[thebodger]

Does the Y axis have hydraulic counter balance? If yes, check that it's working correctly.

[underthetire]

I know the first high speed Mori horizontals had a problem overheating the y axis motors, they actually came out with a retrofit to install the Fanuc fan shroud around the motors. Might want to look in to that, I know Fanuc still supplies them as I just installed one on a retrofit package at work.

[onemanshop]

Does the Y axis have hydraulic counter balance? If yes, check that it's working correctly.

Does not have a hydraulic counter balance, just the motor brake.

[onemanshop]

underthetire thanks for your answers.
I want to lift the spindle head up by itself to see if it will slide down freely and work on adjusting the gibs if does not come down.

[onemanshop]

Appears to confirm tuning problem, gain too high?
Al.

I will also look into adjusting the gain.
I am wondering if the gain is high because the motor is removed and has no load. Under normal condition this motor holds the whole spindle head.

[Al_The_Man]

Normally the motor should not vibrate or get hot when disconnected from the machine, if this is a vertical axis and there is considerable back feeding force, then the axis also requires proper counterbalance in place.
I am wondering if the original tuning was to overcome this back feed force?
Al.

[tc429]

Dont recall parameters on a 15, but i would first look at " load inertia" parameter setting... Uncounterbalanced machines ive seen often had a fairly large number in there(usually must be zero if motor is uncoupled).

Reducing load inertia ratio parameter usually softens response at short,slow,small movements, often crank it up a bit for stickslip issues. Reducing this a bit *might* cool the servo a bit, at expense of following error increase...

It sounds like you may have a serious stickslip thing going on, with no counterbalance the slide should drop like a rock- machine destroying type of thing- surprised the slide didnt drop with motor removed(assuming it was blocked so it couldnt drop much at all).
Is the way lube working properly? Ive gotten a few sticky machines to free up by adding like a half teaspoon of tungsten disulfide powder well mixed with a quart of way lube, dumped into the tank, pump the heck out of the lube... It leaves a film behind slick as snot- use at own risk, i havent had any issues with plugging any injectors or anything as the powder is submicron... I bought it here: Lower Friction stuff stinks like puke and dog crap, but only up close, sure frees up sticky sliding surfaces, seen currents drop from >80% to 25 in minutes, and stays there months later, running standard oils after the one time additive... Was never a believer in snakeoil claims, but i hurt the 2nd synchro in my mustang at the track powershifting, put up with a balky 2nd for a year, was going to get the $ynchro kit from ford, but a buddy suggested first just try royal purple atf... 80 bucks, what the heck... 15 minutes after the change, 2nd was better than ever, felt like a new tranny, shifting at 6k no problem, no more 'lockouts' 3 years later still fine... Some of the synthetics/additives these days are pretty slick (haha)

[onemanshop]

Dont recall parameters on a 15, but i would first look at " load inertia" parameter setting... Uncounterbalanced machines ive seen often had a fairly large number in there(usually must be zero if motor is uncoupled).

Reducing load inertia ratio parameter usually softens response at short,slow,small movements, often crank it up a bit for stickslip issues. Reducing this a bit *might* cool the servo a bit, at expense of following error increase...

It sounds like you may have a serious stickslip thing going on, with no counterbalance the slide should drop like a rock- machine destroying type of thing- surprised the slide didnt drop with motor removed(assuming it was blocked so it couldnt drop much at all).

Thanks for the hint.
It looks like it sticks, I ordered the tungsten disulphide powder it sold by the pound, you said half of tea spoon - it will last me forever.
Am still working on the machine got the ball screw out and I am checking it out.