Japan Servo
Japan Servo KH56JM2B058 NEMA 23 Two Phase Hybrid Stepper Motor, marked No 5621
- 4 photos
Never used. The original pack has been opened, or the quantity was split off a full reel or tube. Leads are original and unclipped.
New old stock, open stock on the grading scaleSend the quantity you need. You get a quote back with shipping before anything is charged.
Video
Filmed on the bench. Sound is stripped from product clips.
- 0:17
Still from the handling video, close on a corner mounting lug and the wound stator, with only part of the label in frame.
Specifications
| Specification | Value |
|---|---|
| Identification | |
| Part number | KH56JM2B058 |
| Manufacturer | Japan Servo |
| Condition | New old stock, open stock |
| Date code | Not recorded |
| Package | NEMA 23 frame |
| Country of origin | Not recorded |
| Family | Not recorded |
| Stock number | 9V4JS2MG |
| Identification | |
| Series | KH56JM2 |
| Case marking | No 5621 |
| Suffix status | B058 is not a published catalogue suffix, consistent with an OEM specific build |
| Family level, KH56JM2 series | |
| Motor type | 2 phase hybrid stepping motor |
| Step angle | 1.8deg per step |
| Full steps per revolution | 200 |
| Frame size | 56 mm square, NEMA 23 |
| Body length | 42mm |
| Shaft diameter | 6.35mm |
| Pilot boss | 38.1 mm diameter, 1.6 mm high |
| Mounting holes | 4 through holes, 4.5 mm diameter, on a 47.14 mm square pattern |
| Weight | 400g |
| Detent torque | 25mNm |
| Holding torque, published catalogue variants | 422 unipolar to 490 bipolarmNm |
| Rated current, published catalogue variants | 1.0 to 3.0A per phase |
| Operating temperature range | 0 to 50C |
| This unit | |
| Termination | White multi pin connector header recessed into the case, not flying leads |
| Full nameplate text | TYPE KH56JM2B058, NO.5621, JAPAN SERVO CO.,LTD., MADE IN JAPAN |
| Shaft | Plain round, no flat visible in the photographs |
About this part
The KH56JM2B058 is a two phase hybrid stepping motor in the Japan Servo KH56 frame, the 56 mm square NEMA 23 size. Japan Servo, now Nidec Servo, publishes the KH56JM2 series with catalogue suffixes 901, 902, 903 and 951 and their double shaft equivalents. B058 is not one of them, and the extra case marking No 5621 is consistent with a customer specific build code, so this is almost certainly an OEM winding made to an equipment maker's order.
Motors of this family show up in printers, copiers, plotters, scanners, laboratory instruments and medical analysers, driving lead screws, carriages and paper transports. What the frame reliably gives you is the mechanical interface: 1.8 degrees per step, 200 full steps per revolution, a 6.35 mm shaft, a 38.1 mm pilot boss and four 4.5 mm holes on a 47.14 mm square pattern, so it drops into any NEMA 23 mount.
What the frame does not give you is the winding. Rated current and voltage for a custom suffix can sit anywhere inside or outside the catalogue spread, so drive it from a constant current driver and start low. On old stock, check the shaft for rust and flats, turn it by hand for bearing roughness and even detents, measure both windings for matched resistance and continuity, and inspect the lead exit and connector for cracked insulation.
Questions about this part
What current and voltage should I drive it at?
Not published for the B058 suffix. Measure the winding resistance per phase and compare against the catalogue variants, which run 0.58 ohm at 3.0 A per phase, 1.39 ohm at 2.0 A and 4.9 ohm at 1.0 A. Then set a constant current driver conservatively and watch case temperature.
Is this a NEMA 23 motor?
Yes. The KH56 frame is 56 mm square with four 4.5 mm mounting holes on a 47.14 mm square pattern, a 38.1 mm pilot boss and a 6.35 mm shaft, which is the NEMA 23 interface.
How many leads does it have, and what are the colours?
That depends on the winding. Catalogue unipolar variants have six leads, bipolar variants four. An OEM suffix may use a different harness or a moulded connector, so ring out the actual motor rather than trusting a colour chart.
Can I run it as bipolar if it is a six lead unipolar motor?
Yes. Ignore the two centre taps and drive the four outer leads from a bipolar chopper. You get more torque at low speed than unipolar half coil, at the cost of higher winding inductance.
Does it hold position with power off?
Only weakly. The series detent torque is 25 mNm, which is enough to stop a free shaft drifting but not enough to hold a load.
Who made it and can I still buy a datasheet part?
Japan Servo Co., Ltd., now part of Nidec as Nidec Servo. The KH56JM2 series datasheet is still published, but this specific suffix is an OEM build and is not orderable as a catalogue item.
What should I check before installing an old stock unit?
Turn the shaft by hand and feel for even detents with no grit, check both windings for equal resistance and no shorts to the case, inspect the shaft and pilot for rust, and flex the lead exit gently to look for brittle insulation.