Our gripper supplier photographed the first collar samples under a strip light and the softer-pad samples under diffuse light. The second set looks cleaner. We have no agreed appearance method, and neither set was shown releasing into the receiving tray. What should the comparison establish before we select pads?
Use identified before-and-after samples under an appearance method agreed by quality. Changing both the pads and the viewing conditions leaves the photographs unable to explain why the marks look different.
The supplier has retained both sample sets. There are no before-handling photographs of the first set. I have not assumed every visible mark came from those pads.
Have the supplier identify the pad material and contact shape in each complete assembly, because softer can mean several different changes and you will eventually need to replace what you select
Liam, quality can inspect the retained collars. Naomi, both assemblies use different contact shapes as well as different materials. That difference was absent from the summary quote.
Keep those as two complete candidates, then. The comparison can still be useful, but it will not establish that material softness alone accounts for any improvement.
Liam, yes, including the held collar position and withdrawal after release, since a changed contact shape can move the collar even when the gripper body looks unchanged
Both now have the same requested transfer and tray. Quality has agreed the viewing method for the next samples. The original photographs remain background, with their limitations noted.
Replacement references requested, but no maintenance comparison yet. No pad selection. Thanks Liam; inspecting the actual collars has been more useful than enlarging two differently lit photographs.