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I have been working with a ridged portable saw for some time now and have all of the other main tools for my shop and I am looking at table saws now.

I found a Delta Unisaw looks fairly new 7' or so wide for $600. It has a 3 phase motor and for $300 more they are selling a rotary phase converter they say cost $1000.
I have only seen a picture and other than that these two ladies who are selling it dont know much about it.
Seems like a nice saw at a good price. I understand that a 3 phase saw can be worth less than a single phase. If so alot less?
Also I know you can put a single phase motor in the saw I was thinking maybe I could sell the motor and the 3 phase and converter and with that money I get from that
buy a single phase motor.

I am going to have a look at the saw today its a bit of a drive so I guess I have to get it if I like it.

Sound like a good deal? Does anyone have issues with running a saw on a phase converter?
If you have any insight on what I should be looking for in terms of the model of the condition of the saw and motors that would be sweet!

There are also several grizzly saws of the same style single phase 3hp 1023rlx I believe looks like they run about $1500 new.
One guy is selling for $575 and says the motor had to be re-built after he bought it about two years ago.
Delta or grizzly which is the better deal?



Thanks

You could buy an import 3hp VFD for <$150 too. http://shop.ebay.com/i.html?_trkparms=6 ... p=15&_sc=1

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Oh? I wonder if the switch needs to be changed for that?

Those prices are reasonable, not awesome but you also live on the West Coast so maybe machinery fetches more than it does here in the Midwest.

$300 for a rotary phase converter is not bad assuming it's a name brand unit & not someone's home made rig. Rotary phase converters are better than static phase converters but they cost more so don't compare the two. If it's big enough, you can also power other machines off of it.

A variable frequency drive (VFD) is another option like Andy pointed out. If you get a VFD, you will either bypass the saw's original switch and use the VFD's panel to Start/Stop or you may be able to use the saw's switch in conjunction with the VFD. I can help you with this if needed.

I recommend factorymation.com for VFD's. They offer support before & after the sale. This one would work:
http://www.factorymation.com/s.nl/it.A/ ... ategory=32

The other option would be to replace the motor with a single phase motor but this would be expensive. You would have to find a Delta motor because it has a bracket welded to the motor body.

Good luck,
Kevin Looker

_________________
I'm not a luthier.
I'm just a guy who builds guitars in his basement.
It's better than playing golf.

Rotary inverters provide excellent 3phase power, the static converters work, but there is a bit of loss. One of the issues with the rotary is that you may need to turn the converter on, then the saw, two switches, annoying, the static converters go in line and do not have a switch, so they just stay on better.

3 phase is not worth less money wise, but the motors are cheaper to make and will outlast a standard motor. Sometimes with some of the smaller machines there are bargains because home shops don't want to deal with it.

3 phase motors are much like adding cylinders to a car motor you will get more out of a 8 cylinder then a single piston. If you ever rip 8/4 stock you will appreciate the extra juice, if it is just for small stuff, perhaps overkill and you will not notice the benefits.
Rob

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3-Phase is no more powerful than single phase, 3HP single phase is just as powerful as 3HP 3-phase.

3-phase is more efficient because it's like having 3 power lines going the motor. Power = voltage X current so each line only needs to carry 1/3 the current of an equivalent size single phase motor. Less current means smaller gauge power lines which cost less.

Kevin Looker

_________________
I'm not a luthier.
I'm just a guy who builds guitars in his basement.
It's better than playing golf.

Thanks for the clarification Kevin, I am not an engineer, and perhaps should just use the term "juice" to show that I am not being technical here.

In my experience with table saws in various shops is that the efficiency does translate into some benefit in the spinning of the blade, I mean a pound of feathers weighs the same as a pound of lead, but if you were hit on the head with either, there would be a difference.

