/
2 20mm x 20mm x 500mm Openbuilds V slot extrusions http://openbuildspartstore.com/v-slot-linear-rail/
4 6mm eccentric spacer http://openbuildspartstore.com/eccentric-spacer/
4 6mm solid spacer http://openbuildspartstore.com/aluminum-spacers/
8 12mm long thread m3 cap head bolts
18 M5 10mm Cap head bolts (the support braces require 3 each, for double bracing, add 6 bolts and T-nuts)
22 additional M5 T-nuts (I reccommend the drop in ones for these, they make it considerably easier
12mm long Cap low profile cap head bolts (M5) for securing control box spaced out to clear boltheads
1 M5 heat set insert if you will not be doing the micrometer upgrade
12 M5 washers
Stock parts that will be reused:
The Z height set bolt spring assembly
The existing M5 bolts, washers, and T-nuts that secure the stock Taz 5 Motor mounts, and upper leadscrew mounts to the chassis frame