SAFETY RULES And

SAFETY RULES and OPERATING INSTRUCTIONS ROCKWELL/BEAVER 6" BELT and 12" DISC SANDER Safety Guidelines

Read carefully before operating any machines !!!!

(1) Prior to or before operating this machinery ensure that the operator has been properly trained and understood the owners operators manual.

(2) Learn the machine's applications and limitations, as well as the specific potential hazards peculiar to this machine. Follow available operating instructions and safety rules carefully.

(3) Keep working area clean and be sure adequate lighting is available.

(4) Do not wear loose clothing, gloves, bracelets, necklaces, or ornaments. Wear face, eye, ear, respiratory and body protection devices, as indicated for the operation or environment.

(5) Inform the technician if the tool seems to be malfunctioning or is damaged.

(6) Keep hands and the body parts well away from sanding belts and disks.

(7) Be sure the power is disconnected and locked out from the machine before tools are serviced.

(8) Never leave the machine with the power on.

(9) Keep guards in place and in working order.

(10) Don't force the tool. It will do the job better and safer at the rate for which it was designed.

(11) Don't overreach. Keep proper footing and balance at all times.

WARNING!

Working wood is inherently dangerous. Using hand or power tools improperly or neglecting standard safety practices can lead to permanent injury or death. So don't try to perform operations you learn about in magazines, from friends or others until you're certain that they are safe for you and your shop situation. We want you to enjoy your craft and to find satisfaction in the doing as well as in the finished work. So please keep safety foremost in your mind whenever your are in the shop. Read carefully before operating the machine.

General Procedures

1. Eye protection meeting current ANSI safety standards must be worn at all times while anyone is working in the shop.

2. Never make any adjustments to a machine while it is running.

3. Never walk away while a machine is still in motion.

4. Disconnect electrical power when changing belts or disc or anytime an injury could occur if the machine is accidentally turned on. Generally this requires that the machine be unplugged or the circuit breaker turned to the off position.

Belt Sander Fundamentals:

1. Tie back your hair if it falls forward when you tilt your head downward.

2. Do not sand the face of pieces that are less than 3/4" thick unless you use a push shoe or some other means of supporting the stock.

3. Never place your fingers over the right hand end of the stock you are sanding. If the stock gets away from you, your fingers will be pinched or may get stuck between the moving belt or the casting over the belt.

The stationary sander is a combination belt/disc sander designed for fast or accurate stock removal. Use the belt sander for fast and aggressive removal of excess material to straighten edges or finish interior curves. Use the disc sander when greater accuracy is required to true outside curves, or to maintain a particular sanding angle.

Rockwell/Beaver 6" Belt and 12" Disc Sander (Our stationary sander is a combination belt/disc sander.)

Disc Type Sanders

1. Appropriate eye protection shall be worn.

2. Follow all previously presented general safety rules and precautions for sanders.

3. Before starting portable or fixed disc sanders, check the condition of discs for excessive wear and tear. Replace any defective disc before using sander.

4. When using a table or fixed disc sander, sand only on the downward travel of the disc.

5. When using a table or fixed disc sander, do not work with pieces that are too thin or too small/short, or that cannot be controlled. Use jigs or holding devices for small work pieces.

Disc Sander: Introduction

Disc or Circular sanders as they are sometimes called are one of the most useful workshop power tools that you will come across. In simplest form they can take the form of a spinning disc, which is attached by a mandrel inserted in the chuck of a hand held electric drill. These, with a disc of abrasive attached are very useful in rubbing down large areas. For example car body panels. The disc is normally made of rubber or some flexible material, which gives when the disc is rotating and you apply pressure with it to the work piece. The disc of abrasive material, which you can buy in various grades is held in place on the disc by a simple washer. You can make up your own from normal wet & dry or sandpaper, but this is a little time consuming. However the ready prepared discs are quiet cheap and last a long time with careful use.

This, the simplest form of disc sander can be made to form a serviceable bench workshop sander with a little work. It involves making a jig to secure the electric drill to the bench and an adjustable table set at right angles to the disc on which to hold the work.

Bench Circular Sander

This machine is one of the easiest to use in the workshop. With careful use it can save you hours of tedious work hand sanding. However to the untrained the spinning abrasive disc is not the best thing to come into contact with fingers!

They all however have the same parts and operating them is exactly the same in principle, although different manufacturers and different versions of the same machine can vary considerably in detail.

