View Full Version : Need Help! MAHO MC600 X-axle keeps on correcting position

03-03-2012, 12:41 PM

I have a MAHO MC600 with a philips 432 control. Building year 1980-1985.

The problem I have is that the X-axle keeps on correcting its position
fowards and backwards all the time. The motor moves forward maybe 1 to 5 degrees clockwise and then counterclockwise 2-4 times per second.

The manner it does this is not really regular. The frequency changes between
2-4 times per second and also the turning in degrees seem to vary between
1 degree and 5 degrees.

This behaviour is independent of the position of the x-axle. At happends on all positions.

I have attached a short video showing what the X-axle is doing.
What do you think could this be?

play in the spindle?
bad contact from encoder to control?
half damaged encoder?
dirt inside of the encoder?
a small damage in the logic control?
a half damage in the servo-power unit?

I have no idea yet. Did somebody else have had a similar problem?
please make suggestions how to narrow down this problem

thank you very much in advance


03-03-2012, 12:51 PM
Can't see the video, however, this is a common problem on early scale machines with dc motors.
Sometimes it's a balance adjustment on the drive
Sometimes it's mechanical backlash. Axis motor feedback does not agree with scale feedback, so it hunts between. I've seen it so bad the machine shakes.
Sometimes it's just a dirty tach on the motor.

03-04-2012, 08:08 AM
Hi onthetire ;-)

thank you very much for answering. I uploaded a mpg-video which was not accepted.
OK I converted it to MOV and reduced the size and the bitrate to get it under 500kB.
I guess you can still see what is happening even if the picture is on its way down to "LEGO-graphic" :-))

Forum-members please take a look into the short video and make suggestions.
best regards


03-04-2012, 01:03 PM
Ok, saw the video. Same answer im afraid. I'd start by checking mechanical backlash.

05-12-2012, 12:33 AM
underthetire is right. Start with the simple things. Slop in the ways, slop in the ball screw bearings, in the ball screw itself. Usually when machines do this, they are trying to compensate for slop. Put an indicator on it and find the slop.

If that is not it, then look at electrical. machines from that age commonly had a drive problem.

09-20-2012, 07:12 AM
Добрый день Stefan. У меня такой же станок MAHO MC600 как и у тебя. Проблема - смена инструмента. Инструмент выпадает из руки. Есть ли у тебя есть параметры пружины сжатия руки.
Спасибо. Юрий.

09-21-2012, 12:52 AM
Hi Zamet,

I want to state my opinion about your posting very clearly:
this is an english speaking / writing forum! SO I expect EVERYONE writing in english. I put your russian comment into the google translator.

From what the google-translator made out of your information I conclude
your problem has other causes than mine. It makes me upset that you took some of my time for a useless answer.

by Stefan

09-21-2012, 01:56 AM
Ziehen Sie sich einen Keil.