Three Track Thickness Gauge For Soft Strip ... - Vollmer America

Three Track 

Thickness Gauge 

For Soft Strip 

Operating- & Service Instructions 

3f-E1 erstellt am 2.7.2001 geprüft am freigegeben am Bemerkungen 

Rev.01 Seiten: Name: Rietdorf Name: Name:

measuring - controlling - recording - automation - documentation 

G G G 

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Content.................................................................................................. Page 

Safety Precautions, please read carefully! ................................................... 3 

Intended use of this machine ......................................................................... 3 

Spares .............................................................................................................. 3 

Design and Function ...................................................................................... 4 

VMF amplifier .................................................................................... 6 

Nominal size setting ........................................................................... 6 

Measurement head adjustment...................................................................... 8 

Alignment............................................................................................ 8 

Passline height .................................................................................... 8 

Measurement tracks............................................................................ 8 

Measurement load............................................................................... 9 

Measurement ................................................................................................ 10 

Calibration......................................................................................... 10 

Nominal size and tolerance limits ................................................... 11 

Measurement start and end .............................................................. 11 

Note.................................................................................................... 11 

Important note: ................................................................................. 11 

Pneumatics.................................................................................................... 12 

Maintenance ................................................................................................. 13 

Measurement rollers and guide roller ............................................. 13 

Measurement traverse ...................................................................... 13 

Transducers .................................................................................................. 13 

Trouble shooting .......................................................................................... 14 

If the gauge measures wrong ........................................................... 14 

If the gauge marks the strip ? ........................................................... 14 

Repairs .......................................................................................................... 15 

Transducer / Hard metal pin ............................................................ 15 

Measurement roller replacement ..................................................... 16 

Note.................................................................................................... 16 

Subject to change without prior notice 

2 3-Track Thickness Gauge Operating and Service Instructions 

3f-E1

FRIEDRICH VOLLMER Feinmeßgerätebau GmbH D-58093 Hagen/Germany Verbandsstraße 60 ( 0049 2334 / 507-0 Fax .. /53015 

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Safety Precautions, please read carefully! 

This gauge is meant to be used exclusively as a fix mounted component of 

a strip processing machine. The strip processing machine must not be started 

up until a written statement was made that the entire machine (into which 

the gauge is installed) is in accordance with the regulations of the EG-Maschinenrichtlinie 

89/392/EWG. 

The gauge manufacturer points out, that this includes the installation of an 

appropriate protection device. The protection device has to be made in such 

a way that the gauge operator does not face any hazard by the running or by 

the possibly breaking strip. 

Nobody is allowed close to the gauge as long as the mill's strip tension is on. 

This manual has to be handed to the machine operator, and one copy must 

be permanently available to operator and service personnel. 

Nobody is allowed to work on or with the gauge, before he has read and 

understood this manual. Feel free to call the Vollmer company in case of 

any questions (phone +49 2334 507 0). 

Hands or fingers which are put into the vertical guide behind the gauge or 

into the slidebase below the gauge, might get caught and heavily injured if 

the gauge head moves up/down or is traversed. 

The pneumatically operated guide rollers might cause injuries on hands and 

fingers. Under certain conditions, the guide rollers might close the gap unexpectedly. 

Therefore the pneumatic system must be depressurized before 

anybody starts to work on this gauge. 

The gauge head might get hot. Therefore check the temperature before touching 

the gauge head. 

Intended use of this machine 

This gauge must be used exclusively for the measurement of cold Lithium 

strip at a maximum speed of 30 meters per minute. The strip may be between 

100 and 250 mm wide and up to 300 microns thick. The gauge must 

be firmly installed in its intended position and electrically, electronically 

and pneumatically connected as intended by the Vollmer company. Any 

alteration might cause severe damage or injury. 

Spares 

Please order spares referring to the part number and drawing number of the 

enclosed documentation drawings. To speed up our work, please do also 

state the Project number which is written as P-Nr. on the identity plate of 

the gauge. 

