So a cheap $40 1X30 vertical like the Harbor Freight or a more expensive 4X36 with disk sander option (like the Ryobi - $100)?  I was thinking about a Grizz or Kalamazoo but then thought for those prices I might as well go bigger. But these cheap ones will have other uses for me... bows, knife handles, etc.

IMO, I would stay away from the HB grinder. If you were only using it on wood it might be ok, but I think metal would be too hard on it. But, if the warranty policy is good on the HB use the hell out of it and return for a new one.

HB will take back anything you have a reciept for , no matter what. Go for it, if you find you need more horsepower or use it more than you thought go bigger and better. I'v egot a grizz and when I can afford it will get a burr king. They are the best, hands down imo.

I wouldn't buy anything with less than a 3/4 hp motor and would stay away from Harbor Freight products.  Buy a grizzly knife grinder and upgrade to a full tilt knife belt grinder later.

It seems like the cheaper ones are all either 1" wide or 4".  The 4" would have better application for me in terms of grinding bow lams and shaping handles.. but probably not very good at all for knives right?  But are the 1" any better?

I'm starting to think I should just go ahead and get a belt sander for my wood applications and just keep going with my files on the blades I guess? And wait until I can afford one made for blades...

A 4x36 combo belt grinder / 6" disc sander is an inexpensive sander that you will still use when you do buy a real knife grinder.  It is useful for flattening scales, putting bevels on bolsters, and even roughing out handles.  Also for roughing up tangs before glueup.
You can get them for around 100 or so.  I have a Delta brand and like it.
Even BETTER, is the Rigid Oscillating belt sander/spindle sander.  I love mine, but they are 200.  It does not have a disc sander but it is useful in it's own ways.
Dan

Too funny ...Wish I would have read this thread before I went out today. First stopped at Lowes debated on the Rigid Oscillating sander...... but cheaped out and went to Harbor Freight and got the  1"X30" vertical. Got home plugged it in and the thing did about 1 RPM..... ( Well for about 1 minute till the smoke came out) So that's what led me here to get some advise...So looks like it's back to Lowes (After I get my $$ from Harbor Freight)

I just ordered a Craftsman 2x42 with disk sander. Supposed to be a little fast... but this thing will be great for flattening lams on my bows when I upgrade.  And I'm modifying the platen (putting in a ceramic layer over the metal)in way that is supposed to dramatically improve the perfomance of this beast.

I'd check out availability of the sanding belts what every you job is. I just got a Kalamazoo 1x42 & love it for knife sharping From Jantz

Trugrit has alot of the good Gator and Zirconia belts and all that for my sander for knife grinding.  But there is no local supply for any belts for this sander... which is a bummer.

look up Hog Abrasives on the web...they have some tremendous prices on the basic grits we all use to create a knife...as does Pop's Knife Supplies.