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Quick answer: MAGEON needs four documents to open a quotation and five to release production: a machine general arrangement, a 2D interface drawing, a 3D model, and a jointly signed interface confirmation drawing, supported by WPS, PQR, material certificates and NDT records.
Most delays in a custom undercarriage project are not caused by manufacturing difficulty. They are caused by documentation that was incomplete, ambiguous, or in two different versions on two different desks. A well-specified drawing set is what separates a 45-day project from a 90-day one.
This is the documentation standard MAGEON works to when a customer asks us to build a custom undercarriage, written so that a customer's own engineering team can prepare for it without a discovery call.
1. The drawings we need to open a quotation
Four documents, in ascending order of precision. The first is enough for a budgetary indication; the fourth is enough to cut steel.
| Document | Purpose | Accuracy needed |
|---|---|---|
| Machine general arrangement | Weight distribution, envelope, mounting position | ±5 mm |
| Interface drawing (2D) | Bolt pattern, centre height, drive interface | ±0.2 mm on hole position |
| 3D model (STEP / IGES) | Clearance verification, clash check | ±0.1 mm |
| Interface confirmation drawing (jointly signed) | Production release | ±0.1 mm |
The joint signature on the fourth document is the single most important control in the whole process. It is a joint drawing because the interface belongs to both parties: the chassis maker owns the face, the machine builder owns what bolts to it.
2. Frame tolerance standards
MAGEON manufactures crawler undercarriage frames by laser cutting plate, CNC bending, and full-penetration welding followed by post-weld heat treatment. The tolerances we hold and verify are:
| Characteristic | Tolerance | Measurement |
|---|---|---|
| Frame length / width | ±1.0 mm | After heat treatment |
| Interface face flatness | 0.3 mm over 500 mm | Surface plate and indicator |
| Interface face parallelism | 0.2 mm | Per datum |
| Bolt hole position | ±0.2 mm | CMM |
| Guide rail parallelism | ±0.5 mm | CMM |
| Track roller axis coplanarity | ±0.3 mm | Fixture check |
| Frame twist after welding | ≤ 1.5 mm/m | Straightedge and feeler |
Frame twist is the tolerance that most often gets skipped and most often causes trouble. A twisted frame does not just fail the flatness check; it loads the rollers unevenly, which accelerates wear on the idler and sprocket bearings and produces the vibration that customers describe as "the machine feels different after a year".
3. Welding and material documentation
Every custom undercarriage frame is produced under a qualified welding procedure. MAGEON maintains WPS and PQR records for each joint configuration, and these travel with the chassis:
- Welding procedure specifications — for each joint type, the process, consumables, parameters and sequence
- Procedure qualification records — the test results proving the procedure meets the applicable standard
- Welder qualifications — recorded per welder per process
- Material certificates — mill certificates for every plate and section used, traceable to heat number
- NDT records — visual plus magnetic particle or ultrasonic on critical structural welds
For a custom undercarriage destined for a regulated market, this documentation is not paperwork for its own sake. It is what allows the machine to be certified, what lets a customer's own quality department release the machine, and what makes a warranty claim ten years later answerable.
4. Interface control: the details that actually matter
Beyond the bolt pattern, four interface details cause the majority of field problems on custom crawler undercarriages:
Centre height. The vertical distance from the ground plane to the mounting face. Getting this wrong means the machine's mass distribution changes and, on a tracked machine, the front idler carries more than the design intended.
Hydraulic hose clearance. The route from the machine's valve block to the drive motor must clear the frame, the track chain envelope, and the full steering and travel envelope in both directions. A design that is correct in 2D can be impossible in 3D.
Drive rotation and hose orientation. A motor mounted in the wrong rotation direction, or hoses crossed, produces a machine that travels but steers incorrectly — a fault that is frequently misdiagnosed as a control problem.
Stiffness at the interface. A flange that is thinner than the frame section it attaches to will flex under load, changing the effective centre height and concentrating bolt loads. MAGEON specifies the interface plate thickness as a function of the frame section, not as a fixed value.
5. What MAGEON returns to you
- 3D model of the proposed chassis, in the customer's native format
- Interface confirmation drawing, for joint signature
- General arrangement drawing with full dimensional and tolerance data
- BOM with manufacturer and specification for every purchased item
- Weight and ground pressure calculation for the stated machine configuration
- Estimated service life of the track chain under the stated duty cycle
6. A practical checklist
- Does the interface drawing state tolerance for hole position, not just hole size?
- Is the centre height dimensioned from the ground plane, and is the ground plane itself defined?
- Are the hydraulic routing and travel envelope shown in the 3D model?
- Does the material certificate set cover the actual heat numbers used, or only a generic mill certificate?
- Is frame twist a stated acceptance criterion on the inspection plan?
- Is there a defined hold point where the customer signs off the interface before steel is cut?
If the answer to the last question is no, add it. That hold point is worth more than any amount of additional inspection later in the process.
Conclusion
Custom undercarriage drawings are not an administrative burden — they are the mechanism that makes a bespoke product repeatable and verifiable. MAGEON treats documentation as part of the deliverable, not as paperwork generated after the fact, and we are happy to review a customer's drawing set before quotation to identify anything that would cause trouble in production.
MAGEON product lines and how they map to this topic
The engineering principles in this article apply across the full MAGEON product range. Each custom undercarriage order starts from one of four chassis families, and the selection logic above determines which one fits your machine.
| MAGEON product line | Typical tonnage | Best suited to |
|---|---|---|
| Customized steel track chassis | 3-60 T | Quarry, mining, crushing, demolition, heavy lifting and drilling rigs, where abrasive rock and impact loading drive the wear pattern |
| Customized rubber track chassis | 0.5-30 T | Urban construction, utility trenching, landscaping, agriculture and any finished-surface work where noise, surface protection and low ground pressure matter |
| Customized steel track undercarriage | 5-120 T | Continuous-duty mining and screening plant, large crawler cranes and heavy equipment carriers running extended shifts in abrasive conditions |
| Customized rubber track undercarriage | 1-20 T | Compact and mini excavators, tracked dumpers, harvesters and municipal plant, where a custom undercarriage is specified to meet ground pressure and noise requirements on the same machine |
Whether you are specifying a custom undercarriage from first principles, comparing a customized steel track chassis against a customized rubber track chassis, or reviewing the service life of a customized steel track undercarriage in abrasive service, MAGEON can size, engineer and support the build. Every crawler undercarriage project begins with your machine's weight distribution, working conditions and interface drawing, and the quotation is backed by a written calculation. Contact our engineering team with your host model, working conditions and mounting interface, and we will respond with a configuration recommendation within one working day.