Mach 3 wierdness

[ger21]

Did you use a 1/8" tool? Maybe your steps/inch are set incorrectly.

[randyf1965]

Yes 1/8" tool.

Step/unit calculated 5/16-18 threaded rod 1/18=.0556" per rotation . Using 1/4 micro stepping for 800 steps per rotation so 800*18= 14400 steps per inch which come out to be 14400 steps = 1.0008" I think I could live with 8 ten thousandths.

I will measure movement with a dial indicator to be sure 14400 steps moves 1"... it it doesn't how can I correct it?

[randyf1965]

ok using a dial indicator I can move the axis out 10 inches and back and be over length by ~.002"

[ger21]

It's not a question of moving 10 inches and back. That should always be the same unless you're missing steps. You need to know, if you move 10 inches, does it really move 10 inches. A simple test is to cut a smal square and measure with a caliper. Something like:

G0 Z1
G0 X1 Y1
G1 Z-.125
G1 X5.125 Y1
G1 X5.125 Y5.125
G1 X1 Y5.125
G1 X1 Y1
G0 Z1

With a 1/8" tool, does this give you a 4" square?

[randyf1965]

OK, here is the 4" square... turns out to be 3.965" square. Do I need to add 126 steps to my steps/unit? That would add 0.00875"/inch or .035 over 4 inches.

oh and the grooves and holes are from other testing

[ger21]

I think so. Try it and see.

[randyf1965]

After a couple of cut, measure, adjust steps/unit I am within +.001 - .001 which for a homemade wooden cnc router...... I am happy with.

BUT and everybody has a but I still can't get cutter compensation to work right

Downloaded sheetcam got the temp license file manually walking thru mapping it out seeing how it works.

[ger21]

Originally Posted by randyf1965 BUT and everybody has a but I still can't get cutter compensation to work right

Does the rib still come out the wrong size?

[randyf1965]

I think you posted this code.. I changed G42P0.0752 (instead of .0625) and I can get the part to come out correct.

I see with Sheetcam it just codes the part with the step in it IE on the notches it cuts from the edge in then steps over .075 and cuts back out. Too late to try this tonight (Kids asleep and the router is LOUD *grin*). How loud is the Hitachi router my old Crapsmen is a SCREAMER.

Just thought of something.. I will rotate the part and see if the notches turn out right. OR cut it REALLY to check for slop

