Motorized Lead Screws
Stepper Motor Linear Actuator

www.thomsonlinear.com

Motorized Lead Screws
Precision engineered to be compact, powerful, quiet and efficient
New Motorized Lead Screws from Thomson combine a hybrid stepper motor and a
precision lead screw together in one compact envelope. Patent-pending Taper-Locktechnology allows quick decoupling and secure, properly aligned connections. This
combination offers several advantages over a traditional solution.
Increased Torque Density
Thomson Motorized Lead Screws offer increased torquedensity over alternative solutions. By optimizing the
motor performance and matching this with the ideal
lead screw and nut design, Thomson has been able toincrease the load capacity by up to 30% while
maintaining the same motor footprint.
Improved Efficiency
Thomson provides a more efficient solution
to reduce power consumption, improve operating battery
life, and decrease motor footprint. With this improved
efficiency, an increase in system load performance or areduction in power consumption can be expected –all while having a lower cost of ownership.
The Taper-Lock Advantage
The patent-pending Taper-Lock design provides the ability toquickly decouple the lead screw from the stepper motor.
The connection is secure, robust, and self-aligning.
Reduced Noise
Thomson can optimize your motor configuration andwindings to limit motor harmonics and reduce motor
noise at your application operating points.

2

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Motorized Lead Screws

Technology Overview
Thomson Motorized Lead Screws come in two basic configurations – rotatingscrew (S) and rotating nut (N). Rotating screw assemblies actuate by having the
motor rotate a lead screw and translate a load that is attached to the lead nut.
Rotating nut assemblies actuate by rotating a nut within the motor body. Motion
is achieved by constraining the motor and translating a load attached to the leadscrew or constraining the lead screw and translating a load attached to the motor.
Rotating Screw Configuration (S)The rotating screw design features our patent-pending Taper-Lock design to connect
the lead screw to the motor shaft. This design allows for rapid prototyping, field
serviceability and reduced inventory. Ideally suited for applications where highlevels of maintenance are anticipated, frequentdisassembly/reassembly is required orwhere easy removal of the lead screw
is necessary.

Rotating Nut Configuration (N)The rotating nut design features our patent-pending integration ofa lead nut into the motor rotor to maximize screw diameter which
increases load capacity. Ideally suited for
applications where no visible rotation isdesired or where it is necessary totranslate a load on either side of
the motor.

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3

Thomson Advantage
The Thomson Taper-Lock
Fixing the motor to the lead screw usually requires a coupling assembly (A), a counter-borepress fit (B) or a hollow shaft press fit (C). The assembly process may also entail the useof adhesives or welding, but the bottom line is that all these solutions make it difficult or
impossible to change lead screws or perform maintenance. Thomson has solved this issue with
our patent-pending Taper-Lock coupling (D) that requires only a single retention fastener.
B

Coupling assembly• space demanding• reduces stroke• increases system inertia• requires radial support bearing• may reduce accuracy

C

Counter-bore press fit• reduces stroke• requires machining• difficult to assemble• run-out and alignment issues• difficult to replace quickly

Thrust Force Comparison
Thomson optimized motors will result in up to a
30% increase in thrust over the competition. Thatmeans you will get a smaller and more efficientsolution with the same power output.

Hollow shaft press fit• requires machining• difficult to assemble• run-out and alignment issues• difficult to replace quickly

Motor housing temperature [°F]

Load [N]Load [lbs]Temperature vs. Operation TimeOperation time [h]Linear speed [in/s (mm/s)]
Competitor

Thomson Taper-Lock• high accuracy• requires no extra space• easy to replace quickly• easy assembly and alignment

Temperature Rise Comparison
Thomson offers more efficient motors where more
torque can be output with less heat loss – meaningthat our motors can be operated with higher power
input while maintaining lower heat generation.

Load vs. Speed

ThomsonD

Motor housing temperature [°C]A

ThomsonCompetitor

The curves where generated with a 1.5 A / 2.33 V, 1.8° NEMA 17 single stack, rotating screw stepper motor. Test ran with a 0.9°, 24 VDC chopper drive and a 4-2516 lead screw at an
ambient temperature of 20 °C.

4

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Motorized Lead Screws

Application Examples
Where to Use Motorized Lead Screws
Lead screws convert rotary motion into linear motion. Stepper motors and lead screws arecomplementary products. They operate within the same design specifications for speed,load and life. A typical method to marry these products into an application is by using
external bearing supports and a drive coupling. Although this is acceptable, it is not the mosteconomical approach, requires more components and a larger footprint. The ideal solution is to
directly couple the screw and motor, eliminating the external supports and coupling.
Rotating Screw Applications
A rotating screw Motorized Lead Screw is ideal for applications
that require precise linear motion and have dedicated external
supports such as linear bearings or profile rails. Examples are:
• Medical devices• X-Y stages• 3D printers
Rotating Nut Applications
A rotating nut Motorized Lead Screw is ideal for applications
that require precise linear motion and also have integrated antirotation. Examples includes:• Fluid/syringe pumps• HVAC control valves• Pipetting devices• CNCswww.thomsonlinear.com/mls

5Application Examples
These common applications show that the Motorized Lead Screw will not only reduce thetotal number of components but also will reduce the overall footprint and make assembly andmaintenance quicker and easier.
3D Printing
Innovative multi-axis printers are revolutionizing rapid prototyping and consumer products. A printer equippedwith the Motorized Lead Screw can achieve key design advantages as outlined in the table below. Eliminationof supports and couplings improves the print volume while reducing the component count and system cost.

