Models provided:

25mm + 30mm Festool style Wingbolts

Simply print the model then take the m6 bolt and slide it down from the top (aligning the head with the cut-outs) until it seats in the recess. It should be a tight fit, but clearance is provided by cut-outs in the wings.

If your hex bolt heads are too large, you will need to scale the model accordingly, but don't do so until you've tried mechanically seating the bolt. I recommend you use a wing-nut installed on the bolt and keep tightening until it pulls the bolt into the model. It is intentionally tight and its hard to do just by pushing due to the path it takes. Harder to explain than do.

Background:

These are created by remixing https://makerworld.com/en/models/79464#profileId-84041, which was a remix of https://www.printables.com/model/113905-festool-knob-v2.

Printing Guidance:

There are no specific demands for the print profile - make your standard trade-offs for smoothness vs speed with layer height etc. You may need to scale based on the size of the bolt you insert into the model, but you know what to do there if that's an issue.