Product Selection Standard

Linear Motion System Types

  • A. Non-Captive
  • B. External Linear
  • C. Captive
Why choose one form factor over the other?
1. What is the best mechanical fit for your application?
2. How do you plan to attach the screw?
3. Is rotation of the screw acceptable?
4. Does your application require an encoder or brake?
5. What is the stroke of your application?
What environmental considerations do you have?
Fastech linear motion systems are designed to operate in dry and non-corrosive environments. Standard products do not have an IP rating. Operating non-IP rated linear systems in dirty or corrosive environments will signifi cantly reduce product life.
Very high or low temperatures may cause significant changes in the nut fit or drag torque.
Maximum dynamic Load
Each Nema frame size motor has a mechanical load maximum that should not be exeeded. See Speed/Torque curves for the individual frame sizes.
Motor Selection
In order to select the right motor combination with the lead screw several factors should be considered:
1. How much torque is required?
2. What is the desired step angle?
3. Detend or holding torque requirements?
4. Physical size restrictions?
5. What type of drive (amplifier) are you using?

Product Selection Guide

To reduce complexity and cost of a design, it is important to accurately size a motor/lead screw
combination. Below are a few simple steps in selecting the necessary components for a given application.
Step1 - Choosing a motor NEMA size(Force requirements)
Here is a general overview of the output thrust vs. NEMA size:
NEMA Sizes Max. Thrust Recommended Load Limit
NEMA 8 78N (17.5lbs) 43N (9.7lbs)
NEMA 11 230N (51lbs) 150N (34lbs)
NEMA 14 450N (100lbs) 230N (52lbs)
NEMA 17 710N (160lbs) 230N (52lbs)
NEMA 23 1400N (315lbs) 920N (210lbs)
NEMA 34 2400N (540lbs) 2160N (485lbs)
As the NEMA size of the motor is increased, the output thrust of the actuator is consequently increased.
Step2 - Choosing a screw lead(Force and Speed requirements)
After estimating the required thrust and choosing a NEMA size that may fi t your application, the speed and acceleration of the load must be consideredand evaluated to choose an appropriate screw lead.
Due to the nature of lead screws, the output speed and output thrust achievable by a motor/lead screw combination are two inversely proportional variables (i.e., increasing the required thrust will lower the achievable speed for a motor/lead screw combination). Therefore, the maximum output force of a system is lowered for applications that require higher speeds. For complete motor/lead screw selection data, please refer to the speed/thrust curves for each NEMA size.
Step3 - Lead Screw Material
There are many inter-related variables to consider when selecting the right linear motion system for your application. Your load and speed requirements will determine other variables such as the size of motor, the lead of the screw and ultimately the voltage and current requirements of your electronic motor drive. Depending on your application, trade-offs can be made with many variables as your finalize the system that will meet your performance, form factor and cost specifications.
Quantify these basic variables first :
• Load that you need to move (or push – Thrust)
• Velocit
• Distance to travel (Stroke)
• Time required to move from point A to point B (Acceleration required)
• Torque requirements of your entire system
• How much backlash is acceptable in your system?
• What is the required positional repeatability?
• Is this a Vertical or Horizontal orientation?
Using the PRODUCT SELECTION SYSTEM along with the associated Nema motor frame size pages in the next sections, you will then be able to drill down to specific c part numbers for both the lead screw and the associated step motor. The linear system is ordered as two part numbers.
※ Note : A linear ststem must be ordered as two part numbers.

Product Selection System

17 N 2 1 15 K 4 - 101.6 T M S

① NEMA Size
NEMA Code 8 11 14 17 23 34
Motor Size(mm) 20 28 35 42 57 86
② Lead Screw Shaft Style
N = Non-Captive Linear
E = External Linear
C = Captive Linear
③ Step Angle
2 = 2 Phase with 1.8°
4 = 2 Phase with 0.9°
3 = 3 Phase with 1.2°
5 = 5 Phase with 0.72°
④ Motor Length / Stack
1 = Single Stack
2 = Double Stack
⑤ Rated Current/Phase
XX = X.X (A)/Phase
⑥ Lead Screw Code
⑦ Number of Lead Wires
4 = Qty 4 Flying Leads
6 = Qty 6 Flying Leads
8 = Qty 8 Flying Leads
⑧ Lead Screw Length / Stroke
XXX = XXX mm Lead Length(For External Linear/Non-Captive Linear)
XXX = X.XX inch Stroke(For Captive Linear)
※ Please define the length of lead screw for Captive Linear Type as inch. And the length of lead screw of Captive Linear is standardized so please refer to specification in detail. (Example : Please refer to Page 28 to check specifications of Captive Linear Screw Lenght of 35mm motor)
⑨ Lead Screw Surface
T = Teflon Coating
S = Standard (No Teflon Coating)
⑩ End Machining
M = Metric
S = Smooth
N = None
⑪ Nut Style
S = Standard Flange Nut
A = Anti-backlash Nut