Ok, strange question here. My father-in-law picked up a slightly used 14' slide out topper while in Florida this winter for our 5th wheel. Only problem is the slide out is just 12'. Can you take apart one end and cut it down to a shorter length (12') without destroying it? It's an A&E brand if that helps.
Of course you can. Just take the fabric off, cut it and sew (or have a fabric shop sew) a seam on it. You will have to cut the tube to fit the slide and reassemble it but it can be done with a little ingenuity.
1994 Ford F250/7.5L/410 gears
2001 Keystone Sprinter 276RLS 14' slide
Make sure you have all the "pieces and parts" to attach the topper to the slide before starting this job. There are special mounting brackets and stand-offs required at each end. No sense in shortening it, only to discover that it can't be mounted.
With all that said, it is possible to shorten the tube and fabric, but it's questionable if it's worth the effort. Be very careful when working with the springs. Release the tension slowly and count the turns.
Thanks for the quick repsonses. Like you said it's the springs that make me nervous. I have all the mounting brackets and other parts for it. From just taking a quick look it seems fairly simply as long as I can get the tension spring back like it should be. As far as "is it worth it" they are free to me so yes it's worth a little time and trouble. He also picked up a 6' for my front slide out that fits fine. So I think I came out pretty good since the last estimate to buy them new and have them installed was around $800 and they gave these to us for free!
I just had my slide topper off working on it. I don't see any problem in shortening the awning. Sewing a seam on the fabric would be the biggest thing. There are two springs if it is an A&E. The inside ends slide on three ribs inside the tube, so that is no problem. The torsion on the springs is 13 turns. One turns clockwise and the other counter clockwise. Grind the pop rivits and punch them out of the wheel. I used bolts and nuts when replacing.
To shorten, Take it apart and cut off X amount off of the tube and then cut off X amount (minus 1") off of the cover. Before you cut the cover pull both of the splines back out of the hem enough that you wont be cutting them. Fold the hem (of the cut edge)over 1" and then sew it (I put two rows of stitching), now the topper has a finished length equal to X. Reinstall the splines. Mount the assembly onto your rig according to A&E specifications.