Well all lathes are dangerous if not treated with respect, yet some are more
than other's. I have a lathe which because of poor castings and design nearly
removed my eye. The tool rest which is a very poor casting snapped during my removing
the bark off a log I was preparing to turn into bowls. The company in question
retooled the rest to accept a steel pin, and as yet I haven't had any more
problems. I will email anyone whom is interested the name of the
company.
If you have a dangerous problem with any tools you have
purchased. You should report the faults to Consumer Product Safety
Commission at www.cpsc.gov/incident.html
or by phoning 1-800-638-2772
A few lathes are produced with defects, some just annoying, and others are
very dangerous.
Tail stock movement
Both of the above idea's work but with a slight drawback. The tool rest will
tend to align itself to the filed area's or too an indentation caused by the
tightening of the bolt or handle.
We all know that we can use a microwave for heating up left over's, exploding eggs, and
heat water for the constant supply of caffeine we desire. Yet with careful use we can dry
our wet thick turnings enough to allow us to complete the articles months before the
normal air drying process.
The trick is patients and a open-hearted wife, and a microwave, brown
paper bag big enough to hold one item at a time. Place the wet turning in the bag and
loosely fold the top, place in the microwave on defrost for one minute, remove open the
bag and allow to cool for one hour. Its a good idea to weigh the piece before starting,
for this you will need a scale that is capable of measuring in ounces or less to monitor
the weight loss as the water evaporates.
Depending on the type of timber you may have to repeat this process
several times. Allowing the timber to cool completely before repeating the trip to the
microwave. The key is to weigh before cooking and repeat the process until there is no
change in weight between two cooking.
The next step is to wait until the turning has reached moisture
equilibrium with the surrounding air for at least 24 hrs, longer if possible.
Movement will occur ,but with luck it will be minimal. Tolerance is the key
Remember to wear the correct dress, loose long sleeved clothing
is defiantly out, the idea turning jacket is short sleeved, no pockets
in the front but at least two in the back. A collar which has a Velcro fastener
to stop the chipping reaching your skin, and must fit comfortably down to your
thighs. Rings, Watches,
Neck chains should be removed before entering the
workshop, these items can cause serious injury and possibly death. So be
warned.
Fingernails should be kept short for two reasons. One if the
nail should catch in a chuck, it would be on your finger for long. Two, it is
easy to scratch your finished masterpiece and ruin many hours of work. Not to
mention that polish, lacquers and dust have a way of diving under the
fingernails just to annoy you.
Hair if long should be tied up in some way or tucked under a
tight fitting hat. Ladies you could wear the old fashioned hair net, anything
to stop those golden locks from entering the machinery, but do not tie with a scarf
or any thing which might come loose with out you knowing it.
Back to the top
Much of the machinery in the modern workshop consists of
rotating spindles on which ether you place your wood (Lathe), or such a
circular saw you push the timber against the rotation of the blade. Both
of these actions will if wrongfully used cause serous injury. If you don't
know how to use a machine do not touch it.
Learning the manual does not make you an expert, just an well informed
learner. Find
someone whom is willing to help you learn the correct method and operation of
the machine. Join a club, you can yet the information of your local club by joining
the AAW or the national woodturners association
in the country where you live. Take lessons from a teacher, or a turning professional.
I have too many friends with missing fingers, and I don't want to
add you to my list. When you ask them why they did it, the reply "I
thought I could get away with it" seems a little stupid.
You MUST respect the machine, as it has no respect for you.
Band saws seem tame enough, but more accidents occur on them than other
machine. Machines have powerful motors, and you are advised to remember that
your body is a lot softer than steel blades spinning at high speed.
Before you start your lathe you should always check for
loose items. i.e. tool rests, chucks, tailstocks, face plates and any tools
laying on the lathe. (They should never be there at all.)
Rotate the timber you are about to turn two or three times,
to check the clearance between the tool rest and the work piece. Check the
tailstock is tight.
