Shopbot User Tips

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!

Feeds and speeds

Spindle Speed

The Shopbot does not appear to pick up spindle speed instructions unless you have first opened up the Spindle RPM Control menu (under Tools):

My speeds aren’t changing on my Spindle when I run the warm-up routine and during cut files. What is the problem?

• Note: On ShopBot desktops and MAX, the RPM must be manually adjusted.

The Spindle RPM Control window needs to be open in order for the spindle to change speed. If you see this window pop up during the warm-up routine or software start-up, do not close it. To open it manually, type TR in the ShopBot console (the blank box next to the ShopBot CNC logo). Click on RPM to open the fill-in sheet, and make sure that the correct VFD is selected. Start when SB3 start is set to 1, and the Hz scale is set to 60 for a V1000 spindle and to 100 for a 74X spindle.

The RPM Control window is not available on software versions earlier than 3.6.X.

Perhaps the fact that this can be done via console means that it could also be added to Gcode files by the post-processor? I'm not really sure. I did just notice this, though, a bit lower down in the FAQ:

I want the RPM Control Window to open every time I start ShopBot 3

This can be accomplished in one of two ways:

1) ...blah blah blah...

2) Navigate to C:\Program Files (x86)\ShopBot\Virtual Tools. Open this file with a text editor like Notepad or SBEdit. Edit this one line of code:

VT = Spindle [&R]PM Control, Virtual Tools\Spindle Control\Spindle Control.exe, 0, 0

Change the last number, which is a zero, to one. It will now look like this:

VT = Spindle [&R]PM Control, Virtual Tools\Spindle Control\Spindle Control.exe, 0, 1

Save the file, close and reopen the SB3 software to see the changes take effect.

This needs to be done only once for your Shopbot login.

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 and Cutting Feed

Material	Cutting Speed (FPM)
Low Carbon Steel	90
Alloy Steel SAE 4140	50
Cast Iron	70
Aluminum	300

Drilling Feeds

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

Recommended Feed and Speed Rates

RPM = (12CS)/(pixD)

Feedrate = RPMxfxn
n = number of teeth
f = feed per tooth

Cutting Speed

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

Feeds for End Mills (feed per tooth)

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

Answer:

RPM Range:	2292 - 6112 RPM
Feedrate Range:	23 - 61 IPM