Jump to content

old Rockwell drill 3 phase to single phase


Recommended Posts

I’ve been looking for a drill press for awhile. Got tired of only finding stuff from Taiwan and China. So today I bought an old Rockwell Delta 17-600. I got it pretty cheap because it has a 3 phase motor. It appears to be a dual voltage 220/440- 1 HP motor. I was wondering what the opinions were on the best way to convert this press to single phase. I could supply  either 220 or 110 volt. Or if I should just get a different motor entirely?

 

Everything i find, people get a VFD box and put on them to convert and have variable speed. I will only be drilling steel with it though so I really don’t have much use for variable speed. I would just set it to something pretty slow and leave it. What do y’all think would be my best option for getting it to single phase? I’ll include a pic of the motor plate.  Thanks!7873F8D9-D2FF-48F9-8FCA-56BC9E5CB42D.thumb.jpeg.707b168d215ed7716b1798e030d07e87.jpeg

88B63D51-FC44-4E3D-BE5B-7C63D404AA80.jpeg

Link to post
Share on other sites

My two cents is this: If it were me and I wasn't married to keeping the motor "original" for originality's sake, I'd swap the motor. It's simple enough. Otherwise, @vtfireman85will know what to do.

Link to post
Share on other sites

That is one option or purchase a 1 1/2hp 230V VFD and wire the motor connections for 220V and supply your VFD with your single phase and connect the output of the VFD to your 3 ph motor, the VFD will produce your 3rd phase, look for that ability in the product specs, this size should be relatively inexpensive and give you numerous other abilities 

Link to post
Share on other sites

IMO you have 2 choices, swap the motor or go to a frequency drive. Is it stored in heated space? Frequency drives do not like temperature swings, or super duper cold. They are a good choice for a single piece of equipment probably 1/2 the cost to buy an ebay drive vs the cost of a new baldor motor to replace. You want a 2-3 hp drive to power that 1 hp 1 phase motor from 1ph to 3ph 

Link to post
Share on other sites
3 minutes ago, vtfireman85 said:

IMO you have 2 choices, swap the motor or go to a frequency drive. Is it stored in heated space? Frequency drives do not like temperature swings, or super duper cold. They are a good choice for a single piece of equipment probably 1/2 the cost to buy an ebay drive vs the cost of a new baldor motor to replace. You want a 2-3 hp drive to power that 1 hp 1 phase motor from 1ph to 3ph 

We have a couple of conveyors at work done that way just used on a as needed basis work great

Link to post
Share on other sites

Thanks very much for the replies! The drill press will be in my insulated but not heated shop. Although here in west Texas it would rarely if ever get below freezing in there. So far here is what I have found.34CE1C70-A68D-4CEA-ADCC-59CF81BB4788.thumb.png.8c5dc9e490dd3b7372fb901db561f3c5.png947AD322-9742-4565-B45A-79034F886D66.thumb.png.a706b9b00a31694b82c1042acb5b4ded.pngA285AB69-4676-4909-92A1-962D31A9747E.thumb.png.8e6c94925946be6ca41cb01a9b95acd9.png7D7D525D-1EE6-487B-90FA-39999BF42FE4.thumb.png.a665162a9d07b89feace2b6a43807140.png4F2972C4-7405-4C86-B324-C73CD125B5B6.thumb.png.8391da61f94976caac7d4cc85fdb63f8.pngE24C18F7-1516-441E-98E8-9591BB59DD6B.thumb.png.0aa80e0da7e4d9c8d101268b3c76d5e2.png Do these look like they would work or Does one look like it’d be preferable? They range from about $180-200 for the 2HP to $240 for the 3HP one. Thanks!

Link to post
Share on other sites

That seems like alot of trouble for a 1hp 3 phase motor. 

I'd just put an equivalent 110v single phase motor on, preferably Baldor.

Thx-Ace 

  • Like 1
Link to post
Share on other sites

You can always build or buy a static phase converter. I have built a few. They work fine but your available HP is reduced by about 1/3. Unless you're in a production shop setting, you will be fine. If you have access to some capacitors for cheap, your costs could be next to nothing. Search for "homemade phase converter", there is a lot of info out there. BTW, you can get all of the capacitors you will need from junked out residential air conditioners.  

  • Like 1
Link to post
Share on other sites

I would go with the middle 2 hp, a couple questions, do you know if the 3 ph motor is good? Do you think you will ever but 3 ph equipment again? VFD’s are a great solution for individual pieces of equipment but can start to get pricey if a lot of pieces require them, then phase converters and other things can look more attractive

Link to post
Share on other sites

TUBALCAIN is an old shop teacher with a website he has tried several variable frequency drive systems on different drill presses and all of them were failures because at low speeds the 3 phase systems have very little torque.  He says swap the motor to a single phase or get a phase converter at the normal frequency and use standard mechanical gearing.  You will observe that all of the 3 phase powered lathes milling machines and such always use mechanical gearing.

