More speed isn't what you need, more power is. Unless your machine can stand having you push quite firmly. My little 1x30 certainly can't do that, it's a constant balance of pressure and speed. Realistically, it is either spinning far faster than I'd like or about to stall. I don't use it for much of anything these days, but even the 2x42 craftsman grinder has a similar problem. It's a lot more powerful, but it's still a speed demon rather than a power house. Most of us that own them would love to trade speed for torque but with a direct drive setup like that it's just not practical.
Your exact choice of new grinders is up to you, but that's pretty much the only practical option. As a current owner of a 2x42 craftsman who is in the process of upgrading I highly suggest you bypass this machine and go straight to a more capable 2x72, preferably a KMG style machine. That can be a nwg, gib, kmg... any of many machines with similar designs. The Grizzley and Coote machines have similar issues to the smaller machines but are still significantly more capable than the smaller machines. The cost/benefit is simply not as good as the KMG style machines. The better tracking, easier speed adjustment, easier to modify design, ease of changing your point of contact for grinding... It's a heck of a lot easier to switch a kmg style machine from a large contact wheel to a small wheel, to flat platen, to slack belt...
Don't get me wrong, the 2x42 is pretty decent for what it is. Many of us have used it to good effect. The problem is that it's simply a larger and slightly stronger version of what you have, not a complete change in the situation. I'm all but counting the days until my 2x72 arrives. I've actually put all new blade grinding on hold until then.
Remy, I also agree with most of your post except that the Coote Grinder is going to have the speed verses torque problems etc..
As you said, It is a fixed machine but they are a great grinder for the cost, I have a step pulley set up on mine with a 2hp 120v 1750ish RPM motor from early post WWII. It will always have a place in my shop along with my KMG and my Flagship Hardcore grinder.
If you are on a tight budget and need a solid 2 x 72" machine that you can flat grind, hollow grind, and Slack belt with all you need is a couple of pulleys from the Hardware store, some link belt, And really most any old motor of a 1hp or more, You can be turning out some knives very quickly.
This is what I did some 13 plus years ago and in about eighteen months I had sold enough and was able to put aside enough to get my ultra smooth and quiet Hardcore 2 x 72"
The Coote Grinder still has a important place in my shop, I use it for handle sculpting mostly,
The two wheel design is a benefit if you enjoy making convex knives or using it for the sculpting as I said.
If you think vibration is a problem mount the Coote on a 4 x 4" by the tower and this will really take care of it. I learned or better said, Figured out a bunch of ways to use the Coote 2 x 72" for many many uses of knife making so feel free to contact me if you buy one.
I know you were trying to just show the benefits of the 2 x 72 KMG, No Weld, etc grinders .
But it is my understanding that these follow the Bader line of Grinding machines.
Having a center arm, While the Hardcore follows the BurrKing design. Another excellent top line of grinding machines. That are to the right of center.
Most importantly is forget the short belt machines and go with a 2 x 72" of your liking like Ed and Remy
pointed out! You also get the best belt selection in 2 X 72"
Cheers!
Laurence
www.rhinoknives.com/