The best way I have found to check the thrust bearings for the ball screw is to use a dab of grease in the little center drilled spot at the end of the screw. Then use the grease to hold a small steel ball bearing in place and put your indicator right on the ball. A regular dial indicator works better than a test indicator because it helps hold the ball in place.
Thanks so much for that Video, I'm having a backlash in my X-Axis and I thought it is the ball screw now I'm going to do all the checks to make sure I repair the right part.
So is that singular backlash number used for center, negative, positive BL settings?Little confused about how I account for all 3 settings? The center BL setting confuses me most. It makes sense that I flip the gauge around for neg and pos positions but center the manual says nothing about how to configure that. I’m using the programmatic calibration.
The three backlash values are for different areas of the screw. A lot of times the center will have more wear and thus more backlash. So the center is just that, the middle third of the screw. The pos and neg and the other 1/3 of each end. You should run the backlash measurements in each area and apply them as needed.
Yes, Fadal has 3 for X and Y, 1 for Z. But it depends on what the machine is doing. If you have two vises on the table then the wear will be at the 1/3 and 2/3.
I have a VMC20 and i indicated x and y and it comes back to zero yet when I circle interpolate large radius i get somewhat of a wave in my circle as opposed to smaller holes 2 inch and under I dont have that issue? could it be thrust bearing under a load?
Thanks for your recent videos. Is it possible to make video about machine capabilty like "learn mode" when you have done with your series? I heard that an operator using learn mode without prob just by touching off the part, program the exact part to dublicate it, I am not sure about what I heard but according to manual sounds possible. what do think?
Yes, LE command. As I have mentioned that I heard an operator without using probe by touching off with an indicator and use of FADAL LE command can reverse engineering a part. I am not sure if I heard it correctly but I think it make sense according to my understanding reading the FADAL user manual.
Good day what do you think it could be happening and check everything mechanical machine and not found problems adjust the backlash to manual mode obeyed pulses pulses but at the time of orbiting in f1000 generates an obbation enbes of a syracuse and there is no difference If the program works with values of backlash or without them has the same error only with a velosity of f15 leaves the measure well for fabor help me to understand
Hello, the translations are a bit rough there. But I think you said you get errors at fast feed rates but not slow feed rates? It might not be backlash at all. Typically when you get a feed rate dependent error check the servo drive gains, balancing, and matching.
@@AtManUnlimitedMachining Hi, I have this exact problem. my backlash value is dependent to the feed, and it is also exacly proportional: the faster i go, the smaller my bl comp should be... everything started when i decided to level the machine (it was really hight on the back) and then i check the survey data, and it was completly wrong in the y (all zeros untill the midddle of the machine and then 10, 20, 30 ecc.). I think that the old owner changed the y axis card without changing the survey. I replaced the datas with the ones that i found, wrote by a fadal operator in the very first calibration in the factory. i also changed the gain in the Y survey from maximum to normal. Now my machine cuts at the exact length in the y (+/- 0,01 mm on 300mm test). then I noticed that my circles now have steps every 90 degrees, when the axis change direction (the problem there was't before, so I think it is not a mechanical problem). My backlash is ok at low feeds, but it should be reduced at hight feeds. I also tested the axis drives: the balance is ok, the signal gain is ok, the following error is correct in the test program. I can't adjust correctly the compensation pot, but i tried ajusting it, and my backlash on fast feed does't change, and the steps on the circles doen't change... I also tried to put back the gain in the Y from normal to maximum again, but nothing change. Any Idea of what is going on? thanks a lot, and sorry for the bad english.
Hello, if your referring to backlash, it will actually show up at the 90 degree points, IE 0,90,180,270 when the axis reverses direction. The controllers do a really good job at compensating for backlash when properly setup. Please refer to this video where we do a circular interpolation with a ball bar and plot the error around the full rotation. th-cam.com/video/GhU7gTWo11s/w-d-xo.html Errors at 45 degree points, IE 45, 135, 225, 315 are typically related to squareness or servo tuning.
Correct, there is a procedure to test and adjust the gains on each servo drive. They are located in the control cabinet on the right side above the card file. I would check that and see if there adjusted correctly and balanced.
Super helpful. Thanks for sharing.
The best way I have found to check the thrust bearings for the ball screw is to use a dab of grease in the little center drilled spot at the end of the screw. Then use the grease to hold a small steel ball bearing in place and put your indicator right on the ball. A regular dial indicator works better than a test indicator because it helps hold the ball in place.
Thank you Wes, I will try that method when I replace the Z ball screw shortly. Never tried that method before.
Thanks so much for that Video, I'm having a backlash in my X-Axis and I thought it is the ball screw now I'm going to do all the checks to make sure I repair the right part.
Many times with Fadal its the thrust washers at the end of the screw and the whole screw moves. Happy hunting and I'm glad it was helpful.
Really cool you make these. Lot of knowledge
Thanks
Hello from China
Thank you! Super helpful!