Make sure the floor is clear of odd items which might cause you to stumble or
slip into the lathe. Just as the lathe needs its feet firmly on the ground ,
So Do You. Check the speed of your lathe. If you have to slow it
down remove the power supply, and manually reposition the belt to the slowest
setting.
Start you lathe with your body to one side of the timber
you are turning, incase of bark, loose timber or even water hitting you before
you are sure that it is safe to start work.
Back to the top
Dust can also be a killer, perhaps not as fast but just as
deadly as the machine which helps to produce it. Sanding is the biggest
problem, but turning dry timber also throws a fine dust into the air which you
breath. There are several methods of removing dust from the air available,
unfortunately non of them are very cheap, and some are better than others. The
first method is to filter the air just around your face, which is fine if you
intend to mask up as soon as you start work, and keep the mask operational
until you leave the shop. The second method is to extract the dust from the
air with a filtration unit. The final method is to remove the dust at its
source i.e. the lathe, saw, planer etc. Any of these methods are good but all
should be combine with a second method to gain the greatest benefit.
Back to the top
A neat workshop is not only a pleasure to work, in but also
contributes to the safety aspect and the functionality. If you have a band saw
which you leave pieces of timber, steel squares, and other equipment laying on
the table surface, you are asking for trouble. For eventually
something will get knocked into the path of the saw blade with deadly consequences.
Lathe tools should be in a rack, within arms reach of the
work position. Preferably one which is on some sort wheels, or caster's to
enable it to be moved for out board turning and to the grinder for the
sharpening. This is only feasible if the floor is kept clean and free of
off cuts of timber and shavings. Off cuts on the floor can be very dangerous
to only you or the people working in the area. Toss them into a wooden
box out of the way.
Clean shops invariably produce clean neat work, and a safer
environment for all concerned. Make a point of putting tools away. Put up a
notice to remind yourself and others to do likewise.
Back to the top
The most important thing about
any tools is to keep the sharp and clean. A clean tool will handle better and
slide across the tool rest without the friction of rust holding it back,
making for smoother finishing cuts. It goes without saying that a sharp tool
will not only cut better but is far safer than a dull one, less risk off
catching, tear out's and damage to yourself and the item you have
created.
Its a good practice to clean and sharpen all the tools you
have used during your days turning, making sure that all sharp tools are laid
or held in a rack where the cutting surface is unable to rub against anything
which might dull the sharpened edge. 3 in 1 oil or WD40 applied on a cloth, I
keep mine in a jar beside my sharpening station (grinder, oil stone, diamond
files). If you keep you shop neat and tidy your work will follow suit.
Back to the top
SELF CENTERING BOWL FINISHING CHUCK (Details of the curves used for the
slots on the discs. Continuation of the article from Vol. 5 No. 7) It was most
interesting to see a reproduction of Doug Longworth's self centering bowl finishing chuck
in the center fold of our last issue. Doug has been asked how he obtained the curves for
the sliding jaw buttons and I observed that they are identical to the curves used to
obtain a French handrail wreath used in stair building. Chris Medlicott, being the wide
eyed editor that he is, immediately gave me the task of reproducing a drawing with
explanation for this issue.
The curves are known by various names, the main one being logarithmic. A study of Greek
architecture shows that they used them extensively in design, the most well known being
the Ionic Volute, used in scroll decorations at the top of the pillars at the
Parthenon and other great buildings. Some of the designs are exceptionally complicated and demand a
high degree of geometric knowledge in order to understand or reproduce. It must be kept in
mind that all this was achieved without the aid of computers.
In 1864 a Frenchman named JEAY submitted a paper to the Royal Society of Arts setting out
a design for a handrail wreath, where the handrail finished over a newel or cluster of
balusters at the foot of a staircase and for his efforts he was awarded a Silver Medal.
