Thanks, I had missed that thread. Everyone on this forum knows more about locks and keys then I do, but I don’t know how much you guys know about making a model of a part.
If you know all this then consider it info for the new people.
As you probably know measurement is everything. The minimum tool would be a caliper, either dial or digital. It is usually best to build your model the way you think the key would be manufactured. First the full profile (Thickness and width, and length.) Then cut the grooves in the key (if it has them) or cut away stock to produce the shape. This keeps each step small and reminds you to think about how it was made so you don’t draw something that is impossible to make. Also it makes it easier to go back and change things if they done add up.
(Example, you make a slot on one side, then one on the other side, then you measure between them and don’t get the same number as the real key. Time to go back and check everything.
For places to narrow or to small for the calipers you need some junk. For example, to find the depth of a narrow slot, find a piece that will fit in there and stick out some. Drop it in and measure the key + the scrap. Measure the scrap and subtract that.
If you are using digital calipers you can measure your scrap, and zero the caliper, then you will get a direct measurement. For width, find something that will fit nicely and measure that. Shim stock, scrap, business cards, and stuff from the kitchen are all handy.
To measure odd shapes such as the bitting it may be helpful to clamp the key to something so that you have a flat surface parallel with the center of the blank. then you can measure from the flat to the key at a number of points along the key. In general, what I am saying is that it is often helpful to build jigs to help get measurements. These can be very crude and made from scrap.
Once you have a good blank, another technique if your CAD will allow it is to take a picture of the profile you want, and then superimpose that picture on your model and trace.
In the case of the key I modeled I found the radius of each bit, and then took a picture, overlaid my blank and placed the radius on the picture to form the surface.
BTW A set of Radius gauges are handy but if you don’t have them find something that just fits (Scrap, office supplies, or something from the kitchen, and then measure that somethings diameter.
Pictures are also handy to get angles. You can blow up the picture enough to be able to measure it with a protractor. BTW Usually angles in anything that has been machined are even numbers. 15, 22.5, 30, 45, 60, ETC If I measured one at 14 I would assume it is really 15.
Measure measure, then make a jig and measure some more.
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