[petethered]

Anyone want to play a game?

"Let's guess what the end diagnosis is".

My 440 is having a problem with what I've been calling "x-axis slipping". I'm working with Tormach, but I figured it might be entertaining to take bets as to the final cause. To be clear, I'm going to go through the support process with them since there's obviously something ****ing whacky hardware wise, so you are just spitballing...

TO MAKE IT MORE INTERESTING, ONCE IT'S FIXED THE FIRST PERSON WHO GUESSED RIGHT WILL GET A PRIZE... I'll buy you a Tormach Tshirt or 2 of their coffee mugs ( one for you and the significant other in your life... be it wife, girlfriend, coworker, dog... no judgement here ). US Only.. sorry, not willing to pay international shipment...

I'm bored, and it's not a problem I've seen in any other video, so I figure it will make an interesting guessing game.

---

First, let's see it in action ( I recommend turning your sound down ):

https://youtu.be/34zb0UwXzBA?t=15s

( jump to around 15seconds since the forum isn't respecting the time code )

Anyway, it starts doing parallel passes then in the middle of an X move, it freezes with a "buzzing" noise coming from the motor area, the MACHINE THINKS IT'S MOVING, and then at the next change in direction i starts moving again ( with interesting effects as seen in video one where it plows through the material ).

It happened 3 times on the 22nd, with it working fine for a bit in between ( 2 or three operations ).

It happened on both an XPositive ( operator left to right ) and a XNegative move ( operator right to left ). ( Instance 2 was moving left to right, instance 3 right to left )

The third time I captured it in the video above.

Entertaining, no? That was a very nice piece of hybrid stabilized wood that was destroyed... about $15 in materials and 10mins on the backside ( this was the second operation ) down the toilet.

---

Now, if you were listening, the compressor kicked in right before.... The compressor and the machine share the same surge protector ( a Tripp-light ) and I have a dedicated 20 amp circuit with the machine, compressor, and controller on it.

Electrical noise/interference?

Nope...

This is NOT related to my compressor. I was able to replicate it with nothing but the CNC and the controller plugged into the circuit and surge protector.

https://www.youtube.com/watch?v=9Kwf...utu.be&t=6m45s

( jump to 6m45s since the forum doesn't seem to be respecting the time code )


Replication Steps:

• Get a 440 with the new controller and flood coolant kit in it
• Follow the standard start procedures ( controller, power, estop, green button, reset on pathpilot )
• Ref X, Y, Z
• Load up a dirt simple gcode file ( my test file is a facing pass with 0.5mm y-stepover so it does lots of passes in a smaller amount of space )
• Stick in a tool
• zero the machine somewhere in mid air with 50mm usable x distance on both sides, and 25mm usable on both sides of the y axis ( the origin is centered in a 100mm x 50mm space in my test file )
• Run the file
• Wait for it to happen

And, here is where my "good user, reporting problem WITH test and replication steps" breaks down.

The problem is intermittent, in the video above, it happened at around 6:45 or so... I ran the program a second time for the full run ( 18mins ) and it didn't occur.

---

Some more information:

The spindle does NOT need to be running for it to occur, I've replicated it with the spindle off and only doing the moves.

https://www.youtube.com/watch?v=DMygy9nfIiM&feature=youtu.be&t=25s

( jump to 25seconds since the forum doesn't seem to be respecting the time code )

The "gross" slipping buzzing is not the only thing occurring. In the video uploaded on this one, if you listen closely you can hear it doing smaller versions of it ( buzzing ) and stutter stepping.

---

The first possibility from the engineers at Tormach was the coupler between the X-axis motor and the ballscrew being loose...

This ( of course ) caused me another problem with one of the screws holding the cover plate on rounding out on me... I ended up ordering a pretty cool set of bolt/screw extractors, drilling it out and extracting the screw ( saving the threading in the housing )

Anyway, today the set arrived and I got the screw out. All 4 of the coupler bolts were/are "hand tight"... there was zero play in them at least up to the point that I could hand twist with a T-Handle. I didn't risk putting any more torque on them then what I could do with my hands, but I imagine that if it didn't move then, it was plenty tight... will find out from Tormach Monday probably.





-------

So there we are... I just emailed Tormach ( it's a Saturday, so I'm not expecting to hear back from them anytime soon ) and figured we could play "let's guess what it ends up being".

