My scissors blind tends to let it slide up also, especially on roads that aren’t particularly smooth. I really have to crank on the knob to get it to stay put, and it was that way when the coach was brand new. Fiddling with it while trying to drive is no picnic, so I often just rely on my Cocoon wrap-around sunglasses to cut that side glare. Fred’s suggestion is a good idea, and I haven’t checked the top as Eric mentions, as it’s harder to get at.
But I was thinking of trying a rubber washer on one side or the other of the curve-slotted plate where the knob bolts through, like Fred mentioned except with rubber. Or maybe an O-ring. On some friction-dependent devices I’ve done that, because the rubber tends to grab metal better, especially when compressed. The O-ring or washer should have a hole close to the bolt size or it can be too floppy to work right, and a washer with a wider outside diameter proffers more surface to grab and hold.
As noted though, I haven’t tried it yet myself, so consider it a theory based on other experience. Too much washer, or a washer on both sides of the plate, may result in the opposite problem... the shade not moving easily up or down. Just the right balance of rubber size would need ferreting out.
Joel
