Avid Benchtop Pro Crashing into nothing

[AlpaccaSlapper]

My 1 week only avid cnc benchtop pro 3x2 with nema 34 motors has developed a strange issue where seemingly randomly one or more of the axis will lock up like in a crash. It has happened while manually jogging the machine, while the machine is running a program, and while the machine is going to a offset location like the MTC location or the work offset zero. Once it happened during a program, and i was slow to hit the estop so i noticed that after about a second of being "crashed" the machine kept working as normal but had lost a significant amount of steps. So far I've mechanically checked both x and y axis and found no signs of anything that could cause an issue like this. My wireing generally seems pretty neat, but all the slack is birds nested in a heap under the table the router is on. I havent run the windows settings optimizer thing avid recommends since i use my "cnc control computer" (laptop) as my main work computer too.
Wondering if anyone has thoughts about what this could be. Thanks for reading!

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[ger21]

Something may be binding.
Acceleration may be set too high.
Something in the PC may be causing it.

[Samsancas]

Hi AlpaccaSlapper. I'm having the exact same problem. And I even check the same things. Did you find a solution for your issue? I have AVIDCNC 4896 PRO with the same motors, NEMA 34.

[CNCMAN172]

This sounds like EMI noise to me. Try moving the machine around with the power to the spindle removed. If it works correctly with spindle motor off it is clearly EMI

[mactec54]

My 1 week only avid cnc benchtop pro 3x2 with nema 34 motors has developed a strange issue where seemingly randomly one or more of the axis will lock up like in a crash. It has happened while manually jogging the machine, while the machine is running a program, and while the machine is going to a offset location like the MTC location or the work offset zero. Once it happened during a program, and i was slow to hit the estop so i noticed that after about a second of being "crashed" the machine kept working as normal but had lost a significant amount of steps. So far I've mechanically checked both x and y axis and found no signs of anything that could cause an issue like this. My wireing generally seems pretty neat, but all the slack is birds nested in a heap under the table the router is on. I havent run the windows settings optimizer thing avid recommends since i use my "cnc control computer" (laptop) as my main work computer too.
Wondering if anyone has thoughts about what this could be. Thanks for reading!

Take some photos of the wiring you either have a Ground loop or EMI, that could be causing this problem, a pile of cable can be a bad thing also, so try and tidy that up.

[subnoize]

I had an issue where the fully threaded "Tension Post Fastener" would catch on a misaligned "Tension Bracket" and at first the axis would appear to lose steps. (https://www.avidcnc.com/support/inst.../rpDrive/#4318)

I have suggested to the factory that the M8 x 90mm Hex Cap Screw should partially threaded. Something like McMaster-Carr 91310A562 (the threading isn't long enough though)

If you look at the tension assembly on the axis and push down on the head of the bolt (or Tension Post Fastener) it should push the pinion gear off the rack easily. It is doesn't move then the bracket is catching the threads.

When that assembly fully freezes up from the bracket alignment engaging the threads you will get some serious play in the axis.

While I haven't yet changed over to the partially threaded bolt myself, I am waiting for the excuse to do so. When I do I will use a lite machine oil on the unthreaded portion, nothing drippy though.

As of today the tensioner assembly is on my "pre-move" checklist and I watch them like a hawk.

[mactec54]

I had an issue where the fully threaded "Tension Post Fastener" would catch on a misaligned "Tension Bracket" and at first the axis would appear to lose steps. (https://www.avidcnc.com/support/inst.../rpDrive/#4318)

I have suggested to the factory that the M8 x 90mm Hex Cap Screw should partially threaded. Something like McMaster-Carr 91310A562 (the threading isn't long enough though)

If you look at the tension assembly on the axis and push down on the head of the bolt (or Tension Post Fastener) it should push the pinion gear off the rack easily. It is doesn't move then the bracket is catching the threads.

When that assembly fully freezes up from the bracket alignment engaging the threads you will get some serious play in the axis.

While I haven't yet changed over to the partially threaded bolt myself, I am waiting for the excuse to do so. When I do I will use a lite machine oil on the unthreaded portion, nothing drippy though.

As of today the tensioner assembly is on my "pre-move" checklist and I watch them like a hawk.

Only someone that has one would know this, so good information. can this happen at any random point in the travel??

[subnoize]

In the beginning when it first freezes, it will freeze at its highest point of travel. Thus it will introduce a tiny bit of backlash in the beginning. Over time the rapid changes in direction of the axis will push the frozen tensioner further open and the backlash will grow. As the backlash grows the axis will swing more wildly and yes, it looked very random to me. I had one side of my Y axis freeze up and since that side was swinging back and forth freely, movement in the X axis also introduced movement in the Y axis.

Another quick way to check the axis are fully engaged in the rack gear is engage the motors and push and pull on each axis. Any wiggle in there is a problem. Then check the bracket and tensioner post has free motion. AND that the tensioner post returns to fully engage the pinion gear into the rack. Mine would push down but not return to fully up.

Have you eliminated Windows from the picture? Keep networking turned off, uninstalled any antivirus. Turn off ALL programs in "Start at boot."

