NEMA23 Motor Mount, Extended
Motor accessories · 2 styles · 2 options in stock
Parts that go with stepper motors — couplers, dampers, pulleys, cables. The parameters are listed in order of importance: the one at the top decides the most, and no amount of care further down makes up for getting it wrong.
This page lists 2 options: Style / variant Equipped with 57 planetary decelerator / For use with 57 stepper motor. From ¥29.87.
The parts of this item
Figure 1 — Power, motor and signal must stay separate. Drivers are rarely killed by quality — they are killed by unplugging motor leads live.
What each parameter decides
Every parameter below shows the real range available on this page, and what goes wrong if you pick it wrong. Work through them in this order and you will not go far wrong.
| Parameter | Available here | What it decides | If you get it wrong |
|---|---|---|---|
| Style / variant | Equipped with 57 planetary decelerator / For use with 57 stepper motor | the structural and shape differences | it will not fit, or it will not do the job your mechanism needs |
How to choose, step by step
- Which motor it goes on — Confirm the frame size and the shaft diameter first — everything here is sized from those two.
- Which accessory — Equipped with 57 planetary decelerator / For use with 57 stepper motor. A coupler transmits torque, a damper cuts noise, a pulley drives a belt.
How the options on this page are distributed
Figure 2 — how the 2 options on this page are spread across each parameter: the bars on the left show how many options sit in each band, the panel on the right shows the real range of every parameter and how many steps it has.
Variant quick reference
| Style / variant | Part no. |
|---|---|
| For use with 57 stepper motor | MT-017-57BJDJY |
| Equipped with 57 planetary decelerator | MT-017-57XXJSY |
Reading the part numbers
| Part no. | Configuration |
|---|---|
MT-017-57BJDJY | Style / variant For use with 57 stepper motor |
MT-017-57XXJSY | Style / variant Equipped with 57 planetary decelerator |
You can order by part number or by selecting the parameters. The part number is fastest, but it does not always encode every parameter — the selector on this page is the authority.
5 common mistakes
- Shaft fit matters to 0.1 mm. An 8 mm coupler bore on a 6.35 mm shaft only works with a bushing, otherwise it cannot clamp and it slips.
- A damper costs you rigidity. It does cut noise, but under high acceleration it introduces compliance.
- Pulley and belt must be the same series. Mix them and the belt jumps teeth.
- Measure before you order. Take the old part off and measure it, or send us a photo with the caliper reading — that beats guessing from a model number every time.
- Everything here is in millimetres. Where a size is imperial, convert it: 1" = 25.4 mm, 1/4" = 6.35 mm, 3/32" = 2.38 mm.
When to replace it
You do not replace this until it fails — but "still looks usable" and "still reliable" are two different things. Any one of these and it is time:
- The coupler bore has worn and it slips even when clamped.
- The damper rubber has aged and cracked.
- The pulley teeth are sharpened and the belt jumps.
Fitting and use
Check before assembly
- Wipe every mating surface with a lint-free cloth. No chips, no burrs, no old grease. One chip is enough to make a bearing noisy.
- Measure the fits — shaft, bore, centre height — against nominal. More than 0.02 mm out and you should check whether you have the right part.
- Check the orientation: the side with the shoulder, step or oil hole has to face the right way. Fitted backwards, it is usually scrap on removal.
Assembly
- Press if you can; do not hammer. If you must tap, use a brass or nylon drift and put the force on the ring that is being fitted, never through the raceway.
- For an interference fit, heat to 80–100 °C first (oil bath or hot plate — never an open flame on a bearing). Hot fitting is easier and safer than cold pressing.
- Tighten fasteners in a diagonal pattern in 2–3 stages. Taking one down fully first distorts the housing and cocks the shaft.
Running in
- Turn it by hand first. It should be smooth, with no tight spot and no axial play. If there is a tight spot, loosen and reseat — do not run it in.
- Run it slowly and unloaded for 10–20 minutes, then feel the temperature. A clear rise means too much preload or poor alignment.
- Re-torque the fasteners after running in, then apply load.
Three things not to do
- Do not hammer. It brinells the raceway, you cannot see it, and it whines forever afterwards.
- Do not mix brands or precision classes in a matched pair. The load shares unevenly and the poorer one always fails first.
- Do not skip lubrication on parts that need it. A few hundred hours dry and it seizes.
Matching parts
- Motor, driver and coupler — buying them together saves trouble
Lead time, custom work and shipping
- Stock sizes: dispatched in 1–2 working days, subject to stock
- Custom: non-standard sizes, materials and treatments are possible — send quantity and drawing
- Shipping: from Shenzhen; domestic courier by default, DHL or dedicated line for export
- Volume: quantity pricing available, contact us for a quote
If you cannot find the size you need, or you are not sure which one fits, send us the problem you are solving — what machine it goes on, the dimensions of the part you have, what it has to achieve — and we will match it.