That is the question. I am a hobbyist who has made knives since the early 90s and a few way before out of necessity. I live in an apt. and have to put my grinder on a big heavy duty cart to take outside. I use a 1x42 with an 8" disc on the side. The disc is great for flattening wood and setting angles. I do my finishing by hand with silicon carbide (SC) wet-dry sandpaper and diamond compound, but that's a conversation for another day. For small knives I'm good with the 1x42, if I go big I use an angle grinder to get my initial bevels and contour. I live on a fixed income and a budget. Because of size constraints I really cannot go bigger than a 2x48 or 2x42. There are not a lot of choices for those two, the best is the Kalamazoo 2x48 at $436 shipping included, it has a 1/2 HP Baldor motor and is good quality and American made. Of the 2x42s available the Palmgren is the best at around $200. Since they both can grind vertical or horizontal and Tru-grit carries a big variety of belts for both one of those two is what I'll go for next.
The 2x72 is the grinder of choice for almost all knifemakers. The Grizzly is hands down the cheapest at less than $600 shipping included from Grizzly. It seems to have tracking problems and needs some tweaking just to warn you and it will need a harder platen before long. Ray and the guys can tell you all about both of those problems. Kalamazoo makes a 2x72 for $730, but it only has the same 1/2 HP motor as the 2x48. You can buy it without the motor for $550 and get a nice 1 HP for $300 or less, just remember it has to be enclosed. Those are the 2 options for less than $1000 for 2x72 and both will need platens that are not mild steel. My Delta came with a mild steel platen, I took a 1"wide piece of 1/8" O1 and put a slot on one end and bent it in a press and Heat treated it and tempered it to about RC61-62 and it has stayed good for a long time. Or you can get a ceramic plate. Also do not forget you can build your own 2x72, USA Knifemakers sell plans for them, plus there are lot of YouTube vids about that.
I know a lot of makers will tell you get the 2x72 and if you have the money that's fine and your 1x30 is OK for wood handle shaping and sharpening and probably with the right belts could make some small knives, but if your belts won't get tight take it back and get a refund or buy their 4x36 with the credit take the 3/4 HP motor off (throw the rest away) buy the 2x48 Kalamazoo without the motor for $280 plus $26 shipping from Jantz supply and put it on that. A powerful 2x48 for less than $400 and the Kalamazoo has a rubber contact wheel and the motor won't get in the way because it will be behind it running it on a pulley.
So there you go, lots of options, but take that defective sander back to HF if nothing else.
