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4th axis question
« on: December 15, 2010, 09:57:29 PM »
Good day,
I'm having an issue with my 4th axis, (running Mach3)
I can't get the rotation feed to speed up as fast as I want. I have radius correct turned on but the only difference it seems to make is, if I set radius to 0.0001 to use Z as radius, the feeds speed up as the radius increases (which seems backwards) Setting it at any radius other then 0.0001, just slows it down all the time.
The part is an eliptical lobe shape, and the feeds speed up as the cutter raises and lowers at the lobe part, but slows back down for the other 180 degs, the constant radius circular arc part.
I can jog the rotary table fast enough to use it as a lathe, but when cutting it's slow.
any idea's?
Thanks,
Ray

Offline ger21

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Re: 4th axis question
« Reply #1 on: December 15, 2010, 10:36:14 PM »
What is the 4th axis velocity set at in motor tuning. It typically should be much higher than the other axis, because it's in degrees/minute.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
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Offline Greolt

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Re: 4th axis question
« Reply #2 on: December 15, 2010, 11:03:52 PM »

Setting it at any radius other then 0.0001, just slows it down all the time.


Mach3 has a long standing bug in the "Use Radius for Feedrate" feature.    That is, setting a value of zero in the "Rotation Radius" DRO will disable the feature.

Quote

.......if I set radius to 0.0001 to use Z as radius, the feeds speed up as the radius increases (which seems backwards)


Sounds a bit odd that the rotary axis feedrate speeds up as the Z axis DRO value increases.  It does not do that here.

Are you sure you have the Z axis travelling in the conventional direction?  Up is positive and down is negative.

Greg
Re: 4th axis question
« Reply #3 on: December 16, 2010, 11:19:50 AM »
What is the 4th axis velocity set at in motor tuning. It typically should be much higher than the other axis, because it's in degrees/minute.

X is 320 S/P 2200.2 V, 110 acc
Z is 320 S/P 1300.2 V, 65 acc
A is 4.44 S/P 40002 V, 500 acc

Thanks,
Ray
Re: 4th axis question
« Reply #4 on: December 16, 2010, 11:25:32 AM »
Yes Z is setup correctly, Z- feeds down on machine and DRO.
With radius correct turned on, is A feed still deg or is it now inch/min?
I'll try turning radius correct off again and running a feed of 5000-10,000, now that I have figured out how to change the max feed output in VM from 400.
Thanks again,
Ray

Offline ger21

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Re: 4th axis question
« Reply #5 on: December 16, 2010, 11:43:05 AM »
In Config>Toolpath, did you check "Use Radius for feedrate", or whatever it's called?
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html
Re: 4th axis question
« Reply #6 on: December 16, 2010, 11:51:08 AM »
Yes I did.
I just tried running a cut feed rate of 30000 (VM is setup in metric so programs as mm/min, which converts to 1181.10 inch/min) so G code has a feed of 1181 which should be deg per minute on the A correct?
Doesn't make enough difference to see from 200 /min??
I tried this with and without radius correct, only difference is with R/C it still speeds up over the lobe?
Ray
Re: 4th axis question
« Reply #7 on: December 16, 2010, 09:46:11 PM »
Did some more testing. When it speeds up as z goes up and back down, while cutting the lobe, it's not the radius correct doing that. It was the slight increase in speed the radius correct was giving. Increasing the feed rate with radius correct off does the same thing.
Had cut feed set at 5511.8 and over riden to 13779.50, but feed rate in Mach DRO only shows 1000-1750 bouncing around. Cuts the approx 180 deg of circular arc perfectly, takes 15-20 sec, then when it gets to the second approx 180 deg, with the raise lobe, it cuts that part in 1-2 sec. Like it's using angular feed while Z is fixed and lin feed while Z is moving?
I spoke with Visualmill today and they said it's controller problem??
Does this give anyone any other idea's?
Thanks again,
Ray

Offline ger21

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Re: 4th axis question
« Reply #8 on: December 16, 2010, 10:12:14 PM »
What does the code look like?
Gerry

2010 Screenset
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JointCAM Dovetail and Box Joint software
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Re: 4th axis question
« Reply #9 on: December 17, 2010, 12:01:10 AM »
What does the code look like?

