Mill center HURCO VMX 40/50 - broken spindle drive belts

Hello to all the specialists - magicians
The machine is Hurco VMX40 / 50. The spindle drive belts are broken. The exchange itself will probably not be easy, because I have no experience with this machine and I do not know what to unscrew in turn. If anyone can advise me, please. I am also asking for the orient spindle procedure after replacing these belts (inverter Yaskawa VS-626M5), I will be grateful for the tips.

I've replaced belts on a VMX42, VMX24 and a few other machines. I'm not an expert but I've had no issues.

1. Remove the broken belt and all the belt fragments left in the belt area. Don't want any old belt pieces getting caught up in the new belt. I use a shopvac to get into the back areas of the housing.

2. Loosen up the four motor bolts. Don't need to take them out. Get them about a 1/4 of an inch above the motor mount. Take a breaker bar or a large screw driver and gently slide the motor forward as much as possible. I usually am able to do this by putting the breaker bar or screw driver between the rear motor bolt and the frame of the motor and edging it forward. They usually move fairly easily. Some I have had to slightly lift the front end of the motor to break it free.

3. Remove the four nuts from the drawbar clamp/unclamp cylinder just above the top of the spindle. This will give you enough space to fit a belt between the drawbar cylinder piston and the top of the spindle.

4. There is an opening around the top of the spindle and the frame large enough to fit a belt through. I keep the belt as horizontal as possible and feed the belt through the opening until the whole thing is in the belt housing area. It's a bit tricky at first but once you do it once you'll be able to get them in quickly.

NOTE: The belt can only go in one way. It's possible to put the belt in upside down. Make sure the belt is oriented the correct way which will match the direction of the gear splines. I hope that makes sense because it's a pain in the tail to get the belt back out. haha

5. Usually the belts out of the box have an end that is naturally opened wider than the other end. Feed the wide end to the back and manipulate onto the motor belt pulley. Keep tension on the belt from the front so that it doesn't fall off the motor belt pulley. Then take the breaker bar or large screw driver and inch the motor back until the belt is tight. I don't know what the exact tension of the belt should be but I mark the original position of the motor and then ensure the belt is tight.

It usually takes about two hours to get them changed out including removing the covers etc...

Hi,
thanks for the tips
How do you do the "orient spindle" routine after replacing the belts? The spindle must be in the tool change position.

Depends. If there is a homing sensor, which is usually a little proximity switch located at the spindle and is triggered by a notch on the spindle collar, you may not have to do anything after changing the belts.

If there isn't a home sensor then it would be a pulse count setting on the drive. Not sure which drive you have but it was the P2-02 Marker Pulse offset parameter on our VM10HSi. I believe it was the same on our VM1 as well but am not quite sure.


By the way. Hurco service is exceptional in my experience and have always been incredibly helpful to me with these type of issues. I don't mind trying to help by sharing my experiences because I owe back the help I've received from this forum in the past but would recommend contacting them as well just to be on the safe side.