This design was received with great appreciation as handrail geometry was reaching its
zenith or culmination, ending all the guesswork and trial and error methods. The English
method was and still is, based on the eight centered Roman Volut'e or Scroll, which while
it overcame many problems and logically set out a pre determined method of obtaining the
finished article, failed to give a pleasing visual easing of the curves because the rail
diminishes in four distinct
Jeay's method however, is simplicity itself and by placing a pin in the eye of
the scroll template and by rotating the template a limited number of various positions can
be obtained. Any person engaged in designing should have a plywood template of this wreath
design as it has limitless applications. I have a number of them that I have made from
plywood and when I am designing furniture or setting out staircases or handrail easements
or bends, I find that I can draw a curve freehand to the shape required and then by
placing the template[ over the drawing, true up the lines, so that they not only answer to
the problem but look pleasing to the eye.
It should be obvious to everyone that a "French Curve" used in technical Drawing
and drafting is in reality a number of these templates joined together and reproduced in
plastic. The trouble however with a plastic French curve is their limited size and the
ease with which they can be broken, so it makes sense to make up some templates in
plywood, in an assortment of sizes that will give you years of use.
To obtain the shape of the wreath take paper or plywood and draw line A. B. with C.D.
intersecting at right angles at center E. With E as center divide each quadrant into four
equal parts. Determine the position of 0. From 0 draw a line at right angles to A. B. to
point 1. Draw a line at right angles from I to give 21 from 2 a line at right angles to
give 3 and so on, continuing around the spiral till you have reached the point desired.
As can be seen, I have shown two positions on the wreath where a straight handrail can
join, but for the purpose of making a template, the spiral should be continued for at
least three or four convolutions. To obtain the outer handrail lines shown, it Is
necessary to step up half the width of the rail each side of each point using 2 compass,
but for the purposes of a template, simply join up each point freehand. After cutting out
using a fret saw, a piece of heavy sand paper should be used to give a smoother spiral to
the edges. If it is not possible to obtain a French curve to join up all the points, then
It would be advisable to make two patterns, the first being heavily sanded to give a truer
line and then this pattern being used to set out the second pattern.
Don't restrict yourself in regards to the size of the pattern, for the bigger they are,
the more uses they can be put to and when it came, to designing furniture full size, a
pattern measuring at least 900 mm to 1.000 meter across is invaluable.
—David Lindsay.
Note: The following Material was supplied by Jon Schilling:
Technical Comments about the Longworth Chucks by Jon Schilling &
Carl Asch
My woodturning neighbor Carl Asch and I made three of these Longworth chucks and I have
listed our recommendations and observations below:
1. Make the chuck as large as your lathe can turn. This chuck will easily
adjust to turn the largest or the smallest diameter that you have, and I think it could
take the place of the cole jaws except for the diameters under 7 or 8 inches. (Item D )
2. We used 3/4" MDF and 7/16" birch plywood 'cause we already had it on hand..
(Items C& D)
3. Have a wood turner friend help you and make two chucks. It helped, especially when
routing the arcs to have two sets of hands and eyes.
4. Use a 6 or 7" waste block if your chuck exceeds 16 or 18". I feel this gives
more stability and strength to the chuck. As with any other waste block make sure you use
suitable wood. you don't want this block splitting and coming apart. (Item B)
5 . IF YOU ARE GOING TO USE THIS CHUCK FOR OUTBOARD TURNING, be sure to read the
instructions carefully concerning construction for outboard turning. (Item 8)