I'm happy to answer any questions, but not going to do anything with the machine without express directions from Tormach, so no physical tests... sorry.

[petethered]

Oh... that endmill in the first videos is pretty ****ing cool... it's an 3/8 Onsrud 2 flute ZRN Bull nose ( 0.375 diameter ) with a 0.1560 radius! 0.063 flat spot on the end ... I rough out leaving around 4mm on the walls and then do contour finishing passes with this and I get a really sweet fillet.

[MetalShavings]

TIghtening those set screws would be the first thing I'd consider doing. I don't own a 440 but my 770 also has similar set screws. If it was going to slip in any of the axis's, that's where it would most likely happen. It looks like tightening those screws might take care of the problem. Also; before you actually check to see if it did fix the problem, you might consider dabbing a spot of white paint on both the threaded shaft and the collar as a witness mark. If it was loose screws that were causing the slippage, your witness line will no longer align and you'll have some visual confirmation that it was indeed loose screws that were responsible.

I'm not looking for t-shirts. I'm just imagining the frustration of having paid what we pay for our mills only to have it not work as designed.

MetalShavings

[petethered]

TIghtening those set screws would be the first thing I'd consider doing. I don't own a 440 but my 770 also has similar set screws. If it was going to slip in any of the axis's, that's where it would most likely happen. It looks like tightening those screws might take care of the problem. Also; before you actually check to see if it did fix the problem, you might consider dabbing a spot of white paint on both the threaded shaft and the collar as a witness mark. If it was loose screws that were causing the slippage, your witness line will no longer align and you'll have some visual confirmation that it was indeed loose screws that were responsible.

I'm not looking for t-shirts. I'm just imagining the frustration of having paid what we pay for our mills only to have it not work as designed.

MetalShavings

Yeah... I'll admit it's kinda maddening The worst part of the whole thing is that I had the week off work AND the wife was out of town.... I was going to get some quality time in with the machine.

As far as I can tell, they are tight... I couldn't move them by hand with a T-Handle, and I don't want to try torquing it more without clear instructions from Tormach incase it goes sideways on me.

[pickled]

Have you been feeding your Mogwai after midnight or been careless with water around the shop (1980's cinematic reference)? Not sure of the control board/driver configuration on the 440. I had a problem somewhat like this with my 770- only it was the Z axis. What I ended up identifying was that the fast blow power supply fuse to the driver supply voltage for the Z axis had a measurable resistance value. That looked a bit odd compared to all the others. Weirdest thing I had come upon in a while. Usually fuses are orthogonal in nature, but this one was having an identity crisis. I swapped it out and the problem never happened again. Other than that driver cable not being seated or Tormach China didn't apply the correct Armstrong method when tightening screw terminals. The ubiquitous intermittent "ground fault" comes to mind. Systematic troubleshooting is such a joy LOL. Sorry that you are having to deal with this. That stock you are using looks great BTW! It sucks that you lost it that far into the game :-(.

[CountrySmith]

I had a similar problem with my 770. The machine was running Mach 3 through the parallel port.

The machine would suddenly lose/change position. I first observed the problem on the z axis when it tried to bore through the table to the lead screw. Afterwards, I observed it on all three axis

We tried a number of fixes, swapping stepper drives, removing non-essential software, , shut off any external devices, chokes on the parallel cable, different cable, reinstall software. The final solution was to replace the Tormach controller. That was over four years ago and the problem has not reoccurred.

RJ

[Zetopan]

I'm not familiar with the Tormach 440 (1100 owner here) but if you cannot find a mechanical problem be sure to check the X axis drive wiring for a loose connection at the driver end. You may just have a wire clamp that has a loose set screw. If the driver looses connection to one of the motor phases the motor will buzz with very little torque.

[LeeWay]

Has it occurred first thing in the morning on the first run? I have seen warmer connections fault out intermittently, but operate fine when cooler.

[Tkamsker]

I pay for the extra Europe shipping cost if i win - therefore you send the pieces to the beautiful Austria in middle of Europe ok ? ,..


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[shred]

Got any neighbors with amateur radios transmitters? Axis stalling like that doesn't seem likely to be coupling slippage. I'm guessing loose wire somewhere.

