The newest addition to the family of Engravographs, Models TM-3/GM-3, will give you vast opportunities to enter and succeed in many fields of engraving.
This instruction booklet applies to Model IM-3 (equipped for rotary engraving, which is used on plastics, metals, and other materials where a routed-out or deep cut is desired), and Model GM-3 (equipped for diamond-drag engraving, a process used on jewelry, trophy plates, precious metals, and metal cups and bowls, to give the engraving the appearance of hand engraving). It is easy to equip your machine for both types of engraving--just consult the accessories catalog for the necessary parts.
This instruction manual will guide you through the detailed operations of your machine. Simply remember that whether you are using rotating or diamond equipment, the engraving process consists of the following basic steps:
Engraving is as simple as performing the steps above. If you have any questions about operating your machine, Shor offers no-charge tech support is standing by to help you.
Set the machine on a level surface with ample room behind to allow back-and-forth movement of the pantograph. If you ordered the machine with a motor, be sure the machine is placed near a grounded 110-volt AC outlet. To mount the motor (standard on Model IM-3): (See Figure 2)
Position the motor on the mounting plate located at the end of the motor bracket. Use the two screws and lock washers (provided in the bag with the motor pulley) to secure the motor in place.
Install the motor power cord as shown in figure 1 and secure it with the gray cover, place and tighten the six screws.
Mount the motor bracket assembly on the machine base. Remove the alien screw from the base of the motor bracket. Place the motor bracket on the base inserting the positioning pin in its location and tighten the alien screw.
Install the motor pulley on the motor shaft and tighten the set screw with the key provided. When positioning the pulley, the set screw must face the flat position of the motor shaft. Mount the rotating spindle on the spindle link of the pantograph, locking it into position with the lever screw and lever, as shown at left. If you have a GM-3 model, simply install the diamond assembly.
The work holding vise clamps the item to be engraved. The work holding vise on the TM-3/GM-3 can move the engraving area vertically, horizontally, and the item up and down. It can also be turned around, to any angle from its home position, as determined by the protractor located on the machine base.
Turn Crank Handle "A" (See Figure 3).
Loosen Lock-Knob "D" and slide work holder. When position is reached, retighten Knob"D".
Loosen Knob "B", and slide work holder to the right or left. Retighten Knob "B".
Loosen Lock-Knob "E". Unlock alien screw on protractor index ring. Turn Knob "F" of the Wire Jack. Tighten alien screw on protractor index ring and lock knob "E".
Loosen Lock-Knob "E" until the workholder swivels freely. Turn work holder around to the graduation setting desired using protractor index. Tighten Lock-Knob "E" to lock work holder in position.
This is the most important part of your engraving machine. It is the mechanism that transfers lettering or designs from the master copy type to the item being engraved. By adjusting the settings on the pantograph you can produce up to 25 different sizes of finished engraving, from a single master template. (See Figure 4)
The numbers on your pantograph scales, also known as the ratio settings, range from 2 to 7. That means that the largest finished engraving pattern that you can produce from a given master will be one-half the size of the original brass master. Similarly, the smallest finished engraving size you can produce will be one-seventh the size of the original brass master character.
The size of the finished engraving will always be smaller than the size of the brass master. Scales "A" and "B" control how much smaller the finished engraving will be. Scales "A" and "B" must always be set on precisely the same value or the engraving will be uneven. Scale "C" can be set on any value, but when set on the same value as "A" and "B", it can precisely center the engraving on a concentric object. (See figure above right)
When no pressure is applied, the pantograph is automatically pulled up by a tension spring located under the machine base. The spring tension can be adjusted to your own preference. To adjust the tension, pull the knob located on the front of the machine base, underneath the copy table and screw IN to increase the tension or OUT to decrease the tension.
