Use and Care Manual

YOUR SAFETY
IMPORTANT PLEASE READ & UNDERSTAND THIS INFORMATION BEFORE USING
YOUR PRECISION MIDI CHUCK
DANGER: THIS CHUCK IS CAPABLE OF CONTRIBUTING TO SERIOUS INJURY, AS
WITH ANY OTHER POWER TOOL ACCESSORY, IF USED IMPROPERLY ON THE
LATHE.
Please also read and understand the lathe owner’s manual. If you do not have a
manual, contact the supplier of your lathe to obtain one before using the lathe and
Chuck.
User must be professonally trained to use this chuck. Vocational school courses are recommended.
As with other chucking methods, an extremely cautious and sensible approach is necessary. Follow
closely strict guidelines in this manual for different jaw types on wood blank diameters and length, plus
turning speed.
BEFORE USING THE PRECISION MIDI CHUCK MAKE SURE THAT -
• ALWAYS WEAR EYE PROTECTION WHICH COMPLIES WITH CURRENT ANSI STANDARD
Z87.1 (USA). WE RECOMMEND THAT A FULL FACE SHIELD TO BE USED AT ALL TIMES.
• Make sure chuck is properly secured on lathe spindle. Follow mounting instructions for your lathe for
faceplates and other spindle fixtures.
• For safety, DO NOT ROTATE CHUCK UNDER POWER WITHOUT WOOD BEING GRIPPED.
• WARNING: EXCESSIVE SPEED IS A SERIOUS LATHE HAZARD. ALWAYS TURN AT THE
SLOWEST SPEED POSSIBLE.
• Speed will vary with wood blank size. The larger the blank, the slower the speed. Consult your lathe
manual or lathe information plate for speed guidelines.
• DO NOT ATTEMPT TO USE THE CHUCK UNLESS THE LATHE SPEEDS ARE KNOWN,
YOU MUST STRICTLY FOLLOW THE MAXIMUM SPEED LIMITS SET OUT IN THE
OPERATING SECTION OF THIS MANUAL. DO NOT EXCEED THEM UNDER ANY
CIRCUMSTANCES.
• EXAMINE WOOD CAREFULLY. ONLY MOUNT WOOD THAT IS SOUND, If any cracks, splits,
or weakness is found in wood - DO NOT MOUNT ON CHUCK. DO NOT MOUNT ANY WOOD
THAT IS LIKELY TO BREAK UP DURING TURNING (E.G. ROTTEN OR SPONGY WOOD). DO
NOT USE POORLY JOINTED/LAMINATED WOOD.
• Make sure wood is clamped firmly. Follow mounting instructions for different gripping modes
and jaw types. In the expansion mode do not use undue force or jaws may split the wood.
• Do not exceed maximum guidelines in this manual for wood blank diameters/length set out in
this manual for different modes and jaw types. DO NOT USE WITH ANY COPYTURNER
OPERATIONS
• Check wood is securely held in chuck, before operation. Check grip by vigorously wrenching
wood blank back and forth. If any loosening occurs, re-examine holding area for adequate grip (Follow
mounting guidelines) and any damage to holding area. Rotate manually to make sure of clearance
before switching power on.
• WARNING FOR SAFE OPERATION. IT IS RECOMMENDED THAT TURNING BE CARRIED
OUT WITH JAW SLIDES NOT EXTENDING BEYONG THE CHUCK BODY. HOWEVER THE
JAW SLIDES CAN EXTEND ABOUT 6.35MM (1/4”) BEYOND THE BODY OF THE CHUCK TO
GIVE A WIDER RANGE OF EXPANSION, IF REQUIRED. EXTRA CAUTION MUST
BE EXERCISED WHEN TURNING WITH JAW SLIDES EXTENDING BEYOND THE BODY OF
THE CHUCK.
• Irregular or out of balance stock needs to be turned at the slowest possible speed until it is in
balance. For use on outboard/left-hand rotation - MAKE SURE INSERT IS SECURELY LOCKED
WITH GRUBSCREW BEFORE USE. Use only hand held woodturning chisels to shape wood being
held in chuck.
