I was thinking you mean in the post processor.  Anyway it's a bummer that the code will end up so long from the spirals but at least it works and clears up some of my confusion.  Thanks for the help.

To recap for future inquiries attached are the settings to use with RhinoCAM with incremental arcs.

Toolpath with a helix, spirals, and circular arcs:


RhinoCAM:
Output Spiral motions as linear segments checked.


Post Processor:
set arc format to Vector from Center to Start (incremental)
delete K and Q words from the block format of Spiral and helix




Mach3:
Check arc format as incremental


Here is the Gcode produced with these settings:

G00 G49 G40.1 G17 G80 G50 G90
G20
(Hole Pocketing)
M6 T3 G43 H3
S5000M03
G00Z0.2500
X0.1250Y-0.0002
G01Z-0.2960 F7.3
G17
G03Z-0.5473I-0.1250J0.0002 F10.0
G01X0.1327Y0.0231
X0.1358Y0.0491
X0.1336Y0.0768
X0.1257Y0.1051
X0.1118Y0.1328
X0.0920Y0.1586
X0.0664Y0.1813
X0.0356Y0.1996
X0.0004Y0.2125
X-0.0382Y0.2189
X-0.0789Y0.2181
X-0.1204Y0.2095
X-0.1612Y0.1929
X-0.1997Y0.1682
X-0.2343Y0.1359
X-0.2634Y0.0964
X-0.2858Y0.0509
X-0.3000Y0.0006
X-0.3051Y-0.0532
X-0.3004Y-0.1087
X-0.2854Y-0.1640
X-0.2600Y-0.2173
X-0.2246Y-0.2666
X-0.1797Y-0.3100
X-0.1265Y-0.3456
X-0.0663Y-0.3719
X-0.0007Y-0.3875
X0.0682Y-0.3913
X0.1385Y-0.3827
X0.2076Y-0.3612
X0.2735Y-0.3271
X0.3335Y-0.2810
X0.3857Y-0.2236
X0.4278Y-0.1566
X0.4580Y-0.0817
X0.4750Y-0.0009
X0.4782Y0.0428
X0.4773Y0.0870
X0.4723Y0.1314
X0.4631Y0.1756
X0.4498Y0.2192
X0.4323Y0.2618
X0.4108Y0.3030
X0.3854Y0.3425
X0.3561Y0.3798
X0.3232Y0.4146
X0.2869Y0.4466
X0.2474Y0.4753
X0.2051Y0.5005
X0.1602Y0.5220
X0.1131Y0.5393
X0.0642Y0.5524
X0.0138Y0.5611
X-0.0376Y0.5650
X-0.0896Y0.5643
X-0.1418Y0.5587
X-0.1937Y0.5483
X-0.2449Y0.5330
X-0.2949Y0.5129
X-0.3432Y0.4882
X-0.3895Y0.4588
X-0.4332Y0.4250
X-0.4740Y0.3871
X-0.5114Y0.3452
X-0.5451Y0.2997
X-0.5748Y0.2509