Generic design
Thomson Motorized Lead Screw design!

Generic vs. Thomson

6

Generic

ThomsonZ-Axis Stroke [in (mm)]9.6 (244)

11.4 (289)

XY-Stroke [in (mm)]8.7 × 14.2 (220 × 360)10.6 × 16.8 (270 × 427)

Number of Unique Linear Motion Components

28

16Interchangeable Lead Screws

Yes

Yes

Self-Aligning Assembly

No

Yes

External Support Bearing Required

Yes

No

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Motorized Lead Screws

Application Examples
Fluid Pump
Syringe pumps represent a significant segment of the medical industry
and the design requirements depend upon high torque density andefficiency. Regardless of the mounting configuration, a Motorized Lead
Screw can increase pump pressure, reduce equipment footprint, and moreaccurately disperse fluid.
Rotating Nut(configuration N)

Other Applications
The Motorized Lead Screw
provides higher performance ina smaller and less complicatedpackage. Designed for simple
transport or critical applications,a Motorized Lead Screw solution
eliminates redundant components,
increases stroke length, provides
greater axial force, and reduces
power consumption. Other
applications include:• X-Y stages• HVAC control valves• CNCs• Pipetting• Robotics• Packaging• Scanning• Lens focusing• Plumbing• Laser cutting

Rotating Screw(configuration S)

Medical Scanner
When it comes to planar motion, a Motorized Lead Screw
can outperform the competition by delivering more thrust,more stroke, and lead screw interchangeability – making it
the easiest to maintain Motorized Lead Screw on the market.

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7

Lead Screw Sizes
Inch Lead Screws
Linear travel / full step [in]Lead [in]0.00015625

0.03130.00025000

0.05000.00031250

0.06250.00041670

0.08330.00050000

0.10000.00062500

0.12500.00083300

0.16660.00100000

0.20000.00125000

0.25000.00200000

0.40000.00250000

Type and screw diameter [in]
ML11

ML14

ML17

0.188

0.250

0.250

•

•

•

•

ML23
0.313

0.375

•
•
•
•

•
•

•
•

•

•
•

•

•

•

0.5000••••0.00375000

0.7500••0.00500000

1.0000•••Metric Lead Screws
Linear travel / full step [mm]Lead [mm]

0.005

1.00

0.010

2.00

0.015

3.00

0.020

4.00

0.025

5.00

0.030

6.00

0.040

8.00

0.050

10.00

0.060

12.00

0.100

20.00

Type and screw diameter [mm]
ML11

ML14

ML17

4

6

6

•

•

•

ML23
8

10

•

•
•

•

•
•
•

•

•

•
•
•

•

•
•

•

Note: Other sizes and leads available – please contact Thomson for more information about custom lead screw availability.

8

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Motorized Lead Screws

Specifications
Basic Specifications
Lead Screw
Material

303 Stainless Steel
None

Standard Coating (1)Standard Lead Accuracy[in/ft (µm/300 mm)]0.010 (250)Precision Lead Accuracy[in/ft (µm/300 mm)]0.003 (75)Straightness[in/ft (µm/300 mm)]0.005 (125)Lead NutStandard MaterialInternally lubricated acetalHigh Performance MaterialInternally lubricated engineered thermoplastic[%)

Nut Efficiency (2)Typical Linear Travel Life

35 to 85
10 × 10 6 (250)[in (km)]

Motor
Frame Size
Step Size
Max. Axial Load

(3)

NEMA 11

NEMA 14

NEMA 17

NEMA 23

[°]

1.8

1.8

1.8

1.8

[lbs (N)]20 (89)50 (222)75 (334)200 (890)

Max. Radial Play[in @ lbs (mm @ N)]

0.001 @ 1 (0.03 @ 4)

End Play[in @ lbs (mm @ N)]

0.002 @ 2 (0.05 @ 9)

Concentricity of Mounting Pilot to Shaft[in (mm)]0.003 (0.08) TIR

Perpendicularity of Shaft to Mounting Face[in (mm)]0.003 (0.08) TIR

Max. Case Temperature[ °F (°C)]

Storage Temperature[ °F (°C)]

Max. Humidity (non-condensing)140 (60)[%]

176 (80)-4 to 122 (-20 to 50)
85

Magnet Wire Insulation

Class B 130 °C (266 °F)

Insulation Resistance

100 Mohm @ 500 VDCDielectric Strength

500 VAC for 1 minute

AssemblyMax. Backlash with Standard Nut[in (mm)]0.010 (0.25)

Max. Backlash with XC Anti-Backlash Nut[in (mm)]0 (0)RunoutOperating Temperature[in/ft (µm/300 mm)]
[ °F (°C)]

0.007 (175)
15 to 125 (- 10 to 50)(1) Contact Thomson for optional lead screw coatings.
(2) Depending on lead.
(3) Max. axial load based on a L10 life of 10000 hours of continuous motion at speeds of 100 to 300 RPM.

