"Eric R Snow" wrote in message
...
I need to make a thumb for the 580CK Case tractor backhoe.
The bucket on the front of the machine will keep the same angle as it
is raised and lowered. So, for example, if the operator tilts the
bucket to a ten degree angle with one lever it will keep that angle as
the bucket is raised or lowered with the other lever. I want to plumb
the thumb to work the same way. It appears to me that it may be
valving that makes the front bucket behave this way. Anybody know how
this is done?
Thanks,
Eric R Snow

If this is the machine I am thinking of, there is a level compensating slave
cylinder on the right side of the machine. This adds or subtracts fluid
from the bucket tilt cylinder as appropriate. The hoses to this cylinder
don't go back to the valve body, just across the bucket tilt lines. It is a
fairly common method to accomplish this action.

Shawn