ribbon corrugation

[floid]

I've had a Nady RSM-5 for a couple years that I've left stock because, unlike its brother, it seemed to do alright when I first got it. But I don't really use it much.
Anyway, the other day I set it up and found it sounded terrible - an almost gated type sound. Looked inside, and saw the ribbon had sagged out of the motor roughly half an inch.. I've got 2.5u foil, so figure just re-ribbon it like i've been meaning to.
I do my corrugations with one of those tube squeezer thingies. And i've read about using gears, combs, and other methods. But I notice the ribbon in there had what seem to be especially deep corrugations, maybe as much as twice as deep as what my rig creates. So I'm wondering if deeper corrugations contributed to the sag, if there's some tradeoff in sensitivity, if round vs angled does something, etc.

[jimjazzdad]

Ah, fun with aluminum foil...
I am no expert, but have re-ribboned a few. The gears I use to corrugate the ribbon make fairly deep 'valleys' (maybe 1 mm?). No doubt this contributes to sag in the long term as there is more material in a ribbon of a given corrugated length. However, if you regard the ribbon as a spring, deeper corrugations allow for more deflection, affecting level and perhaps frequency. I have no idea what the ideal corrugation depth to ribbon length ratio is. Maybe others more erudite in the subject will chime in?