The best way to explain how to select a good ratio setting is to work with an example. Assume that you are using a style of master copy type in which the typesize is 5/8 of an inch. You are engraving a name badge, and have decided that you want a finished letter-height of 1/8 of an inch. To find the setting that will give you this result, divide the typesize of the master by the desired height of the finished letter. That is, 5/8 divided by 1/8 equals 5. Thus, you will need to set the ratio scales "A" and "B" on 5. (See figure above right).
The accompanying Ratio Chart (See figure 5) can help you speed your choice of a ratio setting. The most common type sizes are shown in the left-hand column. The horizontal numbers indicate the various ratio settings. By matching both down and across the chart you will reach a desired finished engraved letter height.
The height of the finished lettering is not the only value you need to consider. The pantograph reduces the width of the engraving by the same amount it reduces the height. In the example given above, suppose that you have assembled the Brass Master Copy Type lettering for the message you wish to engrave and it measures 10" across. The item you are engraving is a name badge of 3" width. Will the engraving fit on the badge? To find out, divide the length of the line of type by the ratio: 10" -. 5 = 2. Thus, the width of the finished engraving will be 2 inches, small enough to fit on a name badge with room to spare on each side of the lettering as margins, to give the name badge an appealing look In actual practice, however, you probably will not bother with this simple calculation Instead, you will simply insert and center the copy into the Copy holding slide, as will be described further on. Then, by placing the tracing stylus in the extreme right and left portions of the copy, you will be able to visually determine how close the engraving tool comes to the edge of the engraving material.
1. Use a larger name badge.
2. Switch to a lower ratio.
3. Change typestyle to a more condensed style, i.e. one that fits more letters into a given line-width.
For Scale "A", loosen the lever screw on the cutter spindle (See figure 5) or diamond assembly and align the center mark on the cutting instrument with the desired ratio setting on the scale. Then, re-tighten the lever screw. This operation is the same for both diamond spindle and/or rotating spindle.
For Scale "B", loosen the lever screw across from the scale and slide the pantograph bars until the hairline mark aligns with the desired ratio. Then, re-tighten the lever screw.
For Scale "C", loosen locking knob and push work holder either to the same ratio setting as Scales "A" and "B" or until the spindle is located over the desired engraving area.
This is the part of the machine where the engraving actually takes place. There are two interchangeable spindles that can be used with Models IM-3 or GM-3. The diamond assembly (see Figure 6A), standard on Model GM-3, is used on metal items only. The rotating spindle standard on Model IM-3 (see Figure 6B), can be used for motorized engraving on all types of material where a deep or wide cut is desired, utilizing carbide or high-speed steel cutters. The depth of cut is changed by changing the bottom micrometer setting applied onto the pantograph; the width of cut is varied with the width of the tip-size of the cutter selected. Both types of spindles are attached to the pantograph by means of a lever screw and washer. When changing from one type of spindle to the other, the same lever screw and washer can be used.
When attaching either spindle, make sure it is flush against the pantograph casting. Even more important, do not tighten the lever screw until you are sure it is entering the spindle casting straight-on. Otherwise, you could strip the threads on the spindle housing. Both types of spindles are operated by hand pressure applied onto the pantograph.
With a little practice, using the material supplied with the machine, you will quickly get the sense of how much pressure to apply for an even, attractive engraving. You can vary the depth of a line somewhat by increasing or decreasing the pressure, when using the diamond spindle; but be careful to use a light touch with thin, flexible or hollow-engraving items, such as gold charms. The diamond insert, located at the bottom of the shaft of the diamond spindle, can be removed for replacement using an Allen wrench. A diamond graver for rotating spindle is also available.
To use the graver, remove the motor belt and retaining nut from the spindle, and engrave without using the motor.
For more than occasional use, purchase a diamond spindle. The rotating spindle can be used with a wide range of cutters to perform a wide variety of engraving jobs: Cutting through the top layer of a plastic material to let the contrasting color show through. This is by far the most common engraving job. Engraving in depth in single-color plastics, metals, or other materials, often to permit filling with paint or some other coloring agent. Reverse engraving on clear acrylic and 2-flex.