X-0.6000Y0.1992
X-0.6206Y0.1450
X-0.6362Y0.0887
X-0.6467Y0.0307
X-0.6519Y-0.0285
X-0.6516Y-0.0883
X-0.6459Y-0.1483
X-0.6345Y-0.2080
X-0.6176Y-0.2669
X-0.5952Y-0.3244
X-0.5675Y-0.3800
X-0.5345Y-0.4332
X-0.4966Y-0.4836
X-0.4538Y-0.5306
X-0.4066Y-0.5738
X-0.3553Y-0.6128
X-0.3003Y-0.6471
X-0.2419Y-0.6765
X-0.1806Y-0.7006
X-0.1170Y-0.7192
X-0.0514Y-0.7319
X0.0154Y-0.7386
X0.0831Y-0.7392
X0.1510Y-0.7335
X0.2173Y-0.7175
G03X-0.2173Y0.7175I-0.2173J0.7175
X0.2173Y-0.7175I0.2173J-0.7175
G01X0.1250Y-0.0002
G03Z-0.7737I-0.1250J0.0002
G01X0.1327Y0.0231
X0.1358Y0.0491
X0.1336Y0.0768
X0.1257Y0.1051
X0.1118Y0.1328
X0.0920Y0.1586
X0.0664Y0.1813
X0.0356Y0.1996
X0.0004Y0.2125
X-0.0382Y0.2189
X-0.0789Y0.2181
X-0.1204Y0.2095
X-0.1612Y0.1929
X-0.1997Y0.1682
X-0.2343Y0.1359
X-0.2634Y0.0964
X-0.2858Y0.0509
X-0.3000Y0.0006
X-0.3051Y-0.0532
X-0.3004Y-0.1087
X-0.2854Y-0.1640
X-0.2600Y-0.2173
X-0.2246Y-0.2666
X-0.1797Y-0.3100
X-0.1265Y-0.3456
X-0.0663Y-0.3719
X-0.0007Y-0.3875
X0.0682Y-0.3913
X0.1385Y-0.3827
X0.2076Y-0.3612
X0.2735Y-0.3271
X0.3335Y-0.2810
X0.3857Y-0.2236
X0.4278Y-0.1566
X0.4580Y-0.0817
X0.4750Y-0.0009
X0.4782Y0.0428
X0.4773Y0.0870
X0.4723Y0.1314
X0.4631Y0.1756
X0.4498Y0.2192
X0.4323Y0.2618
X0.4108Y0.3030
X0.3854Y0.3425
X0.3561Y0.3798
X0.3232Y0.4146
X0.2869Y0.4466
X0.2474Y0.4753
X0.2051Y0.5005
X0.1602Y0.5220
X0.1131Y0.5393
X0.0642Y0.5524
X0.0138Y0.5611
X-0.0376Y0.5650
X-0.0896Y0.5643
X-0.1418Y0.5587
X-0.1937Y0.5483
X-0.2449Y0.5330
X-0.2949Y0.5129
X-0.3432Y0.4882
X-0.3895Y0.4588
X-0.4332Y0.4250
X-0.4740Y0.3871
X-0.5114Y0.3452
X-0.5451Y0.2997
X-0.5748Y0.2509
X-0.6000Y0.1992
X-0.6206Y0.1450
X-0.6362Y0.0887
X-0.6467Y0.0307
X-0.6519Y-0.0285
X-0.6516Y-0.0883
X-0.6459Y-0.1483
X-0.6345Y-0.2080
X-0.6176Y-0.2669
X-0.5952Y-0.3244
X-0.5675Y-0.3800
X-0.5345Y-0.4332
X-0.4966Y-0.4836
X-0.4538Y-0.5306
X-0.4066Y-0.5738
X-0.3553Y-0.6128
