Little Machine Shop Mini Lathe User manual

The premier source of parts and accessories for mini lathes and mini mills.
Mini Lathe User’s Guide
from LittleMachineShop.com

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Copyright © 2002, LittleMachineShop.com
All rights reserved.
Some photos Copyright © 2002, Frank J. Hoose, Jr.
All rights reserved.
Frank J. Hoose Jr. of Mini-Lathe.com took many of the photographs in this
document. Be sure to visit the Mini-Lathe.com Web site, which has a wealth of
information about the mini lathe.
LittleMachineShop.com
http://www.littlemachineshop.com
396 W Washington Blvd #500 • Pasadena CA 91103
[phone] • [email protected]

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Contents
Introduction ................................................................................5
Specifications ..............................................................................5
Safety Considerations .....................................................................5
Features.....................................................................................6
Front View ...............................................................................6
Rear View ................................................................................7
Basic Accessories...........................................................................7
Cleaning .....................................................................................7
Mounting Your Lathe ......................................................................7
Operating Controls ........................................................................8
Motor Controls...........................................................................8
High/Low Speed Shifter ................................................................9
Power Feed Forward/Neutral/Reverse Lever ..................................... 10
Power Feed Lever ..................................................................... 10
Carriage Hand Wheel ................................................................. 10
Cross Slide Feed Handle.............................................................. 10
Compound Rest Feed Handle ........................................................ 11
Compound Rest Rotation............................................................. 11
Tailstock Lock Nut .................................................................... 11
Tailstock Quill Hand Wheel .......................................................... 11
Tailstock Quill Locking Lever........................................................ 11
Adjustments .............................................................................. 12
Carriage ................................................................................ 12
Cross Slide Gibs........................................................................ 12
Cross Slide Nut ........................................................................ 13
Compound Rest Gibs.................................................................. 13
Apron Position ......................................................................... 13
Half Nuts ............................................................................... 14
Lead Screw Mounting ................................................................. 14
Drive Belt............................................................................... 14
Lubrication................................................................................ 15
Lubricating the Transmission Gears ................................................ 17
Changing Chuck Jaws.................................................................... 17
Grinding Tool Bits........................................................................ 18
Grinding Tool Bits ..................................................................... 20
Grind the Front Relief ................................................................ 20

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Grind the Left Side Relief............................................................ 20
Grind the Top Rake ................................................................... 20
Round the Nose........................................................................ 20
Adjusting Tool Bit Height ............................................................... 20
Turning .................................................................................... 21
Manual Turning ........................................................................ 21
Turning with Power Feed ............................................................ 22
Facing ..................................................................................... 22
Turning Angles ........................................................................... 23
Threading ................................................................................. 24
Change Gears .......................................................................... 24
Threading Dial ......................................................................... 27
Tool Bit ................................................................................. 28
Compound Angle ...................................................................... 28
Setting the Cutting Tool ............................................................. 29
Threading Process..................................................................... 30
Common Accessories .................................................................... 30
Cut-Off Tool Holder................................................................... 30
Quick Change Tool Post .............................................................. 31
Indexable Turning Tools.............................................................. 32
4-Jaw Chuck ........................................................................... 32
Faceplate............................................................................... 33
Centers and Dogs...................................................................... 33
Steady Rest and Follower Rest ...................................................... 34
Maintenance .............................................................................. 34
Cleaning ................................................................................ 35
Motor Brushes.......................................................................... 35

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Introduction
This user’s guide covers the 7x10 and 7x12 mini lathes that are sold by
Grizzly Industrial, Harbor Freight Tools, Homier Mobile Merchants, Micro-Mark,
Northern Tool & Equipment, Enco, and Wholesale Tool.
These lathes are made in China, in several different factories, but to a similar
set of plans. The general operating principles covered in this document are
common to all of them.
Specifications
The following specifications are common to these lathes.
Metric Lathes
Inch Lathes
Swing over bed
180 mm
7”
Between Centers
200 mm / 300 mm
7.9” / 11.8”
Spindle Taper
3 Morse taper
3 Morse taper
Tailstock taper
2 Morse taper
2 Morse taper
Spindle Bore
20 mm
0.79”
Cross Slide Travel
65 mm
2.56”
Compound Rest Travel
55 mm
2.17”
Spindle Speed
100–2500 RPM
100–2500 RPM
Automatic Feed Rate
0.1 mm / Revolution
0.004”/ Revolution
Screw Threads
0.4–2.0 mm in 10 steps
12–52 TPI in 18 steps
Safety Considerations
Always use common sense when using a power tool. Review the safety
instructions that came with your lathe. Besides the general safety rules for any
power tool, the following are specific considerations for the mini lathe.
Your mini lathe is just that, a mini, or small lathe. Don’t attempt jobs that
are beyond its capacity.
Check the work piece after you place it in the chuck or other work holding
device. Be sure it is secure before turning on the lathe.
Don’t wear loose clothing or jewelry when operating the lathe.