Link to post
Share on other sites

I really have to agree with HARDTAIL, VFD.  The machines I bought almost ALL the parts for the last 2-3 years I worked for the food/chemical processing equipment company had two DANFOSS VFD's in each machine, they ran 2-3 hp gear motors to power rotary pumps to pump ice cream mix into the freezer and pump ice cream out of the freezer. There was a programmed controller to tell the VFD's exactly what to do since the pump speeds controlled almost everything our machines did. We ran those gearmotors from about 8 hertz to 180 hertz, an armature exploding from over-speeding is an ugly sight, and even with TEFC motors you couldn't run them too slow or they overheat.

   But with the help of one of our EE's, our food lab machine shop hooked a T.B. Woods VFD to a little drill press that had been identified as scrap, but the ability to speed it up or slow it down as well as forward & reverse, and start/stop saved it from a slow boat to China.

  By ALL means, add the VFD,  put the drill press in "A speed", not too fast, not to slow, error to the slow side just a bit.  They are not hard to wire up.

Link to post
Share on other sites

Thank you all very much for the help and replies! I believe my 3 phase motor is good. But that is just going off what the previous owner told me when I bought it. It does roll smooth just turning it. I don’t really plan on having any more 3 phase equipment in the future besides this press. I believe I’ll get a VFD on the way and give it a try. I’ll let everyone know how it turns out and I might have some more questions. Thanks again!

  • Like 1
Link to post
Share on other sites

Being able to vary speed and reverse would be very nice.

I have an old walker turner. Mine has 4 speeds of power down force. The slowest spindle speed is 500 which is pretty fast for larger size drills in steel.  I have drilled some inch holes or better being careful.  I did pick up a 3/4 hp motor and variable drive i havent installed yet. The motor on it is 1 hp now I think so I'm not sure how it will work out. 

I also have an old tool room lathe with 3 phase I haven't figured out how to power yet. Not sure the motor size but maybe some of these options would work for that too?

Link to post
Share on other sites

You didn’t say what the spindle is MT taper?

Some of those old drill presses you could literally watch the big bit turn which was ideal for big holes on hard material, ideally you could have speeds from 100-3000 rpm for all bit sizes in a variety of materials, the key here is torque for those big slow holes, you may have to play with your sheave sizes to set it up to achieve this, 60 hz would match your original pulley speeds exactly, you can see by the specs of that drive it can deliver 400 hz which is getting close to 7 times faster or 7x1725 way too fast so you will have to play with selecting a sheave combo to give you the torque you need for slow speeds

The first drives we had a work 25 years ago would burn up the drive or motor or both if they ran below 30hz or 50% speed for extended periods of time but they have come a long way since then but the motor needs a certain speed to cool or dissipate heat, the beauty of the VFD is you have all your speed control at the tip of your finger forever once it’s setup properly, one more thing they have almost zero tolerance for moisture, buddy fried a couple instantly using coolant on his mill, mount it high and dry

Dr E has some good advice for speed starting points

  • Like 1
Link to post
Share on other sites

About 10 years ago I bought a Bridgeport mill and in order to keep the factory 3PH motor on it, I powered it with a VFD. Even though the Bridgeport is a variable speed machine, I very rarely crank the V/S control on the Bridgeport but use the VFD for the speed I want as it is much handier/quicker.  When I was doing some work on my older step pulley turning lathe, I took the 1PH motor off and installed a 3PH motor so I could control the speed with a VFD to control the speed.

There is a ton of programable settings on most VFD and it took some time studying the manual to figure out how I wanted it setup. Two of the most important settings are the min and max HZ which controls the fast and slow RPM limits.

Link to post
Share on other sites
3 hours ago, hardtail said:

You didn’t say what the spindle is MT taper?

Some of those old drill presses you could literally watch the big bit turn which was ideal for big holes on hard material, ideally you could have speeds from 100-3000 rpm for all bit sizes in a variety of materials, the key here is torque for those big slow holes, you may have to play with your sheave sizes to set it up to achieve this, 60 hz would match your original pulley speeds exactly, you can see by the specs of that drive it can deliver 400 hz which is getting close to 7 times faster or 7x1725 way too fast so you will have to play with selecting a sheave combo to give you the torque you need for slow speeds

The first drives we had a work 25 years ago would burn up the drive or motor or both if they ran below 30hz or 50% speed for extended periods of time but they have come a long way since then but the motor needs a certain speed to cool or dissipate heat, the beauty of the VFD is you have all your speed control at the tip of your finger forever once it’s setup properly, one more thing they have almost zero tolerance for moisture, buddy fried a couple instantly using coolant on his mill, mount it high and dry

Dr E has some good advice for speed starting points

I have dealt with many different brands of drives at the mill we service, pretty much all of them recommend staying within 30-40 percent of rated frequency. That said they have a pair if augers that have been running 24hrs a day, 6 days a week since 2009 at 12hz, i keep telling them is time to fix it, they keep ignoring me, yet the augers keep spinning.... slowly. 
I would think there would be some real value in a VFD on a mill or drill press. 3ph motors are cheap, 3Ph equipment tends to be fractionally less money than 1ph and more widely available.. benefits abound. 

