Description

Product Overview

This custom CNC machined yoke shaft is a core oscillating linkage component designed for high-speed computer embroidery machines. It adopts one-piece turn-mill integrated machining, combining twin-ear yoke body and dual-end stepped shaft in a single solid blank. The part transfers reciprocating swing motion to drive needle bar or hook assembly inside embroidery heads, requiring excellent fatigue resistance, precise hole coaxiality and low inertia for continuous high-frequency operation.

Our CNC machining services support custom yoke shaft manufacturing per your CAD drawings or samples, including prototype, low-volume trial run and mass production. Secondary operations such as heat treatment and plating are available to meet textile machinery working conditions.

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CNC Machining Service Parameters Table

表格

Item	Specification
Product Name	CNC Machined Yoke Shaft for Computer Embroidery Machine
Machining Process	CNC Turn-Mill Composite Machining, Drilling, Boring, Deburring
Supported File Format	STEP, IGES, Solidworks, DXF, PDF 2D drawing
Material Options	C45 / 1045 Carbon Steel (Standard), 4140 Alloy Steel (High-performance upgrade)
Surface Treatment	Yellow Zinc Plating + Yellow Chromate Passivation
Optional Secondary Process	Induction Hardening on pin holes & shaft journals
Surface Roughness	Ra 3.2μm as standard; Ra1.6μm for mating surfaces after grinding
Standard Tolerance	ISO 2768-m (±0.1mm general dimension)
Tight Tolerance	±0.01~0.05mm for critical holes, shaft journals, coaxiality
Inspection	CMM, micrometer, pin gauge, roughness tester, first article inspection
MOQ	1pc for prototype; 50pcs+ for mass production
Lead Time	Prototype: 3–7 working days; Mass order: 10–20 working days
Industry	Textile Machinery / Computer Embroidery Machine Spare Parts

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Application Scenarios

This integrated yoke shaft is used as swing linkage in multi-head computer embroidery machines.

1. High-speed embroidery head motion transmission: converts cam rotary movement into reciprocating swing to drive needle or hook mechanism.
2. Textile machinery replacement spare parts for embroidery machine maintenance and overhaul.
3. Custom oscillating yoke linkage for similar textile equipment requiring low-inertia swing components.
4. R&D prototype for new embroidery machine model verification.

Working condition: Continuous high-frequency small-angle reciprocating swing, repeated alternating fatigue load, moderate surface wear on pin holes, limited installation space inside embroidery head.

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Material Analysis

Primary Material: C45 / 1045 Carbon Steel (Recommended Standard)

• Reason: Compatible with yellow zinc plating & yellow chromate passivation. Balanced tensile strength and toughness for high-frequency swing. Can apply local induction hardening on pin holes and shaft journals to improve wear resistance while keeping substrate toughness against fatigue fracture. Cost-effective and widely used for textile machinery moving parts.
• Limitation: Without heat treatment, pin hole wear rate increases under long continuous running.

Upgrade Option: 4140 Alloy Steel

• Reason: Higher fatigue strength and impact resistance, suitable for high-speed heavy-duty embroidery machines running 24/7 continuously.
• Limitation: Higher raw material & processing cost, requires careful control of residual stress after machining and heat treatment.

Materials Not Recommended

• Aluminum alloy: Yellow zinc plating is not the standard surface treatment for aluminum; aluminum usually uses anodizing. Although lightweight, aluminum has lower wear resistance for pin joint.
• Brass / Bronze: High density increases swing inertia, causing vibration and noise at high embroidery speed, high cost, only used for bushing, not yoke shaft.

Surface treatment note: Yellow zinc passivation mainly provides corrosion protection. Plating layer is thin and not suitable for friction mating surfaces. Functional contact areas are normally masked or post-ground.

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Tolerance Capability

1. General linear dimensions: ISO 2768-m, ±0.1mm, default for non-critical geometry.
2. Critical pin holes & stepped shaft journals: ±0.01 ~ ±0.05mm, guaranteed with fine boring & grinding.
3. Geometric tolerance: Coaxiality, concentricity, perpendicularity controlled via one-setup turn-mill process, to avoid assembly binding during high-speed swing.
4. Notes on tolerance: We only apply tight tolerance on functional critical features. Over-specifying full-part tight tolerance will raise production cost and extend lead time. GD&T requirements can be implemented upon drawing request.

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Manufacturing Difficulties

1. Coaxiality control of dual-end stepped shaft + twin ear yoke hole One-piece structure with features distributed on multiple axes. Multi-clamping will introduce position error. We adopt turn-mill composite single-setup machining to reduce re-clamping deviation, ensure smooth reciprocating swing without jamming.
2. Thin small locating pins on the yoke end The tiny protruding cylindrical pins are easy to vibrate and tool deflect during milling. Need optimized cutting parameters, rigid fixture and low-feed finishing pass to avoid pin bending or chipping.
3. Fatigue risk after heat treatment If induction hardening is requested, heat-affected zone must be strictly controlled. Improper hardening may create internal residual stress and lead to fatigue fracture under high-frequency reciprocating swing.
4. Consistency for mass production For batch orders, fixture calibration, tool wear monitoring and regular CMM sampling inspection are required to maintain hole pitch and shaft dimension consistency across thousands of pieces.
5. Surface treatment protection Masking mating functional surfaces before zinc plating, to prevent plating layer affecting fit clearance of pin holes and shaft journals.

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FAQ

Q1: What is a yoke shaft on embroidery machine?

A: Yoke shaft is an integrated oscillating linkage part. The central twin-ear yoke connects with cam or follower pin, while two end stepped shafts act as swing pivot. It transfers reciprocating motion for embroidery needle / hook mechanism. It is also known as swing yoke assembly in textile machinery industry.

Q2: Can you produce this yoke shaft only from samples without CAD drawing?

A: Yes. We can reverse scan your physical sample and generate CAD + 2D engineering drawing for quotation and machining. We will confirm critical dimensions and tolerances with you before production.

Q3: Is induction hardening mandatory?

A: Not mandatory. For low-duty embroidery machines, C45 steel without heat treatment works fine. For high-speed 24-hour continuous running machines, induction hardening on pin holes and shaft journals is strongly recommended to extend service life and reduce wear.

Q4: What inspection reports can you provide?

A: First Article Inspection (FAI), dimension inspection report, material certificate, heat treatment report and surface coating test report on request.

Q5: Can I customize different material or surface finish?

A: Yes. We can switch to alloy steel, or change surface treatment to black oxide, hard anodizing (if aluminum) based on your requirement.

Q6: What is the difference between yoke shaft and fork shaft?

A: Yoke shaft refers to the integrated part with twin-ear clevis yoke for oscillating linkage, commonly used in textile and embroidery machinery. Fork shaft mostly refers to shift fork shaft in gearbox transmission. They are sometimes mixed in search queries but serve different mechanical functions.

Q7: What file types do you accept for CNC machining services?

A: STEP / IGES / SolidWorks CAD files preferred. We also accept PDF 2D drawings with dimension and tolerance markups.