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Features
Front View
1. Headstock
2. Motor controls
3. 3-jaw chuck
4. Bed ways
5. Carriage
6. Tool post
7. Cross slide
8. Compound rest
9. Compound rest feed handle
10.Tailstock quill
11.Tailstock quill locking lever
12.Tailstock
13.Tailstock quill hand wheel
14.Change gear cover
15.Lead screw
16.Carriage hand wheel
17.Apron
18.Cross slide feed handle
19.Threading dial
20.Power feed lever
21.Tailstock lock nut
16
14
1
2
3
8
5
17
18
6
9
7
15
19
12
21
4
13
11
10
20

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Rear View
1. High/low speed shifter
2. Power feed forward/neutral/reverse lever
Basic Accessories
The following accessories come with most mini lathes. Some mini lathes come
with additional accessories.
Chuck key for the 3-jaw chuck
Outside jaws for the 3-jaw chuck
Change gears: 30, 35, 40 (2), 45, 50, 55, 57, 60 and 65 teeth
Hex wrenches: 3, 4, 5, and 6 mm
Open end wrenches: 8 x 10 mm and 14 x 17 mm
Cleaning
Your lathe will arrive coated with grease to protect it from corrosion during
shipment. Follow this procedure to remove the grease:
1. Wipe most of the grease off with rags or paper towels.
2. Clean the surfaces with mineral spirits (paint thinner).
3. Coat the surfaces with oil.
See the lubrication section for specific recommendations for lubricants.
Mounting Your Lathe
All mini lathes come with rubber feet that attach to the same holes used to
secure the lathe for shipping. If you want your lathe to be portable, simply
install these feet.
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1

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Note: If your lathe didn’t come with them, adding chip tray braces
(LittleMachineShop.com part number 1328) spreads the feet by several inches
and makes the lathe much steadier.
You can also bolt your lathe to your workbench. The following diagram shows
the holes required. The wider bolt pattern is for the 7x12 lathe, while the
narrower bolt pattern is for the 7x10 lathe.
Mount the lathe to the workbench with 6 mm bolts. The bolts should be about
10 mm longer than the thickness of the workbench. Use fender washers on the
underside of wooden benches to prevent the bolt heads from pulling through.
Operating Controls
There are several controls used to operate the lathe. Become familiar with
them before you use the lathe.
Motor Controls
1. Speed control
2. Forward/off/reverse switch
3. Power switch
1
2
3

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There are several versions of the control panel on the mini lathe, but they all
include the same controls. In some cases the power switch is a big red
“emergency” switch, and in some cases it is a rocker switch.
The big red emergency switch latches in the off position when you press the big
red button. To turn the switch on, slide the big red button in the direction of
the arrow. The big red button will swing up to the on position.
The power switch interrupts the input power to the speed control circuit
board.
The forward/off/reverse switch switches the polarity of the speed control
circuit board output power between the speed control circuit board and the
motor.
You control the motor speed by adjusting a potentiometer that provides the
speed setting value to the speed control circuit board. On some lathes there is
a safety switch on the speed control potentiometer that forces you to return
the control to minimum speed when starting the lathe.
CAUTION: Always turn the speed control to the minimum speed position before
starting the lathe. Starting the lathe with the speed control set to a higher
speed can damage the speed control circuit board.
To power up the lathe:
1. Turn the speed control to the minimum speed position.
2. Place the forward/off/reverse switch in the off position.
3. Turn on the power switch.
To start the lathe:
1. Ensure that the speed control is set to the minimum speed position.
2. Move the forward/off/reverse switch to the appropriate position.
3. Advance the speed control to the desired speed.
To stop the lathe:
1. Turn the speed control to the minimum speed position.
2. Move the forward/off/reverse switch to the off position.
3. If you want to power down the lathe, press the big red switch or the rocker
switch to turn off the power.
High/Low Speed Shifter
The high/low speed shifter is on the back of the headstock. It selects the
spindle speed range.
Low speed range
50*–1100 RPM
High speed range
50*–2500 RPM
* Minimum speed varies.

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Never move this lever when the lathe is turning. You might need to turn the
spindle slightly by hand as you move the high/low speed shifter.
Power Feed Forward/Neutral/Reverse Lever
The power feed forward/neutral/reverse lever controls the direction of
rotation of the lead screw. When this lever is in the forward, or top, position
the lead screw moves the carriage toward the headstock. When this lever is in
the reverse, or bottom, position, the lead screw moves the carriage away from
the headstock. In the center, or neutral, position the lead screw is disengaged
and does not turn.
There is a strong spring in this lever. Pull out firmly on the end of the lever
while moving it.
NOTE: In many cases the detents for this control are not well formed, and in
some cases are not in the correct position. If your power feed will not stay
engaged, or if it does not disengage properly, inspect the detents in the back
of the headstock and move or enlarge them with a center punch.
Power Feed Lever
The power feed lever locks the half nuts around the lead screw, which engages
the power feed.
The power feed is engaged when this lever is down, and disengaged when this
lever is up.
Carriage Hand Wheel
The carriage hand wheel moves the carriage toward or away from the
headstock, depending on which way it is turned.
Use this hand wheel to position the carriage. Because this hand wheel moves
the carriage quickly it is not easy to use this hand wheel to move the carriage
while you are turning.
You cannot turn this hand wheel when the automatic feed is engaged.
Cross Slide Feed Handle
The cross slide feed handle moves the cross slide across the ways. Use this
handle to advance the tool into the work and for facing cuts.
The dial on this handle indicates the relative position of the cross slide. The
graduated dial can be repositioned for convenience.
On some lathes there are 40 divisions on the dial. On these lathes, each turn of
the handle advances the cross slide 1 mm or approximately 0.040”. The
distance is actually 0.03937”, an error of a little less than 2%.
Other lathes have 50 graduations on the dial. On these lathes, each turn of the
handle advances the cross slide 0.050”.