In this technique, letters are cut deeply in reverse on clear material. This gives the engraving an attractive, three-dimensional effect when viewed through the material. Burnishing on brass or aluminum. This process is not deep cutting. It is often used on coated brass to produce engraving that can be darkened with oxidizing agents.
Cutters are inserted into the spindle from the top. The cutter heads have left-handed threads, so they must be screwed into the spindle pulley counter-clockwise. If you are having trouble removing the cutter from the spindle, make sure that you are turning it clockwise. Make this point clear when training new operators on your machine. Many a spindle has been damaged by turning the cutter in the wrong direction.
The rotating spindle has a micrometer for controlling the The cutter penetrates the engraving material. You must adjust the vertical position of the cutter so that when the micrometer is set on zero, the tip of the cutter is flush with the bottom of the depth-nose which is held in place by the retaining nut. Then, if you advance the micrometer setting to 8, for example, the cutter will penetrate .008", or 8/1000's of an inch into the material.
Select a depth-nose with a hole wide enough to accommodate the cutter you plan to use. Insert it into the retaining nut, and screw the retaining nut onto the micrometer. Make sure the depth-nose is seated flush in the retaining nut. Set micrometer on (0) zero.
Insert cutter through top of spindle pulley (see Figure 8).
Clamp a piece of flat engraving material into the work holder.
Remove the copy holding slide from the copy table On the copy table, position the leveling tool provided with the machine. (see Figure 9)
Loosen locking knob "E" and protractor index ring screw; raise or lower the workholder so that the surface of the engraving material will be flush with the bottom portion of the leveling tool. When this operation is completed, tighten locking knob "E".
Loosen the set-screw on the cutter head so that the cutter shaft slides freely. To loosen the set screw on the cutter head, use the cutter head wrench (Part No. 31-210-00) supplied with the machine.
Lower the pantograph until the depth-nose rests on the surface of the engraving material.
Holding the pantograph in this position, press the top of the cutter shaft to make sure that cutter tip is flush with the tip of the depth-nose and the surface of the material.
Continue holding the pantograph in this lowered position, and re-tighten the cutter head set-screw with the cutter head wrench.
Loosen the knurled screw on the micrometer indicator assembly located at the bottom portion of the cutter spindle and advance the micrometer to the desired depth-setting and tighten the knurled screw.
Before turning on the motor, rotate the spindle pulley by hand to make sure the spindle turns freely. If it does not, the cutter may be rubbing against the inside of the depth-nose. If that is the case, you will have to switch to a wider depth-nose and begin again. The cutter must NEVER touch the depth-nose during engraving, as it will destroy the cutter and nose.
This is the part of the machine that holds the master copy type or design template in place. Type comes in four basic sizes for corresponding copy slide varieties: 5/8", 1-1/4", 2-3/4"double-grooved slide, and 41/2". You can also purchase an adjustable copy slide for oversized masters.
Simply loosen the two knurled screws located on bottom of the slide, slip the slide onto the copy table and retighten the knurled screws. Another easy way to line up a copy slide is to bring its top edge flush with the top edge of the copy table. Even so, always verify that the graduation on the right and left scales are the same.
Note: When using a double-grooved slide (1-1/4" and 2-3/4"), the engraving spindle will be located exactly in the center of the work holding vise when:
Scales "A", "B" and "C" are set at the same ratio.
Slide is set flush with the copy table.
Workholding vise scales are all set to zero. Most standard copy slides come with a scale for centering the type. When you first attach a copy slide to the copy table, you will need to center the scale with respect to the workholder.
Adjust the workholder's left/right scale on "0" (zero).
Set the pantograph on any ratio. (Scales "A" and "B"). We suggest ratio of 4.
Insert a pair of flat holding jigs onto the workholder.
