Northrock Fish Scaler Part - Heavy Duty Core
The Northrock Electric fish scaler comes in 2 versions: Standard and Heavy Duty. The difference is in the diameter of the inner drive cable (core). The Standard duty is 5/16 (compressed to 1/4" at the ends) and the Heavy Duty is 3/8" (compressed to 5/16" at the ends). They are not interchangeable, and the only way to tell what you have is by measuring.
Northrock heavy duty core - the metal cable is 3/8" in diameter and has 2 square ends 5/16" in diameter. The core looks like this:
If you are replacing an existing core, you must get the same size. It will not work otherwise.
When you replace the drive core or flexible shaft casing, follow this guide.
You can print it out. You can also use the guide to troubleshoot any problems you might have in operation. It is almost always the result of loose connections or a damaged core or casing.