Fadal 4020 Squealing

[Bakeng]

This is driving me crazy.
I have a Fadal 4020 with a centroid control.
When machine cuts in x axis around a square with a finishing pass removing .015" it cuts smooth as silk. When it gets to the y movement it squeals like crazy (see video).

I have had a fadal tech that's has been a tech for fadal for a very long time. Has him stumped.
In the last few years the machine has had the following;
New ball screws
New thrust bearings
New saddles and gibs
New Spindel
New Draw bar

I have extensively checked gib settings, head movement (0), etc.

 

[EmGo]

When it gets to the y movement it squeals like crazy (see video).

That's called "chatter". Why just in Y I don't know but could you kick the feedrate up from snail to tortoise, maybe ?

 

[Speedie]

Put and indicator on the spindle and the tip to the tslot. Grab a pry bar and try to see if you get any play. It could also be servo feedback

 

[Bakeng]

0 play in all directions (.0001"-.0002")
I have tried feed rates from 1ipm to 50ipm and rpms from 300-4000 all squeals in y.

 

[Bakeng]

Servos have bin tuned multiple times.

 

[pcasanova]

try swapping x-y drives and see if if issue follows, and if no change, swap the servos between y-z. disconnect the servo on the y and see if it moves by hand freely. This is a pain, but swap the z-y servos and see if the issue follows. I had a z that would stutter and drop, replaced the ball screw same thing. swapped servos and problem followed the servo. Like I said a pain and had to reset the z tool change parameter but figured out what it was.

 

[EmGo]

Guys, watch the video. It's screaming like a stuck pig because he's not feeding it. At 1,000 rpm and no depth of cut and .1 ipm feed with the cutter stuck out a foot, yes it's going to chatter. Why in just Y is kind of a mystery but the whole process is not good. (Polite way of saying machining parameters are crap)

 

[Pat (pti)]

What are your cutting parameters, material, and endmill?

Does your machine make the same noise when you move the axis while not cutting?

Have you tried any other materials with the same results?

 

[RC Mech]

I retract my earlier “like”. Having watched the video, kick it up to a real aluminum feed rate (60+ IPM) and use a 3 flute end mill rather than whatever 4 flute coated totally incorrect end mill you’re currently using.

 

[Garwood]

That's a strange one.

Touch stuff- put your hand on the part, the vise, the spindle housing.

 

[70olds]

Am I crazy or is the machine "movement" in X (table moving left and right) while this is happening, not Y? I have never seen t slots in the Y direction before so I assume you are looking at this from the front of them machine. Are Fadals built or named differently?

Stupid question but does it make any noise if you run the same program but move the cutter away .050"? What about running 2" above the part? We have a MacTurn that squeals very similarly if you are in the right part of the stroke but it's just the way the way covers sit.

 

[EmGo]

Am I crazy or is the machine "movement" in X (table moving left and right) while this is happening, not Y? I have never seen t slots in the Y direction

By jove, missed that as well, you're right, he's got that flopped too.

Just jack up the feed and use the right end mill, to start with. Example

https://files.catbox.moe/dg3wrj.mp4

 

[DouglasJRizzo]

By jove, missed that as well, you're right, he's got that flopped too.

Just jack up the feed and use the right end mill, to start with. Example

https://files.catbox.moe/dg3wrj.mp4

Just noticed that as well. It's chattering in X. He's also barely crawling through the part and that cutter looks like it's scrubbing more than cutting.

 

[EmGo]

that cutter looks like it's scrubbing more than cutting.

He could maybe replace it with one of those shredded stainless steel pot scrubbers wrapped around a dowel, would work better

 

[13engines]

Workholding. Something about that vise or how it's being used is crap. Take that same chunk out and toe clamp it left side and right to the table and make the same cut in X (not Y) as you're doing now. The end mill is fine. The speeds could be better. But the huge difference in X and Y cutting sound says workholding to me. That or looseness in the Z axis ways or a Z axis tilt or tram issue. Also like Garwood said, put your hand on things, but try not to loose any fingers in the process.

You might try another end mill whether it's squealing or not. Sometimes if you have an end mill with an overly wide primary relief land they'll want to squeal. Especially on large length to diameter cuts.