In a message dated 2/15/99 10:36:59 AM EST, mmarr@idcnet.com writes:
<< Seems to me that the pictures of the Churchill puller that I have seen show
that the jack screw has a large diameter with fine thread. Going back to
Physics 101, inclined planes and resolution of forces, this means that as
the screw is turned, relatively more of your effort (torque) is converted
into axial force and relatively less into frictional force because the
component of the turning force normal to the plane of the screw thread
increases as the thread becomes coarser, thereby increasing the frictional
force on the nut. I bet that most of the home made pullers I have seen
described have relatively small diameter, coarse threaded jack screws.
Thus, much of the energy applied to turning the jack screw is absorbed
overcoming the inherent friction in the system, and ultimately in straining
the jack screw. If this is the case in your example, my suggestion is to
buy the largest practical diameter, finest thread (hardened) nut and bolt
that you can find and use this. (Remember, for a given number of tpi, the
larger the diameter, the lesser the angle of the inclined plane.) Even
better, find a tool and die shop that can make a hardened jack screw/nut
combination, say 1.5 ins in diameter and 16 tpi, then weld this to your
existing puller in place of the screw you are presently using. Remember to
use lots of lubricant on the jack screw, to minimize the demon friction.
>>
The tool is hydraulic, filled with grease. There's no screw masher like a
regular puller.
Thought I'd mention it.
Ken Nuelle
58 TR3A
62 TR3B
64 TR4
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