Gearbox subassemblies and mechanical kits for robots
A subassembly is a set of parts delivered assembled and inspected against agreed criteria; a kit is the same set delivered unassembled, counted and labeled for your own assembly.
Pico supplies the mechanical side of a robot joint as one deliverable: gears, housings, shafts, purchased bearings and fasteners, built from your design as a prototype or pilot batch first, then as repeat supply.
At a glance
| Deliverable | What you receive | When it fits |
|---|---|---|
| Loose parts | Individual parts to your drawings, inspected as the scope defines | Your team assembles and sources the other parts |
| Kitted parts set | Every part for one build, counted and labeled per unit, purchased parts included | Prototype and pilot builds your team assembles |
| Subassembly | The set assembled and inspected against agreed criteria | You want a unit ready to install in the joint |
| Subassembly with agreed test | A subassembly plus a functional check agreed in the scope, with records per unit | You need measured results before the unit reaches your bench |
What is a gearbox subassembly or mechanical kit?
Both start from the same bill of materials. The difference is who assembles the parts and what is checked before they ship. A kit suits a team that wants to learn the assembly on its first builds. A subassembly suits a team that wants to install a checked unit and move on to the rest of the robot.
A kit is packed per unit, so a build that is short a part shows it before assembly starts, not halfway through.
What can a subassembly include?
- The gear set from your custom gears drawings: sun, planets and ring gear, or spur and helical stages
- The planet carrier, pins and spacers
- Housings, covers, shafts and adapters: the robot joint parts around the reducer
- Purchased bearings, seals, retaining rings and fasteners, each named with its source
- Lubricant, as specified on your drawing or agreed in the review
Motors, encoders and drive electronics are not part of what Pico supplies. If the joint uses a motor or encoder you already buy, the inquiry says so, and the mechanical interfaces (motor pilot, shaft coupling, encoder mount) are planned around it. A complete robot joint module or actuator with motor and drive is outside that scope; Pico supplies its mechanical side.
For the reducer inside the subassembly, see custom planetary gearboxes and the overview of robot joint gearboxes.
How are subassemblies inspected?
Acceptance criteria are agreed before the pilot build and written into the scope. They usually cover four things.
| Check | How it is defined | Record |
|---|---|---|
| Critical dimensions | Features and tolerances named on your drawings | Measured values per build |
| Rotation | Smooth rotation without binding or tight spots, checked by an agreed method | Result per unit |
| Backlash | An agreed method, for example angular play at the output with the input locked and a small reversing torque applied | Measured value per unit |
| Build record | Part revisions, purchased parts and their sources, lubricant used | One record per build |
Pico publishes no backlash, torque or stiffness figures for its subassemblies. Those numbers depend on your design, and they are reported only as measured on your parts, by the method agreed in the scope. Where each check is performed, in-house or at an outside lab, is stated in the scope.
Why kit the parts for a prototype or pilot build?
- One purchase order instead of one per shop, and one point of contact for the whole build.
- One revision record. Every part is listed at its revision, so a drawing change is easy to check against the parts it affects.
- Traceability per build. When a pilot unit behaves differently, the record shows which parts and sources went into it.
- Fewer handoffs. Each handoff between shops is another place where a tolerance or a material choice can go wrong.
How does a pilot build become repeat supply?
The pilot proves the drawings, the assembly steps and the acceptance criteria. Changes it shows are made as revisions before repeat orders start. Repeat orders then use the same drawings, inspection plan and point of contact, at the volumes your program needs.
The four-step process is the same for every program. If assembly or any other step must happen in the US, mark it in the inquiry; US manufacturing requirements are answered per step. When you are ready, describe your build with the parts list, quantities and timing you have.
Questions
Do you supply complete actuators with motors and electronics?
No. Pico supplies the mechanical side: gears, gearbox subassemblies, joint hardware and kits. If your joint uses a motor or encoder you already buy, we plan the mechanical interfaces around it.
What does inspection of a subassembly include?
It is agreed per project before the pilot build: which dimensions and functions are checked, how, and what records you receive. The agreed criteria are written into the scope.
Can a kit include purchased parts like bearings and fasteners?
Yes. Kits can include purchased components such as bearings, retaining rings and fasteners, each listed in the scope with its source.
Can assembly happen in the US?
Mark US manufacturing as required or preferred in the inquiry. The proposal states where each step, including assembly, happens.
Can we supply some of the parts ourselves?
That can be scoped. The proposal lists which parts you supply, how they enter the build, and how they appear in its records.
Describe your build
Send the parts list or drawings, whether you want a kit or a subassembly, the checks you need, quantities and timing. Partial information is fine.
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