• USE THE RIGHT CHISEL FOR THE JOB AND DO NOT FORCE TOOLS. Use safe and
commonly approved chisel techniques. Wherever possible stand to one side of the revolving
wood.
• WEAR PROPER CLOTHING. Do not wear any loose clothing, neck ties, gloves, bracelets, rings
or other jewellery that could get caught in moving parts. Wear protective hair covering to contain
long hair.
• DRUGS, ALCOHOL, MEDICATION. Do not operate chuck or lathe while under the influence of
drugs, alcohol or any medication.
• KEEP CHILDREN AND VISITORS AWAY. All children and visitors should be kept in safe distance
from the work area.
Make workshop childproof with padlocks, master switches, or by removing starter keys.
Thank you for purchasing Nova Precision Midi Chuck - the ideal chuck for
Mini, Midi and smaller lathes with up to 12" diameter swing. We are
confident that it will be a great aid towards fast workholding and will
enhance your woodturning capability. The Precision Midi is designed for a
range of wood holding modes while being quick and easy to use.
NOVA PRECISION MIDI CHUCK
INSTRUCTION MANUAL
FITTING CHUCK TO LATHE
Check if the chuck thread specification matches the lathe spindle thread you have.
This is important for accuracy. The chuck body must contact an accurate register on lathe, either a
shoulder on spindle or bearing face etc to ensure chuck will run true. Any modification required (e.g.
spacer) would be the responsibility of the customer. A good check is to see whether it screws home the
same as a faceplate or similar spindle fitting.
DO NOT USE UNLESS CHUCK IS PROPERLY FITTED TO SPINDLE
CHUCK OPERTATION
Adjustment: Two levers are provided for adjustment of the jaws - one fits into the chuck body, the other into
the scroll ring, please refer to chuck diagram for lever positions. If your lathe has a spindle lock then you
only need to rotate with the scroll ring lever. Remember to release spindle lock after adjustments. Using
two levers, hold the chuck in place with the body lever and rotate the other lever in the scroll ring to
activate jaw movement. To achieve faster action you can rotate both levers:
a) Chuck facing you. When the two levers are pulled together the jaws will contract
(further inwards). This action will contract jaws around a spigot for clamping.
b) Chuck facing you. Pushing the levers apart will expand the jaws (travel outwards).
This action will expand jaws into a dovetail recess for clamping. When clamping make
sure to give an extra squeeze on the levers to give a final ‘nip up’ to the jaws. Use
tailstock to help support work in chuck while clamping.
Action Adjustment : Refer to parts diagram. This is an optional and unique feature of
Nova chucks where a 6mm grub screw is adjusted to change the action of the chuck
more to user requirements (usually to achieve a stiffer movement). As the grub screw is screwed against
the fibre washer a tighter action results.
MOUNTING & DISMOUNTING OF JAWS
The Precision Midi chuck comes with no jaws attached. With the many jaws available, it is very easy to
use your single chuck for a very wide range of applications. All jaws in the Teknatool range for the
Precision Midi are secured and attached the same way.
Attaching Jaws - To mount the jaws to the Precision Midi chuck is another easy process. Firstly wipe
clean all jaw slides making sure a clean contact. Repeat this with all four jaws you wish to attach. Jaw
slides are numbered one to four and have a corresponding jaw - of the same number. Place a jaw on its
correct jaw slide and position into the groove (location ring out from the jaw into the groove of the jaw
slide). The first few times you may need to GENTLY tap the jaws into the locater slot with a block of wood
or plastic mallet. Place M6X6 counter sunk screws in jaws and screw them to finger tight (a little
grease smeared under the heads at this stage will make the later removal easy) When both screws are
in nip up them and back them off half a turn. Repeat this on the remaining three jaws, now using the
Allan key scroll all jaws towards middle until they all come together. Now with all jaws touching and
exerting equal pressure on each tighten all screws up. This will ensure a perfect run out. Check if there
are gaps between the jaws. If this happened, it will probably be due to a jaw being placed on a wrong jaw
slide. (e.g. a #2 jaw on a #3 jaw slide)
Removing Jaws - using the 4mm Allan key supplied, unscrew all M6 counter sunk screws (there are
eight of them). The jaws will come away once screws are released. However sometimes due to dust
particle build up after heavy turning, the jaws may need a very light tap with a plastic hammer to dislodge
them. It is important to keep them in their set and don’t mix them up with other jaws of the same type.