What is max value of backlash that can be controlled by gain 1851 parameters for backlash control.
For zero position of dial gauge, how much load should be given on dial gauge?
Disculpe se me bloqueo el eje y tal ves se excedió la carrera y no me deja mover el eje me podría decir que hacer? Soy de puebla mexico
How much should be repeatibility of ball screw?
Good morning can you remove ball usillo game?
So is that singular backlash number used for center, negative, positive BL settings?Little confused about how I account for all 3 settings? The center BL setting confuses me most. It makes sense that I flip the gauge around for neg and pos positions but center the manual says nothing about how to configure that. I’m using the programmatic calibration.
The three backlash values are for different areas of the screw. A lot of times the center will have more wear and thus more backlash. So the center is just that, the middle third of the screw. The pos and neg and the other 1/3 of each end. You should run the backlash measurements in each area and apply them as needed.
Or through software?
It should have three backlash comps per axis , because most of the wear will be towards the center of the screw ...
Yes, Fadal has 3 for X and Y, 1 for Z. But it depends on what the machine is doing. If you have two vises on the table then the wear will be at the 1/3 and 2/3.
Ball screw centre out how to setting perfect centre sir please sir tell me
I have a VMC20 and i indicated x and y and it comes back to zero yet when I circle interpolate large radius i get somewhat of a wave in my circle as opposed to smaller holes 2 inch and under I dont have that issue? could it be thrust bearing under a load?
Hello, it could be a number of things, thrust bearings, ball screw, couplers, resolver or encoders..... More testing would be needed.
did you fixed that issue?
Thanks for your recent videos. Is it possible to make video about machine capabilty like "learn mode" when you have done with your series? I heard that an operator using learn mode without prob just by touching off the part, program the exact part to dublicate it, I am not sure about what I heard but according to manual sounds possible. what do think?
Are you referring to using a touch probe to set work offsets and tooling length, diameter off sets?
Ah, ok, your talking about a Fadal command called "Learn Mode" or "LE". Yes I can show the use of that command.
Yes, LE command. As I have mentioned that I heard an operator without using probe by touching off with an indicator and use of FADAL LE command can reverse engineering a part. I am not sure if I heard it correctly but I think it make sense according to my understanding reading the FADAL user manual.
Let me see what I can come up with.
What kind of grease do you use for ball screw lubrication?
I personally use Mobiltemp Shc 32
Good day what do you think it could be happening and check everything mechanical machine and not found problems adjust the backlash to manual mode obeyed pulses pulses but at the time of orbiting in f1000 generates an obbation enbes of a syracuse and there is no difference If the program works with values of backlash or without them has the same error only with a velosity of f15 leaves the measure well for fabor help me to understand
Hello, the translations are a bit rough there. But I think you said you get errors at fast feed rates but not slow feed rates? It might not be backlash at all. Typically when you get a feed rate dependent error check the servo drive gains, balancing, and matching.
@@AtManUnlimitedMachining Hi, I have this exact problem. my backlash value is dependent to the feed, and it is also exacly proportional: the faster i go, the smaller my bl comp should be... everything started when i decided to level the machine (it was really hight on the back) and then i check the survey data, and it was completly wrong in the y (all zeros untill the midddle of the machine and then 10, 20, 30 ecc.). I think that the old owner changed the y axis card without changing the survey. I replaced the datas with the ones that i found, wrote by a fadal operator in the very first calibration in the factory. i also changed the gain in the Y survey from maximum to normal. Now my machine cuts at the exact length in the y (+/- 0,01 mm on 300mm test). then I noticed that my circles now have steps every 90 degrees, when the axis change direction (the problem there was't before, so I think it is not a mechanical problem). My backlash is ok at low feeds, but it should be reduced at hight feeds. I also tested the axis drives: the balance is ok, the signal gain is ok, the following error is correct in the test program. I can't adjust correctly the compensation pot, but i tried ajusting it, and my backlash on fast feed does't change, and the steps on the circles doen't change... I also tried to put back the gain in the Y from normal to maximum again, but nothing change. Any Idea of what is going on? thanks a lot, and sorry for the bad english.
Good as it may be possible that when I do an orbit in X and Y the measurement is fine but at 45 degrees this out of measure
Hello, if your referring to backlash, it will actually show up at the 90 degree points, IE 0,90,180,270 when the axis reverses direction. The controllers do a really good job at compensating for backlash when properly setup. Please refer to this video where we do a circular interpolation with a ball bar and plot the error around the full rotation. th-cam.com/video/GhU7gTWo11s/w-d-xo.html
Errors at 45 degree points, IE 45, 135, 225, 315 are typically related to squareness or servo tuning.
Thank you very much for your support and boy to review your video
Thanks for the comments and for watching!
You mean the gains of the servo amplifier card ga4568ea
Correct, there is a procedure to test and adjust the gains on each servo drive. They are located in the control cabinet on the right side above the card file. I would check that and see if there adjusted correctly and balanced.
Ok I'll check and let you know
Can't see nothing