What happened to the blades marketed @15 years ago ..
that had '6 blade edges' ?
I think they died as people realised they gave no benefit and were generally poor even when new.
The wipe is performed by the edge of the blade. If the blade twists enough for more of the side of it to wipe, it is already past its best. Anything designed to fall over enough to use another 'edge' is too flexible and will effectively reduce the pressure on the screen, giving an inferior wipe. The multi-blade was just a marketing gimmick.
I remember the original Panda, with its flat glass, not being really suited to blades designed for curved screens, so they lost their effectiveness quickly. I used to change mine twice a year, so was always looking at the alternatives.
I remember a very silly conversation with a young lad at an accessory shop. The multi-edge blades only cam in pairs. The Panda had one blade.
"These will last forever, you'll never need to buy another blade."
"But I only need one, so no need to buy a pair."
"You'll have a spare!"
i dont really get smearing, its more the juddering that i get issues with. the blades last about a month before starting to judder across the screen. made worse by that infernal second dry wipe!!!!
... often this is fixable by "adjusting" the arm a very small amount with 2 pairs of pliers.
Panda arms (especially the long one) seem to develop a slight twist, causing the blade to judder on a dry screen in one direction.
I would never recommend anyone to twist of bend the arms. You'll probably only makes things worse.
Arms wear. They should be tight on the spindle taper. The flexible hinge near their base wears, and can allow the arm to flex. New arms are the answer. The spring loses tension. Again, new arms needed.
The blade 'trails' across the screen. It lies over a little, so the trailing side of the edge does the wiping. At each end of the sweep it flips as it starts its return journey.
Every time it stops in its 'park' position, the blade is laying one way. Always the same way. Like bending a piece of paper, once bent, it can never be properly straightened, so the blade takes on a 'set', gradually worsening, so resisting this flip. On the upstroke it resists flipping, so the edge tries to dig into the glass surface, which causes the judder.
The time taken to get to this stage varies dependent on sunlight and use, or lack of use.
Two tricks to prolong their life.
1. Occasionally, with the blades parked, push them lightly downwards towards the base of the screen and release. This should flip the blade, ready for the upstroke. This helps to negate the 'set'.
2. With the original style rubbers, they can be removed from the blade frame. Two or three times a year, remove them and turn them around, so the park position is now trying to 'set' them the opposite way. They may judder a little on the way down for a day or so, but generally recover quickly and take longer to judder again. If you've got the aero type blades, they cannot be turned around.
