Roy, as I stated before, the bandsaw I have at work runs almost 100% of the
time at 125 FPM blade speed, with an 18 tooth blade on it for metal cutting.
When we need to cut a 2x4 or a small piece of plywood, Lexan or other, we
rarely change anything, and have found this to be satisfactory. We used to
spend more time changing blades than cutting.. For more extensive work, we
do make changes, of course. One of the saws I have at home has a reduction
gearbox off of a conveyor system, with sprocket drive to the bandsaw for
fine speed tuning and best motor placement. I switched out the 3 phase NEMA
C face motor with a single phase motor I had laying around by just extending
the through studs from the motor into the motor mounting holes in the
gearbox, and double-nutted the studs to the gearbox, since my motor was a
base mount type, and not a C face. C face motors just stab into the gearbox
and bolt up, anyway. The motor and gearbox was mounted so the motor hangs
vertically to reduce mounting stresses. If you don't feel the need to change
speeds, this is a very economical way to go. These gearboxes are all over
most industrial salvage yards and very economical, because the average guy
sees the 3 phase motor and walks away.

RJ

"Roy" wrote in message
...
On Wed, 31 Dec 2003 23:14:35 -0500, Artemia Salina
wrote:

===As you know, the import bandsaws use a worm and wheel for speed
===reduction. Is fabricating something like that out of the question?
===Actually, I guess it would be difficult to switch it in and out of
===the drive train to move between metal and wood cutting speeds.
===
===Did you abandon the DC motor because you got sidetracked with the
===VFD idea? The DC motor sounds like the most viable set up to me.
===Have you done any tests with it to see if it loses torque at low
===RPMs?
The DC motor I have is rated on the data plate at 5100 rpm, and to
bring that down to a useable rpm with a gear reducer and jack shaft is
really not a feasible idea once I started to think about it. I would
have to get that motor down around 1400 to 1700 rpm for most gear
reducers, so I am already at a pretty low rate of speed and power with
the DC motor I have. A 1745 or 1800 rpm ( or even lower rpm) motor
puts me in that range already at a much higher torque , and reducing
that down or through a gear reducer seems more feasible, espeically if
coupled to a VFD.

I really do not know, but I don;t want to do and undo something as I
would rather do it right to start if its possible. I am figuring
(actually guessing) I should be able to use a 2 hp VFD, with a gear
reducer of 40 or 60:1 and a jackshaft to get the speeds and torque
that would be satisfactory, but even my guessing is just an uneducated
shot in the dark! I just do not have any faith in a used treadmill
motor on something such as this.

Making a worm gear setup is beyond my capabilites. I guess I would be
happy to just use it for metal as thats my main concern, as I am not
into doing any real woodworking per se, and I imagine it would cut
wood to some degree with a wood cutting type blade.
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