[petethered]

Have you been feeding your Mogwai after midnight or been careless with water around the shop (1980's cinematic reference)? Not sure of the control board/driver configuration on the 440. I had a problem somewhat like this with my 770- only it was the Z axis. What I ended up identifying was that the fast blow power supply fuse to the driver supply voltage for the Z axis had a measurable resistance value. That looked a bit odd compared to all the others. Weirdest thing I had come upon in a while. Usually fuses are orthogonal in nature, but this one was having an identity crisis. I swapped it out and the problem never happened again. Other than that driver cable not being seated or Tormach China didn't apply the correct Armstrong method when tightening screw terminals. The ubiquitous intermittent "ground fault" comes to mind. Systematic troubleshooting is such a joy LOL. Sorry that you are having to deal with this. That stock you are using looks great BTW! It sucks that you lost it that far into the game :-(.

So, you're thinking more:

Attachment 332004

vs

Attachment 332006


I admit... I just spent 10 minutes going through google images trying to find a Gremlin with some sort of tool in it's hand

[petethered]

I had a similar problem with my 770. The machine was running Mach 3 through the parallel port.

The machine would suddenly lose/change position. I first observed the problem on the z axis when it tried to bore through the table to the lead screw. Afterwards, I observed it on all three axis

We tried a number of fixes, swapping stepper drives, removing non-essential software, , shut off any external devices, chokes on the parallel cable, different cable, reinstall software. The final solution was to replace the Tormach controller. That was over four years ago and the problem has not reoccurred.

RJ

Hmm... well, that would be interesting... they recently recalled the 440 controllers and gave us new ones, that would mean the new one is bad.

[petethered]

I'm not familiar with the Tormach 440 (1100 owner here) but if you cannot find a mechanical problem be sure to check the X axis drive wiring for a loose connection at the driver end. You may just have a wire clamp that has a loose set screw. If the driver looses connection to one of the motor phases the motor will buzz with very little torque.

Yeah... that's what I figured they would have me do next... check all the wires and fuses. It would be awesome if it was as simple as "opps! loose wire!"

[petethered]

Has it occurred first thing in the morning on the first run? I have seen warmer connections fault out intermittently, but operate fine when cooler.

Well... if memory serves, in the "Nope, not the compressor" test that was the first time I ran that program, so the machine had only been running for as long as the video + ref/jogging/zero time.

The other were for sure when machine was warm.

- - - Updated - - -

I pay for the extra Europe shipping cost if i win - therefore you send the pieces to the beautiful Austria in middle of Europe ok ? ,..


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Sure, but did you actually guess what the problem was?

[petethered]

Got any neighbors with amateur radios transmitters? Axis stalling like that doesn't seem likely to be coupling slippage. I'm guessing loose wire somewhere.

I'd be pretty surprised If I did

I live in Center City Philadelphia...



( My building is sandwiched between that concert all and the tall building behind.

I guess you could run an antenna up on the roof of some of the Brownstones around here, but my guess is there's so much scattered EM and tall buildings you'll get **** signal.

[LeeWay]

I suspect a motor connector pin or similar connection.
Not sure what type they use on them. I haven't even looked close enough at the lathe to see whats on it. I will say that I had very similar experiences with my plasma cutter running a G540. A pin or two would heat up in the motor connection and stall out. It would not do it every day though. Intermittant troubles are the absolute worst to diagnose.

[pickled]

So, you're thinking more:

Attachment 332004

vs

Attachment 332006


I admit... I just spent 10 minutes going through google images trying to find a Gremlin with some sort of tool in it's hand

Yes Sir, that's most definitely what I'm thinking! If you find one of those cruel little ******** raising a raucous in that cabinet I want a new T-shirt for sure!

[MichaelHenry]

There's probably no connection but we found a number of dicey wiring issues inside Tripp-lite surge protectors at work a few years ago. It might be worth removing the Tripp-lite from the circuit for a trial or two and see what happens.

[RTP_Burnsville]

As mentioned above my vote would be for an electrical connection issue (likely a ground connection). I would also suggest a torque wrench for tightening the any critical screws or bolts. Sorry, but hand tight is really not good enough. Also cleaning the interface between the parts being torqued is also a good idea especially couples and such things.

Likely it will be some silly thing, usually is..... Good luck.

Robert

[petethered]

There's probably no connection but we found a number of dicey wiring issues inside Tripp-lite surge protectors at work a few years ago. It might be worth removing the Tripp-lite from the circuit for a trial or two and see what happens.

Really? Since when? Isobar used to be the cream of the crop when it came to surge protection.