It looks like a bunch of letters and numbers, LOL
Seriously, here is a snipet from the code.
Everything is fine while Z is at 0.6917", when Z starts to raise it seems to go to rapid feeds and the A keeps up, once Z goes back to 0.6917" it's back to normal.
X1.8110  Z1.0947 A-3600.000 F31.5
X2.0866  Z1.0947 A-3600.000
X2.0866  Z0.6917 A-3600.000
X2.0866  Z0.6917 A-3600.000 F1968.5
X2.0866  Z0.6917 A-3600.909
X2.0866  Z0.6917 A-3601.818
X2.0866  Z0.6917 A-3602.728
X2.0866  Z0.6917 A-3603.636
X2.0866  Z0.6917 A-3604.545
X2.0866  Z0.6917 A-3605.455
X2.0866  Z0.6917 A-3607.273
X2.0866  Z0.6917 A-3608.182
X2.0866  Z0.6917 A-3609.091
X2.0866  Z0.6917 A-3610.000
X2.0866  Z0.6917 A-3610.909
X2.0866  Z0.6917 A-3612.727
X2.0866  Z0.6917 A-3613.182
X2.0866  Z0.6917 A-3614.091
X2.0866  Z0.6917 A-3614.545
X2.0866  Z0.6917 A-3615.454
X2.0866  Z0.6917 A-3615.909
X2.0866  Z0.6917 A-3616.818
X2.0866  Z0.6917 A-3617.273
X2.0866  Z0.6917 A-3618.182
X2.0866  Z0.6917 A-3619.091
X2.0866  Z0.6917 A-3620.000
X2.0866  Z0.6917 A-3621.818
X2.0866  Z0.6917 A-3622.727
X2.0866  Z0.6917 A-3623.636
X2.0866  Z0.6917 A-3625.455
X2.0866  Z0.6917 A-3626.363
X2.0866  Z0.6917 A-3627.273
X2.0866  Z0.6917 A-3629.091
X2.0866  Z0.6917 A-3630.000
X2.0866  Z0.6917 A-3630.909
X2.0866  Z0.6917 A-3632.727
X2.0866  Z0.6917 A-3633.182
X2.0866  Z0.6917 A-3634.091
X2.0866  Z0.6917 A-3634.545
X2.0866  Z0.6917 A-3636.364
X2.0866  Z0.6917 A-3636.818
X2.0866  Z0.6917 A-3637.727
X2.0866  Z0.6917 A-3638.182
X2.0866  Z0.6917 A-3640.000
X2.0866  Z0.6917 A-3640.909
X2.0866  Z0.6917 A-3641.818
X2.0866  Z0.6917 A-3643.636
X2.0866  Z0.6917 A-3644.545
X2.0866  Z0.6917 A-3645.455
X2.0866  Z0.6917 A-3647.273
X2.0866  Z0.6917 A-3648.182
X2.0866  Z0.6917 A-3648.636
X2.0866  Z0.6917 A-3649.091
X2.0866  Z0.6917 A-3650.909
X2.0866  Z0.6917 A-3652.727
X2.0866  Z0.6917 A-3653.182
X2.0866  Z0.6917 A-3653.637
X2.0866  Z0.6917 A-3654.545
X2.0866  Z0.6917 A-3656.364
X2.0866  Z0.6917 A-3657.273
X2.0866  Z0.6917 A-3658.182
X2.0866  Z0.6917 A-3658.636
X2.0866  Z0.6917 A-3659.091
X2.0866  Z0.6917 A-3660.000
X2.0866  Z0.6917 A-3661.818
X2.0866  Z0.6917 A-3663.636
X2.0866  Z0.6917 A-3664.546
X2.0866  Z0.6917 A-3665.455
X2.0866  Z0.6917 A-3666.591
X2.0866  Z0.6917 A-3666.818
X2.0866  Z0.6917 A-3667.273
X2.0866  Z0.6917 A-3668.182
X2.0866  Z0.6917 A-3669.091
X2.0866  Z0.6917 A-3670.909
X2.0866  Z0.6917 A-3671.818
X2.0866  Z0.6917 A-3672.727
X2.0866  Z0.6917 A-3674.545
X2.0866  Z0.6917 A-3676.136
X2.0866  Z0.6917 A-3677.273
X2.0866  Z0.6917 A-3678.182
X2.0866  Z0.6917 A-3680.000
X2.0866  Z0.6917 A-3680.909
X2.0866  Z0.6935 A-3680.909
X2.0866  Z0.6987 A-3681.818
X2.0866  Z0.7038 A-3682.728
X2.0866  Z0.7088 A-3683.636
X2.0866  Z0.7137 A-3684.545
X2.0866  Z0.7185 A-3685.455
X2.0866  Z0.7232 A-3686.364
X2.0866  Z0.7278 A-3687.273
X2.0866  Z0.7369 A-3689.091
X2.0866  Z0.7414 A-3690.000
X2.0866  Z0.7458 A-3690.909
X2.0866  Z0.7503 A-3691.818
X2.0866  Z0.7548 A-3692.727
X2.0866  Z0.7594 A-3693.637
X2.0866  Z0.7640 A-3694.545
X2.0866  Z0.7731 A-3696.364
X2.0866  Z0.7777 A-3697.273
X2.0866  Z0.7821 A-3698.182
X2.0866  Z0.7909 A-3700.000
X2.0866  Z0.7994 A-3701.818
