How to approve machinery size changeover
Approve changeover through a witnessed trial on the machine being supplied: run the original size, change format, then return to it. Agree tooling, settings, acceptable output, setup waste and timing boundaries beforehand. Record every intervention and release only the combinations that pass. Share the trial brief with Cambridge China Bridge.
Define the formats you are approving
The machinery sourcing guide covers general performance, documentation and installation. Add a changeover schedule to your order: product drawings, material, size combinations, required output quality and operating speed. Specify which formats must be demonstrated and which remain untested.
Ask for the usable adjustment range of each relevant mechanism, including guides, feed systems, clamps and discharge equipment. Distinguish adjustment with existing parts from changes needing replacement tooling. Do not assume that separately advertised width and height ranges work together. Include boundary sizes and awkward combinations in the agreed trial.
Match tooling and recipes to each format
Require a format sheet identifying tooling, mounting positions, spacers, gauges and tools needed for adjustment. Mark parts so operators can match them to the sheet. Confirm what is included in the supply, what must be purchased separately and which parts are shared between formats.
Record the saved recipe name and revision, parameter values and units, plus manual settings that the controller cannot store. Capture screen images and physical reference positions. Ask an operator to load the recipe and fit the tooling using the written instructions; record any undocumented correction or help from the supplier's engineer.
Measure the whole changeover
Put the sequence into the factory acceptance test. Use agreed production material and identify the actual machine, tooling and operator. Record from the last acceptable output of the outgoing format until the incoming format produces acceptable output consistently at the agreed speed. Include cleaning, tool replacement, warm-up, adjustment and inspection.
Agree how setup waste will be measured and classified before testing. Keep rejected output, purged material and recoverable material separate. Log material consumed, faults, stops and adjustments during setup. A selected good sample does not show the waste generated before it or whether the machine can sustain acceptable production.
Prove the return to the original format
Run the original format to establish a baseline, change to the agreed alternative, then return using the recorded tooling and settings. Compare dimensions, functional quality, appearance, speed and setup waste with the baseline against agreed limits. Record any fresh tuning rather than quietly rewriting the recipe.
Repeat the sequence as agreed and include a different trained operator where practical. Preserve the run log, measurement results, labelled samples and video showing the changeover. If the return needs undocumented engineer intervention or output drifts outside the limits, keep that format unapproved until the cause is corrected and the sequence is retested.
Working out your own order? Send us the product on WhatsApp and we reply the same working day: WhatsApp us
Make approval usable at your UK site
HSE advises producing a safe system of work for using and maintaining machinery. Ask your machinery safety adviser to review the changeover procedure, including tool handling, isolation, stored energy and any powered setting tasks. Do not accept a demonstration that relies on bypassed safeguards as evidence of an acceptable changeover.
Issue an approval record naming the accepted formats, tooling and recipe revisions, results and unresolved exclusions. Require updated instructions and saved settings to accompany the machine. Use the site acceptance test to check the sequence with your operators, utilities and material after installation. Factory approval does not establish performance under different site conditions.
Frequently asked questions
Does a machine's size range prove it can run my products?
No. Ask the supplier to demonstrate your actual size combinations with the agreed material, tooling and output limits. Separate adjustment ranges may not be usable together.
When should changeover timing start and finish?
Agree boundaries before the trial: from the last acceptable outgoing product to consistent acceptable incoming output at the agreed speed. Include preparation tasks or record them separately.
Is a saved recipe enough to approve changeover?
No. Record manual adjustments, tooling and physical reference positions too. Demonstrate that an operator can restore the format from the instructions without undocumented tuning.
What if the original size fails after changing back?
Keep the return changeover unapproved. Record the failure, require a correction and repeat the agreed sequence. Do not accept an isolated good sample as proof of repeatability.