Replacing machine guards and machine covers can be aggravating. The guard may have been dropped, twisted or holes on the component could have been damaged. The frame of the machine could have even shifted.
If any of these issues crop up, place as many bolts as possible in the guard or cover. If a hole doesn’t line up, place a Phillips screwdriver into the hole and then force the cover into a position that will allow the rest of the bolts to be inserted. Carefully insert a tap into any remaining holes that won’t accept a bolt; the tap will cut threads in the cover itself, allowing the bolt to be placed.
Bearings should never be installed using a punch. Using a punch will eventually cost you the price of a bearing or will shorten the life of a bearing. Chances are that the punch will slip and damage the bearing seal. When installing a bearing on a shaft, the force to install a bearing should be against the part of bearing next to the shaft (bearing center).
Pressing the bearing by using force anywhere else will shorten its life or could destroy the seals of the bearing. The installation can be accomplished using a tube or pipe that has an inside diameter that is just barely larger than the diameter of the shaft. The reverse applies if you are installing a bearing inside a frame or pipe roller. Apply the force on the outer ring of the bearing. This can be done by building a tool made to seat the bearing. The role of this tool is to apply equal force around the outside edge of the bearing. The tool can be welded together from scrap parts or it can be fabricated by a local machine shop. The point is to use the right force in the right location on the bearing to prevent damage.
Upgrade the air fittings on a press from compression fittings to instant tube fittings. The fittings seal on the outside of the tubing, which make for a quick connection that doesn’t leak.
Compression fittings, by contrast, are frequently over tightened, causing air leaks. Alternatively, the ferrule in the compression fitting will be out of place while tightening, also causing a leak.
Installing the instant tube fitting is simple: Just push the tubing into the fitting for a good leak-free connection. Another advantage: The tubing is easily removed, simply by pushing the outside ring inward, then pulling the tubing from the fitting.
Bottoming taps are used whenever it is necessary to cut the threads of a tapped hole as close to the bottom of the hole as possible.
I normally use this type of a tap when I am trying to remove shaft and motor keys. The shaft or motor key can be wedged so tight that it is impossible to remove them with a hammer and chisel, which is my normal way of removing a key.
When it’s not possible to easily remove the key, I drill a hole in one end of the shaft or motor key, making sure to drill only as deep as the thickness of the key. I then thread the hole as deep as possible with a taper tap to make sure the tap goes in as straight as possible.
Then, I tap the hole with a plug tap so that I relieve as much stress as possible on the bottoming tap. Finally, I tap the hole with the bottoming tap to get as many threads in the hole as possible. This prevents the threads from pulling out whenever I attempt to remove the shaft or motor key.
Once the threading is complete, thread a 36-inch piece of all-thread into the tapped hole. Then, slide a heavy weight on to the all-thread. The only requirement for the weight is that it must have a hole larger than the all-thread. I normally drill a hole in a slide-lay locking handle from a Goss Community press. Once the weight is on the all-thread I add a washer and nut.
To remove the key, slam the weight against the washer and nut assembly on the all-thread’s end. It’s akin to using a slide hammer to remove a pulley.
Frank Bourlon is executive and training director at the Newspaper Production and Research Center. He can be reached at firstname.lastname@example.org.