This is something we do often. Many customers come to us with a gear that is worn out or broken. They do not have a drawing. They do not have a CAD file. They just have the old gear in their hand. We can reverse engineer worn gears with no drawing.
First, we inspect the gear carefully. We measure the outside diameter, inside diameter, length, tooth count, tooth thickness, and tooth profile. If the gear is worn, we look for unworn areas to estimate the original size. We also check the mating part if you have it, because that tells us how the gear is supposed to fit.
Once we have all the measurements, we create a drawing based on what we found. We send that drawing to you for review and approval. This is your chance to check if the design looks right. If we have questions, we will ask before we start cutting metal.
We also check the material. We do a hardness test and sometimes a spark test to identify the steel grade. This helps us choose the right material for the replacement gear.
When you approve the drawing, we make the gear. The new gear will fit and perform like the original when it was new – or better if we improve the design.
We keep a copy of the drawing in our system, so if you ever need the same gear again, we can make it without having to reverse engineer it again.