What's new
What's new

89 Maho MH600C Y axis problems

markp

Hot Rolled
Joined
Oct 7, 2006
Location
Petaluma CA 94952
My Maho MH600C has been working well for several years with no issues. I went to home it yesterday and it gave an 09 error in vertical Y axis (Z axis as I am configured). I had the 4 the axis dividing head on the table so I took that off to remove some weight. Same error. I tried reversing the direction to home by changing constant 280 to reverse the limit switch approach direction and same error. I removed dynamic following in that axis and now no error but the axis still does not move.

However, I noticed that after pressing the -Z once, the Y axis (Z axis as I am configured) servo motor was spinning until I reset the control. No weird noises, just the sound of the servo spinning if you get close to it. I cant get in there to see until I remove the apron. Im guessing that just requires removing the top and bottom button head allens at the hinges. Not much room to see even then as the table is all the way down. I might just lift it up a few inches. Think its either a broken drive belt or something funky with the clutch. The axis does not drift during any of this. Anyone have any suggestions? I dont see any reference to mechanical problems with the Y axis on the forum.
 
Mark-- does this have the motor mounted in the base (at the rear of the column)??

One problem I had (it cropped up a number of times) is that oil would drip down the vertical ball screw, through the thrust bearing stack and into the clutch on the bottom of the screw. Incredible pia to block the table, remove the belt, drop the clutch off the bottom of the screw, clean and reassemble.

In failure the servo would spin continuously (as the clutch was slipping) as it tried (unsuccessfully) to drive the axis to position. On mine it was just as bad in both directions.
 
I found and read the thread about your issues with the vertical axis. I got my borescope and had a look underneath. The belt looks ok. Powered up and with the feed set at 5% I pushed the -Z axis button and the motor started buzzing. I could see the pinion was oscillating a few degrees back and forth. I felt under there and its moving at a low frequency back and forth. Im not getting any errors on screen.

On the Indramat drive. With the drive at rest, the LED's are the same on all the drives. On the Z drive, once activated as above, the BLC2 led (rotor position detector) flickers at about the same frequency as the motor pulley is oscillating. The LEDs below BLC2 are lit. I havent had an extra person around to push the feed on the other drives to compare LEDS yet. Bad tachometer? I read somewhere about magnets coming unglued in the tach....
 
I pulled the end cover off of the Y axis motor. Dont see any magnets maybe under the electronics board? Also, I found the easy way to lift the Y axis up. Theres a hex cap screw on the end of the motor shaft. Just put an allen in there and you can jack the table up. Theres even a small cap on the center of the cap so you dont even have to take to cover off. All you need is a penny to unscrew it. Now I dont get a limit switch error 05.

I had someone push the axis buttons and in the three working axis, the rotor position LED activity, BLC2 and BLC1 (or BLC3) jibe with the manual description for their operation: ie: When the motor moves correctly, two of those three LEDS are supposed to flash alternately. On the vertical Y axis, only BLC2 will oscillate when activated.
 
I was able to isolate the problem to the Z axis Servo Drive. I released the brake on the Z motor by applying 24vdc at pins F and G on the power connector and made sure that the motor/ballscrew could be rotated smoothly with an allen wrench. Then swapped the Z and X drive wiring. Z axis then worked fine, kept the speed to 5% as I didnt switch the personality modules. X now has the same error as Z had. Ordered a used drive off fleabay for 280. Ill get around to looking at the old drive one of these days.
 
I received the drive, swapped the personality modules and installed it today. Everything seems to work fine! Its a newer rev drive. mine was 1988 vintage, this is a 97 vintage. FWIW I got this from Nutek Sales on ebay. They were professional to deal with, (they put it in a static bag and packaged the drive correctly), unlike a lot of other machine tool related purchases Ive made on ebay. .
 
Mark-- does this have the motor mounted in the base (at the rear of the column)??

One problem I had (it cropped up a number of times) is that oil would drip down the vertical ball screw, through the thrust bearing stack and into the clutch on the bottom of the screw. Incredible pia to block the table, remove the belt, drop the clutch off the bottom of the screw, clean and reassemble.

In failure the servo would spin continuously (as the clutch was slipping) as it tried (unsuccessfully) to drive the axis to position. On mine it was just as bad in both directions.

Hi Sneebot, Sorry for replying on an old thread.
I have a maho MH500E and I have the Y (Z for me) axis shakking. It got worst and worst. It still is precise but when travelling at rapid the whole machine is shaking. Do you think it could be related to the same thing ? I have the same configuration with motor on base and a lot of oil at the base of the ball screw.
Do you need to block the table to disassemble the cluth as there is the brake activated ?

Thanks a lot
 








 
Back
Top