6. Use nylon washers 7,16" X 7/8" against both sides of the chuck.
(Figure 3)
7. We spent a great deal of time sanding the slots. We found that having these slots clean
allowed for more free movement of the chuck. (Item 10 )
8. We recommend cutting some finger holes in the MDF disk, too. NOTE: Be careful and don't
place these holes on the same arc as the holes that you cut into the plywood disk. you
don't want these holes to coincide with holes in the other disk, because of the danger of
getting a finger caught. (Might not seem apparent to you now, but when you get ready to
cut them, it will make sense) (Item 9 )
9. Instead of using screws to attach my faceplate to the waste block I made it so that I
could easily remove and reinstall the faceplate. I did this by countersinking 4 1/4"
dia bolts to the waste block before gluing and screwing it to the MDF circle. (You have
to layout the holes to match the faceplate for easy installation) You countersink from the
side that will be glued to the MDF, drill the holes, insert the bolts and attach the
faceplate to the waste block before you glue up the MDF and the waste block. By using this
method your face plate will always be accurately centered every time you reinstall the
faceplate from some other project. (Figure3)
10. Take your time when you actually reverse the plywood disk and insert the bolts. There
are two different places where each arch intersects another arc. Place a bolt into an
intersection and attempt to rotate the disks. It won't move freely in the wrong
intersection, but will move freely when you have the bolt in the right place. (Item 11)
11. I have used the chuck to turn the bottom of 3 large platters and using approx. 200
rpm's it worked very well. Bert Stanford turned the bottom of a 12" dia and 10"
deep walnut bowl and it worked well for that size too. Here is my point:
a. Be sure to use slow speeds.
b. When gripping an object, loosen the bolts holding
the rubber jaws about a 1/4" and tighten the chuck by using the finger holes. Then,
tighten the bolts holding the rubber jaws and you will gain more pressure with the jaws.
c. If you have concerns about tightness, take a rope
or some twine and tie it around the jaws and you will also increase the holding power and
insure safety of your object.
The LONGWORTH CHUCK List of materials Needed Secures Object
4 Rubber Jaws (#8 Single Hole Beaker Stopper
#201-640)
(Nurnberg Scientific 503-246-8297)
Secures Rubber Jaws
4 1/4" x 3"Hex Cap Screws
8 3/8" 3 7/8" Nylon Washers
(Vancouver Bolt 360-699-4406, or 503-289-1261)
8 1/4" Flat Washer
4 1/4" Wing Nuts
Secures Waste Block to Face Plate
4 1/4" x 3"Flat Head Bolt
4 l/4" Hex Nut
Centers Plywood to MDF
1 1/4" Brass Flat Washer
Attach MDF to Waste Block
8 # 14x 2" Wood Screws
1* 24" x 24" x 3/4" MDF
1* 24 X 24" X 1/2" Hardwood Plywood
1 8" x 8" x 2" Hardwood
Waste Block
* NOTE: Adjust sizes of MDF and plywood to meet maximum size for your chuck.
Back to the top
[This material is from Woodturning Magazine No. 3, Spring 1991. It is published here
for woodturners around the world to share by permission of the publishers: WOODTURNING,
GMC Publications, 165 High Street, Lewes, East Sussex, BN7 1XU ENGLAND. Telephone 01273
488005. Facsimile 01273 478606. We thank them for sharing.]
I am a member of the Northshore Woodturners Guild in New Zealand. Like many others, we
exchange our newsletter with other clubs, including some in Australia. They in turn send
us copies of their newsletters to our mutual benefit.
I don't remember the date, but I think it was early in 1989, that a copy of a bulletin
from the Hunter Valley Club in New South Wales, Australia, was brought to my attention by
our Club Editor, Nelson Rundle. It contained part one of a two part article by a Mr.
Longworth on a self centering chuck which held the rims of bowls, enabling the turner to
complete work on the base of the bowl. Quite a useful tool for removing all evidence of
how a bowl was originally chucked when leaving bowls with screw holes, chuck recesses,
etc. in the bottom is no longer acceptable.
Unfortunately Mr. Longworth died shortly after the first article and the second part was
never completed, The first article contained a rather rough drawing and I was asked it I
could possibly draw up something more precise I decided to go further than that and to
actually make the chuck. After one or two experiments with compasses and protractor, I
eventually produced a three jaw model which created a lot of interest among our members,
and several more chucks were make from the plans I had produced.
Interest was also shown by visitors to our club who went away, made a few modifications
and, as I see from our National Quarterly Magazine, have almost claimed it as their own
The inspiration however was that of Mr. Longworth of Hunter Valley and to him should go
all the praise. It is interesting to note that Mr. Longworth's own club wrote to us to
obtain plans of the chuck which we had made available to our members. I have no doubt that
eventually it will be produced commercially, probably in metal with a Multitude of jaws.
