Well I got them home today and found that they are both 3 phase. David-- can you tell me all about your VFD. My lathe has one, but where do I buy one and how to set it up. Thanks. Sam
Well I got them home today and found that they are both 3 phase. David-- can you tell me all about your VFD. My lathe has one, but where do I buy one and how to set it up. Thanks. Sam
I have one, too. Thats my avitar.
John
My question is more along set up and even hook up of the VFD
I replaced the huge heavy 3 ph. motor with a 3/4 hp 3450 rpm motor that runs on 120 volts. It spins a 7 1/4" blade at about 4400 rpms with plenty of power.
John
You can easily replace the motor and pulley but I like the old large frame cast iron motors. I would run the two hot legs to the motor box and then into the existing toggle switch- it should be a three pole and you can just use two. From the toggle you go to the vfd so it has a shut off to power it on and off. From the vfd you go back to the motor with the three legs and ground and connect directly to the motor leads. You can get more advanced if you want the vfd start stop to be remotely located. I just used an enclosure without a door to keep the saw dust out and use the buttons on the unit. It is the buttons on the vfd that control the saw. the toggle just fires up the vfd. I would recommend an additional brake resistor for the vfd so you can stop the blade quickly. A regular vfd will be overpowered by the mass of the blade and fault if you adjust the stop time too short. the additional braking capability only costs about $50 and is worth it. Dave
David. Excellent. Thank you. Yea I like the idea of keeping the big heavy motor for weight and stability of the saw. Can you tell me what brand VFD you got and where
I had an old one from somewhere. Factorymation and driveswarehouse get good reviews over at owwm.org and you can specify the brake resistor. You can check prices online. Jack Forsberg over on canadianwoodworking. com also sells vfds. I have his email if you pm me. Dave
I have a flock of VFD's in the shop along with a RPC. Either a Teco FM50 or an Automation Direct would work fine.
IMO you won't gain anything with a VFD other than added complexity and something else to fail. My Hammond has a single phase Baldor 1 1/2 HP 3450 motor which makes it easy to get the proper SFPM on the blade. Used single phase quality motors in the 3/4 to 1 1/2 hp range can be had for less than $50.
Larry
If you find a cheap single phase motor, go for it. The existing switch can be used. Just save the old motor so you can sell it with the machine later. Original usually increases the price. If I were replacing with a 3450 rpm, I'd go 2 hp as it will have the same torque as the existing 1750 1 hp on the saw now. That will handle hardwood to about 2" just fine. I would not want less though. Bogging down a saw never goes well. Dave
If I was to replace the motor. Please give me what frame motor I should buy. I'm looking on eBay. I typed in 3/4 3450 motor. What exactly should I get.
You are unlikely to find an exact fit for the mounting but look at the frame size on the existing motor. If post 1964 it will be a current designation. frame nomenaclature changed in 1952 and 1964. 3/4 hp is too small. As I posted earlier, it will take a 2 hp 3450 rpm motor to equal the 1 hp 1750 you have now. No reason to go smaller. Dave
PS. the motor swap is easier long term but not necessarily cheaper or easier up front. The new motor needs to have the same shaft diameter and length to accomodate the existing double pulleys. If not, you are shanging them and the belts. A vfd costs less than $200 including the brake resistor. I doubt you can do a motor swap for that unless you get really lucky. Shipping alone for a motor and sheaves adds costs.
Last edited by David Kumm; 03-28-2017 at 10:27 AM.
Even with having a full sized sliding saw, I could see grabbing one of these if I stumbled on one at the "right price" to keep tucked in the shop for quick utility. It seems fairly compact and is presumably accurate.
--
The most expensive tool is the one you buy "cheaply" and often...
At the time that saw was new, V belts didn't have the strength that they have today. You can run 1 1/2 HP with a single belt, so you don't have to keep the double sheave pulley.
I used a piece of plywood to make a motor mount adaptor mockup. It worked well enough I painted it and left it on. Never a problem with it or the single belt.
John
Here are a couple of pictures of my motor swap. Also a shot of how I mount 7 1/4" saw blades. If you don't countersink the screws and raise the blade too high, you will break the screw heads off on the bottom of the table.
John