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Do you offer a direct replacement for Boshert chucks??

DMontalvo Guardian Safety Chucks are able to be direct, drop-in replacements for Boschert Safety Chucks, in both flange-mount and pedestal-mount styles.

What if my shaft loads into the chuck OK, but then is very difficult to open?

Check alignment of the chucks on the machine frame. If misaligned, this would be one of the symptoms.

What is the procedure for changing the inserts?

Remove the hand wheel from the chuck, slide the two bottom inserts out from the back of the hand wheel, and slide the new ones in. Remove the bolts holding the two top inserts in place, and replace with new. Reattach the hand wheel to the chuck.

What if I am having a hard time opening and closing the handwheel without undue force?

Check the following: Journal tolerance incorrect, Journal/shaft too long, Chuck not properly aligned, Front face bevel missing or too small, Excessive deflection of roll shaft


What do I do if my chuck closes fine without a shaft but doesn’t close with a shaft?

If the chuck is difficult to close with the shaft installed, it is typically an indication that the chucks are not properly aligned across the machine frame. Proper installation dictates that the chucks be precisely aligned for proper operation.

What happens when the operator hits the handwheel with a hammer?

If the operator is using a hammer to open/close the chucks, this indicates either a serious misalignment problem, or more commonly, it indicates that the ball catch, safety lock (if so equipped) and pivot pins require cleaning and lubrication. Excessive journal seat wear could also contribute to this problem which would require replacement of the handwheels.

Are the journal seats replaceable?

The journal seats are designed to be the sacrificial part in the safety chuck/airshaft system. Typically the airshaft journals are hardened to a higher Rockwell value than the safety chuck journal seat. This ensures that the handwheel journal seat will wear before the airshaft journal. When the handwheel journal seat has worn excessively, it is time for handwheel replacement. Changing the handwheels is a very simple process, and involves removing the five mounting bolts on the face of the handwheel and removing it. Installation of the new handwheel is as simple as placing the new handwheel in place, and re-installing the mounting bolts.

How do I know when it is time to replace the handwheels?

The most common indicator is deformation of the journal seat such that the airshaft journal no longer makes complete contact with the seat. Excessive wear is also indicated by excessive noise, or a definitive “click” or “clunk” as the roll rotates.