CNM - Charpy/Izod
Specimen Preparation Machines
The Blacks CNM range of machines have been specially designed to allow laboratories and test houses to produce their own standard and sub-size Charpy / Izod test pieces ready for cutting the appropriate notch.
Two variations of the Charpy Specimen Milling Machine (CNM) are available to cover a wide range of materials.
CNM-158A1 FIXED SPEED
CHARPY SPECIMEN MILLING MACHINE
The Fixed Speed Machine is recommended for customers who are producing specimens in carbon steels, easily machined low alloy steels, non-ferrous and plastic materials.
This machine has a fixed cutter speed of 1.98 m/sec(50Hz), 2.38m/sec(60Hz) and a variable feed rate for the samples of 2.5-9.0 mm/sec.
For customers producing specimens in a wider range of materials, see the CNM 140A1 with variable cutter speed.
CNM-140A1: VARIABLE SPEED
CHARPY SPECIMEN MILLING MACHINE
The Variable Speed Machine is recommended for customers
who are producing specimens in carbon steels, more difficult to machine
alloy steels, stainless steels, non-ferrous and plastic materials.
Please contact RJW Ltd if cutting superalloys.
This machine has a variable cutter speed of
1.0-2.5 m/sec and a variable feed rate for the samples of 2.2-9.0 mm/sec.
The varying of the cutter speed for differing materials improves the cutter tip life.
Machine Design and Method of Operation
The machines are of robust design and construction, enabling them to
specimens to the surface finish and tolerances required by International Standards.
Both machines are designed for mounting onto a customer’s bench and are
with an easily removable swarf (cuttings) tray.
The cutting process is carried out without cutting fluids.
A fully encapsulating removable cover allows ready access to the motor and
for periodic maintenance.
A D.C. thyristor drive control provides the variation in speed
of the rotary fixture, for both the Fixed and Variable Machines.
The fixture speed sets the feed rate which the samples are machined.
An A.C. thyristor drive control provides the variation in the
cutter speed, on the Variable Machine only.
Work Holding Fixture:
The circular fixture allows up to four specimens to be machined during the same operation.
Various clamps, anvils and clamping screws are available to suit the type of rough cut blanks being used.
One circular fixture is included with each machine. For maximum machine production a 2nd fixture (optional extra) is recommended, so that whilst the 1st fixture is being machined, the 2nd fixture can have its samples loaded.
The cutter is fitted with five ISO carbide inserts, which are easily replaceable.
A micro adjuster allows for accurate control of specimen size and allows for compensation of cutter tip wear.
Fixed Speed Machine
900 x 500 x 650 mm
Variable Speed Machine
900 x 500 x 715 mm
Weight: 210 Kg
380 or 415 or 440 Vac
(customer to advise their voltage for setting at our works)
3 phase, 50/60 Hz, 4 KVA
480 Vac optional
View a 10 minute video showing the operation of our Charpy and Izod Specimen Machine.
Fixed Speed Machine
Using two work holding fixtures, 4 machined specimens can be produced every 20 minutes with the feed rate set in a mid-position . The mid position is a typical setting for general carbon steels.
Variable Speed Machine
No specific production rate can be quoted for the variable speed machine due to the variation in machine feed & speed settings, which are dependent upon the sample material.
rotating fixtures complete with clamps, anvils, clamping screws and a
bench mounted holding bracket. The customer to advise pocket
Sub-size specimen fixtures and a bench mounted holding bracket. The customer to advise the sub-sizes required, for the fixture to be set at our works.
ISO replaceable inserts.
Specimen size go/no go gauges
supplied with UKAS certificate.
Spare parts and consumables for all machines available: Spare Parts
By arrangement, special testing may be undertaken using our in-house test facility to determine optimum equipment for difficult to machine materials.
Contact us, stating the specimen’s material, size & standard, for further guidance.
CNM user manual available to download.
Motorised Broaching Machines
An ideal accompaniment to the specimen machines are our Motorised Charpy
Each machine undergoes a full inspection, run-in period and test cycle prior to despatch.