Personally, offered a choice of either for the same cost, I like 3 phase, IMHO. Perhaps I am just a fan because as I upgraded to 3 phase my shop life got easier, not because of more power, but pro quality tools. It saddens me that ol reliable, my scmi 5hp 3ph shaper sits cold and lonely in storage, poor thing, don't worry, daddy will find a place to plug you in again soon.

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Robert,

I have 3-phase so I can foster parent your shaper if you're worried about it's emotional health. I'm sure it could radius some braces.

Kevin

_________________
I'm not a luthier.
I'm just a guy who builds guitars in his basement.
It's better than playing golf.

As to your question about Derlta vs. Grizzly, from too much experience I consider Grizzly to be garbage. I never learn though! Every few years I buy another Grizzly product, though I don't keep it long. The cheap stuff is O.K., because you obviously know you are buying something cheap, and you get what you pay for. Some years ago I bought a top of the line Grizzly tablesaw. Garbage. I now have a Powermatic. About 4 years ago I bought a top of the line floor drill press. Garbage! I now have a variable speed Delta. The last thing I bought was a 12" carbide insert jointer. It was around $3000.00. It was unuseable as it arrived. It needed $600.00 worth of machine shop work to make the fence useable. Unfortunately I'm still stuck with that one. Spend your money on either new or older better brand name products. At least they are worth fixing if you have a problem. I also don't consider Jet to be any good. I have more stories about those sad purchases. As far as 3 phase goes, I did use a rotary phase converter to run a 36" Northfield band saw for awhile. If you are in a small shop, like I am where almost everything else is single phase, it just is easier to stick with single phase in my opinion. Good luck. It's fun buying tools.

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Rotary converters are great........... You will have to have double the amperage at the connection ......... for instance If you need a 50 amp at a converter for 3 phase 50 amps you will have to have 100 amps of single phase current coming to the connection......... So size your wire appropriately.............. by the way all three legs of 3phase are not the same voltage.........one is called a wild phase....... and their function in a motor is not necessarily as previously posted....

If this saw is one of the older Uni-saws......... there is no comparison to a less expensive Grizzly...........Grizzly does purchase some European equipment and much of this is fine quality ( some of their panel saws....). All makers have various levels of equipment......... You would be better served to compare apple for apple.

Kevin

I just got back from looking at the saw. It has a kill switch in a box that has to be turned on, and then a 10 second wait for the phase converter to spin up, then you can turn the actual saw on.
All that seems like it could grow old fast. Also it seems to have very little use but was purchased in 1990 and has been sitting around for years. When the saw was on it seemed to make allot of noise
with a good deal of vibration which had me worrying if the 5hp motor could take damage just sitting like that for so long. The top as well as the geared components inside the saw had rust as you would expect
if not greased and cleaned from time to time and it seems a bit squeaky. I thought it could be allot of work to take everything apart and lube it up again and it was hard to tell the shape its in when is making all
that noise and vibrating. It did have a nice biesemeyer fence and side table on it and if I had three phase at $600 might be worth a little work. Its a model 34-806.
I didn't even look at the grizzly based Pegasusguitars experience seems like they might need work thats defiantly not worth it.

I'll keep looking, thanks for all of the insight every one its always much appreciated.

FWIW, I was using a friends Delta 10" tilting arbor tablesaw,
with I think it was a 2 horse motor,
and that thing never let me down.
I've heard that model has the same guts as a unisaw,
but lighter base.
Single phase 220v.
More than enough for git-building.
They can be had for around $300 around here.
Now I'm using an old Delta Homecraft 8",
3/4 horse.
No problems with that either, except it would be nice to have a 10" blade.
Old tools rule.
You can fix them.
Keep looking.......

Unisaws are great saws. It could have serious problems or it could be the belts.

If you're into it, you can make a posting on the Old Woodworking Machinery web site, OWWM.org. There a lots of contributors there that know everything about Unisaws and other great machines.

Kevin Looker

_________________
I'm not a luthier.
I'm just a guy who builds guitars in his basement.
It's better than playing golf.