Operating and Service Instructions 3-Track Thickness Gauge 

We care about 

your Health. 

Please follow 

the safety 

precautions. 

Especially if 

you have many 

years of professional 

experience, 

you will be a 

3

P 


Design and Function 

This 3-track-gauge is designed to measure the thickness of strip with a soft 

surface simultaneously on three tracks. 

The strip, e.g. lithium, passes the gauge supported by the guide roller U. 

From the top side - above the guide roller - three measurement rollers M run 

on the strip. Each measurement roller is installed on a measurement lever L 

which can rotate around a bearing B when the roller runs over a "bump" or 

when it goes up or down due to strip thickness alterations. The up and down 

motion of each measurement lever is measured by an individual LVDT transducer 

T and indicated by an individual VMF measurement amplifier. 

The measuring traverse V can be lifted pneumatically, to ease the feeding 

of the strip end through the gauge. During calibrating and measuring, the 

weight of the measuring traverse is carried by two side rollers E. One of 

them drives rotary pulse encoder P so that the thickness data can be linked 

to their strip length position. 

The Vollmer 3-Track Thickness Gauge is designed to measure soft strip. The letters 

are explained in the text. 


M 

T 

V 

U 

E 

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V 

U 

Weight W can be adjusted to alter the measurement load which the measurement roll 

puts on the strip. 

At its rear end, each transducer has a differential transformer. The movable 

core of this transformer is connected to the measurement tip which is resting 

on the measurement lever. In this way any movement of the measurement 

roller is measured inductively. 

All changes within each of the three transducers are passed to a VMF measurement 

amplifier, where they are subtracted from the nominal value (if 

one was is set). The amplifier indicates a measurement result as deviation 

from zero, i.e. the difference to the nominal size. Nominal size is set electronically 

by a thumb when decade switch for each measurement track. 

The three measurement rollers can be shifted laterally, so that they can measure 

the strip thickness on any desired distance to the strip edge. 

Amplifier measurement data can be used as signal for controlling and for 

quality control documentation according to ISO 9000. It is available on two 

analog voltage outputs. 


M 

L 

W 

E 

5


FS4 

VMF amplifier 

The gauge is always installed with one VMF measurement amplifier for 

each measurement track. The measurement amplifier continuously indicates 

the difference between measured strip thickness and selected nominal size. 

The amplifier in detail is described in a separate manual. 

The operator can select the resolution of the analogue indicator by the measurement 

range selector MB. Full deflection can indicate from 1000 microns 

(.030 ") down to 10 microns (.0003"). The zero potentiometer NP allows to 

eliminate small deviations of the gauge zero. 

Nominal size setting 

Nominal size is set for each track by the thumb wheel decade switch FS4 

below the amplifier. The nominal size selector FS4 shows the selected nominal 

size in microns (or in steps of 0.0001", depending on the FS4 type). 

MB NP 

I/O C1 

Measurement amplifier cabinet of the Vollmer 3-Track Thickness Gauge: Thumb wheel 

decade switch D for nominal size setting in thousandth inches; main Power switch O/ 

I ; Calibration roller drive on/off C1 and calibration roller drive speed selector C2. 


C2 

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If the required material thickness - e.g. 200 µm - is entered as nominal size 

and if the measurement is 202 µm, the amplifier will indicate +2 µm. 

So it is possible to stay within the highest sensitivity range of the indicator 

no matter of the material thickness. In this range the full deflection of the 

indicator covers a range of +/-10 microns. 


7


Measurement head adjustment 

Alignment 

When the gauge is installed into an inspection line, installation height and 

levelling of the gauge are derived from the inspection table. If the gauge 

was removed from its position, take care to reinstall the gauge's base angular 

to the passline and parallel to roll axes in the mill. 

Passline height 

The gauge should be installed at such height that the lower guide roller touch 

the strip without lifting it considerably. The height is correct if the guide 

roller is permanently driven by the passing strip. 