Disc Sander: Hazards & Safety

Being hit by objects flying off the machine is a problem, which is normally caused by insecure holding of the workpiece against the table. The most common cause of workpieces flying out of the disc is the fact that the operator has not taken into account the direction of spin of the disc when the machine is turned on. This machine rotates in a clockwise direction. Taking note of the direction of spin is important as only one half of the visible disc (90 degrees out of 180) or a quarter is spinning down toward the table ensuring that anything in contact with it is pushed down on to the table. (normally the right side of the disc) If you attempt to hold the workpiece up against the other side you will find that the action of the spinning disc will be to throw the workpiece out at you. This will result in you being hit by the piece or, by attempting to catch it will result in your fingers being cut. To summarise make sure the workpiece is held securely. If it is impossible to hold (ie it is too small) make a jig and attach it to the workpiece to increase the distance between you and the spinning disc when operating.

Ingesting Dust

There are 2 ways to reduce the volume of dust produced by the sanding process. The first way is to insure that the dust collector is on and that the specific vent to the machine you are working on is open. The second is to always ensure that you wear a suitable dust respirator that will protect you from the type of dust being produced by the material you are using. This type may vary depending on what you are sanding.

Abrasion

As mentioned previously the spinning disc is quite capable of cutting through your skin and your fingernails very easily. The best way to prevent this is to:

Ensure that the gap between the table and the spinning disc is kept as small as possible. The distance between your fingertips and the disc is kept as large as possible. This can be achieved by making jigs to increase this distance, by attaching MDF to the workpiece for example to make it easier to hold. Keeping a secure hold on the workpiece at all times. Being aware of the relationship & distance between your fingers and the disk.

Sanding Metals

Disc sanders are not designed to sand metals particularly ferrous metals. This is because the action of abrading the metal may produce sparks. These sparks if sucked up by the extraction system could cause an explosion and/or fire (ever tried throwing flour at a lit Bunsen burner?). Metals are also very tough materials and you would have to push really hard to abrade them quickly. This would over tax the motor and could lead to damage. Use an angle grinder from sculpture (or a hand file). So for these reasons: DO NOT USE THE DISK/BELT SANDER FOR THIS OPERATION.

Sanding Plastics

Be aware that plastics (Styrene, perspex, styrofoam) are all effected by heat, this causes them to melt. The action of abrading the material whilst sanding generates heat by friction. This, if the operator is overzealous causes the generated swarf to melt and stick back onto the workpiece. You can also cause the actual workpiece itself to melt. This causes inaccurate sanding and should be avoided.

Sanding Plaster

Plaster is not to be sanded on the disc sanders because as it is so soft it abrades easily and will stick to and "Gum up" the disc making it appear like a white sheet of icing sugar. This is very difficult to get off and "Gums up " the disc for the next operator. Use a Surform instead and some elbow grease. So for these reasons: DO NOT USE THE DISK/BELT SANDER FOR THIS OPERATION.

Disc Sander: Machine Parts

The machine comprises of the following parts. These descriptions are for a standard machine with a disc diameter of about 10 inches (280mm). However disc sanders can vary in size enormously from small hobby versions of a couple of inches across or less or large industrial ones with a disc size of 3 feet and up. Ours has a 12" diameter disc.

1: Motor

The motor is held rigid in normally a metal casting for strength and stability. It is always advisable to mount the sander to a bench using bolts or screws through the holes in the casting. Ours is mounted to its' own stand.

2: Starter Switch.

This is a simple on (green)/off (red) switch, which allows the machine to operate. It is mounted on the front frame of the sander in a place, which can be reached easily. It is positioned so that you do not have to reach across the spinning disc to turn the machine off. It should be able to be reached comfortably without stretching in an emergency when you have to turn off the machine in a hurry.

3: Disc

The disc is the part of the machine that actually moves. It is normally made of metal either aluminium or steel. The steel ones are more durable as they are less likely to be damaged by over enthusiastic work than the aluminium ones.

4: Table

The table is the actual working part of the machine where you hold the work to be abraded by the spinning disc. As such has to be pretty robust to allow for pushing pressure of the workpiece as it is pushed against the disc as well as being stable enough for accurate work. The table can be made from a number of different materials although normally aluminium or steel.

5: Guard

The guard follows the line of the disc and is normally part of the casing itself. It covers the rotating spindle of the motor and also the back of the spinning disc. Its main purpose is to prevent any loose clothing or hair, being caught in the spindle when the machine is being operated. 6: Table adjustment lever/bolt/knob

The table although for normal use is kept locked at 90 degrees to the cutting surface can be adjusted from 90 degrees to 45 degrees on most machines by means of a lever/bolt or knob. The casing and the table have two holes through which they are attached to each other by bolts.

7: Slot / Groove for attachments

The groove runs along the length of the table parallel to the cutting disc. It is used for fixing attachments in position. The attachment most normally used is the protractor fence. The groove is normally machined into the bed of the table at the manufacturer.

