Servo noise on a sharp 2412?

[longcut]

I was just curious if anybody else had a similiar problem. During a part change, (program ended M30, waiting for cycle start) I noticed that the servos (I'm assuming) tend to make a a noise that is soft at first then increases the longer it sits. If I go into MDI or just move one of the axis it goes away. Granted, I have a very quiet shop at night so it probably would not be noticed in the standard work environment, but I don't recall it did when I bought it...about (3) years ago. Not a big deal, just want to make sure I'm not doing something wrong or making it worse buy ignoring it. Thanks

[wisp]

Hi longcut, i have a 2412, and it doesn't make any noise like you describe. It sounds like the servos are "hunting". this usually happens when the gain is not set properly in the control. basically, when sitting still, the servo jumps back and forth between marks on the encoder. Hunting is nothing major, its actually normal, but you will need a maintenance man, or someone who can tune them on a Fanuc control to where you cannot hear them hunting. If they get REALLY out of tune, the hunting will get so violent the table/spindle will jerk back and forth.

Also, you may want to adjust your gib strips per the instructions in the manual, if they have wore and loosened up slightly, this may be allowing the table to move a tenth or two, and creating the hunt in your servos, just an idea, i am not maintenance pro. I adjusted my gibs last weekend, took about 2 hours, but was not hard to do.

cheers,
Michael

[longcut]

I appreciate the information. I did get in contact with sharp and their tech said the same thing.... maybe making a change in the parameter would help also.
I would like to check the machine gibbs though. (basically because I'm anal
Did you come across any problems with how they explained it in the manual? I have found that some explanations are pretty vague.
I did replace the tool clamp cylinder, pulled the belleville(sp) washers out and disassembled more than I needed to do so. (tool holders weren't releasing) A local machine builder had stopped by to pick up a table to be scraped and mentioned that after too long I'd be down to the leveling screws! LOL Matt

[wisp]

Yea, the manual is written in Koreanglish and can be a challenge to read. To adjust the gibs:

1. Remove way cover screws and slide the covers back.
2. loosen the gib locking screw two turns, it’s on the right side of the table for X and the front for Y.
3. tighten the adjusting screw as tight as you can, then back off one turn. Adjusting screw is on opposite side of table.
4. tighten the locking screw
5. replace way covers

The locking screw for the Z is on the bottom, the adjusting screw is on the top side.

Don't forget to check your machine for level once a year though.....

BTW, do you put any oil in the small reservoir above the spindle, near the tool change cylinder? I didn't see any mention of it in the manual, or what type of lubrication goes in it. I have been putting DTE light in it, the same as the air oiler takes.

cheers,
Michael

[longcut]

I think I have been using the same type, DTE 32 turbine oil. I have not checked the level because I just replaced the air/hydraulic cylinder a few months back. Some of the early ones (mine) had air only and was not building enough pressure to compress the bellville washers. (They didn't even charge me when it was out of warranty!...of course I did the work but I think the cylinder alone was worth $1000.00)
I can't say enough about Sharp. Granted it's not an OKK work horse, but I only do part time work and the service from Lot and Charlton is very helpful.
The box ways at the price they are selling machines is way above comparison. When the "bullets" start hitting the sheetmetal and the spindle torque shows 50-75%, I'm glad those aren't linear guides I'm riding on! Keep in touch -thanks, Matt

[krfrea]

longcut, I have had my 2412 for a year now and have not been able to find where to read the spindle torque...can you help me out please.