However make one yourself, it's not difficult.
You will need
a. A wood lathe.
b. A router with a swing arm so that you can cut out an arc of a circle. Most
routers have a little jig which attaches and allows this facility.
c. An electric drill
d. A screwdriver
Building Material
A. A small face plate (not more than 100mm [4"]). Use a larger face plate if
you wish but the jaws can come no closer than the width of the face plate. So the smaller
the face plate the smaller the bowl which can be worked,
B. A small wooden block 30mm [1-1/8"] thick and the same length and breadth as the
face plate
C. Piece of (6mm [1-1/4"]) good quality plywood,
D. Piece of (20mm [3/4"] thick) close density particle board, plywood or wood board
The size of the latter will depend on the maximum size of the bowls to be used. If the
chuck is to be operated in board of the lathe its dimension will be limited to the maximum
throw of the lathe. Otherwise, obviously, it will not fit on the lathe.
E. Four gutter bolts with wing nuts 6mm [1/4"] diameter. Note that you will need the
same diameter router bit for cutting the slots. The length of the screws will be the sum
the thickness of the plywood plus the thickness of the particle board, plus the thickness
of the rubber jaws, plus about another 20mm [3/4"].
F. Rubber jaws. I use doorstops. Sink plugs are another good alternative. Any rubber shape
with a hole through it.
Construction
1. Screw the wooden block B firmly to face plate and mount face plate on the lathe. Remove
surplus wood until you have a disc the same size as the face plate. Check that the face of
this disc is true. If it isn't, clean it up.
2. Take the piece of plywood C and the piece of particle board D and cut each into a
circle. The diameter should be close to the maximum size you require the chuck to be. This
doesn't have to be precise as you will true it up later on the lathe. The best method of
cutting the wood is by using a band saw, a jig saw, a coping saw, a fret saw or any saw in
that order.
3. Glue and screw the face plate and wood block to the center of the particle board disk.
Get it as accurate as possible but don't get neurotic about it.
4. Place the face plate in a vice, or between two pieces of timber, with the particle
board uppermost. Now tack the piece of plywood to the particle board. Avoid tacking
through the center of the piece. Use sufficient tacks to make it secure, Don't use too
long a tack as they will have to be removed later. Make sure that the heads of the tacks
do not protrude or else later on they will impede the movement of the router.
5. Mount the chuck on the lathe and clean up the edges so that we have two precise disks.
Using a pencil, and with the lathe rotating at slow speed, accurately locate the center of
the disk. It Is very Important that you locate the exact center, so take your time over
this. Now remove the chuck and mount in the vice, or across two pieces of timber, as
previously. Make sure it is in a stable and comfortable position for you to work on.
6. From here on it all gets a bit nerve wracking. We are going to make a 4 jaw chuck, It
would be better if it were a 6 or more jaw chuck. The more jaws the more firmly it will
grip. However a 4 jaw works well enough and is more simple to describe. One day I will
make one in metal and make it a 10 jaw.
Through the center draw two diameters each at right angles to the other. Now draw three
circles around the center:
1. One the same diameter as the face plate.
2. One 21 mm [13/16"] in from the outer edge,
3. One midway between the two circles just drawn.
If you don't have a compass large enough then just mark along one of the diameters the
radii required, Then remount the chuck in the lathe and, resting a pencil on the tool rest
at each marked spot. rotate the lathe at a very slow speed and describe the circles. Then
remove the chuck and set up as before.
7. At the intersection of the mid circle with each diameter, a small indentation should be
made. There are four of them (C1, C2, C3 and C4 as shown in Figure 1). These points should
be very accurately marked as they are the centers about which the router will rotate. So
take a lot of care here.
Figure 1. Showing Router Movement.
8. Now prepare the router for use. The router bit needs to be the same diameter as the
gutter bolts. It will need to be deep enough to cut through both the plywood and the
particle board. Set it up so it will swing about a center. The radius of the swing is from
the center just calculated to a position just past the other side of the inner circle. The
slot so made should not enter the inner circle but just graze the edge, Set the radius
carefully because once you have started, you may not change it or allow it to change.