8: Extraction pipe connection.

The extraction system for the removal of dust is here. As with any workshop procedure that involves the creation of fine dust and chipping, effort should be made to minimise contact with the substances produced. The general points for this are common sense, e.g. wearing a suitable mask and only working in an area of adequate ventilation. The dust produced is not only a hazard to the operator but also those in the workshop at the time. It is no good making sure that you are adequately protected from the dangers of the dust if other people are working close to you without such safe guards. The dust can also get into switches and other electrical connections, which could lead to short circuits. Most of the manufacturers of disc sanders have made some allowance in their design for the attachment of a dust collector which will draw the dust created away from the operator to a central machine which then filter out the harmful substances from the workshop environment. This allowance is usually in the form of a moulding, sometimes part of the casing to which an extractor pipe can be fixed. For the budget minded this could be as simple as the end of a suitable vacuum cleaner. Our machine is hooked up to a dust collector and it should be turned on when you are sanding.

Disc Sander: Operation

The image below shows someone using the machine. The operation is normally called "Sanding". Note that unlike the other sanders this particular type of machines "Downside" is on the right (because it is spinning clockwise). This reminds you to check the direction of spin each time you turn on a sander. This will hopefully prevent workpieces being flung out at you. In operation the machine is extremely easy to use. Having checked that the dust extractor is on and the table is set at 90 degrees and locked, you turn on the motor with its starter switch. This spins the disc. Then, you hold the workpiece down on the table about 25mm from the spinning disc. When you are happy that the table is not going to move suddenly and that you have a good hold of the workpiece, you can move the workpiece slowly up against the spinning disc on the table. The machine will then abrade away the material of the workpiece. The rate of the abrasion will depend on how hard you push the workpiece up against the disc. Pushing too hard however will result in you slowing the disc down rather than cutting faster. This might even bend the backing plate to the disc causing it to rattle, so it is not recommended.

Disc Sander: Sanding Freehand

This is the simplest way to use a sander. The operator is sanding freehand, the downward pressure of his hands on the workpiece and its consequent pressure on to the table, is keeping the workpiece secure.

The easiest operation to do on a sander is to rely on your hands to hold the workpiece down on the table and manipulate against the disc for abrading. The workpiece although being held securely can be moved about as the material is abraded. You must ensure however that you keep your fingers as far away from the spinning disc as practical and if necessary stop the machine and adjust your grip if you fingers are getting to close to the spinning disc. Disc Sander: How to Cut With a Protractor

Set up for sanding using the protractor rest as a guide and rest.

The protractor rest fits into the machined slot that runs parallel the entire length of the table. The protractor rest itself is exactly the same as the ones that fit on to the bandsaw. As their name suggests they comprise of a rest with an attached protractor scale. By releasing and tightening a locknut, you can set the rest at any angle from 90 degrees to 45 degrees. This will result in any workpiece set against the rest and presented to the disc to be abraded and will be sanded at the angle you have pre-set. This is very useful for cutting angles and mitres, because several pieces that are being sanded one after the other using the protractor rest will have the same angle sanded on them.

However to be safe you must ensure that the protractor rest is securely locked in position at the desired angle prior (using the integral lock-nut) to starting work.

Disc Sander: Sanding Small Workpieces

Here the operator has correctly decided that the workpiece is too small to handle. They have attached the workpiece to a larger jig (MDF in this instance) to increase the distance between themselves and the disc and to allow better handling whilst sanding.

If you decide that the workpieces that you intend to sand are too small to be conveniently held freehand you will probably decide to use a jig of some sort to aid in this task. These serve two purposes: The first and more important is to increase the distance between your fingers and the disc. The second is to make the small workpieces easier to manipulate by having them attached to a larger piece, which is easier to hold and control. It is also less likely that you will let go of the larger jig whilst operating than the small workpieces. The easiest way to do this is to attach the pieces by means of double-sided tape, superglue or even masking tape. The bond should be sufficiently strong to resist the forces you are going to employ whilst sanding.

Disc Sander: Tilting Table for Mitred Sanding

As well as relying on the angles that can be sanded using the protractor rest, you can also use the table adjustment facility as well to aid sanding. Most disc sanders if you look underneath have a mechanism by which you can adjust the table. This is usually accomplished by undoing the 2 levers/locknuts or knobs, which will allow the table to swing free and then to move the table to the desired angle. Once at the correct angle (normally a graded scale is provided to help you). The Levers/locknuts/knobs are tightened again to prevent the table from moving from its' new position.

