Shopbot User Tips
From Pumping Station One
Post-Processors
When creating toolpaths for the PS1 Shopbot, there are now two distinct options:
- Shopbot TC_PS1(Inch) and Shopbot TC_PS1(mm)
- For general usage of the Shopbot (typically cutting)
- Shopbot TC_PS1-NO_SPIN(Inch) and Shopbot TC_PS1-NO_SPIN(mm)
- For dragging, engraving, and other tasks where the bit (may not actually be a bit) must not spin.
Be careful when creating a toolpath file that you select the right post-processor!
Positioning your work
Feeds and speeds
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<title>Cutting</title> </head> <body>
Cutting Speed
Drilling
Cutting Speed [CS] is based on Surface Feet per Minute [FPM or SFM].
RPM = (Cutting Speed(ft/min) x 12/1(in/fr))/Diameter of Cutter(in) x pi
RPM = (12CS)/(pixD)
| Material | Cutting Speed (FPM) |
| Low Carbon Steel | 90 |
| Alloy Steel SAE 4140 | 50 |
| Cast Iron | 70 |
| Aluminum | 300 |
| Drill Dia.(in) | Feed per Revolution(in) |
| under 1/8 | .001 to .002 |
| 1/8 to 1/4 | .002 to .004 |
| 1/4 to 1/2 | .004 to .007 |
| 1/2 to 1 | .007 to .015 |
| over 1 | .015 to .025 |
Example
1/2 in drill, Low Carbon Steel
Dia = 0.50
Material LCS : 90
RPM = 12CS/pi*D = 12*90/.5pi = 2160/pi = 687.5
Feed = .004-.007
| Answer: | 687.5 RPM |
| .004-.007 in. per Rev |
REAMING
Speed - 1/2 - 1/3 the speed for drilling
Feed - 2-3 times the feed for drilling
MILLING
RPM = (12CS)/(pixD)
Feedrate = RPMxfxn
n = number of teeth
f = feed per tooth
| Drill Dia.(in) | Feed per Revolution(in) | |
| Material | High Speed Steel | Cemented Carbide |
| Aluminum | 300-800 | 1000-2000 |
| Brass | 200-400 | 500-800 |
| Bronze | 65-130 | 200-400 |
| Cast Iron | 50-80 | 250-350 |
| Low Carbon Steel | 60-100 | 300-600 |
| Medium Carbon Steel | 50-80 | 225-400 |
| High Carbon Steel | 40-70 | 150-250 |
| Medium Alloy Steel | 40-70 | 150-350 |
| Stainless Steel | 30-80 | 100-300 |
Example - 0.50 in HSS two flute end mill cutting aluminum
RPM = 12CS/piD = 12x300/.5pi = 2292 RPM
RPM = 12CS/piD = 12x800/.5pi = 6112 RPM
Feedrate = RPMxfxn = 2292x.005x2=23 IPM
Feedrate = RPMxfxn = 6112x.005x2=61 IPM
| Cutter | Al. | Brass | Bronze | Cast | Low | Med | High | Stainless |
| Dia. | ---- | ----- | ------ | Iron | Carbon | Carbon | Carbon | Steel |
| ------ | ---- | ----- | ------ | ----- | Steel | Steel | Steel | --------- |
| 1/8 | .002 | .001 | .0005 | .0005 | .0005 | .0005 | .0005 | .0005 |
| 1/4 | .002 | .002 | .001 | .001 | .001 | .001 | .0005 | .001 |
| 3/8 | .003 | .003 | .002 | .002 | .002 | .002 | .001 | .002 |
| 1/2 | .005 | .003 | .003 | .0025 | .003 | .002 | .001 | .002 |
| 3/4 | .006 | .004 | .003 | .003 | .004 | .003 | .002 | .003 |
| 1 | .007 | .005 | .004 | .0035 | .005 | .003 | .003 | .004 |
| 1 1/2 | .008 | .005 | .005 | .004 | .006 | .004 | .003 | .004 |
| 2 | .009 | .006 | .005 | .005 | .007 | .004 | .003 | .005 |
| RPM Range: | 2292 - 6112 RPM |
| Feedrate Range: | 23 - 61 IPM |