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9

Lead Screw End Machining
Standard For Rotating Screw (S) Configurations

Standard For Rotating Nut (N) Configurations

Non Standard End Machining Alternative*

Non Standard End Machining Alternative** These are just some examples of non standard end-machining alternatives that are available.
Please contact Thomson for more information.

Inch Lead Screw End Machining Dimensions
Screw
Diameter
[in]

Screw
Lead
[in]

0.188

Recommended Bearing

Dimensions [in]

OD
[mm]

ID
[mm]

W
[mm]

Bearing
Trade
No.

ØD

L1

L2

F

G

ØH

L3

THD

all

7

2.5

2.5

692X

0.098

0.098

0.157

0.022

0.120

0.075

0.250

#4-40

0.250

all

13

4

5

624

0.157

0.197

0.256

0.020

0.217

0.150

0.250

#8-32

0.313

all

16

5

5

625

0.197

0.197

0.276

0.028

0.224

0.189

0.375

#10-24

0.375

all

19

6

6

626

0.236

0.236

0.315

0.030

0.266

0.220

0.500

1/4-20Metric Lead Screw End Machining Dimensions
Screw
Diameter
[mm]

Screw
Lead
[mm]

4

10

Recommended Bearing

Dimensions [mm]

OD
[mm]

ID
[mm]

W
[mm]

Bearing
Trade
No.

ØD

L1

L2

F

G

ØH

L3

THD

all

7

2.5

2.5

692X

2.50

2.50

4.00

0.56

3.05

1.91

6.35

M3X0.5

6

all

13

4

5

624

4.00

5.00

6.50

0.51

5.51

3.81

6.35

M4X0.7

8

all

16

5

5

625

5.00

5.00

7.00

0.70

5.70

4.80

9.53

M5X0.8

10

all

19

6

6

626

6.00

6.00

8.00

0.76

6.76

5.59

12.70

M6X1.0www.thomsonlinear.com/mls

Motorized Lead Screws

Ordering Key
Ordering Key
1

2

3

4

5

6

7

8

ML

23A155S

M08-02-23000

S

FSS

-001

1. Product type
ML = motorized lead screw
2. Motor code (1)xxxyyy = see Motor Options tables
3. Configuration
N = rotating nut
S = rotating screw
4. Lead screw code (2)xyy-zzzz = see Lead Screw Options tables
5. Lead screw length (Ls)-xxxxx = xx.xxx inch (for inch lead screw units only)-xxxxx = xxx.xx mm (for metric lead screw units only)
6. Lead screw accuracy
S = standard
P = precision

7. Nut configuration code (3)XXX = rotating nut configuration default
FSS = rotating screw configuration with standard flanged nut
FSH = rotating screw configuration with standard flanged nut in high performance material
FAS = rotating screw configuration with standard flanged anti-backlash nut
TAS = rotating screw configuration with standard threaded anti-backlash nut
8. Custom design code (issued by Thomson)-001 = default (standard design)(1) The exact motor codes are found in the Motor Options tables on the product pages.
The code consist of two parts (xxxyyy) where “xxx” describes frame size and stack number, and “yyy” the current
draw of the motor.
(2) The exact lead screw codes are found in the Lead Screw Options tables on the product pages. The code consistof three parts (xyy-zzzz) where “x” describes if the lead screw is inch (no letter) or metric (letter M), “yy” thediameter and “zzzz” the lead of the screw.
(3) Rotating nut configurations must always have code “XXX” in this position while rotating screw configurations
must have one of the other codes. For custom threaded nut
dimensions contact Thomson.

Example 1:
ML11A051 S 18-0100-04000S FSS-001
ML11A051 S: NEMA 11 motor, single stack, 0.51 A, rotating screw.
18-0100-04000S: Lead screw with a 0.1875 inch diameter, 0.100 inch lead, 4 inch length and standard accuracy.
FSS: Flanged nut, standard backlash, standard performance material.
-001: Default Motorized Lead Screw configuration.

Example 2:
ML17B150 N M06-12-20000S XXX-001
ML17B150 N: NEMA 17 motor, double stack, 1.50 A, rotating nut.
M06-12-20000S: Lead screw with a 6 mm diameter, 12 mm lead, 200 mm length and standard accuracy.
XXX: Default nut sequence for rotating nut.
-001: Default Motorized Lead Screw configuration.

Note: Please visit thomsonlinear.com/mls to access our online Motorized Lead Screw selector and part number generator.

www.thomsonlinear.com/mls

11

Specifications – ML11

Size 11A motor (single
stack type) withrotating screw

Features and Benefits• Higher torque density than the competition.
• NEMA 11 motor (size 28 mm).
• Rotating screw version only.
• Choose between a variety of inch and metric lead screws.

• Recommended max. thrust force 20 lbs (89 N).
• Recommended max. lead screw length of 4 in 		(102 mm) for optimal performance. Longer length 		lead screws available, see diagrams on page 24.

Motor Options
Motor code

Holding torque

Voltage/ phase*[V]

Current/ phase[A]

Resistance Inductance Power
[Ω]
[mH]
draw
[W]

Step
angle
[°]

Motor length,
maximum (Lm)

Rotor
inertia[oz-in2]Motorweight[lbs][oz-in]

[N-m]

[in]

[mm]

11A051

9.3

0.066

3.85

0.51

7.54

5.22

1.96

1.8

1.26

32.0

0.06

0.24

11A100

10.1

0.071

2.19

1.00

2.19

1.53

2.19

1.8

1.26

32.0

0.06

0.24

* Applied voltage can be any value above this number as long as the driver output current is controlled at the rated RMS current.

