General Questions
1. How can I purchase NAKANISHI products?
Please contact our distributor near/in your soil since we do not sell our products directly.
Link to Sales Network
2. What is the procedure to send my Motor Spindles and Micro Grinders for repair?
Please send your equipment through the dealer which you purchased.
If it is impossible, please contact our distributor you prefer.
Link to Sales Network
3. How can I obtain the latest catalogue?
Please contact our distributor you prefer.
You can also download PDF catalogue from our website.
Link to catalogue download page
Link to products list page
4. How can I obtain Operation Manual?
Please contact the dealer which you purchased.
Some operation manuals can be downloaded from our website.
Link to operation manual download page
Link to products list page
5. How can I obtain DXF data or 3D STEP data?
DXF data of motor spindles can be downloaded from our website.
3D STEP data of some of motor spindles also can be downloaded from our website.
Link to products list page
Products Questions
1. What is the difference between Motor Spindles and Micro Grinders?
Motor Spindles are developed to be mounted on machines. Be sure to use them mounted on the machines.
Mircro Grinders are developed for hand works. Please use them as a tool for hand work.
2. What is the difference between Electric Motor and Air Motor?
Electric Motor can be adjusted its speed widely and precisely due to high performance microcomputer.
Also, motor speed is displayed exactly due to high performance rotation speed detector.
Air Motor can be adjusted its speed by air pressure between 0.3 MPa to 0.5 MPa, however, it is not possible to know what the actual speed is.
3. Why should I consider an Electric Motor over an Air Motor?
The versatility of an Electric Motor far outweighs that of an Air Motor.
It is a closed loop system that will put more power to the motor to maintain RPM and torque; it is variable speed to meet the demands of more applications and offers more power and speed.
Air motors are fixed speed, require lubrication and are lower rpm.
4. What is the difference between a NAKANISHI High Speed Motor Spindle and Spindle Speeders?
A NAKANISHI High Speed Motor Spindle is an integrated motor/spindle that does not use machine spindle rotation.
Spindle Speeders are driven by the machine spindle with gears to increase or decrease tool rpm.
5. What is the advantage of an integral motor/spindle?
NAKANISHI High Speed Motor Spindles have no gears. Gears generate heat, vibration and thermal growth which are all deterrents of high speed spindles.
6. How can I install Motor and Spindle?
①We have the Grip Rings for spindle size φ22.8, φ30, and φ40 which help to excessive clamping force and can shorten setup time drastically.
If Grip Rings are unable to use due to restriction of dimension and space, install as shown in ② below.
②We would recommend the installation as shown in Fig.A. In case it is impossible, then try install as shown in Fig.B
Do not install them as shown in Fig.C-1 and C-2.
It may cause damage to the spindle housing and internal components. Also, abonormal rotation and overheating may occur.
- GR-22.8(φ22.8):E2000
- GR-30(φ30):E3000
- GR-40(φ40):E4000
7. How can I fabricate the Split Type Holder?
(1) Rough bore the inside diameter of the Split Type Holder.
(2) Cut a slit (ex. Slit 2 mm) wide.
(3) Tighten the Screw for Removal and Force Open the Slit Area.
(4) Insert a spacer (ex. Thickness = 2 mm) into the Slit Area.
(5) Loosen the Screw for Removal, and tighten the Fastening Bolt with its specified torque.
(6) Finish the Split Type Holder so that the inside diameter of the Split Type Holder is φ22.8, φ30, or φ40 with its tolerance range from -0.01 to -0.015 mm, and its roundness and cylindricity of less than 5 μm.
(7) When inserting Motor Spindle, loosen the Fastening Bolt, and tighten the Screw for Removal, widening the Slit Area.
The final responsibility for ensuring holder's safety for use in a given application is left to the designer of the equipment in which NAKANISHI's Motor Spindle is installed.
NAKANISHI offers Motor Spindle with a wide variety of capabilities and specifications.
Please carefully check the Motor Spindle's specifications against the requirements of your equipment and verify suitability and safety of the Holder prior to initial use.
8. What is the correct procedure to maintain spindle accuracy under normal operating conditions?
Any time a tool or collet is being replaced, it is recommended to remove the collet and collet nut, then clean them as well as the spindle taper with an alcohol swab to remove any cutting debris. This will help maintain spindle accuracy and improve longevity.
1. What is the spindle accuracy?
It is the spindle runout as measured at the tip of taper on the inside diameter of the Spindle.
