I just acquired a Singer 155 with SR155 ribber. No way could I get the ribber bed adjusted properly, the ribber feet that I would clamp down on the table top would lift the ribber bed up too high, so that I could not align it to the main bed.
I figured that the clamps that came with the machine were the wrong ones, as they would not lift up the main bed high enough for the ribber to line up properly. I have seen people's posts about heating up the clamps with a blow torch to bend the steel, etc. Lots of extra effort that is not needed.
I cannot afford a new set of clamps, so I just cut some thin wood and made a spacer in order to lift up the main bed a little higher, about 1/4".
Now everything is all lined up beautifully, the ribber hangs properly and sits on the table correctly.
Now, I gotta clear out my stash of that worsted weight stuff. Our knitting group have offered to do 600 scarves, 600 preemie hats, etc for our local hospital charity. So enough messing around, time to get knittin' !!
That is great, glad to see another quick fix for something rather than going through many things that can or cannot be the problem. I am sure to let others know of what you did. Just like most Bond users have to fix or make tools for their machines, we can do things also for the other machines as well. Hope to get back to see what you make with your double bed.