Inch Lead Screw Options
Screw code

Diameter [in]18-0050
18-0100
18-0200
18-0400

0.188

Metric Lead Screw Options

Lead [in]Travel / step [in]Screw code

0.050

0.00025

M04-010.100

0.00050

M04-040.200

0.00100

M04-080.400

0.00200

Diameter [mm]4Lead [mm]Travel / step [mm]10.0050040.0200080.04000

Note: Other diameters and leads available – please contact Thomson for more information about custom lead screw availability.

12

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Motorized Lead Screws

Dimensions – ML11
ML11xxxxxxS (rotating screw)

Dimensions

Projection

Inch [mm](A)Standard nut (FSS) (B)Maximum Stroke (Smax)
Smax = Ls - Ln - 0.08 in (2 mm)(A) 6-pin connector as standard (X1 = pin 1, X6 = pin 6). Custom connection solutions possible. Contact Thomson for more information.
(B) For dimensions and data on anti-backlash nut, please contact Thomson for more information.

Motor Connection
Molex Connector *
Pin

Phase

1

A-

2

not used

3

A+

4

B-

5

not used

6

B+

B+

6
Phase A

BA+
A-

4
3
1

Phase B

* Molex connector p/n 53253-0670. Mates with Molex connector p/n 51065-0600.

Motor Connector Kit with Flying Leads - Optional• Compatible with the above motor connector.
• Lead length 12.5 in (318 mm).
• 26 AWG lead wires.
• Part number MC11-001.
• Contact Thomson for more information.

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Molex connector p/n 51065-0600.

Lead color (pin no.)green (6)black (4)red (3)
blue (1)13

Specifications – ML14

Size 14A motor (single
stack type) withrotating screw

Features and Benefits• Higher torque density than the competition.
• NEMA 14 motor (size 35 mm).
• Rotating screw versions only.
• Choose between a variety of inch and metric lead screws.

• Recommended max. thrust force 50 lbs (222 N).
• Recommended max. lead screw length of 8 in 		(203 mm) for optimal performance. Longer length 		lead screws available, see diagrams on page 24.

Motor Options
Motor code

Holding torque

Voltage/ phase*[V]

Current/ phase[A]

Resistance Inductance Power
[Ω]
[mH]
draw
[W]

Step
angle
[°]

Motor length,
maximum (Lm)

Rotor
inertia[oz-in2]Motorweight[lbs][oz-in]

[N-m]

[in]

[mm]

14A088

25.8

0.182

3.42

0.88

3.89

5.51

3.01

1.8

1.34

34.0

0.10

0.41

14A135

23.0

0.162

1.71

1.35

1.27

1.79

2.31

1.8

1.34

34.0

0.10

0.41

* Applied voltage can be any value above this number as long as the driver output current is controlled at the rated RMS current.

Inch Lead Screw Options
Screw code

Lead [in]Travel / step [in]Screw code

25-00310.03130.00016

M06-0125-0063

0.06250.00031

M06-0625-01250.12500.00063

M06-120.25000.00125

25-0500

0.50000.00250

25-07500.75000.00375

25-0250

Diameter [in]Metric Lead Screw Options

0.250

Diameter [mm]6

Lead [mm]Travel / step [mm]10.00500

60.03000

120.06000

Note: Other diameters and leads available – please contact Thomson for more information about custom lead screw availability.

14

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Motorized Lead Screws

Dimensions – ML14
ML14xxxxxxS (rotating screw)

Dimensions

Projection

Inch [mm](A)

Anti-backlash nut (FAS)

Maximum Stroke (Smax)

Standard nut (FSS)(A) Flying leads are standard. Custom connection solutions possible. Contact Thomson for more information.

Smax = Ls - Ln - 0.08 in (2 mm)

Motor Connection*
Flying Leads

A+

Red

Lead color

Phase

Red

A+

Blue

A-

A-

Blue

Green

B+

B+

Green

Black

B-

B-

Phase A

Phase B

Black

*Table valid for ML14, ML17 and ML23 motors.

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15

Specifications – ML17

Size 17B (double
stack type) withrotating nut

Size 17A motor (single
stack type) withrotating nut

Size 17A motor (single
stack type) withrotating screw

Size 17B (double
stack type) withrotating screw

Features and Benefits• Higher torque density than the competition.
• NEMA 17 motor (size 42 mm).
• Rotating screw and rotating nut versions available.
• Choose between a variety of inch and metric lead screws.

• Recommended max. thrust force 75 lbs (334 N).
• Recommended max. lead screw length of 8 in 		(203 mm) for optimal performance. Longer length 		lead screws available, see diagrams on page 24.

