The compressor I am looking at is a 2 stage Saylor Beall.
Originally I was looking at the 5hp motor compressors as that was the biggest motor I felt I could run. The idea of the 3 phase motor run off a VFD gave me another thought to look at. That would have changed the ballgame a bit on CFM - from 17.3 on the 5hp units I was looking at to 26.9cfmon the 7.5hp units - almost 10cfm more. However, after looking at the VFD's that would run that size motor I think that is too far deep in to "uncharted waters", in my book, and the power supply (service) to run it seems too questionable at this point in my studies to try and wrap my mind around it. So I am back to the 5hp units. That would be the 705 pump (it is a 2 stage, but it has both cylinders in the same casting = it does not have 2 castings, just 2 cylinders in 1). The 707 pump is a 2-casting pump - which is an option on the 5hp, but nets less than 1.5cfm more (18.5 with the 5hp driven 707 pump vs 17.3 with the 5hp driven 705 pump). The last consideration is the tank. Originally I was looking at 60 gallon vertical compressors for reason of floor space taken up more than anything. However, once you're in the threshold of a $3500 compressor there isn't much difference in cost between the tank sizes. The floor space consideration is still a consideration - I will have to chew on that a bit. As far as the original subject of the thread - motors - the 5hp motors are where I am (paired with the 705 pump - 2 stage with 1 casting housing both cylinders). The 60 gallon model would be their VT-735-60 and 80 gallon variant is their VT-735-80 (splash lube, not pressure lube - I don't think I mentioned that elsewhere, but the subject did come up on my original thread on trying to find a compressor).
Originally I was looking at the 5hp motor compressors as that was the biggest motor I felt I could run. The idea of the 3 phase motor run off a VFD gave me another thought to look at. That would have changed the ballgame a bit on CFM - from 17.3 on the 5hp units I was looking at to 26.9cfmon the 7.5hp units - almost 10cfm more. However, after looking at the VFD's that would run that size motor I think that is too far deep in to "uncharted waters", in my book, and the power supply (service) to run it seems too questionable at this point in my studies to try and wrap my mind around it. So I am back to the 5hp units. That would be the 705 pump (it is a 2 stage, but it has both cylinders in the same casting = it does not have 2 castings, just 2 cylinders in 1). The 707 pump is a 2-casting pump - which is an option on the 5hp, but nets less than 1.5cfm more (18.5 with the 5hp driven 707 pump vs 17.3 with the 5hp driven 705 pump). The last consideration is the tank. Originally I was looking at 60 gallon vertical compressors for reason of floor space taken up more than anything. However, once you're in the threshold of a $3500 compressor there isn't much difference in cost between the tank sizes. The floor space consideration is still a consideration - I will have to chew on that a bit. As far as the original subject of the thread - motors - the 5hp motors are where I am (paired with the 705 pump - 2 stage with 1 casting housing both cylinders). The 60 gallon model would be their VT-735-60 and 80 gallon variant is their VT-735-80 (splash lube, not pressure lube - I don't think I mentioned that elsewhere, but the subject did come up on my original thread on trying to find a compressor).