X2.0866  Z0.8075 A-3703.636
X2.0866  Z0.8115 A-3704.546
X2.0866  Z0.8153 A-3705.455
X2.0866  Z0.8191 A-3706.363
X2.0866  Z0.8228 A-3707.273
X2.0866  Z0.8264 A-3708.182
X2.0866  Z0.8299 A-3709.091
X2.0866  Z0.8333 A-3710.000
X2.0866  Z0.8367 A-3710.909
X2.0866  Z0.8399 A-3711.818
X2.0866  Z0.8430 A-3712.727
X2.0866  Z0.8461 A-3713.636
X2.0866  Z0.8490 A-3714.545
X2.0866  Z0.8519 A-3715.455
X2.0866  Z0.8547 A-3716.364
X2.0866  Z0.8574 A-3717.273
X2.0866  Z0.8601 A-3718.182
X2.0866  Z0.8626 A-3719.091
X2.0866  Z0.8651 A-3720.000
X2.0866  Z0.8675 A-3720.909
X2.0866  Z0.8698 A-3721.818
X2.0866  Z0.8721 A-3722.728
X2.0866  Z0.8743 A-3723.636
X2.0866  Z0.8764 A-3724.545
X2.0866  Z0.8785 A-3725.455
X2.0866  Z0.8805 A-3726.364
X2.0866  Z0.8824 A-3727.273
X2.0866  Z0.8842 A-3728.182
X2.0866  Z0.8859 A-3729.091
X2.0866  Z0.8876 A-3730.000
X2.0866  Z0.8891 A-3730.909
X2.0866  Z0.8905 A-3731.818
X2.0866  Z0.8918 A-3732.727
X2.0866  Z0.8930 A-3733.637
X2.0866  Z0.8941 A-3734.545
X2.0866  Z0.8950 A-3735.454
X2.0866  Z0.8958 A-3736.364
X2.0866  Z0.8965 A-3737.273
X2.0866  Z0.8971 A-3738.182
X2.0866  Z0.8975 A-3739.091
X2.0866  Z0.8977 A-3740.000
X2.0866  Z0.8979 A-3740.909
X2.0866  Z0.8978 A-3741.818
X2.0866  Z0.8977 A-3742.727
X2.0866  Z0.8974 A-3743.636
X2.0866  Z0.8969 A-3744.546
X2.0866  Z0.8963 A-3745.455
X2.0866  Z0.8956 A-3746.363
X2.0866  Z0.8946 A-3747.273
X2.0866  Z0.8936 A-3748.182
X2.0866  Z0.8924 A-3749.091
X2.0866  Z0.8911 A-3750.000
X2.0866  Z0.8896 A-3750.909
X2.0866  Z0.8879 A-3751.818
X2.0866  Z0.8861 A-3752.727
X2.0866  Z0.8841 A-3753.636
X2.0866  Z0.8820 A-3754.545
X2.0866  Z0.8797 A-3755.455
X2.0866  Z0.8773 A-3756.364
X2.0866  Z0.8746 A-3757.272
X2.0866  Z0.8719 A-3758.182
X2.0866  Z0.8689 A-3759.091
X2.0866  Z0.8658 A-3760.000
X2.0866  Z0.8626 A-3760.909
X2.0866  Z0.8591 A-3761.818
X2.0866  Z0.8555 A-3762.727
X2.0866  Z0.8518 A-3763.636
X2.0866  Z0.8478 A-3764.545
X2.0866  Z0.8437 A-3765.455
X2.0866  Z0.8395 A-3766.364
X2.0866  Z0.8350 A-3767.273
X2.0866  Z0.8305 A-3768.182
X2.0866  Z0.8258 A-3769.091
X2.0866  Z0.8209 A-3770.000
X2.0866  Z0.8159 A-3770.909
X2.0866  Z0.8107 A-3771.818
X2.0866  Z0.8054 A-3772.727
X2.0866  Z0.7999 A-3773.637
X2.0866  Z0.7942 A-3774.545
X2.0866  Z0.7885 A-3775.454
X2.0866  Z0.7826 A-3776.364
X2.0866  Z0.7765 A-3777.273
X2.0866  Z0.7704 A-3778.182
X2.0866  Z0.7640 A-3779.091
X2.0866  Z0.7576 A-3780.000
X2.0866  Z0.7510 A-3780.909
X2.0866  Z0.7443 A-3781.818
X2.0866  Z0.7375 A-3782.727
X2.0866  Z0.7306 A-3783.636
X2.0866  Z0.7236 A-3784.546
X2.0866  Z0.7165 A-3785.455
X2.0866  Z0.7093 A-3786.363
X2.0866  Z0.7020 A-3787.273
X2.0866  Z0.6917 A-3789.091
X2.0866  Z0.6917 A-3790.909
X2.0866  Z0.6917 A-3791.818
X2.0866  Z0.6917 A-3792.727
X2.0866  Z0.6917 A-3793.636
X2.0866  Z0.6917 A-3794.545
X2.0866  Z0.6917 A-3795.455
X2.0866  Z0.6917 A-3796.364
X2.0866  Z0.6917 A-3797.273
X2.0866  Z0.6917 A-3798.182
X2.0866  Z0.6917 A-3799.091
X2.0866  Z0.6917 A-3800.000
X2.0866  Z0.6917 A-3801.250
X2.0866  Z0.6917 A-3801.278
X2.0866  Z0.6917 A-3801.818
X2.0866  Z0.6917 A-3802.955
X2.0866  Z0.6917 A-3803.636
X2.0866  Z0.6917 A-3805.455