DOVETAIL OPERATION
Expansion of the jaws into a recess. This function is for bowl and platter turning where the projection (depth)
of the wood blank is not too great i.e. up to 100mm (4 inches). Characteristically these items have a parallel
wood grain. IT MUST NOT BE USED FOR ANY LONG WORK (OVER 100MM) AS THERE WOULD BE
GREAT DANGER OF WOOD TEARING OUT AND DISLODGING FROM CHUCK.
Instructions below apply to the standard 50mm jaws but the general technique is the same with other acces-
sory jaws. However the maximum size of wood blank that can be mounted, the maximum turning speed and
recess size varies with the different accessory jaws. Consult specific instructions included for each jaw set.
This strong holding method, using the standard 50mm jaws bowls up to 310mm (12 inches) in diameter can
be turned. DO NOT EXCEED 600RPM WITH THIS OPERATION. OUT OF BALANCE STOCK MUST BE
TURNED AT THE SLOWEST SPEED POSSIBLE.
50mm jaws: Any recess can be turned between 50mm (2 inches) and 70mm (23/4” inches) diameter.
For smaller lids and thin platters (not exceeding 150mm diameter) only a shallow recess of around 3mm (1/8 inch)
is necessary. It will be matter of gaining experience as to what combinations and sizes will best suit.
USING THE WOODWORM SCREW
The woodworm screw supplied with the Precision Midi chuck is designed for screw chucking. It is a
cylindrical screw which maintains its full holding power along the whole length, unlike normal tapered
screws. The thin thread form is specially designed to cause minimum damage to wood fibers. They grip
better than screws because there is a larger volume of undamaged wood retained within the screw.
The woodworm screw is made complete with the boss section in one piece. The woodworm screw is to be
used with the jaws remaining in place on the chuck. This makes it very convenient for remounting work
directly onto the jaws after the screw is removed.
To convert to this operation , place the boss section into the centre of the chuck and close jaws into the
slots. BEFORE FINAL TIGHTENING MAKE SURE THAT THE FRONT OF THE BOSS SECTION OF
THE SCREW IS SEATED BEHIND AGAINST THE 50MM JAWS. This will prevent any tendency for the
boss section to creep forward when the screw is being used.
The front face of the jaws has been machined to provide an accurate backing surface. This is quite an
advantage, providing a much tighter fit and wider tolerance for irregularly faced stock. This feature is also
quite an advantage when using the screw to mount a bowl for first stage bowl turning - forming the outside
of the bowl straight onto the jaws (the screw is first removed) after the recess has been formed.
The woodworm screws provide 19mm (3/4 inch) of thread beyond the jaws. Irregular, rough tree blanks
(e.g. small sections of tree limbs) not exceeding the above sizes can be held quite firmly BUT caution
must be exercised. Check for adequate contact.
DO NOT USE THE SCREW FOR VERY LARGE WOOD BLANKS. Its intended for small bowl and screw
chucking work. The maximum capacity which should be mounted on the screw - 250mm (10 inches)
diamterX100mm (4 inches) , DO NOT EXCEED 600 RPM FOR THIS OPERATION, use tailstock support.
ITEM NO. QTY . PART NO. DESCRIPTION
1 1 48100 Midi Chuck
2 1 48116 Scroll Ring
3 1 23051 PM Jaw slide 1
4 1 23052 PM Jaw slide 2
5 1 23053 PM Jaw slide 3
6 1 23054 PM Jaw slide 4
7 1 EC48 Circlip External 48mm
8 4 10029 Jaw Set 50mm
9 8 CM5010181 Screw C/Sunk
10 2 79458391 Operating Bar
11 1 G0606 Grubscrew
12 1 NS1000 Washer Fibre
13 1 10006 WoodWorm Screw
Copyright 2007
Publication Number: 107-0708-003