Motor Options
Motor code

17A100Holding torque[oz-in]

[N-m]

77.0

0.544

Voltage/ phase*[V]

Current/ phase
[A]

2.33

1.00

Resistance Inductance Power
[Ω]
[mH]
draw
[W]
2.33

5.61

2.33

Step
angle
[°]

Motor length,
maximum (Lm)
[in]

[mm]

1.8

1.34

34.0

Rotor
inertia[oz-in2]Motorweight
[lbs]

0.23

0.4

17A150

92.0

0.650

1.76

1.50

1.17

3.26

2.63

1.8

1.34

34.0

0.23

0.4

17B100

107.8

0.761

1.69

1.00

1.69

5.66

1.69

1.8

1.89

48.0

0.47

0.7

17B150

102.8

0.726

1.31

1.50

0.87

2.7

1.96

1.8

1.89

48.0

0.47

0.7

* Applied voltage can be any value above this number as long as the driver output current is controlled at the rated RMS current.

Inch Lead Screw Options
Screw code

Lead [in]Travel / step [in]Screw code

25-00310.03130.00016

M06-0125-0063

0.06250.00031

M06-060.12500.00063

M06-120.25000.00125

25-0500

0.50000.00250

25-07500.75000.00375

25-0125
25-0250

Diameter [in]Metric Lead Screw Options

0.250

Diameter [mm]6

Lead [mm]Travel / step [mm]10.00500

60.03000

120.06000

Note: Other diameters and leads available – please contact Thomson for more information about custom lead screw availability.

16

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Motorized Lead Screws

Dimensions – ML17
ML17xxxxxxN (rotating nut)

Dimensions

Projection

Inch [mm](A)

Maximum Stroke (Smax)(A) Flying leads are standard. Custom connection solutions possible. Contact Thomson for more information.

Smax = Ls - Lm - 0.08 in (2 mm)

Motor connection information! See table on page 15.

ML17xxxxxxS (rotating screw)

Dimensions

Projection

Inch [mm](A)

Anti-backlash nut (FAS)Standard nut (FSS)

Maximum Stroke (Smax)(A) Flying leads are standard. Custom connection solutions possible. Contact Thomson for more information.

Smax = Ls - Ln - 0.08 in (2 mm)

Motor connection information! See table on page 15.

www.thomsonlinear.com/mls

17

ML23 – Specifications

Size 23A motor (single
stack type) withrotating nut

Size 23A motor (single
stack type) withrotating screw

Features and Benefits• Higher torque density than the competition.
• NEMA 23 motor (size 57 mm).
• Rotating screw and rotating nut versions available.
• Choose between a variety of inch and metric lead screws.

Size 23B (double
stack type) withrotating nut

Size 23B (double
stack type) withrotating screw• Recommended max. thrust force 200 lbs (890 N).
• Recommended max. lead screw length of 12 in 		(305 mm) for diameter 0.313 in and 8 mm, and 		
16 in (406 mm) for diameter 0.375 in and 10 mm		for optimal performance. Longer length lead screws
available, see diagrams on page 24.

Motor Options
Motor code

Holding torque[oz-in][N-m]Voltage/ phase*[V]

Current/ phase[A]

Resistance Inductance Power
[Ω]
[mH]
draw
[W]

Step
angle
[°]

Motor length,
maximum (Lm)
[in]

[mm]

Rotor
inertia[oz-in2]Motorweight[lbs]

23A155

121.0

0.854

3.77

1.55

2.43

4.20

5.84

1.8

1.78

45.2

1.04

1.13

23A300

123.8

0.875

1.74

3.00

0.58

1.16

5.22

1.8

1.78

45.2

1.04

1.13

23B190

251.2

1.774

3.80

1.90

2.00

5.84

7.22

1.8

2.59

65.8

2.13

1.70

23B390

260.8

1.842

1.99

3.90

0.51

1.45

7.76

1.8

2.59

65.8

2.13

1.70

* Applied voltage can be any value above this number as long as the driver output current is controlled at the rated RMS current.

Inch Lead Screw Options
Screw code

Lead [in]Travel / step [in]Screw code

31-00830.083

0.00042

M08-0220.01000

31-01670.167

0.00083

M08-0440.02000

31-0250

Diameter [in]Metric Lead Screw Options
Travel / step [mm]0.250

0.00125

M08-0880.04000

0.500

0.00250

M08-12120.06000

31-1000

1.000

0.00500

M08-20200.10000

37-00630.063

0.00031

M10-0220.01000

37-0100

0.100

0.00050

M10-0330.01500

37-01670.167

0.00083

M10-0550.02500

0.375

8Lead [mm]31-0500

37-0250

0.313

Diameter [mm]

10

0.250

0.00125

M10-10100.05000

37-0500

0.500

0.00250

M10-20200.10000

37-1000

1.000

0.00500

Note: Other diameters and leads available – please contact Thomson for more information about custom lead screw availability.

18

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Motorized Lead Screws

ML23 – Dimensions
ML23xxxxxxN (rotating nut)

Dimensions

Projection

Inch [mm](A)

Maximum Stroke (Smax)(A) Flying leads are standard. Custom connection solutions possible. Contact Thomson for more information.

Smax = Ls - Lm - 0.06 in (1.6 mm)

Motor connection information! See table on page 15.

ML23xxxxxxS (rotating screw)

Dimensions

Projection

Inch [mm](A)

Anti-backlash nut (FAS)Standard nut (FSS)

Maximum Stroke (Smax)(A) Flying leads are standard. Custom connection solutions possible. Contact Thomson for more information.