J 

K 

Measurement 

tracks 

The Allen bolts J in the front 

end of each measurement 

arm installation clamp the 

measurement arms to the 

front side rod. To alter the 

measurement track, loosen 

bolt J, shift the measurement 

arm to desired 

position and clamp it there. 

At their rear ends, the measurement 

arms can slide free 

on the rear side rod. 

The measurement arms are 

clamped at the front end, but 

have a slide bushing at the rear 

end. The measurement load 

weights are fastened each with 

a grub screw K. 


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Measurement load 

The weight of the measurement lever and the pressure of the transducer's 

measurement spring push the transducer measurement roller down on the 

strip. The more load is resting on the measurement roller, the better it will 

follow the strip surface. Limit for that load is the hardness of the strip surface. 

Reduce the measurement load when the gauge marks the strip. Measuring 

very thin strip might as well require a reduced measurement load. 

Increase the measurement load when the amplifier indicates sudden peaks 

during a measurement. This shows that the measurement roller is bouncing 

on the strip surface. 

For measurement load adjustment loosen the grub screw K and shift the 

weight: 

- increase load by shifting towards the rear side of the gauge 

- decrease load by shifting towards the front side of the gauge 

Shift all the three weights and tighten the grub screw J in the desired position. 


9


V 

Measurement 

Calibration 

The transducers measure zero, when the measurement roller is resting on 

the guide roller. However, there are always imperfections in roundness and 

eccentricity. To eliminate those as far as possible, calibration is done on 

rotating rollers, and of course without a strip in the gauge. 

For calibration, the calibration drive motor CD is pneumatically lifted so 

that it drives the guide roller U. The lifting is actuated by a manually operated 

pneumatic valve ("Calibration") . The switch C1 (see page 6) starts the 

motor and the selector knob C2 controls the drive speed. 

When the calibration motor drives the guide roller, the measurement traverse 

is lowered by means of the second manually operated pneumatic valve ("Measuring 

Traverse"). The traverse is lowered so that the measurement rollers 

come down onto the guide roller. 

Set nominal size to zero on each measurement arm. Then select the highest 

sensitivity range on each of the VMF amplifiers (metric: ±10µm or inches: 

± 0,3 thousandth ", see selector MB on page 6). Then use the NP potentiometer 

to adjust the indicator needle so that it is deviated to + and to - for the 

same amount, i.e. that it swings symmetrically around zero. The swinging 

is caused by the form imperfections mentioned above. When the adjustment 

is finished, lower the calibration motor and switch it off. Then check 

the gauge for zero. 

Zero checking should be performed regularly. Lift the measuring traverse 

and lower it a few times and check, if zero returns. If so, measurement can 

begin, if not, check the entire gauge. 


CD 

U 

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Nominal size and tolerance limits 

After the zero check, nominal strip thickness and width are set mechanically 

(by fine adjustment/micrometer) or electronically by the optional FS4 

thumb wheel switch. 

The upper and lower tolerance limits in microns can either be entered into 

the electronic classifier 2S or 4S (optional item, see separate instructions) 

or into the VMF 2000 amplifier (optional item, see separate instructions). 

Measurement start and end 

Set the strip thickness nominal size for each track by 

the thumb wheel decade switch FS4 below the amplifier 

(the FS4 shows the nominal size in microns or in 

steps of 0.0001", depending on the FS4 type). 

Then lift the measurement traverse so that the strip 

end can be fed through the gauge. 

Lower the measurement traverse after the strip was 

inserted and when it is firmly guided before and behind 

the gauge. 

Note 

The strip must nor run under 

the two side rollers (see pages 

4/5). They need to roll directly 

on the lower guide roller. 

Now the three VMF amplifiers 

indicate the strip thickness 

deviation from nominal 

size. The weight of the 

measuring traverse is carried 

by the two side rollers 

E. This allows to 

measure with a very low 

measurement load and in 

addition it eliminates possible 

errors due to temperature 

extension. 

Important note: 

Always lift the measurement 

rollers and guide the strip end 

through the gauge carefully. 

