House and Car Key Chain

[Paul Jones]

Frank,

Thank you Frank. Our grand daughter recently received her car driver's license and we wanted to give her a key chain for her car keys. We thought making something homemade and unique would be a wonderful gift for her.

There has been some discussion about knurling at HMT and YouTube. In my experience the best way is to pre-calculate and then machine the ideal basic diameter for the knurl pitch before doing the knurling. There are formulas for this but as they say now "there is an app for this" on your smartphone. I use the phone app "Knurling Calculator" for the Imperial pitch knurls from 12 to 80 TPI. It works perfectly each time. In stainless steel, it takes me only two passes from right to left and then back left to right at 140 RPM and a slow longitudinal power feed with lubricating oil when using a simple scissor-type knurling tool (see http://www.homemadetools.net/forum/k...7860#post24656 ). This method guarantees a perfect knurl every time.

Regards,
Paul