CHP-1 Knock-Out Bar
Quantity in Basket:
Catalog No.: CHP-KO
Shipping Weight: 0.25 pounds
The CHP-1 Hydro-Press uses a hardened knock-out bar to stop
the movement of the downward-moving internal punch as the
ram continues down, ejecting the bullet from the die.
This is a spare K.O. bar for the CHP-1 press. It is a good
idea to have a spare, in case the one which comes with your
press is misplaced. The K.O. bar can be bent or damaged
if the bottom position sensor is adjusted too low to stop the
ram movement before stressing the K.O. bar, provided the
drive pressure is also set to a very high level.
Unlike the k.o. bar set for the CSP-2 press, only one height
of bar is needed. This is because the Hydro-press can be
adjusted for any top and bottom of stroke position, whereas
a mechanical press has a fixed top and bottom of stroke.
To adjust for different lengths of dies and punches, different
heights of k.o. bars are used in the hand press. In the
hydraulic press, the sensor is simply moved to establish
a desired top and bottom position for the stroke.
The Solution to Broken KO Bars:
Set the bottom sensor higher, so that the ram stops pushing down BEFORE the internal punch jams between the KO bar and the bottom end of the die.
If you set the ram to stop before the internal punch head smacks into the bottom of the die, then the only force on the KO bar is whatever it takes to push the bullet out of the die. The full force of the press will NOT be applied to the middle of the KO bar and it won't break.
Conversely, if you DO set the bottom sensor just a tiny bit lower than that, you probably will keep breaking the KO bars. If the bullet won't eject all the way, you can always send the die back with a note saying so, and we can relieve the die opening with a larger funnel or bevel, or even take a light cut off the face of the die to shorten it slightly.
Usually the reason people break the KO bar by setting the bottom stop sensor too low is an attempt to get the bullet to eject further out of the die. It won't work. It just breaks the KO bar. Of course, that's a great way to sell lots of KO Bars, so if it's fun to set the sensor that low and hear the bar snap, carry on! Maybe we can do a special on bushel baskets of KO Bars!
Otherwise, we can modify the die slightly and get better ejection at a slightly higher position of the ram. We are only talking about fractions of an inch for easy ejection versus sticking in the end of the die just short of ejection. That could just be normal compression tolerances adding up over time, if the die used to eject fine and now it is just not quite doing it. Easy fix, though.
Caution: Don't try to machine the face of the die yourself in a lathe with regular tool bits. Those dies are EXTREMELY hard and tough. A ceramic tool bit is called for along with proper coolant. Grinding the face of the die requires proper coolant also, because the die temper is adjusted for good wear and shock resistance. Heating it will upset the proper temper. If you are experienced at tool and cutter grinding and know how to keep the workpiece from overheating, fine. Otherwise don't risk ruining your die when it's easy to send it back with the punches so we can test everything together.