X-0.3003Y-0.6471
X-0.2419Y-0.6765
X-0.1806Y-0.7006
X-0.1170Y-0.7192
X-0.0514Y-0.7319
X0.0154Y-0.7386
X0.0831Y-0.7392
X0.1510Y-0.7335
X0.2173Y-0.7175
G03X-0.2173Y0.7175I-0.2173J0.7175
X0.2173Y-0.7175I0.2173J-0.7175
G01X0.1250Y-0.0002
G03Z-1.0000I-0.1250J0.0002
G01X0.1327Y0.0231
X0.1358Y0.0491
X0.1336Y0.0768
X0.1257Y0.1051
X0.1118Y0.1328
X0.0920Y0.1586
X0.0664Y0.1813
X0.0356Y0.1996
X0.0004Y0.2125
X-0.0382Y0.2189
X-0.0789Y0.2181
X-0.1204Y0.2095
X-0.1612Y0.1929
X-0.1997Y0.1682
X-0.2343Y0.1359
X-0.2634Y0.0964
X-0.2858Y0.0509
X-0.3000Y0.0006
X-0.3051Y-0.0532
X-0.3004Y-0.1087
X-0.2854Y-0.1640
X-0.2600Y-0.2173
X-0.2246Y-0.2666
X-0.1797Y-0.3100
X-0.1265Y-0.3456
X-0.0663Y-0.3719
X-0.0007Y-0.3875
X0.0682Y-0.3913
X0.1385Y-0.3827
X0.2076Y-0.3612
X0.2735Y-0.3271
X0.3335Y-0.2810
X0.3857Y-0.2236
X0.4278Y-0.1566
X0.4580Y-0.0817
X0.4750Y-0.0009
X0.4782Y0.0428
X0.4773Y0.0870
X0.4723Y0.1314
X0.4631Y0.1756
X0.4498Y0.2192
X0.4323Y0.2618
X0.4108Y0.3030
X0.3854Y0.3425
X0.3561Y0.3798
X0.3232Y0.4146
X0.2869Y0.4466
X0.2474Y0.4753
X0.2051Y0.5005
X0.1602Y0.5220
X0.1131Y0.5393
X0.0642Y0.5524
X0.0138Y0.5611
X-0.0376Y0.5650
X-0.0896Y0.5643
X-0.1418Y0.5587
X-0.1937Y0.5483
X-0.2449Y0.5330
X-0.2949Y0.5129
X-0.3432Y0.4882
X-0.3895Y0.4588
X-0.4332Y0.4250
X-0.4740Y0.3871
X-0.5114Y0.3452
X-0.5451Y0.2997
X-0.5748Y0.2509
X-0.6000Y0.1992
X-0.6206Y0.1450
X-0.6362Y0.0887
X-0.6467Y0.0307
X-0.6519Y-0.0285
X-0.6516Y-0.0883
X-0.6459Y-0.1483
X-0.6345Y-0.2080
X-0.6176Y-0.2669
X-0.5952Y-0.3244
X-0.5675Y-0.3800
X-0.5345Y-0.4332
X-0.4966Y-0.4836
X-0.4538Y-0.5306
X-0.4066Y-0.5738
X-0.3553Y-0.6128
X-0.3003Y-0.6471
X-0.2419Y-0.6765
X-0.1806Y-0.7006
X-0.1170Y-0.7192
X-0.0514Y-0.7319
X0.0154Y-0.7386
X0.0831Y-0.7392
X0.1510Y-0.7335
X0.2173Y-0.7175
G03X-0.2173Y0.7175I-0.2173J0.7175
X0.2173Y-0.7175I0.2173J-0.7175
G01X0.1250Y-0.0002
X0.0000Y0.0000
G00Z0.2500
M5 M9
M30

