NEMA 8 20 MM Stepper Lead Screw Linear Actuator
The NEMA 8 stepper lead screw linear actuator is a compact 20 mm linear actuator designed for precise linear positioning in space-limited applications.
This size 8 actuator occupies less than 1 in² of mounting footprint and provides up to 45 N of continuous thrust.
Motor Characteristics
| Motor | Voltage [V] | Current [A RMS] | Resistance [Ω] | Inductance [mH] | Weight [g] | Lead Wire No. | Motor Length [mm] |
|---|---|---|---|---|---|---|---|
| 8-2105 | 2.5 | 0.5 | 5.1 | 1.5 | 51 | 4 | 27.2 |
| 8-2205 | 4.4 | 0.5 | 8.8 | 2.7 | 74 | 4 | 38.1 |
Note: Motor insulation class B. Motor temperature rise 80°C. Ambient temperature -20°C to 55°C.
Available Lead Screw and Travel per Step
| Screw Dia. [inch] | Screw Dia. [mm] | Lead [inch] | Lead [mm] | Lead Code | Travel Per Step @ 1.8° [mm]* |
|---|---|---|---|---|---|
| 0.138 | 3.5 | 0.024 | 0.6096 | AA | 0.003 |
| 0.138 | 3.5 | 0.048 | 1.2192 | B | 0.0061 |
| 0.138 | 3.5 | 0.096 | 2.4384 | J | 0.0122 |
| 0.138 | 3.5 | 0.0118 | 0.3 | AF | 0.0015 |
| 0.128 | 3.24 | 0.0394 | 1 | AB | 0.005 |
| 0.138 | 3.5 | 0.0787 | 2 | G | 0.01 |
| 0.138 | 3.5 | 0.1575 | 4 | M | 0.02 |
| 0.138 | 3.5 | 0.315 | 8 | T | 0.04 |
| 0.118 | 3.0 | 0.0197 | 0.5 | AD | 0.0025 |
* Motor wiring and screw lead can be customized upon request. Values truncated.
Dimensional Drawings
External dimensional drawing. Click to enlarge.
Non-captive dimensional drawing. Click to enlarge.
Captive dimensional drawing. Click to enlarge.
| Size A [mm] | Stroke B [mm] | Size L [mm] | |
|---|---|---|---|
| 22.2 | 12.7 | Single stack motor 27.2 mm | Double stack motor 38.1 mm |
| 28.55 | 19.05 | ||
| 34.9 | 25.4 | ||
| 41.3 | 31.8 | ||
| 47.6 | 38.1 | ||
| 60.3 | 50.8 | ||
| 73 | 63.5 | ||
Kaptive dimensional drawing. Click to enlarge.
| Size A [mm] | Stroke B [mm] | Size C [mm] | |
|---|---|---|---|
| L = 27.2 | L = 38.1 | ||
| 10.9 | 9 | 0 | 0 |
| 14.6 | 12.7 | 3.5 | 0 |
| 20.8 | 19.05 | 9.5 | 0 |
| 27.3 | 25.4 | 15.5 | 4.5 |
| 33.7 | 31.8 | 22.5 | 11.5 |
| 40 | 38.1 | 28.5 | 17.5 |
Speed Thrust Curves
Single stack speed thrust curve. Click to enlarge.
Double stack speed thrust curve. Click to enlarge.
Test condition: Testing voltage 24 VDC. Driver model DS-OLS2-FPD bipolar chopper driver at rated current RMS. Motor thrust changes with different voltage and driver selections. A 50% thrust margin is recommended.
Available Options
Encoder photo. Click to enlarge.
Encoder drawing. Click to enlarge.
| Resolution CPR | 100 | 108 | 120 | 125 | 128 | 200 | 250 | 256 | 300 | 360 | 400 | 500 | 1000 | 512 | 720 | 800 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Single Ended Output | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 |
| Differential Output | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P |
Teflon Coating
If your application requires a greaseless screw and nut combination, DINGS’ offers Teflon coated lead screws for stepper linear actuators.
Teflon coated lead screws can improve life cycle and thrust force generation compared with conventional SUS lead screws.
Teflon coating can be applied across the lead screw option range and actuator types including External, Non-Captive, Electric Cylinder, and Kaptive. Anti-backlash nuts can also be combined with Teflon coated lead screws.
External anti-backlash nut. Click to enlarge.
Non-captive anti-backlash nut. Click to enlarge.
Anti-Backlash Nuts
External and non-captive anti-backlash nut options are available depending on the actuator configuration and lead screw selection.
According to the selected screw lead code, the length of the anti-backlash nut can change.
| Rated Voltage | DC 24V ± 5% |
|---|---|
| Resistance | 55Ω ± 10% |
| Power | 9.6W |
| Hold Torque | >0.06 N·m |
| Insulation | B |
| Insulation Resistance | >100MΩ DC500V |
| Dielectric Strength | AC 1000V for 1 sec |
| Retraction Time | 50 ms |
| Release Time | 50 ms |
| Gyration Gap | 1° |
| Emergency Brake Cycle | 200 cycles |
| Lifetime | 500,000 cycles |
| Noise Level | <60 dB |
Brake dimensional drawing. Click to enlarge.
Screw end machining. Click to enlarge.
Customization Options
DINGS’ Motion USA customizes Stepper Linear Actuators, PM Stepper Linear Actuators, Slide Actuators, and Voice Coil Motors for OEM applications.
Motor Platform
NEMA size, stack size, motor type, stepper or BLDC motor options, voltage and current ratings, windings, insulation class, force, torque, and speed.
Linear Motion Design
Stroke length, lead screw selection, shaft configurations, end machining, lubrication on lead screw, and actuator style.
Electrical Integration
Cabling, connectors, lead wire details, harness routing, winding adjustments, and electrical requirements for the application.
Environmental Requirements
Coatings, IP ratings, clean room capabilities, lubrication requirements, and application-specific material or protection needs.
Resources
Downloads
Part Number Construction
1. Motor Size
8 = NEMA 8 / 20 mm frame size.
2. Linear Actuator Type
E = External, N = Non-Captive, C = Captive Cylinder, K = Kaptive.
3. Motor Step Angle
2 = 2-phase 1.8°, 4 = 2-phase 0.9°, 5 = 5-phase 0.72°.
4. Motor Length
1 = Single stack, 2 = Double stack, 3 = Triple stack.
5. Rated Current / Phase
XX = X.X A / phase.
6. Lead Screw Code
Select the code from the lead screw code table.
7. Lead Wire Number
4 = 4-wire, 6 = 6-wire, 8 = 8-wire leads.
8. Lead Screw Length / Stroke
External / Non-Captive: XXX = screw length. Captive / Kaptive: XXX = stroke.
9. Lead Screw Surface Treatment
T = Teflon coating, S = Standard, K = Electrophoretic Teflon, C = Custom.
10. End Machining
M = Metric, U = UNC, S = Smooth, C = Custom, N = None.
11. Nut Style
S = Standard flange nut, A = Anti-backlash nut, C = Customization.
12. Option
EKX = Encoder, P = Manual knob, B = Brake, X = Rear shaft, R = Encoder ready, C = Custom, N = None.
13. Customer Sequence Number
Customer or project-specific sequence number.
Need help selecting or customizing a NEMA 8 linear actuator?
DINGS’ Motion USA can help review thrust, speed, lead screw selection, stroke, actuator type, wiring, connector, lubrication, brake, encoder, and clean room requirements for your application.