Roller Coaster Milled Machines
Scratch / Landing page for the roller-bearings and 2d-sheet-stock axis system.
With RCT, we break axis into individual kinematic elements - and roll those elements into machine designs.
A reasonable system for beginners, and easy to manufacture (with another CNC mill). Particularely, this system begets the Madison Park Vocational Machine
CAD
Available Here: https://a360.co/2qQf6wf
password is rollercoaster
The gantry is built with a set of 'kinematic elements' - a Motor / Pulley Unit, Lateral (into the gantry) and Cross (across the gantry) supports:
These can be jimmied around to make a full set of constraints:
And combined into a complete gantry:
Here's the back of that:
Kinematic Bits
Currently the set assumes 3/8" HDPE, 8x22x7mm bearings, NEMA23 Motors and 9mm Wide GT2 Belts
Version for 1/4" HDPE, 5x11x4mm bearings, NEMA17 Motors and 6mm Wide GT2 Belts.
See cad/assembly/elements/ for kinematic elements, and cad/assembly for one-machine made with these elements.
Motor and XY Constraint:
XY Constraints, with preload adjusting and without:
YZ Constraints ('out of plane'):
Assembling in Rhino
or
filling in
Hardware Notes
CAM
- write down settings from fusion, all is good for full cut but go to 12.7krpm
- do 1st pass at holes, screw down from there. no tabs then ... much happier joints
- don't forget bushing in 3dp set
Some Simulation
It occured to me in class today (Rob Hart fabricated the below component!) that the two-bar flexure I had intended was acting much more like a one-link flexure. Whoops, all well. Still does its job. Here's an image of that in any case:
ooooh
BOM
Machine
- GT2 9mm Belts and 20T 1/4" Bore Pulleys https://www.amazon.com/Aluminium-Timing-Belt-Pulley-2GT/dp/B01COI0FEQ/
Spindle
ER16-C12-L100 Collet Holder (confirm?)
2x 6001-2RS Bearings (confirm?)
GT2 Pulley 5mm Bore 20T GT2 Pulley 12mm Bore 40T GT2 Belt 75T 150L (confirm?)
4x SHCS M3x10 1x SHCS M3x20 4x M3 Washer 1x M3 Locknut 3x FHCS M2.5x8
3DP: Parts!