Hello Otto,

For a first attempt at a Rack and Pinion of miniscule size and in steel, that's terrific work. I assume you will be hardening the parts to help alleviate wear? 

Just as an aside, what sort of lighting did you use as it does look like it was made of Brass?

If I can add a tip to those wanting to take close up pictures, it is of great help if your digital camera has a 'Macro' or 'Double Macro' feature. It's not an uncommon feature in cameras these days. Occasionally in my work I need to take very, very close up pictures of small insects and a double macro feature lets you get as close as an inch or two from the item being photographed without distortion. Just thought I'd mention it. I am very much a point and click person and not deeply into photography at all. Nearly all my controls on the camera are set on automatic anyway, but you can still add on the macro feature. 

Harry

Frankly, I see no need for hardening of the pinion and rack. Forces are very low as is speed and frequency of operation. It is quite possible that heat treating will do more harm to these small parts than normal operation.