Use either the diamond spindle or the rotating spindle with a cutter inserted. Place the tracing stylus on the "0" mark of the centering scale. With the diamond graver of cutter, locate the center hole of the holding jigs.
Slide the scale left or right, as needed, by loosening the screws clamping the copy slide To the copy table. Tighten the screws of the slide when the "0" mark of the scale aligns with the tracing stylus.
For diamond engraving, you are all set to engrave. However, if you require lowering the entire diamond shaft, loosen the set screws in the housing, lower the shaft and re-tighten set screws.
For rotary engraving, you will need to select the proper cutter for the material you are engraving. There are two items you will need to check: the part number and the tip size. The part number corresponds to the material you are engraving. The tip size indicates the width of the line you are engraving. The larger the finished engraved letter the wider the tip size, and vice versa. The accompanying chart shows recommended tip sizes for different letter heights. It is meant as a general guide, and it only applies to single-line styles of type. For multiple-line typestyles, a general guideline is to use a cutter width approximately half or a third of a cutter width you would have otherwise selected for a single-line type style (see chart below).
|Character Height||Cutter Tip Size|
If you need to engrave a single line of type on a symmetrical piece of engraving material (for example, a rectangular brass or plastic nameplate, a plain identification bracelet, or a brass disk), you can automatically centerthe engraving on the item.
Follow these steps:
In addition to setting the two main pantograph scales on the same number, set the centering bracket scale "C" at the back of the pantograph on the identical number.
Set the two workholder scales (front/back and side/side) on "0".
Clamp the item in the center of pair of holding jigs. For flat, rectangular objects, make sure that the right-hand and left-hand sides of the piece line up with the same numbers on the holding jig scales.
If you are using a double-grooved copy slide, align the top of the slide with the top of the copy table (see paragraph 2C).
Compose your type, and insert it into the copy slide. (Be sure to include spaces between words, and punctuation where appropriate.) Note: If the punctuation falls at the end of a line, center the text first without the punctuation; then place the punctuation mark at the end of text and replace end stop. By doing so you will have an aesthetically pleasing layout.
Position the two end stops so that they both align with the same number on the copy slide scale. Lock the type in place and make sure it does not jiggle.
Check for automatic centering.
Centering bracket on same setting as pantograph scales.
Both workholder scales on "0" (zero).
Item clamped symmetrically in holding jigs.
Double-groove copy slide aligned with top edge of copy table.
Type centered on copy slide.
To avoid undue wear on your cutter, engrave no deeper than necessary. Recommended cutting depths for standard engraving materials are shown in table below.
|010" to .015"|
|Gravoply II||003" to .005"|
|Metallex||003'' to .005"|
|Brass||008" (in one or two passes)|
|Phenolic||005" to.015 " (depending on color)|
Insert the tracing stylus in the groove of the master copy type.
If you are using the rotating spindle, turn the motor ON.
Lower the spindle to the surface of the engraving material and trace the letter with the stylus.
Always release the engraving spindle BEFORE moving on to another letter. Otherwise, you will engrave random marks on the item.
When you have finished engraving the line, check to make sure that the lettering is evenly and cleanly traced. If not, retrace where necessary. Do not remove the item from the workholder until you are sure that the engraving is satisfactory. Accurate retracing will be difficult once the item is moved.
Use either 1-1/4" or 5/8'' copyholding slides. Clamp them onto the copy table, making sure that they are parallel both with the copy table and with each other. Also, make sure that the space between the slides is even.
Select a ratio as if all the lines were just one large line of type. That is, consider the distance between the top of the top line and the bottom of the bottom line as your overall letter height. Select a pantograph ratio on the basis of that overall distance. If the individual letter heights are too small to be attractive at the selected ratio, move the slides closer together and start again.
As described in the pantograph section, make sure that the longest line of type will fit onto the engraved item at the selected ratio.
