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V/S Drill press 3ph or Single?

jimmysgarage

Cast Iron
Joined
Jul 22, 2008
Location
Portland Oregon
I have a Clausing 20" V/S drill press. It currently has a 1 1/2hp 3ph Dayton motor on it. I purchased this at a decent price as a "project".... Well, you know where this is going.... After having to replace the V/S spindle, then the motor drive pulley ($575 from Clausing), I now find that the motor has a bent shaft. The search goes on for a motor but that proven to be beyond my finances at the moment. A phase convertor has been quoted locally from $500-$700... So I am thinking of buying a Blador for around $450... Single phase. What would I lose by going to 220v single vs 220v 3ph? Can the single phase be wired with a drum switch to reverse the motor for taping? OR should I just spend it all and buy a 3ph with a rotary convertor? Would I be able to run more than one machine from one convertor? (only 1 machine at a time) Thanks for your help....I'm just lost at this point......:willy_nilly:
 
Sure! You could go to single phase. You wouldn't lose anything, and you could use a drum switch. I doubt the Powermatic has any kind of contactors or control circuitry like my Edlund, so you wouldn't lose functionality. Power-wise 1.5 HP is 1.5 HP.

You can do a hell of a lot better on motor price though.

Surpluscenter.com
Ebay
Local motor shop
etc.

I think you can get that thing re-motored with a single-phase motor for $200, tops. Surplus center had a bunch of drum switches a while back for cheap too. You could get a 3-phase motor on it for maybe $50.

You don't need to spend $700 for a phase converter either. You could build a suitable balanced 5HP converter for $200 in parts, if you know where to scrounge. Check out the Fitch Williams converter in the VFD and Transformers forum and scale it down.
 
I converted my drill press from single phase to 3 ph with a VFD. It has been the single biggest upgrade I could have done. I gave away the single phase motor when I was done and will never go back to single phase. The smoothness is uncannny. The torque is much higher than single phase.
 
Jimmy,

If you want instant reverse, for tapping, then you will need a 3 phase motor. You can not plug reverse a single phase motor. You can not plug reverse with a VFD either.

If you eliminate the instant reversing need then you can use a single phase motor or you can use a 3 phase with a VFD. I like the VFD myself as I do not use my drill press for tapping.

Bruce Norton
Kingsport, Tn
 
A Pmech
I sure am a "bargin" finder but Ebay and the like seems to-iffy when it comes to motors. Many seem to charge so much for shipping that buying a motor new from a local dealer is a better buy. I'll try the surplus center and check with them. My press is a Clausing that has a mechanical driver to adjust the speed, so I am unsure what you mean by Powermatic... like you said though, 1.5hp is 1.5hp... Thanks!
 
Jimmy,

If you want instant reverse, for tapping, then you will need a 3 phase motor. You can not plug reverse a single phase motor. You can not plug reverse with a VFD either.

If you eliminate the instant reversing need then you can use a single phase motor or you can use a 3 phase with a VFD. I like the VFD myself as I do not use my drill press for tapping.

Bruce Norton
Kingsport, Tn

Toolnut,

Wouldn't a VFD be redundant with a variable speed drive unit? Perhaps I don't fully understand the benefits of a VFD... What do you mean "plug reverse" vs. "instant reversing"?.. Thank you!
 
Where I work (R&D facility) we have been slowly converting our vari-drives over to VFD driven.

I can't think of the name of the product right now, but I believe they get the kit from High quality tools.

The conversion consists of a 3HP Baldor TEFC motor with bridgport C face bolt pattern and long shaft. The cone pulleys are replaced with two standard pulleys. The factory backgear is retained for low speed (50-500) and direct is used for high speed (500 - 4000). They use a yakasawa drive in this kit also. There is a control box that replaces where the original speed control dial was that has digital spindle speed, Z height, a pot for speed and a three position switch for FWD/REV

There is a scale that is mounted onto the quill this allows for a tapping feature that automaticly reverses the spindle when it reaches a predetermined depth and returns it to foward when you move the quill above Z 0, generally if I am only tapping one hole I will manually turn the FWD/OFF/REV switch. So yes you can auto reverse a VFD when power tapping.

After using this I replaced the Static phase converter box that came with my Mill in my garage and put a Teco FM100 that I purchased for less than a rotary converter.

BTW factory mation http://www.factorymation.com/s.nl/sc.2/category.32/.f
has a FM 50 2hp 1 phase in 3 phase out drive for $145
 
Toolnut,

Wouldn't a VFD be redundant with a variable speed drive unit? Perhaps I don't fully understand the benefits of a VFD... What do you mean "plug reverse" vs. "instant reversing"?.. Thank you!

The advantage is that you get to run a 3 phase motor.

Some of the advantages of a 3 phase motor over a single phase motor are:

- up to 600% more torque
- much smoother
- more energy efficient (if you care about such things)

Once you experience 3 phase smoothness and torque, you will likely never go back to single phase.
 
