I needed a d-roller and found little information on how to build one. After some experimentation, this solution seems to work very well for me.
Materials
1) 1.125-inch diameter wooden dowel, 24 inches long or greater.
2) 1 sheet of fairly stiff mylar. Dimension is 24x40 inches. (sorry, I dont know the thickness - but in general terms, the mylar seems to be about twice the thickness of Epson Premium Luster).
3) 2-inch wide Gaffer's tape (basically a high quality duct tape) 23 inches long
4) Kraft brown wrapping paper 20x30 inches.
Construction
1) Tape one of the 24-inch sides of the mylar to the dowel. Be neat so that there are no wrinkles in the tape. That's it.
Procedure
It may help to watch the review video that Michael Reichmann made for the D-roller. The procedure is pretty much the same.
1) You will need to lay the mylar and dowel on a smooth, clean, sturdy flat surface. This is important.
2) Lay the print flat on the mylar (with the curl facing down). Line up the edge of the print about 4 inches away from the dowel.
3) Place the brown wrapping paper over the print, with the edge of the wrapping paper about 1 inch from the dowel.
4)Commence rolling. Again, watch the Michael Reichmann video for proper technique, but basically roll it tight and keep it tight. Unroll it carefully, and you will have a de-curled print.
5) It may be necessary to rotate the print 180 degrees and repeat the procedure to get the curl out of the other end.
Final comments:
I have used it successfully on prints up to 16x22 on Epson Premium Luster. I have not used it on any other paper type. If you build this, then you may want to try your technique first on a non-critical print.
A word of caution
If the mylar is not stiff enough, or if the print is placed too close to the dowel, the print may end up with light creases every 3-4 inches (pi*diameter of dowel). The technique described above has worked for me without any visible blemishes.
Also, make sure the flat support surface and the mylar stays clean. Any debris in the system will indent the print.