Finally, spot-check the centering of the engraving. Place the tracing stylus at the top of the top line and see where the cutter or diamond graver will contact the piece. To make this easier, place a piece of scotch tape on the item to be engraved, and make a light mark with the cutter or diamond graver. Then, do the same with the bottom of the bottom line. Shift the forward/back position of the workholder until the distance between the top line and the top edge of the piece is the same as the distance between the bottom line and the bottom edge of the piece. Although the engraving should be centered side-to side automatically (assuming that you have centered the type with the copy scales, and that the side/side workholder scale is set on "0") you can spot-check the horizontal centering in the same way.
Engraving more than one line with a single copy slide is easiest with an odd number of lines. The reason is that you can first engrave the center line, and then position subsequent lines around the center.
Make sure that there is enough room for the lines to fit.
Add up the total height of the engraved lines (1/4" +1/4" +1/4" = 3/4"). Subtract that amount from the total height available (1/4" less 3/4" = 1/2") If the precise spacing between the lines is not crucial, all you really need to know is that you have a reasonable amount of space in which to position each engraved line.
Compose the center line of type and engrave it, using the machine's automatic centering feature. Compose the top line of text.
Shift the forward/back position of the workholder, and spot-check the top and bottom of the engraved line to see where it will fall. When you have located the suitable position, lock the workholder in place, and record the workholder scale setting.
Positioning the bottom line is now easy. Simply shift the workholder toward you, past the "0" mark on the scale. Continue moving it until the arrow points to the same number that you recorded for the top line.
Once the position is confirmed, lock the workholder in this position, compose the bottom line of type, and then engrave it.
If the precise spacing between the line is important, then you must decide how to distribute the '/2" of blank space surrounding the engraved lines.
Suppose we have a similar scenario in example 1, except this time we want to distribute that space evenly between all the engraved lines:
Each of the four spaces will have to be 1/2" divided by 4 = 1/8" in height (you don't have to distribute the space evenly, but the total height must add up to 1/2").
With a fine-marking pencil or sharpened crayon, make a mark '/8" from the top of the plate, and another 1/8" from the bottom.
Proceed as described above, engraving the center line first. Then, in shifting the workholder position to engrave the top line, place the tracing stylus at the top of the top-line of type.
Move the workholder so that the tip of the cutter, or the point of the diamond graver, falls directly on the mark previously set a 1/8" from the top of the plaque.
Engrave the top line, and repeat positioning and engraving operation for the lower line.
Because you will not have a middle line that can be automatically cratered and used as a reference point, the best procedure is to lay out the engraving positions beforehand.
Suppose the same example as above except that this time we will engrave two lines instead of three.
In this case, the total height of the engraved lines (1/4" + 1/4") will be 1/2". The total amount of vertical space remaining on the plate (1/4" minus 1/2") will be 3/4".
If we want to position the two lines evenly within that 3/4", divide that space by the number of spaces between the engraved lines (recall that this number is always one more than the number of engraved lines). Thus, the height of each space between the letters will be 3/4"divided by 3 = 1'/4".
With a marking pencil or crayon, mark off the top and bottom of each engraved line.
Insert type for each line, positioned so that the top and bottom of the line corresponds to the marks, and engrave.
The same principles of allocating available space and laying out engraving positions apply to more complex multiple-line jobs, including ones where the height of various engraved lines are different from each other.
Sometimes you may not be able to engrave a long line" of type in a single set-up. There may be two reasons for this:
1. The line of type is too long for the copy slide.
2. The type fits on the slides, but the plate being engraved is so long that it cannot be supported firmly from underneath along its entire length.
The solution is relatively simple:
Lay out the entire line of type on a table or the floor, and measure it. Find the exact center of the line and mark it with a crayon or a felt-tipped pen.
Measure the plate to be engraved and mark its center as well.
Insert the left-half of the line of type, including the marked letter, and clamp in place. You don't have to bother centering it precisely.
Clamp the plate loosely in the workholder.
