At work we are building a machine to roll up sheets of out product (we are currently getting it made rolled, but its expensive and wasteful when shipping)
basicly the priduct is about 1mm thick plastic with dimples on it in a uniform pattern. the dimpes are about the size of a nickle and about 1/2" deep. this isnt important. what is important is the size. the sheets will be comming in various (known) widths from 5' to 14' and the length will be about 60 feet.
we need to quickly, and precisly be able to roll these into tighty packed rolls that are no larger than 11" across (the ones we have prerolled are less than 11" but they are very tight') so basicly the problem should be a simple one
this is the machine the boss built so far. (simplified but overall accurate enough)
the two rollers on the left are machined true and straight, they roll easy, and are each independantly adjustable up and down on each end by about a foot. they provide tension by pressing down on the material as it rolls thru. they are aligned perfectly level with a laser currently.
the 3 middle bars do not roll, they are welded in place, their job is to provide extra tension via friction, and they do this well. they are not adjustable.
the roller on the right is powered by a motor, unimportant. it has a slot in it to feed the material too, so that it can rotate, and drag the material through all the other rollers, and wind itself up under heavy tension.
we can modify this 100% in any way add or change or subtract. but we dont have 60 feet of length to work with to build a long table.
we have tried using guides and other such things, they have not worked at all. the material is under such tension it jsut goes up and over the guides.
the rolls do not wind up with flush ends, they wind up crooked. what i atribute this to, is that the tension is not on the loose end of the material, holding it straight, a degree or 2 at the feed rollers (the two biig ones) will translate into a lot of movment over 60 feet. some how we need to be able to tension and align the material from the far end, or more hopefully, keep the machine compact and have it align itself as it rolls. we want to roll these sheets up in about 1-2 minuteas a piece, and we will have thousands of them to do, so time savings are critical...
have you guys got any ideas? i was thinking that the material might be more easily aligned if it fed from the back of the machine underneath, and up to the feed rollers then thru the machine as i have shown in the image, so it does a soft fold over on itself. if the loose end and the tensioned winding end are ligned up, the whole thing should stay aligned, no?
anyway what are your ideas anyone who is good at problem solving, this should be a simple thing.... but its proving not to be
oh yah, and when we eliminate the feed rollers form the equation and roll the material up it rolls up perfectly flush every time ( the dimples align themselves and it keeps straight) but the rolls end up being huge in width because they are loose.