2. What is the difference between a standard collet and an "AA" collet?
The spindle runout of standard collet of CHK and CHA Group is within 5 μm, and "AA" collet is within 2 μm.
We have "AA" collet for CHK and CHA group as below.
3. What is the torque value when I tighten collet?
It vary depending on the type of collet and size.
For CHK collet (Dia 3.0-6.35) The appropriate torque is 7.0 N·m
For CHA collet  (Dia 3.0-4.0) The appropriate torque is 6.0 N·m
For CH16 collet (All size) The appropriate torque is 8.0 N·m
4. What is allowable motor speed of Spindle and Reducer?
It is maximum allowable motor speed of Spindle and Reducer.
It is marked as "MAX xxxxx min-1" on housings of each product.
Be sure to use it in a lower maximum allowable rotation speed of the spindle.
5. What is IP rating (solid and liquid protection) of NAKANISHI products?
1 : Electrical Motor Spindle
  IP57 while suppling air for dust prevention and coolant
2 : Air Motor Spindle
  IP57 while suppling air to the air motor (when air motor is rotating)
Electric Motor Spindles
1. Why does NAKANISHI electric spindle require air?
By providing clean dry air to the spindle has the following effects.
・for it cools electric motor and helps a long period of use
・for effect for dust prevention as air purging and can be used in conjunction with coolant water or oil
2. Is it safe to run an Electric Motor and Spindle in wet conditions using machining coolants and oils?
Yes. All NAKANISHI motor spindles have an IP57 Rating by using purging air.
Coolants should however be directed at the cutting tool, not directly on the motor spindles.
3. Can my machine control communicate with the NAKANISHI Controller?
Yes. The NAKANISHI controller has Input and Output functions to communicate with the CNC control.
You can download operation manual of NAKANISHI controller from our website.
Link to operation manual download page
4. Can I run more than one spindle at a time (simultaneously) using a Controller ?
No. Only one motor can run at any given time because controller continiously check motor load and speed by feedback system.
Another controller will be required to run a second spindle simultaneously.
5. Which fuse should be used for each Controller for its replacement?
Please refer below table.
Time lag fuse is used for NAKANISHI controller.
It is available in the market.
Please be aware that fuse without "T" is not appropriate for NAKANISHI controller.
We also provide it, therefore please contact our distributor near/in your soil.
Be sure to change 2 pcs of fuses at one time when you replace.
Air Motor Spindles
1. Can I adjust the speed of my Air Motor?
Although motor speed can be reduced by lowering the air pressure, it is not possible to know what the actual speed is, and power will also be lost exponentially by reducing air pressure.
Therefore, we recommend Electric Motor Spindles.
2. Why do I need a NAKANISHI Air Line Kit?
Air Line Kits atomize, providing an oil vapor to the spindle and motor, providing lubrication, cooling and purging of the spindle and motor.
3. What is the Oil-mist lubrication?
Oil-mist lubrication is required that supplying oil-mist to the air motor from the Air Line Kit.
The lubricator levitates mist lubricating oil into the compressed air.
This oil-mist ensures air motor longevity by lubricating inside of air motor.
The lubricator of NAKANISHI Air Line Kit controls the oil drop volume as 1-3 drops per minute.
4. Which Lubricating Oil can be used?
Please use Liquid Paraffine ISO VG15 (Shell Ondina Oil #15).
We also provide lubricating oil, therefore please contact our distributor near/in your soil.
If you use lubricating oil from other suppliers, please purchase below or its equivalent.
・JXTG Nippon Oil & Energy Corporation : High White 70
・Idemitsu Kosan Co.,Ltd. : Daphne Oil CP-15N
5. What is the definition of rotation direction?
Basically, it is indicated "R/RA" or "L/LA" on model name of NAKANISHI motors.
・for "R/RA" : Forward rotation (clockwise)
・for "L/LA" : Reverse rotation (counterclockwise)
1. What is the purpose of a Reducer?
When an application requires a lower speed and still provide torque and power, a Reducer is used.
By attaching reducer, rotation speed lowers and the torque increases by its ratio.
For example, a 1:4 reducer with a 30,000 min-1 motor will only provide about 7,500 min-1, while increasing the torque as 4 times.
2. How can I use Grease for Reducer?
Be sure to use our specified grease.
The other type grease may cause a damage of reducer.
To extend the durability of the reduction gear, inject grease approx. 0.5 ml at every 70-100 hours use.


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