Approved by independent company.
CE TECHNICAL DOCUMENTS
Held at RJW Ltd, Unit A5 Chaucer Business Park, Kemsing, Kent.
PRODUCER COMPLIANCE SCHEME
With Clarity Environmental Ltd.
Method of Operation:
The rotating work holding fixture is fitted with clamps, anvils and clamping screws to suit the type of blank being used, i.e. rough sawn square/rectangular, round or tubular section and the size of specimen to be produced, i.e. 10mm square or sub-size.
For ease of fitting samples, the fixture is removed from the machine and placed onto a bench mounted holding bracket, one bracket is supplied with each fixture.
Up to four rough cut samples may be loaded into the fixture, which is then re-mounted onto the machine spindle and the cutting cycle started.
The machine cuts the first side of the samples (1st cut).
The fixture is then removed from the machine, turned through 180 degree and refitted to cut the second side of the samples (2nd cut).
After completion of the 2nd cut, the fixture is removed from the machine and placed onto the bench mounted holding bracket.
The samples are removed and remounted into the fixture at 90 degrees. The fixture is then mounted into the machine to cut the third side (3rd cut). The fixture is then rotated to cut the fourth side (4th cut), which completes the production of the 10mm square samples.
Adjustment of the micro-adjuster may be necessary to achieve the required size and dimensional accuracy of the finish machined specimen.
1st & 2nd cut clamp
3rd & 4th cut clamp
10mm Square Specimens
16mm maximum square rough sawn and 18mm maximum diameter section blanks in carbon and low alloy steels can be used, to produce 10mm square specimens to International Specification Standards.
The fixture pocket configuration:
A machine with 1 fixture; 2 pockets with 1st & 2nd cut clamps & 2 pockets with 3rd & 4th cut clamps.
A machine with 2 fixtures; 1st fixture, 4 pockets with 1st & 2nd cut clamps. 2nd fixture, 4 pockets with 3rd & 4th cut clamps.
The customer to advise if round or tube section samples are to be used in 1st & 2nd cut pockets, as “V” serrated anvils will be required.
Customers can order fixtures, with any pocket configuration to suit their requirements.
Sub-size specimens can be machined using a work holding fixture with special factory fitted cartridges. The 10mm dimension is produced on a standard fixture, using 1st & 2nd cut clamps. The 3rd & 4th cuts are machined on a sub-size fixture, which is set at our factory to produce the thinner sub-size thickness.
Standard fixture options available
OPTION 1 – Fixture for 7.5mm specimen – 3rd cut cartridges set to 8.75mm & 4th cut set to 7.5mm
OPTION 2 – Fixture for 6.7mm specimen – 3rd cut cartridges set to 8.0mm & 4th cut set to 6.7mm
OPTION 3 – Fixture for 5.0mm specimen – 3rd cut cartridges set to 6.25mm & 4th cut set to 5.0mm
OPTION 4 – Fixture for 3.3mm specimen – 3rd cut cartridges set to 4.4mm & 4th cut set to 3.4mm
OPTION 5 – Fixture for 2.5mm specimen – 3rd cut cartridges set to 3.6mm & 4th cut, set to 2.6mm
Please note that 4th cut pocket cartridges for the
3.3mm & 2.5mm specimens will be set to 3.4mm & 2.6mm to allow for 0.1mm
to be ground off, to achieve their final thickness tolerance.
Customers can order fixtures with any pocket configuration to suit their requirements.
For instance a combined fixture for 7.5mm and 5mm specimens.
1 off each cartridge set to 8.75mm, 7.5mm, 6.25mm and 5mm.
Please note the maximum depths of cut that can be machined on each type of sub-size fixture are:
Fixture for 7.5mm specimen – 2.0mm
Fixture for 6.7mm specimen – 2.00mm
Fixture for 5.0mm specimen – 1.75mm
Fixture for 3.3mm specimen – 1.50mm
Fixture for 2.5mm specimen – 1.00mm