VFD and Bandsaw

[Factory48]

hey all. I'm looking for a bandsaw for the new shop. I'd like one I can use for wood and metal though the majority of what I'll use it for is metal. There are so many good used (older) machines that are better built, and less expensive than most of the flimsy stuff you see everywhere now. Like most heavy machines that are worth having they are all 3 phase. I have a VFD to convert to 3 phase for my milling machine and my lathe and those work good but I've never seen or used one on a bandsaw before. I'm just wondering if there is anything I should be concerned about? Anyone have experience with this?

thanks!
Lee

 

[Norcal]

With a 3 HP and smaller motor, single phase input drives are pretty reasonably priced & will do well on a BS, going above 3 HP likely means having to derate a drive 50%, for example, a 5 HP motor would need a 10 HP drive, there is more but others can chime in, using a VFD on a bandsaw is quite doable.

I have a Rockwell wood / metal 20" bandsaw that came with a 2 HP motor, had it been 3 phase it would have been easy to add a VFD, as it has a varidrive & a 2-speed gearbox it would not require any speed control through the drive. Now only to find out what lubricant the gearbox requires so I can use it.

 

[Thumper68]

I have a similar saw to Norcal and run it on a VFD with no issues.

 

[Falcon67]

Unless you have a really robust motor on the saw, I'd not use the VFD as a speed control. On my 3 phase mill, about 20 cycles either side of 60 hz is about the practical limit. Not anywhere near enough to slow a saw from 3000 fpm to 100 fpm.

 

[Factory48]

thanks guys. Yeah I really was only planning to use the VFD for the conversion. I would mechanically change the speeds. VFD's are so cheap to install seemed like a no brainer to find a good used 3 phase saw and do it that way. Just wanted to make sure I wasn't missing anything. Thanks for the help!

 

[rsanter]

a VFD on a band saw will be great.
one thing to caution/think about when using a VFD is that you still want to use the step pullies to get close to the speed you want to operate at and use the VFD for more fine tuning.
running a #phase motor at low RPM for an extended period of time can overheat the motor and burn it up.
not for commercial use but there are a couple of home things you can do to help if you plan to run low RPM a lot. add a small box fan like used in the old computer cases to help blow air through the motor would be an easyone

 

[matt_i]

Unless you have a really robust motor on the saw, I'd not use the VFD as a speed control. On my 3 phase mill, about 20 cycles either side of 60 hz is about the practical limit. Not anywhere near enough to slow a saw from 3000 fpm to 100 fpm.

This is my typical advice. You need a greater mechanical reduction in there for metal sawing. It could be more or less a permanent one.