Any suggestions for a decent quality one of the above at a sensible price? Ideally on a 3/8" UNF a couple of inches long but I can die the thread on if not. I'm having a bit of a mare getting a good finish on valves in my B&D valve refacer at the moment and the very rounded off diamond tool might be the reason. I suspect I'm smearing the wheel more than dressing it and the result is lots of chatter on the valve seats.
Also is there much difference in quality between cheap and expensive? A diamond is a diamond after all and I can't imagine some are harder than others. The one I have doesn't seem to have done that much work before ending up looking like a ball bearing though. Ok so it's ten years old but all it has to do is dress a 1/2" thick 5" wheel every few months. I think it was only a few quid from a model making exhibition and maybe has a very crappy diamond in it. Things like camshaft and crankshaft grinders with 1" wide 3 foot diameter wheels must require a huge amount of grit dressing off and I'm sure the dressing tools don't only last 5 minutes. How long do your ones last? I can only use mine dry although wet would perhaps be better if I could rig a coolant feed up.
Final question. Resetting an existing one. I tried on a diamond lap wheel but couldn't touch the diamond in the dressing tool. However my lap wheel is a little plastic impregnated one built in to my engine boring bar and possibly not the right thing at all for dressing another diamond. Anyone succeeded in resetting one and if so how?
-- Dave Baker - Puma Race Engines