Select the pantograph ratio and place the tracing stylus precisely on the marked center letter. Slide the plate until the center mark falls directly below the cutter. Lock the plate in place.
Engrave the left-half of the line, including the marked letter.
Remove all type except the marked letter, and insert the remaining type.
Loosen the plate in the workholder, and repeat Step 5 above.
Do not retrace the center letter, but engrave all the letters to its right. The job is done.
Reverse engraving produces a three-dimensional effect that makes the engraved letters seem almost solid, even though they are the part of the plastic that has been cut away. The lettering is viewed through the material, instead of straight-on, as with other types of engraving. You can perform reverse engraving on two types of material: Clear Acrylic & Laminated 2-flex, in which one layer is clear, and the other (the one you're engraving onto) is opaque. In most engraving operations, it is undesirable to engrave too deeply into the material. Instead, if you want to engrave a wide line, you will use a cutter with a wide tip. That way, you can engrave just a few thousandths of an inch into the material, and still produce a wide line. You can also use a multi-line type. In reverse engraving, however, depth is what makes the engraved line attractive, and tip size is less important. To produce a wide line, you engrave more deeply into the material (see chart below).
|Gravoply||010" to .015"|
|Gravoply II||003" to .005"|
|Metallex||003'' to .005"|
|Brass||008" (in one or two passes)|
|Phenolic||005" to.015" (depending on color)|
Purchase Acrylic or Reverse 2-flex. Then, purchase a set of reverse-type, from the Master Copytype Catalog.
Insert masters from the left, into the copy slide, so that the entire message (including punctuation, if any) is reversed. Take extra care to insure correct spelling.
Set depth at a shallow setting, and engrave one or two letters to test depth. Increase depth gradually, until the width of the engraved line at the surface corresponds to the proper width for the letter height.
Engrave as usual, but go slowly if you are making a deep cut. Engraving too quickly could cause melting. If necessary, engrave entire message at a shallow setting, increase to full depth and retrace.
If you wish, you can fill reverse engraved acrylic with Engravers Enamel (see Accessories Catalog). 2-flex can be backed with a metallic foil to produce the illusion of solid metal lettering.
This is a method of engraving on polished metals, usually brass, that produces a wider line than would have been possible with diamond engraving. Burnishing is often used in conjunction with an oxidizing agent (Gravoxide) that will blacken the newly exposed surface of the metal
The tip size of a burnishing cutter is selected in the usual manner. However, do not try to engrave in depth with burnishing cutters. They are only meant to skim the surface of the metal, using very light-hand pressure.
Replace the diamond insert, if it is producing a double-line or is not engraving smoothly. To replace the diamond insert, open the set-screw with an Allen wrench, # 31-202-00, as shown. Remove the insert and replace with a new one, making sure that the flat surface of the insert faces the set-screw. Tighten the set screw.
Check the tracing stylus periodically for signs of wear or chipping, and check it immediately if it is slipping out of the type as you engrave.
If stylus is worn, order new stylus. Measure stylus length before removing to replace at same length. (Some models may require insert only.) A new or well maintained tracing stylus prolongs the life of brass master copy type.
Cleaning is as important as lubrication, especially if you do rotary engraving. Take care to wipe engraving debris from the machine after each engraving job, and at the end of the day.
The lead screw, locking knob, transport knob, as well as the inside shaft of the rotating spindle, are all particularly vulnerable to interference from engraving chips. Inspect them regularly, and wipe them clean.
Do not attempt to lubricate motor, bearings, rotating spindle bearings, or pantograph bearings. These parts have been positioned to extremely close tolerances, and any attempt to change them could put them out of alignment. All bearings are pre-lubricated at the factory.
Engraving slopes "uphill" or "downhill"
Copy slides are not aligned
Pantograph is set improperly ..
Pantograph is out of alignment.
Workholder is out of alignment. You'll know this is so if the engraved line in the test above is straight.
