Biomedical Engineering Reference
In-Depth Information
Fig. 8.31 Autocorrection of
the lead screw
1
2
3
4
Fig. 8.32 The scheme of the “lever” method
and large wearing of the tools. For this reason, we also propose other methods
that allow a reduction of the exceptional errors.
8.7.1.1 The method of “lever.”
The scheme of the “lever” method is presented in Fig.
8.32
. The carriage moves
linearly on a table with a lever. One end of this lever is connected to the table, and
the other end is connected to the nut that is moving with the lead screw. All errors
of the lead screw decrease by the factor
L
1
/
L
2
when the movement is transferred
from the nut to the carriage. This scheme allows a reduction of the lead screw errors
when we produce the following generation components. For example, if we attach a
tool holder with a cutter to the carriage and want to make a lead screw for a smaller
micromachine tool, this smaller lead screw will have relative errors (errors divided
by screw size) equal to the relative errors of the large lead screw. This method can
be used not only in machine tools but also in micromanipulators.
