Download There are a number of reasons why tapper performance might vary

Identifying and resolving issues with tapper performance –
Customer own driving equipment
There are a number of reasons why tapper performance might vary. These notes are
produced to help you eliminate some of the possible causes and hopefully resolve the
issue. If any of the detail is not clear or you need further advice at any stage please
contact us for assistance.
Physical factors
The performance of the tapper will vary due to the angle of operation, the material to
which it impacts and the holding force or means of fixing to the surface. Additionally,
the method of retaining the tapper may cause fouling of the core, any means of
securing the tapper that involves compression may distort the structure causing
increase of friction and hence poor performance, this may be permanent. It is thus
important to assess these factors when considering performance and any testing for
consistency must be done in the same manner. Sometimes dust and debris can enter
the tapper and cause poor performance or erratic behaviour, the tappers can be
cleaned.
Heat from the coil of the tapper due over use inadvertently or deliberately will also
affect the magnetic properties causing permanent weakening of the field and could
cause distortion to the plastic parts which would increase friction. Note all our
products in series 3 and above include thermal monitoring to avoid this issue. Where
MST3 and above tappers are used with non-thermal sensing driving equipment, overheating is still possible.
There are also tolerance factors to consider, as in all engineering manufacture and
materials it is impossible to reproduce an exact copy. Currently we are not able to
supply or test force characteristics, they do not form part of the specification.
Finally, it is possible that if you have re-stuck the cone to the core then excess glue
could cause rubbing within the bore and it needs to be removed.
Eliminate as many variables as possible
The first step is to eliminate variations caused by driving differences of individual
channels and to ensure each device is tested consistently.
For this test you will need your driving equipment and control software.
1. Disconnect all tappers from your driving equipment and remove all
adaptations you have added to each tapper. They should be as supplied. Note
on MST3 and above tappers you will need an adapter.
2. Make a note of the serial number of each taper, this can be found written on a
sleeve along the connecting wires. A table is supplied at the end of this
document.
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3. Clean each tapper by first removing the core. Carefully insert a pin through the
air hole at the rear (on the label) and push the core out. Examine the core and
bore clean using a damp lint-free piece of material and re-insert the core.
4. Connect the first tapper on the list to the first channel of your equipment.
Lightly grasp the tapper between thumb and forefinger and apply your usual
stimulus. Take care not to exceed ratings.
5. Make a note of the tapper’s performance against the serial number on your list.
6. Replace the tapper with the next on the list and repeat steps 3 & 4 above for
the remaining tappers.
If you find a wide variation in performance between the tappers after performing this
test, then send your results to us. We may subsequently ask you to return one or all of
the tappers for our examination.
If the performance of the tappers is similar and good then there is an issue with your
driving equipment or software, these aspects should be investigated and the problems
resolved.
If the performance of the tappers is consistent but poor, then it may indicate that your
driving equipment is inadequate or faulty or there is a problem with your software
delivering an adequate pulse width.
Check equipment and software performance
You will need access to test equipment (an oscilloscope) to check your equipment and
control software is performing satisfactory. You will also require an adapter if you are
using an MST3 or above tapper and a special monitoring adapter, which you can
make locally, see below or obtain from us for a nominal fee.
You should first complete the test as described in the preceding section and ensure
that the tappers have no added components.
1. Disconnect any tappers connected to your driving equipment.
2. Connect adapter lead to channel 1 of your equipment.
3. Connect oscilloscope to monitor points on the adapter.
4. Apply your usual stimulus.
5. Make a note of voltage and pulse width; a table is supplied at the end of this
document. These respectively should be 12V and >= 5ms.
6. Connect a tapper to the adapter whilst still monitoring with the oscilloscope.
7. Apply your usual stimulus.
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8. Record the results, these should be the same as obtained in step 5. If the results
are quite dissimilar, then there is a problem with your equipment; it could be
faulty or inadequate to drive a tapper.
9. Repeat steps 2 – 8 for all other channels using the same tapper. In all cases
you should expect voltage amplitude to be about 12V and pulse width >=5ms.
If this is not the case then there is something wrong with your driving
equipment and/or control software.
You have now checked that the driving equipment is performing well for one tapper
on every channel. It might be that your equipment cannot accommodate all the tappers
due to an inadequate power supply. The next sequence provides a way in which you
can check this.
Check for adequate drive power
If after the above tests you are still experiencing poor performance on some tappers, it
may be due to an overall inability for your equipment to deliver enough power for all
the tappers.
1. Connect adapter, tapper and oscilloscope on channel 1
2. Apply usual stimulus.
3. Record voltage and pulse width, table supplied at the end of this document.
4. Add a second tapper to channel 2 of your equipment and repeat steps 2 & 3.
5. Add, the remaining tappers, one at a time and repeat steps 2 & 3.
The results obtained should be almost identical, if there is a decreasing voltage as
each extra tapper is added, then your equipment is unable to deliver enough power for
the tappers to work properly for multi-channel operation.
Note if after conducting the above tests you experience different performance on a
few channels, then there may be some equipment issue with particular channels. The
above sequence of tests can be repeated monitoring one of the under performing
channels to see if any voltage drop occurs as the number of tappers is increased.
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If your tests indicate that there is a problem with one or more tappers, then
contact us for further assistance.
M & E Solve
6 Estelle Close
Rochester
Kent ME1 2BP
UK
Telephone: +44 (0) 1634 306439
Fax: +44 (0) 1634 306439
Email: [email protected]
Do not return any items to us without first obtaining authorization and a returns
number; this can be obtained from:
[email protected]
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Monitor test adapter
The monitor test adapter is a simple junction that enables two items (a tapper and
oscilloscope) to be connected to one equipment channel.
You will need a plug and socket for your system and some wire. You will also require
some tools for terminating and a soldering iron.
To each terminal of the plug solder two insulated wires. Form a pair of wires, one
from each terminal of the plug and solder each of the pair to a terminal of the socket.
The other pair of wires on the socket are the monitor (oscilloscope) connection and
can have bare ends.
Note, if you are using our standard jack for connections, ‘tip’ and ‘ring’ terminals are
used. If you have fitted your own plugs then you will need to determine what
connections have been used.
It is important that the wire ends are kept separate and that after you have made
up the adapter you check to ensure there are no shorts. A short circuit or wire
ends that touch may damage your equipment.
Warning ensure to correctly identify which is the ground (earth) connection of
the monitor leads and that this is connected to oscilloscope ground otherwise
damage to your equipment may result from improper connection.
We are able to supply at nominal fee a clearly labelled, correctly wired test
adapter in any of our standard connector range.
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Tappers on common channel
Channel used ______________
Date of test ___________________________
Serial no.
Comments
1
2
3
4
5
6
7
8
9
10
6
Equipment check
Date of test ___________________________
Equipment
No tapper connected
Voltage
Pulse width
1
2
3
4
5
6
7
8
9
10
7
Tapper No. ______ connected
Voltage
Pulse width
Multi-channel operation
Channel no. monitored ______________
Date of test ___________________________
Tappers
in
system
1
Serial no.
Voltage
2
3
4
5
6
7
8
9
10
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Pulse width