Smax = Ls - Ln - 0.06 in (1.6 mm)

Motor connection information! See table on page 15.

www.thomsonlinear.com/mls

19

ML11, ML14 – Performance Diagrams
ML11A100

Motor Speed [RPM]

Force [N]Force [lbs]Linear Speed vs. Force

Force [N]Force [lbs]Motor Speed vs. Force

Linear Speed [in/s (mm/s)]
Lead Screw Code18-0400
18-0200

18-0100
18-0050

Load area not recommended

ML14A088

Motor Speed [RPM]
Lead Screw Code25-0750
25-0500
25-0250

Force [N]Force [lbs]Linear Speed vs. Force

Force [N]Force [lbs]Motor Speed vs. Force

Linear Speed [in/s (mm/s)]
25-0125
25-0063
25-0031

Load area not recommended

Note! All motor load curves were generated with a 40 VDC, 2-phase ON driver and full stepped at the motor rated current.
Performance plots for other lead screw and motor winding configurations can be generated at thomsonlinear.com/mls.

20

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Motorized Lead Screws

ML17 – Performance Diagrams
ML17A150

Motor Speed [RPM]

Force [N]Force [lbs]Linear Speed vs. Force

Force [N]Force [lbs]Motor Speed vs. Force

Linear Speed [in/s (mm/s)]

Lead Screw Code25-0750
25-0500
25-025025-0125
25-0063
25-0031

Load area not recommended

ML17B150

Motor Speed [RPM]
Lead Screw Code25-0750
25-0500
25-0250

Force [N]Force [lbs]Linear Speed vs. Force

Force [N]Force [lbs]Motor Speed vs. Force

Linear Speed [in/s (mm/s)]
25-0125
25-0063
25-0031

Load area not recommended

Note! All motor load curves were generated with a 40 VDC, 2-phase ON driver and full stepped at the motor rated current.
Performance plots for other lead screw and motor winding configurations can be generated at thomsonlinear.com/mls.

www.thomsonlinear.com/mls

21

ML23 – Performance Diagrams
ML23A300

Motor Speed [RPM]

Force [N]Force [lbs]Linear Speed vs. Force

Force [N]Force [lbs]Motor Speed vs. Force

Linear Speed [in/s (mm/s)]
Lead Screw Code37-0167
37-0100
37-0063

37-1000
37-0500
37-0250

Load area not recommended

ML23B300

Motor Speed [RPM]
Lead Screw Code37-1000
37-0500
37-0250

Force [N]Force [lbs]Linear Speed vs. Force

Force [N]Force [lbs]Motor Speed vs. Force

Linear Speed [in/s (mm/s)]
37-0167
37-0100
37-0063

Load area not recommended

Note! All motor load curves were generated with a 40 VDC, 2-phase ON driver and full stepped at the motor rated current.
Performance plots for other lead screw and motor winding configurations can be generated at thomsonlinear.com/mls.

22

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Motorized Lead Screws

Sizing and Selection Guidelines
How to Select Motor and Lead Screw
For a basic sizing determination, use performance charts to find appropriate screw lead and diameter fordesired motor size. Use linear travel speed and dynamic load.
Example:Speed = 2 in/s
Load = 30 lbs

Force [N]Force [lbs]ML17A150
Linear Speed vs. Force

30 lbsLinear Speed [in/s (mm/s)]

2 in/sLead Screw Code25-0750
25-0500
25-025025-0125
25-0063
25-0031

Load area not recommended

Given the speed and load requirements of 2 in/s and 30 lbs, respectively, a ML17A150 motor with an inch leadscrew with a diameter and lead of 0.25 inch (25-0250) will be a sufficient Motorized Lead Screw assembly forthis application*.
Please visit www.thomsonlinear.com/mls for a more detailed sizing calculator or call Thomson to speak with a
Motorized Lead Screw sizing specialist.
*Performance curve upper limits should be avoided for critical and/or high duty cycle applications. Generally a safety factor of 2 is recommended
when sizing an application.

www.thomsonlinear.com/mls

23

Sizing and Selection Guidelines
How to Determine Maximum Permissible Screw Length
In order to determine the maximum possible lead screw length for your Motorized Lead Screw assembly,
the following charts can be used. These charts take in to consideration the maximum rotational speed andcompression load as well as the end fixity of your system.
Column Load
Compression Force vs. Maximum Screw Length

ML110.188 in
4 mm

Force [N]Speed [RPM]

Force [lbs]Critical Speed
Motor Speed vs. Maximum Screw LengthMax. Screw Length (Ls) [in (mm)]Max. Screw Length (Ls) [in (mm)]Unit Size and Lead Screw Diameter Combination

Type of Screw End Fixity

ML14
ML17
0.250 in
6 mm

ML23
0.313 in
8 mm

ML230.375 in
10 mm

ML14
0.250 in
6 mm

ML170.250 in
6 mm

ML23
0.375 in
10 mm

Fixed / Free

Simple / Simple

Fixed / Simple

Fixed / Fixed

1. Determine Maximum Motor Speed
Calculate what the maximum motor speed will be for your specific application.
2. Decide Type of Screw End Fixity
There are four basic types of end fixity (A, B, C and D). The maximum screw length (Ls) for a given motor speed, unit sizeand screw diameter will vary depending on the selection.
3. Check Critical Screw Speed
Check Critical Speed diagram for your maximum speed, lead screw diameter and end fixity to determine the maximum
permissible screw length for your application. For rotating screw configurations (S), the Taper-Lock connection within the
motor can be considered fixed.
4. Check Column Loading
Another limiting factor for the screw length is how much column loading (buckling) the screw is subjected to. Check the
Column Load diagram to see that your load and desired maximum screw length are compatible with regards to the unit
size, lead screw diameter and end fixity being used.
24