Figure 2 shows the direction of cut for a chuck which is to be used inboard of the lathe.
Reverse the direction if it is to be mounted outboard. (Anti-clockwise instead of
clockwise.)
Figure 2. Showing Router Slots.
Now begin cutting the slots They begin at the outer circle and finish when the router
reaches the opposite side of the inner circle. Make sure you do not exceed these
positions. Make sure also that the point of radius of the router is correctly located.
Increase the depth of each cut slowly. Take much time and care over this stage of the
chuck's construction. Its ultimate accuracy will depend on how well you do this routing.
Continue cutting each slot until eventually you come through the other side.
9. When the routing is completed, you must cut several finger holes. The purpose of these
is to assist in the rotation of the chuck disks when positioning the bowl to be worked.
Make four holes, about 15mm [5/8"] across, near the edges in an area well away from
the slots. Lastly, drill a hole through the center of the plywood disk through the
particle board and into the wood block. Ultimately the plywood disk will be located on the
particle board disk by a screw. The first drilling should be deep enough to take the
length of the screw and no wider than is necessary to allow the screw to bite into it. Now
use a drill bit the exact diameter as that of the screw. It is essential to have a snug
fit. Drill only through the plywood disk.
10. Now remove the tacks holding the plywood disk. Rotate the plywood disk. if you have
cut accurately, each set of slots will line up exactly with the next set. Lightly
sandpaper the slots and ensure that the gutter bolts will move easily within them.
11. Lightly grease the surface of the particle board and place the plywood disk back onto
the particle board but In reverse order to what it was before.
The upper surface is now against the particle board and its other side is now uppermost.
Screw the plywood disk to the particle board disk through the center until the screw is
fully home but still allows the upper disk to move freely, Now assemble the jaws as shown
in Figure 3, with the wing nuts to rear. The chuck is now completed.
Figure 3. Shows the assembly of the chuck.
12. Place the chuck back on the lathe and, with the gear ratio at its lowest speed,
start up the lathe. If the wing nuts have not been tightened, the jaws will move towards
the center ... a safety factor which will ensure the chuck will always have some degree of
grip on your bowl. Note that the previously, oh so obvious jaws have now become a blur. I
guarantee that, the first time you use the chuck, you will get a smack across a finger
from one of them. For this reason always run the machine at slow speed. A bruised finger
is better than a broken one.
13. Now get one of your most least liked bowls to try it out. If the edge of the bowl
turns out, apply the jaws to the outer edge of the bowl. If the outer edge of the bowl
turns inwards, apply the jaws to the inside of the bowl edge (Oh bliss, no bruised
fingers). Place the chuck on a bench and lay the bowl on it. Bring the jaws to the edge of
the bowl using the finger holes, and begin to tighten the wing nuts, a little at a time,
until the bowl is firmly gripped. Now place the chuck back onto the lathe and bring the
tail stock up as a safety measure. Position the tool rest and start the machine. It should
run true.
Indispensable
Until you get used to the chuck, use a light scraper for your initial work and keep the
tail stock in position for as long as possible. Having given it a light scraping, try a
gouge and see how it goes. Don't make deep cuts. you don't want to risk a dig in and the
whole thing coming off the chuck, I have ruined two masterpieces on this chuck, so always
have a healthy respect for it. When you have got the hang of it you will find it
indispensable. Happy turning!
Back to the top
Jigs
There are so many jigs and devices on the market today, many of which can be
made at home with a little time and patients. Simple items can be made of Plexiglas, wood
and the odd piece of steel.
-
Finding the center of a log can be made a lot easier if you have a piece
if clear ¼" - ½" Plexiglas the largest diameter that your lathe
can turn. Simply cut the material to circle the largest you can
comfortably handle on your lathe, mark the center and drill a ¼", draw
a strait line through the center point and mark off at 1" intervals. At
each of these points mark with a permanent marker the size of ether the diameter
or the radius.
