Custom gears / technical review
Custom plastic gears from a drawing, CAD file or broken sample.
For appliances, office equipment, light mechanisms, prototypes and legacy machines where the original spare part is unavailable. We review the application first, produce one prototype, and repeat only after a real fit and function test.
- CAD, drawing or sample
- One prototype first
- Repeatable small batches
Suitability gate
First question: should this gear be printed at all?
Load, speed, temperature, duty cycle, shaft fit and failure consequence determine whether Kesten’s process is appropriate. If it is not, we say so before production.
Good starting cases
- Unavailable appliance and office-equipment gears
- Prototype gear trains and low-load mechanisms
- Legacy equipment with a measurable broken sample
- Fixtures, demonstrators and controlled small batches
Prototype-first workflow
From damaged part to a testable replacement.
- 01
Send evidence
CAD or drawing is best. Clear photographs, dimensions and a broken sample are also useful.
- 02
Geometry review
We check tooth count, pitch relationship, bore, hub, mating parts and the operating conditions.
- 03
One prototype
The first part is for fit, mesh, noise, direction and function testing in the real mechanism.
- 04
Repeat only after approval
Once the prototype passes your test, we can quote a repeat part or controlled small batch.
Cases we review
A narrow service for expensive small failures.
Appliances
Mixers, slicers, ice makers, selector mechanisms and other non-critical drives.
Printers & office equipment
Paper-feed, carriage, focus and selector mechanisms where OEM parts are obsolete.
Machines & automation
Covers, adjusters, counters, light actuators, jigs and prototype transmissions.
Non-critical vehicle mechanisms
Interior or convenience actuators only after an explicit consequence-of-failure review.
What to send
Enough evidence to reconstruct the mesh—not only the outside shape.
- Tooth count
- Count complete teeth and note damaged or missing sections.
- Outside diameter
- Measure across the tooth tips with a caliper when possible.
- Thickness and hub
- Include face width, total thickness, hub diameter and hub height.
- Bore and shaft
- Show the shaft interface: round, keyed, D-shaped, square, spline or press fit.
- Mating part
- Photograph or measure the gear, worm or rack that this part must mesh with.
- Operating conditions
- Describe load, speed, temperature, noise, lubrication and how often it runs.
Material follows the application.
We do not choose a material from the gear photograph alone. Geometry, tooth load, heat, sliding contact, moisture and duty cycle are reviewed together. Some cases suit an additive prototype; others need another process or should remain metal. The review decides.
FAQ / review notes
Plastic gear questions
Can you work from a broken gear?
Often, yes—if enough teeth and reference geometry remain. Severe damage may require the mating gear, shaft dimensions or a physical sample.
When is a 3D-printed replacement gear appropriate?
It can be a useful route for one-off prototypes, unavailable parts and controlled low-load applications. Load, speed, heat, duty cycle and failure consequence still have to be reviewed; some cases need machining, molding or metal instead.
Do I need a CAD file?
No. CAD or a dimensioned drawing is the fastest route, but clear photographs, measurements and a deliverable broken sample can start the review.
Can you copy any automotive gear?
No. We consider only non-safety-critical convenience or interior mechanisms after reviewing what happens if the part fails.
Which material will you use?
That is selected after reviewing geometry, load, temperature, speed, wear and environment. We do not promise a material before understanding the application.
Will the first gear be the final batch part?
The first part is a prototype. Repeat production begins only after you test fit and function in the real mechanism.
Technical intake
Send the gear, application and evidence.
Give us what you know. If CAD is unavailable, attach clear photographs and explain whether the broken sample can be delivered. We will reply with questions, suitability and the next quoted step.