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Motorized Lead Screws

Installation Guidelines
Installation
The successful integration of a Motorized Lead Screw in an application is primarily dependent on the screwalignment and subsequent screw runout. If incorrectly mounted, a lead screw assembly will have significantly
reduced system life and may be noisy or inaccurate. Thomson methodically straightens all screws prior toassembly to minimize vibration and runout. The Taper-Lock coupling method also was designed to provide
a concentric interface and optimize alignment. Proper alignment, end support configuration and lead nut
selection are important factors to achieve a well designed installation that will exceed expectations.
1. Select Motorized Lead Screw Configuration
Determine which of the two types of configurations – rotatingscrew (S) or rotating nut (N) – the application requires. See page
3 and 5 for more information.

2. Select Motor Size
Select the appropriate size based on desired performance, motor
frame size, etc. Thomson offers four base models (ML11, ML14,
ML17 and ML23) with optional motor windings, linear travel andload capacity selection.

3. Select Lead Screw
Select the lead screw diameter and length with regard to therequired stroke of the application and the type of end machining
the screw requires.

4. Select Nut
For rotating screw (S) configurations, choose between various
nut mounting styles, materials, and backlash options. Rotatingnut (N) configurations as default always come in a highperformance material, standard backlash nut.

5. Mount the Motorized Lead Screw
Mount the unit into the application using the tolerance
guidelines shown on page 9.

www.thomsonlinear.com/mls

25

Comissioning, Service and Maintenance Advantages
Quick and easy comissioning, service and maintenance are some key points to a successfull installation. The
Motorized Lead Screw will enable just that while keeping spare parts stock and tools required to a minimum.
Rotating Screw Lead Screw Swapping

The unique Taper-Lock coupling allows for quick andeasy assembly and disassembly. This means that one caneasily try out different lead screw motor combinations in
an application. This capability to swap out lead screws
and motors enables the end user to rapidly prototype,validate designs, replace damaged parts or simply
upgrade to higher performance components – all with asimple hex wrench.

Lead Screw Removal - Optional

Due to the secure connection of the Taper-Lock coupling,an additional feature may be added to facilitate theremoval of the lead screw. Remove the fastener securing
the lead screw and use the oversize removal screw togently push the lead screw out. Removal screw thread
sizes are shown in the table below.*

Taper-Lock Removal Thread Specifications
Motor code

ML11AxxxS
ML14AxxxS
ML17AxxxS
ML17BxxxS
ML23AxxxS
ML23BxxxS
ML23AxxxS
ML23BxxxS

Lead scew code
18-xxxx
M04-xx25-xxxx
M06-xx25-xxxx
M06-xx25-xxxx
M06-xx31-xxxx
M08-xx31-xxxx
M08-xx37-xxxx
M10-xxFastener screw
size

Recommended fastenerscrew length [mm]Recommended fastener screw
torque [lbs-in (Nm)]Removal screw
size

M2.5×0.45

18

11 (1.2)

M3×0.5

M3×0.522

20 (2.3)

M4×0.7

M3×0.51420 (2.3)

M4×0.7

M3×0.522

20 (2.3)

M4×0.7

M4×0.718

45 (5.1)

M5×0.8

M4×0.735

45 (5.1)

M5×0.8

M5×0.825

90 (10.2)

M6×1.037-xxxx

M5×0.845
90 (10.2)
M6×1.0M10-xx*Removal thread does not come standard in Motorized Lead Screw assemblies – contact Thomson if internal shaft thread is required.

26

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Motorized Lead Screws

Glossary
Accuracy

A measurement of precision. Perfect accuracy, for example, means advancing a lead nut linearly one inch from any
point on a screw will always require the exact same number of revolutions.

Axial Load

A load passing through the center axis of the lead screw.

Backdrive

Application of a force on a lead nut to cause rotation of the screw; in essence, converting linear to rotary motion.

Backlash

The axial or radial free motion between the lead nut and lead screw; a measure of system stiffness andrepeatability.
Motor with two phases and a single winding per phase (4 lead wires). All Thomson standard stepper motors arebipolar.

Bipolar Motor
Chopper Drive

A constant current stepper motor drive that operates by quickly cycling power on and off, or “chopping.“

Column Load

Column loading is the compression load on the screw. This load has a tendency to buckle the screw and isdependent on screw diameter, screw length and type of mounting.
Condition where the median points of two or more radially-disposed features are congruent with the axis (or center
point).
The condition where the rotary speed of the assembly sets up harmonic vibrations. These vibrations are the resultof shaft diameter, unsupported length, type of bearing support, lead nut mounting method and/or screw rpm.
Vibrations may also be caused by a bent screw or faulty installation alignment.

Concentricity
Critical Speed

Drag Torque

The amount of torque required to drive the unloaded lead screw.

Driving Torque

The amount of effort required to turn the lead screw and move the load.

