[davin]

We have manufacured a waterjet CNC machine size 4 metre width X 3 metre length.
After 100 hours of operation the linear blocks of Y axis have broken down.
Size applied is HSR 25 A of THK. we replaced the blocks but then the same problem happened within 2 days.
We have applied 8 blocks and 4 rails in y axis.

the beam which rests on the Y axis and also consists of Z axis and X axis is 6 feet high.
physical weight 700 kgs. in total

is it a selection problem ??? i am not able to understand.

looking forward to anyone who can help.

[Hack]

Those rails and blocks should not be going bad on you this quickly. Something to check may be to see if the rails are aligned good. If not, it could be causing premature wear. Are the wipers on the blocks in good shape, any bellows installed? Anything that may prevent debris from entering the area? Waterjet media is course and abrasive by nature and can destroy linear motion components if they are not protected.

25 series should be plenty strong enough for all but the largest machines.

Hope this helps.