Messages

1

General Mach Discussion / Re: questions about the G201x

« on: July 03, 2013, 09:32:39 AM »

what is unclear is whether the dip switch settings need to be set according to the motor's current requirements--even without a current limiting resistor.
Since the driver has all the dip switches turned on, I guess I need to change them to my motor's current requirements.

For this particular driver, the current resistor is optional, so I am not going to use it.

tony

2

General Mach Discussion / Re: questions about the G201x

« on: July 03, 2013, 08:14:30 AM »

I got the spec alright, and the motor runs fine
My questions, more specifically, have to do with mach 3 motor settings( is. how many steps per inch?), and my concern that the motor get hot quickly before I do anything....
I have not used any resistors, so I am assuming that the current to the motors is automatic.
tony

3

General Mach Discussion / questions about the G201x

« on: July 03, 2013, 07:45:46 AM »

I am replacing the Keling driver with a G201x. Here are my questions:
1. how is the driver set for half step or some other step?
2. Since the current limiting resistor is optional, why  is it that the motor, within a few minutes of it being turned on, is warm to the touch while the other motors, driven with the Keling drivers are cold and warm up only after a good run?
3. The motor's specs are 2.8a  1.5 ohms, 6.8 mh and they are wired with an 80v ps in bipolar.  Should I use a current limiting resistor?
4. What should mach3 resolution be set at for this driver?

I have not blown the unit, and I want to be sure I get a better feel for these drives.
thanks
tony

4

General Mach Discussion / cannot run Mach from mid point

« on: March 30, 2013, 12:49:22 PM »

Why is it that if try to start Mach 3 from "run from here", the machine goes way off its coordinates?  I've done it  hundreds of times with different code and it always worked fine.  This is a new project, with new code, and it runs fine if I start from the beginning.  If, on the other hand, I bring the machine home, and then set a point in the code other than the beginning, the machine forgets its coordinates.  Why am I missing?
tony

5

General Mach Discussion / Re: Great mystery.......

« on: March 28, 2013, 04:00:05 PM »

The MDF is much denser than the balsa............. might show up flex a lot more too.  Backlash could show more.  What kind of bit do you use?  High speed steel will dull in about 10 seconds in MDF.

Brett

.1875 carbide two flute downcut....

By increasing the acceleration, the machine feels tight and has cut some very nice pieces at 35 ipm.
tony
tony

6

General Mach Discussion / Re: Great mystery.......

« on: March 28, 2013, 01:49:29 PM »

Actually, I had done that. My assumption was that the motors never had sufficient torque , but the balsa was very forgiving. I was doing production work and using multiple depth passes on 3/8 stock. I am assuming, therefore, that the load on the motors was minimal.
When I began to cut MDF, I tried cutting a simple pocket, .125 deep at 58ipm, with a .1875 tool, and it failed to cut evenly.  By evenly, I mean that the x y went off the normal circular pattern.  When I slowed down the machine, things improved, but I was still puzzled by the drastic errors. We're talking about the work being ruined due to the errors. When I reduced the feeds, things looked almost good, except for the z failing to drill all the way down.  The motors sounded fine; the work was not coming out right.  I purchased the machine for Balsa and had never worked with MDF. When I cut pine of similar thickness, things were fine. I have to assume that the mdf's high density places major strains on the motors.

All of this, however, does not explain why I cannot make the motors slip by increasing the acceleration.

If the motors do indeed have that much torque, then the original feed of 58ipm would not have created all the errors in cutting.

When these things happen, it's like going back to school to study math 101.

tony

7

General Mach Discussion / Great mystery.......

« on: March 28, 2013, 11:18:27 AM »

I was getting some slippage when I went from balsa to mdf. So I decided to change the accel velocity for my k2cnc 2514.  I set the new velocity to 70 ipm and the acceleration to 80 in order to make the x and y axis slip.  For this machine, 110 ipm is the maximum speed. To my amazement, neither axis, even when I place a load on it, slips.
I reduced the acceleration to 30 out of fear, but I am still puzzled by the fact that I cannot make the motors slip at such a high acceleration number.  A long time ago, I place damping wheels on all three motors to reduce resonance. I remember that this helped a lot in reducing slippage.
Any ideas? My steppers put out some 280oz/in and my drivers are set at a half a step. My power supply is a healthy 80volts.
I had not trouble running the machine faster with Balsa, but with MDF I assumed that it had to run much, much slower  due to the fact that the parts were not cutting precisely.