Dynamic Load

Load applied to Motorized Lead Screw assembly while in motion.

Efficiency (Lead Screw)

Expressed as a percentage, the ability of a lead screw assembly to convert torque to thrust with minimalmechanical loss. Thomson lead screws range in efficiency from 35 to 85%.
Expressed as a percentage, the motor‘s ability to turn electrical energy into mechanical energy with minimal
thermal loss. Thomson stepper motors range in efficiency from 65 to 90%.
How the ends of the lead screw are fixed or supported.

Efficiency (Motor)
End Fixity or
End Bearing Support
Holding Torque

Torque required to rotate motor shaft while all coils are fully energized with a steady state DC current.

Inertia

The level of rotational resistance of a lead screw or shaft.

Lead

The axial distance a screw travels during one revolution. If thread is 1 start, lead = pitch.

Microstepping

Dividing the motors natural full step by smaller increments. Example: 1.8 º step motor microstepped at 64× will
mean that 1 pulse is now 1.8 º/64 = 0.028 º.

Perpendicularity

Condition of a surface, center plane, or axis at a right angle to a plane or axis.

Pitch

Distance measured between adjacent threads of the lead screw - if thread is 1 start, then pitch = lead.

Pulse Rate

The number of pulses per second (pps) applied to the windings of the motor. 1 pulse = 1 step.

Repeatability

A measure of constancy that is directly related to axial backlash. Higher backlash equates to lower repeatability
and may be corrected by preloading the lead nut if required.

Resolution

The linear distance the Motorized Lead Screw will actuate the lead nut or screw per input pulse.

Resonance

Vibration occurring when a mechanical system operates within an unstable range.

RunoutComposite tolerance used to control the functional relationship of one or more features of a part to an axis.

Side Load (Radial)

A load applied perpendicular to the lead screw axis. Not recommended for lead screw applications as it will reduce
functional life.

Static Load

Static load is the maximum non-operating load capacity above which failure of the motor and/or lead nut occurs.

Straightness

Condition where an element of a surface, or an axis, is in a straight line.

StrokeThe maximum length of extension of a lead nut on the lead screw.

Thrust Force orThrust Load
Travel/Step or
Travel RateThrust load is loading parallel to and concentric with the centerline of the screw which acts continuously in one
direction. Thrust loading is the proper method of attaching the load to the lead screw assembly.
The linear translation of a lead nut or screw for one full step of the motor.

www.thomsonlinear.com/mls

27

USA, CANADA and MEXICO
Thomson
203A West Rock Road
Radford, VA 24141, USA
Phone: 1-540-633-3549
Fax: 1-540-633-0294
E-mail: thomson@thomsonlinear.com
Literature: literature.thomsonlinear.com
EUROPE
United Kingdom
ThomsonPhone: +44 (0) 1271 334 500
Fax: +44 (0) 1271 334 501
E-mail: sales.uk@thomsonlinear.com
GermanyThomsonNürtinger Straße 70
72649 Wolfschlugen
Phone: +49 (0) 7022 504 0
Fax: +49 (0) 7022 504 405
E-mail: sales.germany@thomsonlinear.com
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Fax: +33 (0) 243 50 03 39
E-mail: sales.france@thomsonlinear.com
Italy
ThomsonLargo Brughetti
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Phone: +39 0362 594260
Fax: +39 0362 594263
E-mail: info@thomsonlinear.it
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ThomsonRbla Badal, 29-31 7th, 1st
08014 Barcelona
Phone: +34 (0) 9329 80278
Fax: + 34 (0) 9329 80278
E-mail: sales.esm@thomsonlinear.com
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Phone: +46 (0) 44 24 67 00
Fax: +46 (0) 44 24 40 85
E-mail: sales.scandinavia@thomsonlinear.com

ASIA
Asia PacificThomson750, Oasis, Chai Chee Road,#03-20, Technopark @ Chai Chee,
Singapore 469000
E-mail: sales.apac@thomsonlinear.com
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ThomsonRm 2205, Scitech Tower
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Beijing 100004
Phone: +86 400 6661 802
Fax: +86 10 6515 0263
E-mail: sales.china@thomsonlinear.com
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Thomson
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Powai , Mumbai – 400076
Phone: +91 22 422 70 300
Fax: +91 22 422 70 338
E-mail: sales.india@thomsonlinear.com
Japan
ThomsonMinami-Kaneden 2-12-23, Suita
Osaka 564-0044 Japan
Phone: +81-6-6386-8001
Fax: +81-6-6386-5022
E-mail: csjapan@scgap.com
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ThomsonF12 Ilsong Bldg, 157-37
Samsung-dong, Kangnam-gu,
Seoul, Korea (135-090)
Phone: +82 2 6917 5049
Fax: +82 2 6917 5007
E-mail:sales.korea@thomsonlinear.com
SOUTH AMERICA
ThomsonSao Paulo, SP Brazil
Phone: +55 11 3879-6600
Fax: +55 11 3879 6656
E-mail: sales.brasil@thomsonlinear.com

www.thomsonlinear.com
Motorized_Lead_Screw_BREN-0012-04A | 20150401TJ
Specifications are subject to change without notice. It is the responsibility of the product user to determine the suitability ofthis product for a specific application. All trademarks property of their respective owners. © Thomson Industries, Inc. 201528

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