Link to post
Share on other sites

....of little use to you' Mr R".........I brought off Ebay..out of California, a big gear driven drill press  (American ),,,Cost very little, about $120.00  US....shipping to NZ cost 750 $NZ...I repaired the broken cast base...(broken in transit ...sigh )....We are 50 Hertz     down under....240 volt three phase, so I took the motor into the local   "electric motor shop"
", and for $400.00 NZ they rewired the motor....Works a treat...lowest speed is   40 RPM.....just the ticket for thick steel. Very pleased with it......and spec wise......waaaay    ahead of any Gook product, of comprable size...also way cheaper......

Mike

  • Like 1
Link to post
Share on other sites

I got my mill and lathe 25 years ago I used a rotary phase converter you couldn't get the VFDs cheaply then.

It all works like it did from the factory with the stepped pullies and the back gear for slow speeds  

Link to post
Share on other sites

I love information gleaned from this site. Years ago when faced with a 3 phase tool with no source the only solution was a rotary converter or early solid state, which made for me the only choice of buying something cheap and changing to a single phase motor or passing.

My 5 horse compressor was a 3 phase and I bought it so cheap that buying a motor for it was a no brainer. I actually found the motor in a surplus store somewhere and hauled it home on the plane!

  • Like 1
Link to post
Share on other sites

High power single phase ac motors are actually very rare in industry. Essentially every motor on  USN Ships I was on in the 60,70,80's were 440V 60 HZ 3% . The USN uses 440 VAC 400 HZ 3% for power supplies in weapons systems equipment they also have a few 3% 400HZ motors but most of the 400HZ motors were aviation based systems that used a 23,000 rpm motors for blowers. Constant maintenance issues with rotors spinning at that speed.  And a miserable box to be around due to the vacuum cleaner squeal 24/7.      Co-owned a machine shop  for a few years here in Texas, we ran 220 V 3 % but used step up transformers for 440/540 3 phase because the utility only had 220 VAC at 3 phase. A transformer is a friend in voltage conversion.  Our hardware was all old stuff, we did have a PC controlled torrent punch but all motors except the DC servos were 3 phase  and a 30 gallon can of punches. AP 125 CFM 25 HP 220  3 phase (most 3 phase motors are 220/440 switchable) the power share was the oodity was share with a 550 AC 3% motor on the back-gage the motor was 460. Shear imported  from the UK. Mechanical shear not hydraulic or pneumatic. We had a old LINDE 3 phase mig that would 1/2 steel in one pass! I was the technical asset my $ source was a man from Kenya who had a vision of going home to Mombasa one day and running a machine shop.  My pardners Spouse got tired of eating grits and pulled the plug on our enterprise that never made a dime anyway.  I was just along for the ride with nothing except time invested. 

 

Link to post
Share on other sites

The spindle on my drill press is a MT. But right now it has a Jacobs 1/2” chuck on it. Right now my belt is on 1 speed above as slow as it will go. Maybe that will be a good starting point. I will definitely mount the VFD up out of the way of shavings and in the dry. I’ve read they need plenty of airflow if you mount them in a box. Thank you very much for the info on where to set the hz to start out and what to limit it at. I don’t think I will ever need it sped up from factory just would be nice to get it slower. It appears I have the slow speed pulleys on the press which might be nice. I’ve been reading all I can on VFDs to try to learn as much as possible about them. It will be a learning process getting everything set up.I sure appreciate all the comments and help. 

Link to post
Share on other sites
8 hours ago, New Englander said:

I love information gleaned from this site. Years ago when faced with a 3 phase tool with no source the only solution was a rotary converter or early solid state, which made for me the only choice of buying something cheap and changing to a single phase motor or passing.

My 5 horse compressor was a 3 phase and I bought it so cheap that buying a motor for it was a no brainer. I actually found the motor in a surplus store somewhere and hauled it home on the plane!

Depending on the compressor I suppose a VFD would be ok, personally I would change the motor as not to have to run a VFD all the time. Its fine on a milling machine where you use it and then turn it off, certainly a phase converter on an air compressor is an utterly impractical thing. As most of the timE you would be running a big motor just so you can start a smaller motor when it wants to.  Doesn't take long to make a 1ph 5 hp motor worth while. 

  • Like 1
Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...