I didn't realize what was happening with the spirals. Mach3 can do spirals, but it's very picky about how you do it, and it's undocumented. I would think that very few controls can do G2/G3 spirals.

Yeah the lines that kept giving me the errors were always the first line of a spiral.  If you can think of a way around using a ton of line segments let me know.

Not really been following this as I am not good at code, get easily confused
Actually may be getting confused with this as well but if you use the circular pocket wizard it produces a spiral toolpath, is that the type f thing you are trying to do?
Might be worth looking at the code it produces and maybe you can find a way to get your CAM to output similar, if that is what you are wanting..
Hood

I think you might be on to something there.

I edited the Spiral motion output to something Mach can read by making the [spiral_Lead] R instead of Q and just using X and Y for coordinates as the wizard does.  Here is the tool path in Mach from the wizard:


And here is the code:

G0 G49 G40  G17 G80 G50 G90
M6 T0(TOOL DIA.10)
G64
G21 (mm)
M03 S0
M08
G00 G43 H0  Z2
X0 Y0
G01 Z-10 F20
G2 Y0 X5 R2.5 F30
Y0 X-5 R5
Y0 X10 R7.5
Y0 X-10 R10
Y0 X15 R12.5
Y0 X-15 R15
Y0 X20 R17.5
Y0 X-20 R20
X20 Y0 R20
Y-10 X10 R10
G00 Z2
X0 Y0
G01 Z-20 F20
G2 Y0 X5 R2.5 F30
Y0 X-5 R5
Y0 X10 R7.5
Y0 X-10 R10
Y0 X15 R12.5
Y0 X-15 R15
Y0 X20 R17.5
Y0 X-20 R20
X20 Y0 R20
Y-10 X10 R10
G00 Z2
X0 Y0
G01 Z-30 F20
G2 Y0 X5 R2.5 F30
Y0 X-5 R5
Y0 X10 R7.5
Y0 X-10 R10
Y0 X15 R12.5
Y0 X-15 R15
Y0 X20 R17.5
Y0 X-20 R20
X20 Y0 R20
Y-10 X10 R10
G00 Z2
M5 M9
M30


Now here is the toolpath in Mach for my pocket from RhinoCAM:



As you can see the arc and helix output fine but the spiral does not.  The X and Y value for the spiral is the beginning point and end point whereas in the wizard it is divided into half circles.  The radius is applied to the entire arc instead of segments of increasing radius.  Here is the code:

G00 G49 G40.1 G17 G80 G50 G90
G20
(Hole Pocketing)
M6 T3 G43 H3
S5000M03
G00Z0.2500
X0.1250Y-0.0002
G01Z-0.2960 F7.3
G17
G03Z-0.5473I-0.1250J0.0002 F10.0
X0.2173Y-0.7175R0.3500
X-0.2173Y0.7175I-0.2173J0.7175
X0.2173Y-0.7175I0.2173J-0.7175
G01X0.1250Y-0.0002
G03Z-0.7737I-0.1250J0.0002
X0.2173Y-0.7175R0.3500
X-0.2173Y0.7175I-0.2173J0.7175
X0.2173Y-0.7175I0.2173J-0.7175
G01X0.1250Y-0.0002
G03Z-1.0000I-0.1250J0.0002
X0.2173Y-0.7175R0.3500
X-0.2173Y0.7175I-0.2173J0.7175
X0.2173Y-0.7175I0.2173J-0.7175
G01X0.1250Y-0.0002
X0.0000Y0.0000
G00Z0.2500
M5 M9
M30

Anyone know how I can get the X and Y coordinated to output half circles?

You don't need to use half circles. You just need the start and endpoint to not be more than 1/2" apart. I think actually, the radius from the start to the end can't be more than 1/2" different.

G20 G40 G90
G91.1
S5000
M3
G0 Z0.0500
G0 X0.0000 Y-0.6500 Z0.0500
G1 X0.0000 Y0.2167 Z-0.2500 F75
G2 X0.0000 Y0.2167 Z-0.2500 I0.0000 J-0.2167 F80
G2 X0.0000 Y0.4333 Z-0.2500 I0.00 J-0.2167
G2 X0.0000 Y0.6500 Z-0.2500 I0.00 J-0.4333
G2 X0.0000 Y0.6500 Z-0.2500 I0.00 J-0.6500
G0 Z0.0000
G0 X0.0000 Y0.7500 Z0.0000
G2 X0.0000 Y0.7500 Z-0.2500 I0.0000 J-0.7500 F80
G2 X0.0000 Y0.7500 Z-0.2500 I0.0000 J-0.7500
G0 X0.0000 Y0.7500 Z0.0500
M5
M30

Your right that is what is screwing my spiral arcs.  I have the right format XYZIJ but the values don't work unless I tweak the X and Y values to be lower.  Why is the limit .5"?  That seems so arbitrary.  Is there any way around this .5" limit?

So just playing around, using .5" flat mill a I can do a 1.4999 hole pocket with spiral arcs but not a 1.5.  That just seems like a weird cut off point and I would venture that it could be changed somewhere if it is just an arbitrary value.