Place the Plexiglas on a flat surface and with a sharp set of points (dividers)
mark each circle at the 1" intervals. Take a fine permanent marker, and
follow each scratch carefully, you will end up with something that looks
like the annual rings of a tree. Place it on a log and centralize it, there
is the center, also this will enable you to know the length you require just
add 1" and cut the log.
Back to the top
Freezer
Apart from freezing the carcasses of dead animals, the freezer can be used to store
your wet turnings.
I have rough turned a piece of wet timber
and placed it in the freezer to find out what effect if any it will have on the
timber. I must admit whilst it may preserve it , I have a doubt about the finish
on the item as I expect the cell walls to be expanded and maybe burst as ice
expands within the cell walls.
Another use for the freezer is to store your
cyanoacrylate adhesives
Thinking further on the subject as a freezer
works by removing moisture perhaps this could be a method of drying turnings
after finish turning. I would be grate full if anyone has tried this method to
email
me with the results to publish on my site, and also inform the
LIWA
and the rest of the WWW.
Much information could be shared if only we all knew
where to find it.
Back to the top
Vacuum Chucks
These device's can be a blessing or a curse, but because of
there ease of use and design they are becoming easily available and a
"Must Have" item in the workshop. Several companies sell complete
systems ready to go, other's specialize in just the vacuum systems required to
run the system. The information which follows is from my own personal experience
in setting up a system and does not necessarily apply to all systems.
Essentially there are two ways of supplying a vacuum to your chuck.
One is the a electrical motor vacuum pump, and the other the vacuum is supplied
buy using compressed air through a Ventura system. The advantages and
disadvantages are listed below. To install a vacuum chuck on your lathe it must
have a bored headstock spindle with no cross holes bored through. There is a
system made by Packard Woodworks
which circumvents this problem.
Advantages of the Electric Pump System.
Disadvantages.
-
Price of unit.
-
Yet another plug used.
-
Maintenance.
-
Belt drive.
Solving the disadvantages.
With a little searching of car scrap yards a suitable vacuum
pump (York), can be purchased for around $35, and then all that is required is a
¼ - ½hp electric motor. Bolt both on a single piece of plywood with the addition
a belt and you are ready to go. Motor or pump should be mounted so that the belt
is free running and not too tight or the belt will wear prematurely.
Advantages of Ventura System.
-
No moving parts
-
Easy connection
-
No maintenance
Disadvantages.
-
Compressor required.
-
Noise
-
Air Movement
Solving the disadvantages.
Unless you already have a compressor installed you will have to purchase
one which can raise the cost of installation by as much $300 depending on the
compressor chosen. However this can be a blessing if you purchase air tools at
the same time. Which can assist your in the workshop by everything from carving
to sanding, and drilling. Do not buy a gas powered compressor for this use
as is well understood the fumes will have a strange effect on your turning as
well as the turner. The noise from the compressor can be combated by enclosing
in a loose fitting lined with egg trays, and louvers face down or doubled, for
ventilation. Air movement can be controlled by directing to the outside of the
working area.
Designing and Using Vacuum Chucks.
The main purpose of a vacuum chuck is to hold an object on the
lathe without marking the surface. So with this in mind you can design your
chuck to suit your needs. Of course you can always purchase ready made chucks
but unless you intend to turn the same shape and size of vessel every time you
will eventually be forced to make your own.
Chucks can be made from almost anything which will not buckle
under vacuum pressure, and is not porous enough to allow the air to enter enough
to lose the vacuum. Aluminum, steel, wood, PVC piping, all can be utilized in
the making of your chucks.
Holland 4 Wheel Steady
Improvement over 3 wheel steadies
25% larger swing capacity, fits lathe sizes 12, 14, 16, 18, 20 and 24 inc.
Easy to build of plywood
Plans for sale $20.00 + 2.00 s/h
Custom Built for $275.00 + s/h
email:wmhollan@optonline.net
phone 631-281-0302
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