Ed and I usually agree pretty close on most things, but we do have different views on a few things. Ed looks at tooling from a commercial aspect, his grinders run 6+ days/wk compared to myself who is a hobbyist.
#1: Steel - some things do need steel, but a well designed and built grinder works good with aluminum (my opinion). There is less weight in the tooling arm (and other parts) for an old feller like myself with a bad back. Aluminum MUST have steel inserts in threaded holes that are used (clamps, etc).
#2: Ed says it all there, he has the experience and I wouldn't think of not agreeing with him.
#3: Steer clear of "non-standard" design elements. Well said and I started a thread a while back about why would anybody use an odd size tooling arm.
#4: aluminum tooling arms - I LOVE them, but remember, I'm the hobbyist, not full time like Ed. Aluminum is less expensive for me since I make my own tooling arms.
#5: Home built vs factory? I've always been a fan of home built, I enjoy building almost as much as making knives. BUT - for the full time knifemaker, I expect the time used to build is going to more than offset the money saved building. You do need a decent drill press to build a grinder. There are plenty of plans on-line for building, and perhaps the easiest to build a good quality grinder from is a modified KMG clone with direct drive. There are a few other mods that help the KMG clone work better also.
#6: Motor hp? I'm sure Ed is right for a commercial shop, but I've been using 2 hp motors for a while and can't imagine needing more hp. BUT - as Ed says, you might grown into the need for a larger motor while starting with a small motor you're limited.
#7: VFD or single speed? The ONLY single speed grinder I can imagine is a dedicated high speed grinder for 5,000 SFPM (and faster) grinding. With only 1 grinder, VFD all the way! Ed and I don't totally agree on the Chinese VFD drives. I've got 3 of them in the shop with good results and a couple more with buddies using them. For grinder use, put VFD in box or good filters over the air inlet and they work just fine for a fraction of the cost. Can't imagine one being easier to setup then the last Chinese VFD I got. It has a very good English manual with only a few pages and only 33 (??) parameters that can be changed, and only 2 or 3 of those actually need changing. For $79.50 shipped and delivered 5 days later - can't beat it. With all that said, for a commercial shop - hands down go with a good NEMA 4X rated VFD. Remember, with a Chinese VFD if it's rated for 3 hp, don't try more than 2 hp for best service.
While the above may sound like I'm not agreeing with Ed, 90% (maybe 99%) I totally agree with Ed, have enjoyed talking with him at Blade, and I have learned LOTS over the years from Ed. I really appreciate the effort Ed spends in sharing his knowledge with the rest of us mere mortals. I'm just putting forth another perspective on grinders.
Ken H>
