Position transducer for wood sanding machine

Find out how to control the working table position with a repeatability between 0.2 and 0.3 mm

LT and PYI position transducers

The LT and PYI position transducer controls the position of the working table with a repeatability of between 0.2 and 0.3 mm in sanding machines by managing:

the position of the table according to the thickness because the dimension is displayed on an indicator;
the position of the belt rollers, displaying the different dimensions on an operator panel with the support of a PLC.

Overview

Products: potentiometric transducer model LT and PY1 and 40T96 Indicator
Customer request: Control of the working table position with a repeatability between 0.2 and 0.3 mm
Result: LT-M enabled the position control of the sanding table with a repeatability of 0.1 mm

The process

Sanding and calibrating machine has the function of sanding the wooden panels in the range of few tenths of a millimetre on both the surfaces.

The machine is comprised of a mobile worktable, adjustable in height according to the thickness of the panel and of abrasive belts of different sand density; positioned inside the machine with different position heights.

In the entry level machine versions, only the position of the table is adjusted according to the thickness.

High performance machines require the control of the position of the mobile work table and of the abrasive rollers.

The challenge

Entry level sanding machine:

A potentiometer LT-M 150-200mm stroke and a display instrument 40T96 are used to measure and display the height with an accuracy of 0.1 mm.

40T96 is used to manually change the position of a work table via a 0-10V signal to drive a motor positioner.

High performance machine:

PLC performs the automatic control the position of the work table and of the 3 or more abrasive rollers.

The control includes the setup and management of the different product recipes.

The LT-M sensor is used to measure the position of the work table.

The PY1 75mm stroke potentiometers are used to measure the position of 3 or more abrasive rollers.

Product Benefits

Absolute position transducers unlike incremental encoders
No zero/reset required
Linear positioning repeatability of 0.1 mm
Theoretically infinite resolution
Signal linearity: 0.05% F.S.
Simple mounting using metal brackets
Total dimensions comparable to the electric stroke to be measured (reduced dead zones)
Electrical output updated in real time (without signal conditioning electronics)

Solution

Transducer stroke: LT 150-200 mm, aluminium profile

Transducer stroke: PY1 75mm, aluminium profile

Repeatability: 0.05 mm

Resolution: infinite