Another thing I noticed is that when I set the pulse rate to a number other than 0, Mach 3 brings it back to 0. Is this normal?
thanks
tony

8

General Mach Discussion / need simple procedure for autozero script using multiple tools

« on: March 10, 2013, 08:43:41 AM »

Can someone point me to a 1-2-3 procedure for working with multiple tool changes( manually) in one program when using an autozero tool offset script.  My few attempts have broken into my autozero touch plate, which fortunately sits on a plastic project box rather than steel. It saved me a tool, but it has ruined two touch plates so far. I need to know the procedure for, let's say, Tool 0 or 1 as the datum tool, and then subsequent tools, all using the autozero script.  Again, not to repeat myself, I have no trouble when I am working with only one tool. As soon as I start working with multiple tool lengths, I am totally confused regarding the sequence of steps and this is when I break parts. With an advance thanks.
tc






It's

9

General Mach Discussion / Re: Still one more question on tool wear

« on: March 03, 2013, 09:40:53 AM »

Thanks for the quick reply. I am using a caliper to measure the diameter. Yes, .005 may not be much, but  I had tried larger numbers.  I have been checking the machine since all my holes fall short some .020 from the set diameter. I've checked for backlash, I've changed bearings, and it all seems ok.  I've changed router and bits as well. Finally, I had decided( for production purposes) that I  had to get things moving again, thus the wear comp. Here's my example.... a .375 hole comes in at .355. If I enter .100 in the tool diameter table, I should get a hole larger than .355. It doesn't. If, on the other, I enter a -.020, Mach 3 opens the hole.
I've spent two days on this before seeking help, given that at this point I've exhausted all possibilities. The holes are round, but they always come in small. Yes, I measured the tool diameter and it's .125.  I've reduced acceleration and velocity settings and calibrated the steps.  A micrometer shows accuracy within .001".

The only thing that I have not tried is a multipass in addition to a multi depth code. I notice that the wear correction barely travels one turn. Also, when in tool wear compensation mode, Mach 3 shows a spiral pattern despite the machine cutting correctly.
tc

10

General Mach Discussion / Still one more question on tool wear

« on: March 03, 2013, 08:41:59 AM »

As the code illustrates, the program is set up for tool wear compensation.  My understanding of how Mach 3 works is that only the diameter of the tool in the tool table is recognized for "wear". This is fine , except that if I enter a tool diameter that's smaller or larger than the actual tool diameter set in the program code, nothing happens.
If, however, I enter only the "offset" that I am looking for, then Mach 3 makes the change. For example, if I have a hole cut at .375 with a .125 diameter tool, entering .120 or .130 in the tool table does nothing.  If I enter +.005 or -.005 in the table, in the tool diameter column, then Mach 3 will open or close the hole by that amount.  Is this the way Mach 3 tool comp works? Or is there something missing in Mach 3 configuration? thanks tc
(POST DEV  - NovaLab)
(NWDTOOL N" 1/8 FLAT ENDMILL" T1 D0. F.375 L2.25 CD2. CL1. SD2. C0)
(NWDSTOCK X5. Y12. Z.375 OTC OX-2.5 OY-6. OZ0.)
N100 G00 G17 G20 G40 G49 G80 G90
N110 T1 M06 ( 1/8 FLAT ENDMILL)
N120 (MAX - Z.25)
N130 (MIN - Z-.25)
N140 G00 Z.25
N150 G00 X1.388 Y1.2101 S2000 M03
N160 Z.2
N170 G01 Z-.125 F36.16
N180 G03 X1.513 Y1.0851 I.125 J0. F26.16
N190 X1.638 Y1.2101 I0. J.125
N200 X1.513 Y1.3351 I-.125 J0.
N210 M00 (WARNING-CUTTER COMP APPLIED ON ARC MOVE)
N220 G41 D1 X1.388 Y1.2101 I0. J-.125
N230 G01 Z-.25 F36.16
N240 G03 X1.513 Y1.0851 I.125 J0. F26.16
N250 X1.638 Y1.2101 I0. J.125
N260 X1.513 Y1.3351 I-.125 J0.
N270 X1.388 Y1.2101 I0. J-.125
N280 G00 Z.25
N290 G40 M05
N300 G90
N310 M30
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