Unisaw Rebuilding Questions

[Jack Hoying]

Hello,
I just joined to group today after I was doing some searching on the net about the Unisaw and came across some postings from this group. Looks like you are a very active bunch.
I have a relative who works at a pattern shop who asked me the other day if I would like to have a Unisaw that they had in storage for years. It's a 34-450, 3hp, 3phase model, and it has a starter problem. The price was right (free), so I picked it up tonight. The building it was in was damp, so it has some light rust on the top and on some interior parts. I sprayed WD-40 on everything inside and plan to completely dissasemble in the next day or so. Looks like everything is in good condition on the inside and the tilt and raise functions are smooth.

I plan on replacing the motor with a 3hp, 1 phase and I assume I'll need a new started with that. Also will replace the arbor bearings and the belts. I realize this won't be cheap, but along with the saw, I got a Yost and an Emmert pattern maker's vices. I already have one, so I figure I can offset some of the saw expenses by selling them.
My main questions are.
What is the best way to clean up the light rust on the top surface?
I found a new Baldor 3hp for this saw at $345.00. Is that a good price?
Is there a brand name spray paint color that matches the Delta/Rockwell color?
Does anyone know how to date a Delta/Rockwell Unisaw 34-450, Serial #GC 8453?

Thanks in advance for your help.
Jack Hoying
Fort Loramie, Ohio

[David Fried]

The Old Woodworking Machines website has a list of serial
numbers by date:

http://www.owwm.com/Delta/VintageProject/Part1.asp

Your saw appears to from 1974.

Have fun!!!


Dave Fried

[Chris Rosenberger]

That looks like a great saw.

If it is just light rust, then I would use WD40 & steel wool. Get an area wet with WD40 & rub it with the steelwool until the rust is gone.

The price of the new Baldor motor sounds about right.
There is someone on Ebay that has a new Delta starter listed.

I have been using Sherwin-Williams Machinery gray spray paint.
It looks like that should be close from the picture.

You can call Delta for the age of the saw.

[Ernie Hobbs]

regarding the paint- just take something off of your saw with the original color to Lowes or Home Depot and get them to match. Explain what it's for and hopefully they can select an appropriate enamel paint.

[Dev Emch]

Jack...

First of all, you done good! Real Good! Congrats! Got to love that price.

Now, the tips.

1). I use Sherwin Williams Polane Plus. This is a super nice but very difficult industrial paint. Most folks use more normal paint. Lowes has had some Rust-O-Leum INDUSTRIAL ENAMEL paint in spray cans. I used the forrest green and its good stuff. Check to see if they have a gray color.

2). The price of the motor is a going price since it is a Baldor. But you may wish to consider buying a small rotary phase converter instead. I actually prefer three phase to single phase and feel that its a much better motor. But that is your call. Lots of us have phase converters in our garage. Either way, no biggie.

3). You already have a three phase starter. Most likely, your machine is a 230 volt machine right now and not a 440 volt. You can utilize the current starter with a single phase motor. There are a couple of things to check out however.

3-1). The heaters are amperage dependent. Going to single phase will increase the current draw on each leg so the heaters will need to be resized for this. A heater by the way is a bimetal safety fuse/switch that cuts out when you overheat the motor. Its your safety system. Your local motor shop should be able to help you in getting some new heaters for this application.

3-2). In single phase, you will have two wires comming in instead of three. Technically, you only need to run one of these two wires but you can run two of them through the starter contacts. You have three contacts with the three phase starter. Live a little and run both single phase lines through it.

3-3). Check the voltage on the pull in coil and make sure its compatible with what your doing. Pull in coils on many starters can be replaced with appropriate value coils. In your case, the best way to do this is to use a pull in coil of 230 volts. If you use a 110 volt pull in coil, then you either need a control transformer or a dedicated neutral in addition to the other two main power lines and the chasis ground (green/bare) wire.

3-4). The green button operates your start circuit. The red button kills the run circuit. The pull in coil is first energized by the start circuit vis a viz the green button. Once the saw starts up, an aux contact that is mechanically coupled to your three primary starter relay contacts takes electrical power and supplys the pull in coil. This run circuit runs through the red button which is always closed. The green button is always open. So once you release the green button, it goes from a closed state back to its normally open state. But as long as power flows through the closed relay and keeps the pull in coil energized, the saw remains running. When you push the red button, you open the circuit that is supplying the power to the coil and the coil pops open dropping out the relay contacts. That includes the aux contact which has been keeping the saw running.

This method of "mag" starting is used in both three phase machines as well as many single phase machines. Its an industry standard for this type of control circuit.

Hope this helps and best of luck...

[Dale Amidon]

I've got one of these saws also. I paid $25 bucks for it. I've got a static 3 phase converter that allows the 3hp motor to generate approx. 80% of it's power. That's about 2.2hp out of the 3hp motor. works great! you can build one of these fairly easily of buy one for about $100-$200 bucks. That's a lot cheaper than buying a new motor for 3 to 4 times that. Good luck...

[Chip Lindley]

Contrats! You can't get a better DEAL than that! ( unless it was a single-phase motor)! Unless you plan to acquire other 3-phase machines, best to go with single-phase. The 3-phase motor will bring $100 or so on ebay! You can afford to buy the Baldor. It will be an excellent investment.

As for the starter, it perhaps only needs a good cleaning. The contacts in the pushbuttons or in the contactor could be corroded from the damp. As long as the contactor's magnetic coil is not burned out, and the transformer puts out 24V. you are in business! If you are not comfortable delving into 220V electrics, a motor shop can check out the starter for you. The user's and parts manual for your saw is available at OWWM.com. Also the manual for the LVC 3-phase starter.

This is probably *greek* to you at this point, but a little studying up is in order. New bearings and belts and *shine* will make this saw a keeper for all your woodworking career!