Strip tension must not be 

switched off and the strip end 

must not pass the gauge unattended 

as it may cause serious 

damage. 


E 

. 

11


Pneumatics 

PM PL 

The gauge has two pneumatic circuits. The must be fed with dry compressed 

air of about 3 bar (45 PSI). 

The working pressure measuring traverse circuit is controlled by valve PM. 

The traverse is lifted by a pressure of about 0,2 bar (1,5 PSI). The pressure 

is correct, when the traverse lifts quickly and travels up to its limit stop 

without stopping before. The pressure is too high when the traverse hits its 

upper limit stop unnecessary hard. Each cylinder has adjustable chokes for 

the "down" motion as well as for the "up" motion. 

Valve PL controls the working pressure to lift the calibration motor. Factory 

setting is 0,8 bar (12 PSI). The optimum working pressure is set in the 

same way as described in the previous paragraph. The cylinder has got chokes 

to set the optimum speed at a given pressure. 

A manually operated valve for each circuit opens/shuts the actual working 

flow of compressed air. 


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Maintenance 

The thickness gauge does not need much maintenance. Only the measurement 

rollers and the guide roller are subject to wear. The entire gauge needs 

to be cleaned regularly in order to avoid dirt deposits which might block 

movable parts. 

Measurement rollers and guide roller 

l Clearance? 

The rollers have to move freely. They may have only little axial clearance 

and the measurement rollers must not have any obvious radial clearance. 

Blocking rolls mark the strip. 

ð Replace defective rollers (if the roller's surface is OK, replace only the 

bearings) 

l Deposits on the surface? 

If dirt deposits have accumulated on the the rollers, they cannot run smooth 

on the strip and might mark the strip. 

ð clean rollers regularly (if necessary), replace defective rollers (rework 

if possible) 

Measurement traverse 

l Easy movable? 

The traverse must go up and down to its mechanical limit stops without 

stopping under way. It might get stuck because of major dirt deposits in 

the gauge mechanics, or if - after a long time of operation - the ball guides 

are worn. This would cause measurement errors. 

ð Clean the gauge, call Vollmer for repair if the ball guides are worn 

Transducers 

l Ram easy movable ? 

The transducer rams must be easy to be pushed in and spring back immediately. 

l Measurement tips worn or damaged? 

If the calibration or the zero point are unstable, remove the transducer 

and check the measurement tips: 

l Ball dirty or worn? 

The ball at the end of the measurement ram must be clean, crowned and 

polished to achieve accurate measurement results. Worn balls with flat 

spots or broken out chromium skin may cause measurement errors. 

ð Replace transducer tip 

l Hard metal pin dirty, worn or damaged ? 

The hard metal pin adjacent to the transducer ball must be crowned and 

polished to achieve accurate measurement results. Worn balls with flat 

spots or broken out chromium skin may cause measurement errors. 

ð Replace hard metal pin screw. 


13


Trouble shooting 

If the gauge measures wrong 

l Wrong point remeasured ? 

Cross profile strip thickness varies in many cases. If the gauge is checked, 

strip thickness must be measured in the same distance from the edge as 

the transducers have measured. 

ð check the strip thickness at correct edge distance 

l Transducers dirty ? 

In a very dirty environment, the rams of transducers sometimes get too 

sticky, so that they do not shut completely. If the gauge is then set to 

zero, the indication of a following measurement is too low. After cleaning 

the transducer ram should slide easy in its bushing or bearing for a 

quite long period of time. 

ð increase cleaning frequency 

l Transducers clamped too hard? 

If the clamp screws in the C-frame are clamped too hard, they possibly 

distort the transducer housing which increases the friction in the ram 

guiding. 

ð loosen the clamp screw and re-tighten them with moderate force 

l Gauge zero not constant? 

If the measurement ball at the tip of the transducer ram is loose, then the 

indication is incorrect. 

ð fasten it 

l Indication too low? 

