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At the CBA, we make a lot of our own tools. These are shared design elements and ideas that we use when we're spinning up custom machines: they're parametric, aim to be reconfigurable, and we can make them in the lab with a minimum set of stock hardware.
The goal is to provide a set of components from which most other automation equipment can be composed.
## Usage
This repository should help you figure out how to build your own axis: it contains some explanatory drawings, videos, as well as CAD files and Bills of Materials for various design elements.
A typical machine-wide workflow is described [for machineweek, at this link](https://gitlab.cba.mit.edu/jakeread/machineweek-2018).
[RCTN23-025ALU Fusion CAD File](cad/RCTN23-025ALU_v49.f3d)
In Fusion[^2], you can open this file up and use (from the top menu)
``` Modify >> Change Paremeters ```
Each of these models should have some parameters starred, these are what you'll want to configure. Go ahead and set axis lengths, material thicknesses according to what you're doing. When you're satisfied, you can export the model as a .step file, using the file menu, to prep it for fabrication.
``` File >> Export ```
Make sure to change 'type' to .step, and check the 'save to my computer' box.
Type | Size | QTY | Where Used | McMaster PN
--- | --- | --- | --- | ---
SHCS | M3x12 | 8 | Connecting Lap and Tab Aluminum, and Belt Blocks |
FHCS | M3x12 | 8 | Nice option for flush-mounting things |
SHCS | M3x35 | 2 | Used *only* when pre-loading bearing rollers | 91292A033
SHCS | M3x45 | 2 | Used *only* when pre-loading bearing rollers | 91292A025
Belleville Washer | 3.1mm ID | 12 | Used *only* when pre-loading bearing rollers | 96445K157
Locknut | M3, Nylon | 2 | Used *only* when pre-loading bearing rollers | 90576A102
SHCS | M5x10 | 1 | Connecting Nema 23 Motor |
SHCS | M5x16 | 3 | Nema 23 Motor through arcs |
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
### N23 / 0.25" ALU 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/)
Of course, you'll also need material. In this case, just 0.25" aluminum. I use 6061.
A list of the (perhaps) specialty tools you'll want to have to make this gantry:
Tool | Where Used | McMaster PN or Link
--- | --- | ---
M3 Tap | Extensively |
M5 Tap | Extensively |
M6 Tap | Shoulder Bolts |
Countersink Bit | Flush Mounting |
[RCTBLK-90-025ALU Fusion CAD File](cad/RCTBLK-90-025ALU_v6.f3d)
## Gantry for NEMA23 Motor, 0.375" HDPE
[RCTN23-025ALU Fusion CAD File](cad/RCTN23-0375HDPE_v2.f3d)
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
## Shared 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/)
Stepper Motor | NEMA23 x52mm | 1 | 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 | -or | Torque ! | [StepperOnline](https://www.omc-stepperonline.com/hybrid-stepper-motor/nema-23-bipolar-18deg-19nm-269ozin-28a-32v-57x57x76mm-4-wires-23hs30-2804s.html)
# REF
Find [Open Assemblies Hardware Reference](https://github.com/jakeread/openassemblies/blob/master/hardware.md) for shorthands etc.
# Jake's Notes
- gantries still want fully described end conditions / mounts
- belt tensioning / assembly video
- working examples on video