Disc Sander: Minimising the Gap Between Table & Disc

Step 1

With the angle of the table increased, the gap between the table and the dischas increased also. As a consequence of increasing the angle of the table, you can see that the natural gap between the table and the disc has increased to such an extent that it would be very easy for workpieces to slip down through it. This gap should be minimised to prevent this from happening as much as possible, as well making sure that the gap is not large enough so that one of your fingertips could slip down and become trapped between the disc and the table.

Step 2

This is normally accomplished by either:- undoing Allen key bolts on the side of the table and adjusting the table by pushing it towards the disc. This movement will decrease the gap. Once in position the Allen key bolts are tightened again or (more usually) making a jig and attaching it to the table. The jig is attached so that its top edge is much nearer the disc than the tabletop, thereby decreasing the gap.

Step 3

Small workpieces can be attached directly a jig (made from MDF), below or held up against it and sanded freehand.

Belt Sander: Introduction

Along with the Disc Sander, this machine has a belt sander attached to it also. In practice, like its smaller sibling, (the portable power tool of the same name), the belt sander is extremely simple in its construction and operation. As such the belt sander does not warrant a section on its own. However the summary below shows the basic parts of the machine as well as safety tips and operational procedure.

The belt sander consists of 2 rollers - one of which is powered. These rollers are covered by a belt of abrasive material similar to sandpaper. The rear roller is powered by a motor so that when you turn the machine on the belt spins.

Belt Sander: Hazards & Safety

Observe the general safety points before you begin.

Common hazards include:

Being hit by workpiece, swarf, being flung off the machine. Ingesting dust from the action of machining. Coming into contact with the abrasive belt, particular the edges where the belt is unsupported. Getting, either yourself, your clothes, bobles, bangles, beads, or your hair caught within the spinning abrasive belt, particularly the curved section at the front.

The image below shows the "danger point" - the part of the belt sander where most accidents happen. Belt Sander: Machine Parts

Since the belt sander is usually mounted upon a bench most of its operating parts, such as the motor and drive belts are below bench level.

1: Front Roller

The rear roller is behind the guard. The abrasive belt loops around this part of the machine. Caution should be observed at all times when you are in proximity to the front roller as getting your clothes caught in it will lead to an accident.

2: Tracking Knob

The knob on the outside of the roller is used to twist it. This is only used when a new abrasive belt has to be fitted to the machine. Here the knob is used to twist the rear roller in relationship to the front roller. This allows the technician to set up the machine and ensure that the belt is running centrally to the roller and will not "track across " during the operation.

3: Bed

This is the actual flat area where you push down the abrasive belt to sand the workpiece. You can only see the edges of it.

4: Danger points

This is the most dangerous part of the machine in my opinion. The abrasive belt here is unsupported. The edge of the abrasive belt can also be seen clearly. This small section, because it is exposed, is similar to a moving blade and as such may severely cut the operator. Simply by touching this area by mistake will result in a deep cut to the hand. This edge has been seen to cut through fingernails quickly! So keep away from this area at all times during the operation.

5: Abrasive belt

The belt is approximately 6 inches wide and 2 feet long. The belts come in all the grades ranging from very coarse to very fine - similar to those of sandpaper and wet and dry.

Belt Sander: Setting up & Operation

Setting Up

The Belt Sander does not require setting up as such. The only moving part of the machine is the belt itself. There are no attachments to consider and no removable guard to replace.

Operation

Step 1

When operating you need to reach down in front of the machine to turn on the ON/OFF switch. Because of the position of the roller you have to be particularly careful when leaning down to avoid any contact with the abrasive belt.

Step 2

The Abrasive belt is spins away from you towards the rear guard. It is therefore important that you hold the workpiece against the rear fence. The action of sanding in combination with your grip will keep the workpiece against the fence. You must never hold the workpiece against the middle of the belt, as you will be going against the belt's inclination to pull the workpiece out of your hand and into the guard/frame.

Step 3

In addition to the flat part of the belt, the curved frontal portion of the machine can also be used for sanding. However as the belt is spinning up towards you must ensure that the workpiece is sufficiently large enough to be adequately gripped by both hands.

Step 4

Because of the speed and the abrasive qualities of the belt, it is not advisable to try and use the machine to sand small workpieces. Even by using a purpose built jig to increase the distance between your fingers and the belt, I would still recommend the disc sander. This is because the table provides better support.

Step 5

You have to lean down towards the belt in order to turn it off. So watch out for your clothes! In addition the machine, when turned off takes a while to slow down and stop and under these circumstances it may cut you even it is spinning without power.

Information here is in part extracted from the following website: http://www.herts.ac.uk/lis/ltdu/projects/mm2/start.html