If the transducers are not clamped tight enough in the measurement traverse, 

they might be shifted in their bore. Gauge zero is then shifted too. 

l Additional check for gauges with decade switch (type FS3/FS4): If a 

new transducer was installed, the adjustment of the measurement amplifier 

to the nominal size selector has to be checked by a slip gauge. Set the 

gauge to 0 and insert 500 micron slip gauge. Then set the decade switch 

to 500 and check, if the gauge measures zero. If not, 

ð make a coarse adjustment by the sensitivity potentiometer on the X3 or 

X2 input (whichever is in use) at the back of the VMF 3/11 or 3/22 amplifier. 

For fine adjustment to the nominal size selector switch, use the 

X9 sensitivity potentiometer (see the VMF manual for details). 

l Measurement load too high ? 

ð reduce it 

l Roller surface defective ? 

ð replace roller with bearings 

If the gauge marks the strip ? 

l Roller blocked ? 

ð Replace roller. If the roller surface is not damaged, replace only the bearings. 


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Repairs 

Transducer / Hard metal pin 

MA 

TC 

FC 

The transducers T can easily be removed from their clamping bores in the 

measurement arms MA. Loosen the clamp screw TC and pull the transducer 

off the clamping fixture. When inserting the transducer, it needs to be set 

back into the same clamping fixture. If a new transducer is installed, or if a 

old transducer gets connected to another than its original VMF input, the 

amplifier requires new sensitivity adjustment (see amplifier manual). 

Check the hard metal pin HP for dirt or wear before inserting the transducer. 

The surface has to be crowned and smooth. Replace the hard metal pin it 

if the surface is damaged. Loosen the clamp screw HC and then unscrew the 

hard metal pin. Insert a new HP and clamp it. Readjust the transducer position 

afterwards. It is helpful to remove the measurement roller fixture for 

this work (see following page). Put a drop of oil on top of HP to reduce 

friction. 

Insert the transducer while it is connected to the amplifier. Clamp it where 

the amplifier indicates zero. Eliminate minor deviations by the zero point 

potentiometer. 

Then check the strip thickness gauge with a slip gauge e.g. 500 µm. If the 

error exceeds the tolerance limit, check the VMF adjustment to the nominal 

size selector and the transducer measurement tips. 


T 

15

W 

PR 


Measurement roller replacement 

If only the measurement roller needs to be replaced, leave the fixture MF 

untouched and remove the roller as described in the following paragraph. If 

you want to remove the fixture see the subsequent paragraphs. 

Without fixture removal: Put a cloth (as a cushion) between the roller U 

and the roller M. Unscrew the Allen bolts PR on both sides of the axle and 

take out roller. The roller bearings are held in place by a snap ring and may 

be pushed out after that ring was removed. 

HC 

M 

L 

With fixture removal: The 

measurement roller fixture 

MF is clamped to the measurement 

lever L by clamp 

screw FC (see previous 

page). 

Loosen the screw FC and 

pull the fixture MF of the 

measurement lever. 

Note 

Do not damage the transducer 

by bending its rod when 

pushing the fixture MF back 

into position. 

Once the fixture is removed, 

the pin screw HP is easily 

accessible for cleaning or 

replacement. 

Loosen the two pin screws 

PR (one on each side) and 

take the roller off the fixture. 

Re-insert a new roller. 

Do not overtighten the 

small PR pin screws. 

Push the transducer rod up 

for a few millimetres and 

then put the measurement 

roller fixture back MF onto 

the measurement lever L. 

At this point, the clamping screws HC and PR need to be tightened, but not 

the clamp screw FC. Move the fixture back and forth until you have found 

the highest point of the guide roller (indicated by the VMF. Before tightening 

FC in this position, the roller still needs to be aligned. Align the roller 

by pushing the weight W up while the screw FC is loose. This will align the 

measurement roller parallel to the guide roller. Now tighten FC carefully. 

Finally the transducer zero needs to be readjusted. 


MF 

HP 

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Three Track Thickness Gauge For Soft Strip ... - Vollmer America

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