Commit 9b561532 authored by Jake Read's avatar Jake Read

cleanout and rename

parent 526c2de9
# Roller Milling
# Roller Coaster Milled Machines
Spent some time working this out on the whiteboard today, and threw together some rhino sketches.
Scratch / Landing page for the roller-bearings and 2d-sheet-stock axis system.
![mill](/images/rct-machine-00.jpg)
With RCT, we break axis into individual kinematic elements - and roll those elements into machine designs.
![wb](/images/wb-01.jpg)
![gantries](/images/one-two-three.gif)
I'm going for simple, strong-enough, and easy to build. Using rollers and pulleys, or, just as easily, rack and pinion or leadscrew-type actuation.
A reasonable system for beginners, and easy to manufacture (with another CNC mill). Particularely, this system begets the [Madison Park Vocational Machine](https://gitlab.cba.mit.edu/jakeread/mpvm)
Next up, getting into fusion to get through the details, then fabbing one axis... designing a simple 3axis machine, and fabbing that.
I pulled this off with a simple set of flat-milled parts - I was trying to work with the constraints present in the set of FREP and Milling tools in MODS, to see if we could finish end-to-end gantry generation and milling.
The result is OK, it'll certainly do - there's a line to toe between being kinematically wicked and loosing complexity. This is a bit of a midpoint - all of the axis of constraint have 'tuneability' in that their preloads can be adjusted, but all are over-constrained. There's enough (lots) flex in HDPE that this will be OK. There's a version which (not actually existing yet) is dead simple and totally constrained, and a version which is *perfect* motion-wise.
Overall, it's a bit bulky. There's some detailing left out before it is complete. But I think in terms of an all-arounder axis, this is pretty OK, and certainly OK for being millable from one sheet of HDPE (or alu, whatever).
![one-mill](/images/rob_rct_one.jpg)
![mill](/images/mpvm-v03.jpg)
## CAD
......@@ -82,44 +74,42 @@ filling in
## Hardware Notes
- needs more clearance on belt-side
- belt tensioning?
- when rounding corner, teeth must at some point disengage b/c different lengths
- same size M3 tensioning
### 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
Motor Idlers / Topside Way Bearings mount on M5 SHCS with washers on *both sides* and washers used as bearing shims. Use 3DP bushing (or purchased?) in axel. Important for carrying some moment to plate.
## Some Simulation
Clearances here for pulley to be mounted / tensioned! Consider order of assembly, tensioning.
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:
M5 Nuts 93625A200
M5 SHCS (length not selected) 91292A128
M5 Washers 93475A240
![onebar](/images/preload-sim.png)
also uses long M3's for tuning, nuts, washers. Length to be selected.
## ooooh
### Egregious Errors
- bottom rail extremely unhappy, should be smooth and sideways ways should be clear
![milling](/images/milling.jpg)
### Minor Errors
- missed a few holes in CAM, double check!
- y block internal boxing has co-dependent assy
- bearing bushings not satisfactory
- on double rollers, accomodate washer in between
- motor collar coule be +0.05mm in diameter
- need long M5 for motor -> bearing
- need bigger wall on captive nut for tuning
- need channel in side of motor collet for screw turning
- XZ situation has lots of unaddressed assembly issues
- add clamping features, hole access for final beam -> gantry assembly
- have to watch where bolt heads, bolts are - should include those in kinematic units modules
- y gantries should include two rollers in xy space (machine space) constraints
# BOM
## Some Simulation
## Machine
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:
- GT2 9mm Belts and 20T 1/4" Bore Pulleys https://www.amazon.com/Aluminium-Timing-Belt-Pulley-2GT/dp/B01COI0FEQ/
![onebar](/images/preload-sim.png)
## Spindle
## ooooh
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
![milling](/images/milling.jpg)
\ No newline at end of file
3DP:
Parts!
\ No newline at end of file
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' 015-1-8-bore-extra
SA
CN, 90
IF %(25)=1 THEN GOTO UNIT_ERROR
&PWMaterial = 0.375
&PWZorigin = Part Surface
' Countersink Unfuckery
C7
&Tool = 1
C9
TR, 12000
C6
PAUSE 2
JZ, 0.6
J2, 66.9093, 19.4085
J3, 66.9093, 19.4085, 0.6
J3, 66.9093, 19.4085, 0.2
MS, 0.9167, 0.9167
M3, 66.9093, 19.4085, 0.1
MS, 0.3333, 0.3333
M3, 66.9093, 19.4085, -0.175
M3, 66.9093, 19.4088, -0.1778
M3, 66.9093, 19.4098, -0.1804
M3, 66.9093, 19.4113, -0.1828
M3, 66.9093, 19.4132, -0.1848
M3, 66.9093, 19.4156, -0.1863
M3, 66.9093, 19.4182, -0.1872
M3, 66.9093, 19.421, -0.1875
MS, 0.9167, 0.9167
CG, , 66.8387, 19.421, -0.0353, 0, , -1
CG, , 67.028, 19.421, 0.0947, 0, , -1
CG, , 66.72, 19.421, -0.154, 0, , -1
CG, , 67.028, 19.421, 0.154, 0, , -1
M3, 67.0278, 19.4234, -0.187
M3, 67.0271, 19.4257, -0.1865
M3, 67.0262, 19.4275, -0.1852
M3, 67.0251, 19.4291, -0.1838
M3, 67.0231, 19.431, -0.1798
M3, 67.0223, 19.4315, -0.175
J3, 67.0223, 19.4315, 0.6
C7
END
UNIT_ERROR:
CN, 91
END
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