2x48 vs 2x72 grinder

huntin'monkey said:
It's looking like the difference between the two grinder sizes boils down to physical size (in terms of the space a machine and its belts take up in a shop), longevity and avialability of belts. I knew going into this discuss that 72" belts last longer.
They aren't twice as big as 48" belts though, as some have stated. Their half again as big. So if 48" belts are have to a third as expensive, the longevity issue cancles out. It would mean belt changes more often, a slight annoyance.

A belt twice as big as a 48 would be 96". I'll be putting this into a one-car garage that's mostly filled (my wife would say crammed to the gills) with woodworking tools, so space is definitely a consideration.

Finally, there is the avialabilty factor. As Enzo's most recent post shows, there is decent avialabilty for 48" belts, though not all brands carry all models in 48".
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If space is issue 2x48 Steele Grinder look like very nice grinder . At the and of day longer tool arm will make it 2 x 72 in second . I have 2 x 42 and i like it !
 
Natlek said:
If space is issue 2x48 Steele Grinder look like very nice grinder . At the and of day longer tool arm will make it 2 x 72 in second . I have 2 x 42 and i like it !
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I've thought about that. I think the tool arm size of the 48" is a bit smaller than the 72". The question is how far out can you run the tool arm before it might sag or otherwise mess with stability. You could also make a forward support if that was an issue. I think the platten is a bit shorter, and if so increasing it would help with the extra belt lenght. Don't know if that would be a big issue.
 
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Just a quick comment on the "single phase VFDs".... I wouldn't waste your time (or money). Most of them are PWM controlled and have almost no low end torque, which is most of the point of having a VFD (being able to slow down and still have a useable grinder). A lot of these "single phase speed controllers" are for fractional hp motors, or maybe up to 1hp at the most, which really isn't going to cut it for your average belt grinder. Applications and motor compatibility are pretty limited, and there's really no advantage over using a 3 phase motor with a single to 3 phase VFD. If you shop around, you'll likely be able to find a good 3 phase motor for the same price or cheaper than even a used single phase.

As for the whole size debate, I'm not sure that's really as big of an issue as most people want to make it. If you're mounting your grinder on a work bench, most of the space savings is going to be on the back side of the bench, which is normally against a wall and mostly unused anyway. Tool arms really aren't that much smaller, and practically speaking, you're likely not going to be wishing that the 2 or 3 tool arms you're using were 6 or 8 inches shorter so that you "had more room".

All that said, at the end of the day, any grinder is better than no grinder, and they will all make a knife. Plenty of makers use a 48" belt and have no issues, and plenty of makers get by without variable speed. I used a 3 speed pulley for years and made plenty of great knives on it. I will say that the first time I used a VFD, I wished that I had bought one from the start, but I still had a usable grinder never the less. Buy what you can afford, and if you end up sticking with it, upgrade when you feel it is necessary or convenient.
 
Good points. After looking into it more, I'm definitely off of the VFD+1-phase motor idea.

As far as space goes, every square foot counts in a shop as small an crowded as mine. Spage behind the grinder can definitely be used to store things like belts, especially if they are shorter.

Whichever route I go though, you're right, it's going to be a huge upgrade over the little benchtop wood sander.
 
I know this is thread is kinda old, but I was wondering what you settled on. The new Ameribrade 2x48 came out recently, and if you didn't already find a solution it may offer more than any other 2x48 out there that I've seen. I'm fighting the same indecisions as you, and struggling with that budget vs value equilibrium we all want to hit.
 
The only thing I can really ad to this is, that belt choices today are actually quite comparable between 2x72 and 2x42. I've heard in the past they weren't, but so far I don't think I've been able to find a belt i wanted, but wasn't available for my 2x42.

Plus if you are going to work with high vanadium carbide steels, the diamond micron belts for the 2x42 are considerably cheaper. At least the last time I looked.


All that said. I would rather have a variable speed 2x72, than my single speed 2x42. If you can only get variable speed for a 2x42 I say that is most important, but I honestly think you can find that in your price range for a 2x72.

Edit: I read more, plus double checked the original date this started. You can probably delete this whole comment if you want.
 
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