Make sure the copy slide lines up with the edge of the copy table or with the guide marks on the side of the table. Also make sure the copy slide is tightened securely (See 2C).
Make sure the engraving piece has been set at the proper height using the leveling tool (See 2B,4).
Scales A and B must be set exactly on the same number (see 1-D).
To see if this is so, take a piece of engraving material that is cut so that the top and bottom edges are precisely parallel. Set the pantograph at 4:1 . Remove the screw from an end stop and place the tracing stylus into it. Engrave a horizontal line close to the edge of the material by sliding the end stop across the copy slide. If the line not only slopes but is curved, the pantograph is out of alignment. Contact Shor before returning the machine for repair.
Type "jiggles" when clamped in copy slide.
End stops are loose.
Type is old or worn .
If end stops won't lock when tightened as far as they will go, replacements are needed.
Replace with new type.
Stylus slips out of type when engraving.
Stylus is worn
Type is old or worn.
Resharpen or replace stylus.
Replace with new type.
Engraving material melts or beads up during engraving.
Rotating spindle cannot be lowered all the way down to the engraving material
Micrometer indicator assembly cannot lock bottom micrometer in place when tightened as far as it will go.
Cutter is dull or chipped
Spindle bearings are worn.
Very soft thermoplastic material
Material out of range of the spindle.
Indicator assembly is worn
Match cutter with the engraving material, using chart in Machine & Accessories Catalog.
Call Shor to have cutter resharpened or purchase a new cutter.
To check, test spindle shaft for end play, (there shouldn't be any). Also, give spindle pulley a spin by hand. If spindle shaft spins with a rattling or "wheezing" sound, ball bearings are beginning to wear out. Call New Hermes before returning for repair.
Change spindle speed by reversing the belts.
Use oil as lubricant.
Raise the workholder (see Section A)
Contact Shor about purchasing micrometer indicator assembly
Stylus and spindle are blocked from engraving a letter all the way to the top or bottom.
Spindle is blocked by the edge of the holding jig
For rotating engraving, try switching to a narrower depth nose.
Shim material in holding jigs so its top surface just clears the top of the holding jug.
If practical, turn workholder 90 degrees and clamp engraving item by the sides.
Engraving line suddenly becomes wider (rotating engraving).
Micrometer setting has shifted
Send cutter to Shor for resharpening
Set locking screw tighter
Engraving line suddenly forms a double line (diamond engraving)
Diamond has broken out of its metal housing
Call Shor to order a new diamond graver
Motor is turning but rotating cutter is not turning properly
Motor belt is worn.
Motor pulley or spindle pulley is loose.
Cutter is rubbing against inside of depth nose.
Spindle bearings have frozen or belt idler pulley bearings are bad.
Hand pressure too great.
Check that set screws are securely tightened on both motor and spindle.
On motor pulley, make sure that the set screw is flush with the flat surface on both the motor shaft and spindle shaft.
Switch to wider nose.
Call Shor to return for repair.
Purchase backup spindle.
Engrave with a lighter "touch".
Rotary engraving leaves circular marks around lettering ("nose rubs").
Depth nose is scratched or burred.
Material is scratch-prone.
Engraving speed is too fast
Inspect depth nose to make sure it is highly polished and has no nicks or scratches. Run it over your finger and feel for any roughness. Replace if not perfectly smooth.
Switch to narrower depth nose, if possible.
Engrave through a protective coating, such as Scotch tape. Brush away debris every few letters, to prevent remnants of coating from interfering with depth regulation. Engrave with speed controller.
Engrave with speed controller
Rotating cutter tip breaks or wears out rapidly.
Feed rate too fast .
Engraving depth too deep for one pass.
Material is hard or abrasive.
Incorrect cutter for material.
Engrave at slower feed.
Reduce depth setting and proceed with successive passes at progressive depth settings.
Ease up the friction by using lubricating oil such as Engravolube (for brass, aluminum, steel and other metals.