Need Help!- BP Series 2,under Mach3...really loosing steps ?

[Jerry7]

BP-High-Priests..please help me with the following.....

Been working on making PET blowing molds last 3 month, with very interesting and good results in terms of accuracy and surface finishing on aluminum.

Machine is a BP-Series 2, ex Boss 6, rigid-ram and currently running under Mach-3, HillBillys BOB, all X,Y,and Z original finned stepper motors and boards yet,,,,, and Mastercam X3 for the CAD-CAM stuff, since 2006, with no visible problems...
Right now machining the first half cavity for the future 1.5 liter container...and here is where the nightmare begins....

Never had any problem with the semi-finishing as well as the finishing machining process before, but at the "roughing" machining, and after 2 or 2 and a half hours running the mill, a sudden erratic and non programmed toolpath took place and ruined the stock of material...mostly in straight line and over X axis.

At that moment, mill was running fine with all the stuff...plenty of propper coolant..spindle speed of 3200 rpm at 32 IPM (800m.m./min) aprox of feed rate with a down plunge step of no more than 0.040 each pass...suddenly and without any warning..X axis increased its routine and in straight line, towards the positive side in 1 inch and more, as I hitted the emergency-stop button.

Checked and re-checked the program...simulated it once again...made some air cutting again....nothing wrong were found...end of story.

Only thing I could noted -if this helps somehow- at that moment, was the X stepper motor temperature... after 2 1/2 hours of machining...you couldnt hardly put your hands on it, but remember, at that time, X motor was doing most of the job, due the block position along X axis...so Z and Y motor were only working for the plunge and the step-over.

Comments will be higly appreciated.!!!

(sorry about the bad english writing).
Jerry7

[polaraligned]

Could just be noise.
You been running it 4 years without a problem? Consider yourself lucky and move on.

[Jerry7]

Thanks so far polaraligned....

Any hint in how to "avoid" this so called "noise" ????.....because been using the mill during last 4 years without real issues doesnt give me any peace of mind....at least after a crash like this.

Could this have been happened due a lack of capacity of the original boards...?..- or because "too much" feed rate value (32 IPM) at that moment ?.... or an X over-heated motor ?...anyway....just wondering.

Thanks again!
Jerry7

[mariolizano]

hola Jerry7 queria preguntate que tipo y marca de driver usas en tu fresadora.
saludos

[jacampb2]

Just out of curiosity, you didn't happen to plug in or unplug any USB devices (specifically flash memory) immediately prior to the problem? The only time I have seen Mach behave this way, is when I plugged in a flash drive while in the middle of a run. Windows did the drive poll/auto start box bit, and Mach just kept on happily sending the z axis through the part, the spoil board, and a good .25"s into the table before my $60 Onsrud router bit exploded...

Curiously enough, my BOB has a watchdog timer, and it was enabled and working, and it did not catch the problem. I am extremely careful about USB now, to put things gently. This may not have been the case for you, but it doesn't hurt to throw it out there.

Later,
Jason

[Jerry7]

Hola mariolizano, gusto en conocerte,,no esperaba ver una respuesta y/o consulta en español en esta zona...en fin...te agradezco nuevamente.
Míra, todo los componentes son absolutamente los originales aún. Lo único que realizé a la fresadora fue anteponer una placa BOB (opto-isoladora o foto-aislante), entre la nueva pc q contiene el Mach3 y toda la electrónica original Textron del equipo, Así la opero desde el 2006 sin aparentes problemas.
Sigo atento...
Abrazo fraterno...
Jerry

[Jerry7]

Interesting point, Jason.
But definitively it wasnt my situation, in fact...mill was running continously during 2 or 2 and a half hours without been touching or disconecting anything.
But from now Ill take care in dont touch or make any move with this kind of devices (USB)connectors during a program run.
Be well.
Jerry