High friction washer - Playing Card Shuffler V3

I have very much been enjoying the Playing Card Shuffler V3 by @LukasCenovsky Find it here < Playing Card Shuffler v3 by Lukas Cenovsky | Download free STL model | Printables.com > As with many innovative solutions there can be limitations. Where you are trying to shuffle either, very new cards, very smooth/shiny cards, or even where you are trying to shuffle a double pack of cards such as used in a very common number game; the level of friction from the originally specified 8mm OD x 2mm W plumbing washers was insufficient to grab and move an individual card from the bottom of a stack. This was either because of lack of traction on the card or because of higher mass bearing down on the card. My solution is to create a 4mm crimp edge washer that simply retro fits to the original Playing Card Shuffler V3 spindles (inner diameter of the washer is chamfered back to 2mm). A rough calculation suggests a x8 increase in contact friction over the original washer. I printed in the softest flex I had (TPE 83a shore). No supports required. Very dry filament required. I printed on a 0.15 layer. With this minor tweak the V3 shuffler seems able to handle anything thrown at it, or indeed on to it. Great design Lukas, thank you.