Mercury II vibation on start up

[Albert Nix]

When I start the Laser up for the first time during the day I notice what seem to be a vibration as the table drops. After that I can manually raise and lower the table and it is smooth as silk and if you turn it off and back on again it does fine for the rest of the day. Could it be one of the bearing on the table or do I need to lub the screws that raise and lower the table. Could it be to much slack in the belt? Any Ideas?

[James Terry]

My Mercury does this too. It is the table screws vibrating or resonating. As long as the table continues to work, it really is not an issue since the table does not move during a job. Look in the manual and see what they suggest for a lubricant. I'm sure the screws could use a complete wipe down and then a fresh grease application.

I asked the group once if the self test could be canceled or at least the table drop removed but it doesnt look like it can. There is no adjustment to resolve this issue other than a good greasing.

[Chuck Stone]

If it is shaking while the table is moving up/down, I would check the focus and
compare the top left corner to the bottom right corner and see if it is off. It
sounds like the table isn't level. Lubricating the worm gear might quiet the
noise, but it would only be masking the problem. Something might have loosened
up in there.. could be a table mount, motor mount.. dunno, I'm not a tech. But
that's my guess..

[Rodne Gold]

White lithium grease is a good lube for the lead screws, there is a way of stopping the table drop during boot up , its in the machine menu somewhere. There is no ways to stop boot up x/y axis moves unless you go into the diagnostic mode. The machine need to index the axes and stepper motor encoders on normal boot up

[Albert Nix]

Thanks guys..I will check to be sure nothing is loose...I did spent a little extra time cleaning the lead screws this morning and it worked smooth with no vibration...The screrws may have been a little gummy...I didnt really notice anything out of the way.

[AL Ursich]

Try this test.... Run the machine for an hour then shut it of for 15 min and turn it back on.... What do you get?

Many times it is the Windings of the motors vibrating before they warm up. Little gaps between the wound wires covered with insulating varnish. Even my old Navy Analog Computer did this as the motors came up to temp....

Betting that after the 15 min off that it makes less noise.... But that is reflected in your first post..... Then there is the Driving Components, the position feedback circuits stabilizing for temp....

If it was a Bearing issue then it would do it every time...

Just another WAG..... Wild AL Guess....

AL

[Richard Rumancik]

I think the reason it only does it on start-up is that GCC picked a motor speed during start-up that excites the resonant frequency of the table/supports. When you do a manual table height change, the speed is different. Mine does the same as Albert's. It sounds a bit nasty during the table drop but it lasts only a few seconds, so I haven't been motivated enough to find out how to eliminate it.

The reason for the table drop during startup is to prevent crashes if you happened to leave a fixture or tool on the table. But I suppose that if you never do that removing the operation would be okay. I haven't seen it in my manual however.

[Albert Nix]

After I did a real good cleaning of the lead screws yesterday the problem has not returned....got my fingers crossed.