
 this is a special theoretical part in geometrics. We will consider here the method of unfolding 3dsurface areas made from metal sheets  but you can use the method of unfolding, based on the neutral fibre, for any 3dsurface area  even to desing the form of decals.
There are sometimes designing problems to make complicated hollow containers from sheet metals. From math perhaps you can remember the formulas for designing special variants of simple geometric basic solid surfaces (i.e. tubular arcs, Tform tubes, Yform tubes). So you can get the cuttemplates by using this special formulas. Sometimes this formulas are integrated as "variants" in CADprograms. But what is to do, if there are 3dsurface areas, which are total different from that simple variants? If these 3dsurface areas can be divided in triangles (i.e. they are triangulable), you will get these results manually only with large efforts. And just this method you can use now as a program running under AutoCAD. There is only one condition: The hollow container (or the 3dsurface area) must have a clear upper and lower border(3dpoly)line and the crosssections on any heights has to be equal (or linearsimilar); in case of a closed surfaces the welding seam's location and its path must be defined clearly. After choosing the two borderlines and the welding seam in the right way, you can find the cuttings for solidsurfaces, coming from solids, which are penetrating each other.



But there are lots of locksmithes and plumbers, who are no owners of a CADsystem and even there are lots of designers, who dont need a special CADprogram every day. For those people it is quite useful, if they can make a short sketch of the problem  best way is in CAD of course  and send us this problem by mail or eMail. You will get your result witin the next 2 days. The result could be a scaled dimensioned drawing (on paper or disk by mail), a DWG or a DXF (by eMail or disk), or a correctly dimensioned scaled 1:1 drawing on paper up to DIN A 0 (by mail). The prices depend on our efforts, beginning at 50 Euros for one template by eMail. As mentioned, the computation of the unfolded template is based on the neutral fibre. That means: the thickness and the special material properties will not be considered. This program can be used in other industries too: for instance in glass and ceramics.

