A buyer searching for Harmonic Drive is usually trying to stop a bad substitute. A robot is specified by reach, payload, repeatability, the environment, and the safety function around it. The notes below are selection criteria for a Harmonic Drive. They are not a catalog promise. Confirm every rating on the current datasheet, drawing, or test report for the revision you will receive.
What has to be true of Harmonic Drive
A robot is specified by reach, payload, repeatability, the environment, and the safety function around it. For a Harmonic Drive, start from the duty, then the interface to the rest of the machine or the room, then the document that proves the claim. A lower price that leaves one of those blank is a different product.
Harmonic Drive is easy to confuse with Mapping Module. If the quote could be read as either, add the line that separates them: the rating, the fitment, or the standard named below. Link the drawing number to that line so receiving inspection can reject the wrong one.
Numbers that change the quote
| Line | What to write for Harmonic Drive |
|---|---|
| Environment | Clean, washdown, or a standard industrial hall. |
| End effector | Who supplies the gripper or tool. |
| Safety | The safeguarding of the cell is part of the machine, not a slogan. |
| Payload and reach | Payload at the reach you need, not the maximum of each. |
| Repeatability | The figure and the ISO method if the supplier cites one. |
| Axes and mount | Axes, and floor, wall, or ceiling. |
How to compare two offers
Lay both quotes for Harmonic Drive on one sheet and line up environment, end effector, and safety. If a cell is empty, the offer is not finished. Ask for the missing line in writing. When those match, the honest difference is lead time, the test evidence, and who carries the warranty. Do not average a fully specified Harmonic Drive with a cheaper line that omitted environment.
Documents worth having before the deposit
Ask for the load diagram. Payload falls as reach increases. The file should name Harmonic Drive and the revision, not only the supplier’s homepage. A factory quality certificate such as ISO 9001 can sit beside that file. It does not replace it.
Failures that show up after delivery
- Adding gripper weight and forgetting it counts as payload.
- Ignoring the safety cell.
- Buying reach at a payload the diagram does not allow.
On a Harmonic Drive, the expensive version of the first mistake is discovering it after the goods are in the crate. Put the rejection condition in the purchase order while the supplier can still restate the offer.
A worked RFQ line
Use this shape, then replace the brackets with your duty: “Harmonic Drive — Write payload at reach, repeatability, mount, and who guards the cell.” That sentence is a template, not a rating of any brand. If a supplier’s datasheet uses different units, convert them onto this sheet so the next offer can be compared.
Where words like IP67 belong
Searches often add a constraint to Harmonic Drive: IP67, or explosion-proof / ATEX. Keep those on this page. IP67 is dust-tight plus a defined temporary immersion. It is not a rating for living underwater, and it says nothing about sunlight or salt. ATEX or IECEx is a certificate for a zone, a gas or dust group, and a temperature class. An IP rating does not grant it. Skip the mark if the site is not hazardous. If you need a third constraint, add it as another line on the same drawing. A second URL that only swaps the adjective does not give a buyer a second fact.
Related in this section: how to specify Mapping Module.
Questions buyers actually ask
What should an RFQ for Harmonic Drive include?
Write payload at reach, repeatability, mount, and who guards the cell.
Is a cheaper Harmonic Drive the same part?
Only if environment, end effector, and the documents match. A missing line is a different offer.
Do waterproof, OEM, or IP words need their own page?
No. For Harmonic Drive they are extra lines on this specification. Ask for the test or the drawing that gives the word a value.