Problems with Windows can look like "crashing" at random times.

[mactec54]

In the beginning when it first freezes, it will freeze at its highest point of travel. Thus it will introduce a tiny bit of backlash in the beginning. Over time the rapid changes in direction of the axis will push the frozen tensioner further open and the backlash will grow. As the backlash grows the axis will swing more wildly and yes, it looked very random to me. I had one side of my Y axis freeze up and since that side was swinging back and forth freely, movement in the X axis also introduced movement in the Y axis.

Another quick way to check the axis are fully engaged in the rack gear is engage the motors and push and pull on each axis. Any wiggle in there is a problem. Then check the bracket and tensioner post has free motion. AND that the tensioner post returns to fully engage the pinion gear into the rack. Mine would push down but not return to fully up.

Have you eliminated Windows from the picture? Keep networking turned off, uninstalled any antivirus. Turn off ALL programs in "Start at boot."

Problems with Windows can look like "crashing" at random times.

I must be a lucky one as I have never ever had a windows problem, in over 20 years, I build my own machine computers though.

[subnoize]

I must be a lucky one as I have never ever had a windows problem, in over 20 years, I build my own machine computers though.

That is good then! I found that no matter the machine, most Mach4 users are cutting wood and not holding a high enough tolerance to see the stuttering cause by Windows doing its thing. And that is "all good" as they say!

You really don't need much of a computer to run Mach4. It isn't Mach4 that causes the problem anyways. Custom building a PC for running Mach is a bit overkill IMHO.

I just upgraded to a MeLE J4125 running Windows 10. I wrote a custom plugin that looks and disables wireless when you hit the cycle start and reenables it on completion.

You can pick them up for cheap here: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[mactec54]

That is good then! I found that no matter the machine, most Mach4 users are cutting wood and not holding a high enough tolerance to see the stuttering cause by Windows doing its thing. And that is "all good" as they say!

You really don't need much of a computer to run Mach4. It isn't Mach4 that causes the problem anyways. Custom building a PC for running Mach is a bit overkill IMHO.

I just upgraded to a MeLE J4125 running Windows 10. I wrote a custom plugin that looks and disables wireless when you hit the cycle start and reenables it on completion.

You can pick them up for cheap here: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

That is almost the same as the computer I build which I mount the same way on the back of a 12" monitor.

I have a 10" touch screen tablet that run windows10 and runs any of the cnc software packages also.

The stuttering you are talking about is call the jerk factor, which has nothing to do with the computer, this is a Drive and motor problem. when using steppers, you will always see this just the nature of the beast, I only build machines with Ac servo with 20Bit Encoders you never see the jerk factor with high PPR Encoders

[subnoize]

The stuttering you are talking about is call the jerk factor, which has nothing to do with the computer, this is a Drive and motor problem. when using steppers, you will always see this just the nature of the beast, I only build machines with Ac servo with 20Bit Encoders you never see the jerk factor with high PPR Encoders

Yep, we are talking about completely different things

I am talking about how an improperly configured Windows machine can cause starvation of instructions to the Ethernet Smooth Stepper. Makes for fun machining (sarc) until you nail down the issue.

I have a touchscreen mounted to the frame and that is it for the interface.

[mactec54]

Yep, we are talking about completely different things

I am talking about how an improperly configured Windows machine can cause starvation of instructions to the Ethernet Smooth Stepper. Makes for fun machining (sarc) until you nail down the issue.

I have a touchscreen mounted to the frame and that is it for the interface.

That and a Handwheel is all that is needed

As I said before it would have to be a really bad computer, for it not to be able to supply enough instructions to the Smooth Stepper buffer to keep it going.

[subnoize]

As I said before it would have to be a really bad computer, for it not to be able to supply enough instructions to the Smooth Stepper buffer to keep it going.

I am now more certain we are talking about completely different things and that is a good thing.

I am really happy you have had a positive experience. That always is good news.

To AvidCNC's credit their setup script does a great job of eliminating all of the known issues.

[Exflueger]

My 1 week only avid cnc benchtop pro 3x2 with nema 34 motors has developed a strange issue where seemingly randomly one or more of the axis will lock up like in a crash. It has happened while manually jogging the machine, while the machine is running a program, and while the machine is going to a offset location like the MTC location or the work offset zero. Once it happened during a program, and i was slow to hit the estop so i noticed that after about a second of being "crashed" the machine kept working as normal but had lost a significant amount of steps. So far I've mechanically checked both x and y axis and found no signs of anything that could cause an issue like this. My wireing generally seems pretty neat, but all the slack is birds nested in a heap under the table the router is on. I havent run the windows settings optimizer thing avid recommends since i use my "cnc control computer" (laptop) as my main work computer too.
Wondering if anyone has thoughts about what this could be. Thanks for reading!

Hi There
Did you ever found the root cause? I have suddenly the very same Problem after about two years of flawless operation of the Desktop Pro with Mach3. It came from one day to the ohter and I have no clue where to search more.
Thanks for any answer / hint
Roman