I bought a Hitachi 12V router about a year ago. I removed the plunger springs and mounted it in the side table of my Unisaw. I installed the Height Adjustment Knob that came with it as a bonus. After about four or five times laying the router on its side to remove the bit, the knob broke in half. Actually the whole knob broke off about half way down the shaft, where the plastic joins the metal. I have been using half of a Height Adjustment Knob for some time now.
The other day, I looked up Hitachi on the web and sent them an email telling them in a pleasant way my disappointment in the quality of their "Knob". I really didn't expect to hear anything back from them. To my pleasant surprise, yesterday FedEx dropped off a package to me containing a brand new Height Adjustment Knob. These things are $24.99 at Amazon. (Amazon.com product link shortened)"8013
Apparently Hitachi has had a lot of problems with the knob shaft breaking because the new one's shaft is solid metal. I imagine it is much more substantial than the old design. I am very pleased with Hitachi's customer support. Thank you Hitachi.
Gary in Virginia