A Pmech
I sure am a "bargain" finder but Ebay and the like seems to-iffy when it comes to motors.

The number of bad 3 phase motors I have come across over the past 2 years is exactly one and it came in with the owner knowing it had been horribly abused and had burnt and shorted windings.

I have seen maybe 130 motors in the past year. I can say that it is very rare for any motor older than about 10 years of age to have good bearings in it. I have a motor in my shop right now that is about 6 years old and the bearings are gone.

If you have a bearing puller you can change bearings in most motors for about $6.00

That is all that 3 phase motors require for the most part.

I have purchased several 3 phase motors on Ebay ranging in condition from NOS to almost 70 years old and every one of them was good save for bearings. A used 3 phase motor and a new VFD should cost less than a comparable new single phase motor. I agree that shipping is a killer, but maybe you can find something on craigs list that is local. Visit a couple of motor shops in your area. They might have a good used 3 phase motor sitting around that they will sell you for $40.00.
 
Mr. Butler has it covered as far as three phase motors. If the insulation is good, swap bearings and get it back into service.

Most of the motors I buy on Ebay are new. Last year I bought a brand new, still on the shipping skid with the test report 10HP Reliance XT Extreme Duty 1100 RPM three phase motor. List is over 2 grand. I paid about $200 with gas. Judging by it's 400lb weight, I could have scrapped it and made money on the copper! :)

Jimmy, as I recall, the Powermatic brand 20" and the Clausing 20" are the same machine with a different badge, so I tend to interchange the names in my mind. Sorry for the confusion.
 
Just to make it clear, "plug reversing" = "instant reversing" for three phase
motors. Also known as "across the line" reversing.

Basically just throwing a drum switch right from forward to reverse.

On a three phase motor this will cause the rotor to slow, stop, and speed up in
the opposite direction.

On *most* single phase motors the same operation will result in the start
windings never engaging, so the rotor will simply continue on in the same
direction, ie, not reverse at all.

Jim
 
Sure! You could go to single phase. You wouldn't lose anything,

Huh? I wonder why they even bothered to make 3 phase motors? Don't think you have too much knowledge, or you would not have uttered such a statement.
 
Huh? I wonder why they even bothered to make 3 phase motors? Don't think you have too much knowledge, or you would not have uttered such a statement.

Nah, not much. Just been working on three phase aircraft electrical since I was 11, built a couple of phase converters, wired my production shop, etc. I don't claim to be Tesla, but I think I have ahold of the basic principles. ;)

On a lightweight 20" drill press in a home shop, I don't think you're losing anything. How often do you think he's going to need to form tap 20,000 8-32's on a tote full of Aluminum flanges? I'm not thinking very often... If that was the case, he has the wrong drill anyway. It probably isn't fitted with a tapping reverse since he's talking drum switches. On larger taps I'd be using a Tapmatic anyway, in which case the only need for reverse is left-hand drills.

So... For HIS APPLICATION, which is a home hobby shop, I don't see a significant advantage. Unless he intends to purchase further equipment and has the money or the time required to buy new or scrounge one together.
 
Just as a point of order, I've fitted a small VFD to my shop drill press at work.

Three phase baldor motor, and a small (baldor) 120 volt input VFD that voltage
doubles to run the 1/2 hp motor.

And when I tap lots of holes, I use a procunier tapping head. I don't plug reverse the
motor. And I could, we have 'factory' three phase two inches away from the VFD!
At one time I tapped about two hundred 0-80 holes in niobium. That's a tough
nut to crack and I didn't kill a single tap.

The main benefit of running a VFD and 3 phase motor is the ability to change speed
on the fly. Very tasty. The machine was half horse, single phase before I made this
change. Honestly I've never seen any detriment from running single phase motors
on machine tools. No vibration or chatter or any of the items that tend to be
discussed.

Jim
 
Bent Shaft

I would pull the motor and and set up the rotor in my lathe and support the drive end in a steady rest set up on the motor's bearing. Turn down the shaft to remove the bent section and machine a sleeve to fit the turned down section and the drive pulley. The single phase motors will reverse but not like a 3 phase motor. Use a tapping head to drive taps.

JRW
 
Straighten the shaft? It is hardly worth messig with. But if you really wanted to you could press the shaft out of the rotor and either make a new one or straighten it.
 
A Pmech


Thanks for that clarification.... I should have figured it out. I have been looking and looking on C's list and Ebay. Called local shops and the don't sell used. Now having said that, I know I can find one, it just comes down to how much time I want to spend looking or if I want to be using the drill. I only have 4 hours in the shop, 4 days a week. The rest of the time is with my 4 year old daughter, so time is very important right now. I have actually pulled items from dumpsters/trash before and repaired/restored and made money on them. .......I may have the correct info for the motor, if anyone has one let me know....184 frame Baldor#L3603..Local shop quoted $569 or L3514t with conversion plate CB1814T at $425....these are both 1phase....
 








 
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