I few months ago I picked up a Delta/Rockwell 14” bandsaw. It was in horrible condition and needed a lot of work. I found the saw on Craigslist, called the seller and made an appt to see and eventually buy the saw. I completed the bandsaw a few weeks ago.
While I was loking at the saw I was talking with the seller and mentioned to him I like to use older equipment and was looking for an old unisaw. He told me to look around the “yard”, the place was a storage facility for a lot of junk. The actual owner of the property used to buy lots at auctions and stored it at this location. Under an awning I spotted an old table saw. I wasnt sure of what it was and asked if I could take a look. I made my way back to it, after crawling over old cars and a boat I found a Delta unisaw. I was told the pile I was crawling through was going to be hauled off for scrap!! Including the saw. I asked the seller of the bandsaw if he would speak with the owner of the “scrap” and ask if I could purchase the saw. A month or so later I recieved a phone call informing me that if I wanted the unisaw to come get it. It was given to me!! This is what I found…...
1968 Model with a 2hp 3ph motor.
Now, I dont know about everyone else here but I dont have 3ph power in my home. That is susally something that is only available in commercial areas. But, there are other ways of running 3ph motors on single phase power. One way is buy or build a phase converter, its kinda costly though. Another way is to buy and install a VFD, variable frequency drive, which was my answer.
I was told that the motor on the saw wasnt any good and would have to be replaced. I kinda took it with a grain of salt, 3ph motors are pretty much bullet proof. I disassembled the motor and replaced the bearings. I didnt see any sign of burnt wires, scoring in the commutator or any thing else that would suggest the motor was bad. New bearings installed I was ready to see if the motor would run. But still no 3ph alternative.
I purchased a VFD, 230V single phase input and 230V 3phase output. Now electricity is a foreign language to me when it comes to this type of thing. Luckily I was able to get some help from fellow LJ, Marcb. I bench wired the VFD and motor, plugged it in and held my breath. When I pushed the start button the motor began to spin, very slowly. I adjusted the VFD as per the instructions and it slowly built up speed, I now have a fully functioning motor!!
I have set the VFD to ramp up the motor speed in .5 seconds and when shut down the decel time is 3 seconds, and the VFD has a built in braking system. Its SWEET!! I will add an auxilary switch to control the VFD when I wire it up to the saw when the restoration is complete.
-- My job is to give my kids things to discuss with their therapist....firstname.lastname@example.org