Backlash

[Delw]

FIgured I would mention this incase anyone has been having some backlash issues and want to start adjusting the parameters.

Before you adjust the parameters check to see if the couplings are tight from the motor to the ball screw. its one of those thinsg athare are ALWAYS over looked.

I had some funny sounds coming out of my z axis laterly, I was and still am leaning towards a balls screw. so while the machine was running I jumped on a 55 gal drum to watch and see if I could find the sound.

What I did notice was that the motor was moving both directions but the ball screw wasnt right in tune with the motor.

shut the machine down and went to check the set screw, sure as crap it was backout 4 turns but it was tight. once I tightend it back up things were fine and my back lash was .0003 instead of .004 -.005.

Since I bought this machine I have noticed a not so smooth rapid down, I mean its quiet and all but being around machines for most of my adult life you sence something is not right. it kinda had a hick up only on fast rapids down. its gone now

this machine was a complete rebuild with supposibly all new motors ball scews and bearings. Unfortuantly I trust people, fortunately fadals are not expensive to repair.

So far the only new part that I found was a few screws in the "Y" axis covers and the lexon windows.

the machne kicks butt and rns like a champ and holds size. up until last month I didnt have any problems, then a magnet fell out of a motor. last week I replaced the motor cause another one popped off and didnt want the 3 days down time or to dick with it again.

now I just have to fix some board issues with doing helical threading work and not get a motor overload #12 error.

Delw

[Delw]

oh yeah someone want to talk about how to properly tune your drives? I havent found it in the books yet but havent looked all that hard either. but that is next on my list before I start working on the board issues.

[carbidecraters]

If I had a machine with .004 backlash I would be frightened

[Delw]

I never checked it and never had really any "z" issues as far as size, yesterday I had heard the noise so I figured I would check backlash to see how bad the ball screw was. I was like oh crap better set backlash in the am.

I am curious how I was able to hold .001 thickness's from end to end on 10" parts.
the only thing that had me curious about anything was I always has some coining with a 3/8" enmill doing a finish pass after a pocket rough. the 5/16 1/8 and even 3/32 no problems with coining on there smaller part families.

now tell me how to tune my drives cause I know you know how

[carbidecraters]

Del what year and what size Fadal was it? If it was between 1992-1996 (3016-8030) you would have had AMP-0021 axis amps. If your servos are loud then you may need to turn them down but if not they should be CRANKED. Servo axis amps will not control axis errors. You could have carbon tracking, an issue with the encoder/resolver issue if you have positional errors. It sounds like if the mount was loose it has seen some crashes. Not the end of the world Fadals are built pretty damn well and if you damage a part it can be replaced and IS readily available.

[carbidecraters]

Funny thing about Z axis is if the mount gets loose (which is common) you will hear a BAM when cold starting and peck drilling it will sound like a little ...booom....boom. You can live with it or fix it. The reason it holds good accuracy is gravity in that it will jump back to position after a few turns of the ballscrew and you will rarely see an issue....strange isnt it? Sometimes you can get error #12 motor overload if you dont put a M30 in a program and sometimes it will say "spindle controller does not respond"..this happens on early -4 systems but is consistant if you run a program without a M30 at the end. When does the error occur?

[Delw]

Originally Posted by carbidecraters Del what year and what size Fadal was it? If it was between 1992-1996 (3016-8030) you would have had AMP-0021 axis amps. If your servos are loud then you may need to turn them down but if not they should be CRANKED. Servo axis amps will not control axis errors. You could have carbon tracking, an issue with the encoder/resolver issue if you have positional errors. It sounds like if the mount was loose it has seen some crashes. Not the end of the world Fadals are built pretty damn well and if you damage a part it can be replaced and IS readily available.

I have a 95 /96 40/20 with a -5 system it also has the big axis servo motors
I was under the impression that you tune the axis to get a perfect( for a fadal) circle.

Originally Posted by carbidecraters Funny thing about Z axis is if the mount gets loose (which is common) you will hear a BAM when cold starting and peck drilling it will sound like a little ...booom....boom. You can live with it or fix it. The reason it holds good accuracy is gravity in that it will jump back to position after a few turns of the ballscrew and you will rarely see an issue....strange isnt it? Sometimes you can get error #12 motor overload if you dont put a M30 in a program and sometimes it will say "spindle controller does not respond"..this happens on early -4 systems but is consistant if you run a program without a M30 at the end. When does the error occur?

good point I thought of that about gravity , but figured the counter weight would offset that, I peck drill over 300 holes a day on that machine,

I get the motor overload error #12 when doing a helical thread almost everytime and always comes up on the x or y and never comes up on the Z doesnt make any difference wre the selector is either.
but funny you should mention it cause I am tracing that POS problem for the last 1.5 years.

however once a month I get one while running g18s at high speed 60IM+ but very rarely

fadal and one of the techs in montana say its a a board issue, if you look at the error phrase thats what it shows. checksum error. checksum is usually a mathematical error. in talking with a few techs I was told that some software is bad for this. also someone mentioned it on this website last year. from info I got from the techs I changed every number on the circle including running the feed rates in increments of .5from .5 to 150.5 always the same thing ( not via pot but by program)


A tech here told me it was a resolver issue.
when I replaced the x motor a week ago the first thing I tried was the helical threading on a test part. worked great for 20 test programs,with 3 turns to 40 turns I am thinking f'n a about darn time.
ran some normal jobs and figured I would try it again oooops motor #12

I havent changed the resolver on y axis yet( thats the one the local tech said was bad).
then today I saw the motor in the z problem havent tried helical yet. I will try it tommorrow if that dont work I have a resolver to put into the Y axis also, then if that dont work it has to be boards.

the boards they mentioned it would be is the 1030 board and one of the drive boards but which one?.

hope that wasnt too confusing.

Delw

Delw

[Delw]

Carbide,
I ran the threading program this am. 4 times no problem 5th time problem then 2 times no problem then it was a problem every time.

Changed some of the values worked for a while no problem, then problems.

[carbidecraters]

Take a sharp stick and chase that gremlin out of there you got work to do

[carbidecraters]

Seriously Dell I would check your relays. Unplug them and swap them to different locations. Sometimes gunk and vibration causes a relay to give weird signals. Do you ever hear clicking in the side cabinet?