G40
M3
G0 Z0.1250
G0 X4.2500 Y2.8750 Z0.1250
G1 X4.2500 Y2.8750 Z0.0000 F50
G2 X4.2500 Y2.8750 Z-0.1250 I0.0000 J-0.1250 F150
G2 X4.2500 Y2.8750 Z-0.2500 I0.0000 J-0.1250
G2 X4.2500 Y2.8750 Z-0.2800 I0.0000 J-0.1250
G0 X4.2500 Y2.8750 Z0.1250
G0 X4.2500 Y8.3750 Z0.1250
G1 X4.2500 Y8.3750 Z0.0000 F50
G2 X4.2500 Y8.3750 Z-0.1250 I0.0000 J-0.1250 F150
G2 X4.2500 Y8.3750 Z-0.2500 I0.0000 J-0.1250
G2 X4.2500 Y8.3750 Z-0.2800 I0.0000 J-0.1250
G0 X4.2500 Y8.3750 Z0.1250
G0 X2.7500 Y2.8750 Z0.1250
G1 X2.7500 Y2.8750 Z0.0000 F50
G2 X2.7500 Y2.8750 Z-0.1250 I0.0000 J-0.1250 F150
G2 X2.7500 Y2.8750 Z-0.2500 I0.0000 J-0.1250
G2 X2.7500 Y2.8750 Z-0.2800 I0.0000 J-0.1250
G0 X2.7500 Y2.8750 Z0.1250
G0 X2.7500 Y8.3750 Z0.1250
G1 X2.7500 Y8.3750 Z0.0000 F50
G2 X2.7500 Y8.3750 Z-0.1250 I0.0000 J-0.1250 F150
G2 X2.7500 Y8.3750 Z-0.2500 I0.0000 J-0.1250
G2 X2.7500 Y8.3750 Z-0.2800 I0.0000 J-0.1250
G0 X2.7500 Y8.3750 Z0.1250
G0 X1.0000 Y10.7063 Z0.1250
G1 X1.0000 Y10.7063 Z0.0000 F50
G42P0.0752
G1 X2.0000 Y10.2063 Z-0.1250 F150
G1 X2.0000 Y9.2500 Z-0.1250
G1 X2.1425 Y9.2500 Z-0.1250
G1 X2.1425 Y7.3525 Z-0.1250
G1 X3.5000 Y7.3525 Z-0.1250
G1 X3.5000 Y7.1475 Z-0.1250
G1 X2.1425 Y7.1475 Z-0.1250
G1 X2.1425 Y3.8525 Z-0.1250
G1 X3.5000 Y3.8525 Z-0.1250
G1 X3.5000 Y3.6475 Z-0.1250
G1 X2.1425 Y3.6475 Z-0.1250
G1 X2.1425 Y1.7500 Z-0.1250
G1 X2.0000 Y1.7500 Z-0.1250
G1 X2.0000 Y1.0000 Z-0.1250
G1 X2.9185 Y1.0000 Z-0.1250
G2 X4.0815 Y1.0000 Z-0.1250 I0.5815 J0.0000
G1 X5.0000 Y1.0000 Z-0.1250
G1 X5.0000 Y1.7500 Z-0.1250
G1 X4.8575 Y1.7500 Z-0.1250
G1 X4.8575 Y1.8975 Z-0.1250
G1 X3.5000 Y1.8975 Z-0.1250
G1 X3.5000 Y2.1025 Z-0.1250
G1 X4.8575 Y2.1025 Z-0.1250
G1 X4.8575 Y5.3975 Z-0.1250
G1 X3.5000 Y5.3975 Z-0.1250
G1 X3.5000 Y5.6025 Z-0.1250
G1 X4.8575 Y5.6025 Z-0.1250
G1 X4.8575 Y8.8975 Z-0.1250
G1 X3.5000 Y8.8975 Z-0.1250
G1 X3.5000 Y9.1025 Z-0.1250
G1 X4.8575 Y9.1025 Z-0.1250
G1 X4.8575 Y9.2500 Z-0.1250
G1 X5.0000 Y9.2500 Z-0.1250
G1 X5.0000 Y10.0000 Z-0.1250
G1 X4.0815 Y10.0000 Z-0.1250
G2 X2.9185 Y10.0000 Z-0.1250 I-0.5815 J0.0000
G1 X1.7500 Y10.0000 Z-0.1250
G40
G1 X1.3750 Y10.2500 Z0.0000
G0 X1.3750 Y10.2500 Z0.1250
G0 X1.0000 Y10.7063 Z0.1250
G1 X1.0000 Y10.7063 Z0.0000 F50
G42P0.0625
G1 X2.0000 Y10.2063 Z-0.2500 F150
G1 X2.0000 Y9.2500 Z-0.2500
G1 X2.1425 Y9.2500 Z-0.2500
G1 X2.1425 Y7.3525 Z-0.2500
G1 X3.5000 Y7.3525 Z-0.2500
G1 X3.5000 Y7.1475 Z-0.2500
G1 X2.1425 Y7.1475 Z-0.2500
G1 X2.1425 Y3.8525 Z-0.2500
G1 X3.5000 Y3.8525 Z-0.2500
G1 X3.5000 Y3.6475 Z-0.2500
G1 X2.1425 Y3.6475 Z-0.2500
G1 X2.1425 Y1.7500 Z-0.2500
G1 X2.0000 Y1.7500 Z-0.2500
G1 X2.0000 Y1.0000 Z-0.2500
G1 X2.9185 Y1.0000 Z-0.2500
G2 X4.0815 Y1.0000 Z-0.2500 I0.5815 J0.0000
G1 X5.0000 Y1.0000 Z-0.2500
G1 X5.0000 Y1.7500 Z-0.2500
G1 X4.8575 Y1.7500 Z-0.2500
G1 X4.8575 Y1.8975 Z-0.2500
G1 X3.5000 Y1.8975 Z-0.2500
G1 X3.5000 Y2.1025 Z-0.2500
G1 X4.8575 Y2.1025 Z-0.2500
G1 X4.8575 Y5.3975 Z-0.2500
G1 X3.5000 Y5.3975 Z-0.2500
G1 X3.5000 Y5.6025 Z-0.2500
G1 X4.8575 Y5.6025 Z-0.2500
G1 X4.8575 Y8.8975 Z-0.2500
G1 X3.5000 Y8.8975 Z-0.2500
G1 X3.5000 Y9.1025 Z-0.2500
G1 X4.8575 Y9.1025 Z-0.2500
G1 X4.8575 Y9.2500 Z-0.2500
G1 X5.0000 Y9.2500 Z-0.2500
G1 X5.0000 Y10.0000 Z-0.2500
G1 X4.0815 Y10.0000 Z-0.2500
G2 X2.9185 Y10.0000 Z-0.2500 I-0.5815 J0.0000
G1 X1.7500 Y10.0000 Z-0.2500
G40
G1 X1.3750 Y10.2500 Z0.0000
G0 X1.3750 Y10.2500 Z0.1250
G0 X1.0000 Y10.7063 Z0.1250
G1 X1.0000 Y10.7063 Z0.0000 F50

G40
G1 X1.3750 Y10.2500 Z0.0000
G0 X1.3750 Y10.2500 Z0.1250
G0 X0 Y0
M5
M30

[randyf1965]

I am just trying to get fairly accurate cuts so I can start replacing the parts I cut with a beaver with parts that are accurate. Then after the I will look at cutting pattern for parts and casting them out of aluminum.

[randyf1965]

ok, using rotozip bits... I ordered some 1/8" carbide endmills from Enco should have them in a couple of days, can't find anything local... though I don't know any machinist tool places in Joliet IL