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@@ -44,6 +44,10 @@ I've also made a set of static blocks that can be configured to connect degrees
 
 ![](video/SEQ-rct-add-blk-enc.mp4)
 
+I'll also leave the chassis up to you. You can design it in Fusion, or Rhino, whatever you'd like.
+
+Of course, it's also fair game to do everything in Fusion and build a big parametric model (i.e. instances of parametric gantries could be imported to an assembly as components), if you'd like. Rhino is personal preference. 
+
 ### Modifications / Connections in Rhino
 
 ![](video/SEQ-rhino-modifications-enc.mp4)
@@ -83,11 +87,78 @@ While I cheat by using the CBA's Waterjet and Zund, there are a lot of ways you
 
  - atkapi hello worlding 
 
+# End Effectors
+
+I'm working on a few end effectors. You can grab some of these design files and fabricate them, or try designing your own. Here's the [simple spindle](https://gitlab.cba.mit.edu/jakeread/simplespindle):
+
+![spindle](images/ee-spindle.jpg)
+
+Hopefully to come:
+ - rotary tool w/ inserts a-la Zund
+ - Piezo Touch Probe 
+
 # Reference
 
 - [openassemblies](http://openassemblies.com)
 - [rct gantries](https://gitlab.cba.mit.edu/jakeread/rctgantries)
 
+# BOM 
+
+## Hardware ! per Axis ! For HDPE !
+
+Type | Size | QTY | Where Used | McMaster PN
+--- | --- | --- | --- | --- 
+Button Head Thread-Forming | No. 6, 3/4" | 10 + (4 * rail tab) (lots) | Connecting Lap and Tab HDPE, Belt Blocks, Chassis | 99512A265
+Button Head Thread-Forming | No. 6, 1/2" | 2 | Belt Blocks | 99512A259
+Flat Head Thread-Forming | No. 6, 3/4" | 8 | Flush Mounting HDPE | 95893A258
+SHCS | M3x40 | 2 | Used *only* when pre-loading bearing rollers | 91292A024
+SHCS | M3x30 | 2 | Used *only* when pre-loading bearing rollers | 91292A022
+Belleville Washer | 3.1mm ID | 24 | Used *only* when pre-loading bearing rollers | 96445K157
+Locknut | M3, Nylon | 6 | Used *only* when pre-loading bearing rollers | 90576A102
+SHCS | M5x10 | 1 | Connecting Nema 23 Motor | 91292A124
+SHCS | M5x16 | 3 | Nema 23 Motor through tensioning arcs | 91292A126
+Shoulder Screw | 8mm Shoulder x 8mm x M6 | 10 | Guide Roller Shaft | 92981A198
+Shoulder Screw | 8mm Shoulder x 16mm x M6 | 2 | Belt Guide Roller Shaft | 92981A202
+Bearing Shim | 8mm ID x 10mm OD x 1mm Thick | 38 | Roller Separation | 98089A381 
+
+## Purchase Parts 
+
+What | Spec | QTY | Where Used | Link
+--- | --- | --- | --- | --- 
+608ZZ Bearings | 8x22x7 | 14 | Rollers | [VXB 10](https://www.vxb.com/608ZZ-Shielded-8x22x7-Miniature-Bearing-Pack-of-10-p/608zz10.htm), [VXB 1000](https://www.vxb.com/Wholesale-Lot-of-1000-608ZZ-Ball-Bearing-p/608zz-wholesale.htm)
+GT2 Belt | 10mm Wide, Length Dependent | 2 | Belt! | [Amazon](https://www.amazon.com/Timing-Pulley-Teeth-6-35mm-Printer/dp/B07BS4DVR5/)
+GT2 Pulley | 10mm Wide, Motor Bore Diameter | 1 | Transmission! | [Above, Combo](https://www.amazon.com/Timing-Pulley-Teeth-6-35mm-Printer/dp/B07BS4DVR5/)
+Power Supply | 24v 350W Mean Well | 1 | Power ! | [Amazon](https://www.amazon.com/Enclosed-LRS-350-24-Meanwell-Switching-LRS-350Series/dp/B07BK27V4W/)
+Stepper Motor | NEMA23 x52mm | 2 | Torque ! | [StepperOnline](https://www.omc-stepperonline.com/hybrid-stepper-motor/nema-23-bipolar-18deg-09-nm-1275ozin-2a-36v-57x57x52mm-4-wires-23hs20-2004s.html)
+Stepper Motor | NEMA23 x76mm | 2 | Torque ! | [StepperOnline](https://www.omc-stepperonline.com/hybrid-stepper-motor/nema-23-bipolar-18deg-19nm-269ozin-28a-32v-57x57x76mm-4-wires-23hs30-2804s.html)
+
+## End Effector: Spindle
+
+What | Spec | QTY | Where Used | Link
+--- | --- | --- | --- | ---
+ESC | 40A 6S | 1 | Driving Motor | [Hobbyking](https://hobbyking.com/en_us/yep-40a-2-6s-sbec-brushless-speed-controller.html)
+Motor | 35-36 1800kV | 1 | Motor | [Hobbyking](https://hobbyking.com/en_us/propdrive-v2-3536a-1800kv-brushless-outrunner-motor.html)
+Collet Set | ER16 | 1 | Tool Holding | [Amazon](https://www.amazon.com/Engraving-Machine-Milling-Beauty-Star/dp/B0749FW9D5)
+Collet Holder | ER16x100L | 1 | Bedrock | [Amazon](https://www.amazon.com/a15060800ux0208-C12-ER11A-100L-Straight-Milling-Extension/dp/B012T6DQGM/) or [Ebay](https://www.ebay.com/itm/US-Stock-C12-ER16A-100L-Collet-Chuck-Holder-Straight-Shank-for-CNC-Milling/401225965058?hash=item5d6aee5e02:rk:5:pf:0)
+Spindle Pulley | GT2 40T 12mm Bore | 1 | Transmission | [Amazon](https://www.amazon.com/Orish-Alumium-Timing-Pulley-Synchronous/dp/B01H94CLCY/)
+Motor Pulley | GT2 20T 5mm Bore | 1 | Transmission | [Amazon](https://www.amazon.com/Qunqi-Aluminum-Timing-Pulley-Printer/dp/B01IMR6OR0/)
+Timing Belt | GT2 10mm Wide 75T / 100mm Loop | 1 | Transmission | [Amazon](https://www.amazon.com/RobotDigg-150-2gt-6-Endless-Length-Synchronous/dp/B07B5YK7J9/) or [Robotdigg](https://www.robotdigg.com/category/28/GT2-Endless-Belt)
+6001 Bearings | 12x28x8mm 2RS or ZZ | 2 | Spinning | [VXB](https://www.vxb.com/6001-2RS-Bearing-Deep-Groove-6001-2RS-p/6001-2rsbearing.htm)
+Belleville Disc Springs |  12.3x21.8x0.75 | 2-4 | Preload | [McMaster](https://www.mcmaster.com/94065k42)
+
+## Tools
+
+What | Where Used | Link or McMaster
+--- | --- | ---
+M3 Tap | Extensively for Aluminum Parts | 2673A71
+M5 Tap | Extensively for Aluminum Parts | 2673A74
+M6 Tap | Shoulder Bolts | 2673A75
+Countersink Bit | Flush Mounting | 27535A48
+Hex Driver Set Metric | Cannonical | 5709A18
+Torx Driver Set | Nice, Not Necessary | 6370A1
+Torx Drill Driver | 
+
+
 # FNs
 
 [^1]: Typically, CNC Machines - but ambitiously I would like to include most of robotics and automation here as well. 
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