New Machine comes home! LeBlond Lathe

[oldironcollector]

Well, after looking high and low I finally bought a lathe. It is a LeBlond 15.5 " swing with lots of tooling . Now to get to work on that phase converter!!

Denny

[KeithW]

Nice looking machine. What kind of phase converter are you looking at? I'm about ready to get my mill running and I was thinking of the rotary type.

thx, keithw

[oldironcollector]

From what I understand the rotary is much more efficent than the static type converters and in instances where stalling the machines motor could occur the only way to go is rotary. They are simple and inexpensive creatures to build and that is what I am doing for my machine.

Denny

[KeithW]

Yes, the rotary is more efficient, around 85% vs the 66% for the static. I've got a book that tells how to build your own, but rather than going through all the cut and try involved I'm going to buy a commercial one. About one oops would be all I could afford with my 5HP mill. Just having the motor cleaned, checked out and new bearings installed was about $100. If I burned it up experimenting I think I'd cry . 5hp mill

keithw

[oldironcollector]

Looks like a nice heavy mill! I have all the parts to build one and a friend who has built 20 or 30 of them, some over 15 years in use with no failures so I am not so worried about experimenting! I am just ready to get going .

Denny

[KeithW]

If you don't mind passing along a few details I might get brave and try it. At my own risk, of course. Las Vegas is not real "industrial" but there is a good motor place where I should be able to get the pieces. I actually have 2 5HP mills. My understanding is that a 5HP motor set up as a converter will run them both but only start one at a time. Not that my arms are long enough to push both start buttins at the same time.

keithw

[bdauber101]

I built my own converter, and used a 5hp. 3phase motor , I run my bridgeport and 3hp pratt witney lathe at the same time with no proublem. great things to have when restoreing engines , bdauber101

[Jim Tremble]

Originally Posted by KeithW

If you don't mind passing along a few details I might get brave and try it. At my own risk, of course. Las Vegas is not real "industrial" but there is a good motor place where I should be able to get the pieces. I actually have 2 5HP mills. My understanding is that a 5HP motor set up as a converter will run them both but only start one at a time. Not that my arms are long enough to push both start buttins at the same time.

keithw

Keith

You will have to go 50% larger on the converter motor. ie: 7.5 HP to run a 5 HP motor.

The setup is easy. I think I have a photo of the wireing. I will check. Also, check the archives. that photo has been posted before.

Jim

[John Newman, Jr.]

Gentlemen,
First off, I am no electrician!
I have a Bridgeport mill and use a small static converter to get 3ph to run it. Some time back I had (but have since sold it) a big old (VERY old) lathe with a 7hp 3ph motor in it. The static converter does just fine for the mill, but of course would not start the lathe. However, at the time I wired the lathe 'piggy-back' with the mill and by simply starting the mill motor and letting it run with no load, I could then start and use the lathe without any apparent problems - the overload never kicked off in the converter. Someone once told me that a running 3ph motor will produce more '3rd leg' than it uses if the motor is not under a load. Is this fact? Bull? Old Wives Tale? Was I , or my equipment, at any risk? Or was I simply using the mill motor as a rotary converter? Since I no longer have this old lathe, the issue is rather moot, but I have always wondered if this was a workable solution.
Thanks,
John Newman, Jr.
Saint Louis, MO

[KeithW]

You were indeed using the mill motor as a rotary converter. A rotary converter is basicly a static converter running a motor under no load. Due to the counter emf and other such magic the third leg gets generated by the motor. One problem is that with true 3 phase the three legs are 120 degrees out of phase. With the converter two legs are 180 out and the third is somewhere between depending on load. Not ideal thus the lower efficiency but not bad and lots less expensive than getting real 3 phase installed. I actually have real 3 phase 20 feet from my shop on the pole and it will be lots cheaper to get single installed and run a converter.

keithw

[Richard W.]

Here are some links to building phase converters. A friend of mine has a LeBlond lathe a little newer than yours. His has the hydroshift with electric spindle brake. He built a 15 hp phase converter for his machines. He seems to have all 3 phase equipment.


http://www.metalwebnews.com/electric.html


Richard W.

[oldironcollector]

Thanks for all the input guys, I have put together the converter and fired it up and it all works, only trouble is I did'nt use a start circuit on the converter and you have to give the motor a spin on start up to get it going. Blew quite a few fuses at first for the simple fact that all the fused circuits were fused with lower amp fuses because the lathe was originally 440 volt. We are all set now though. I may add the start caps and circuitry to the converter to make it easier to go. As a foot note I have 3 phase at the street but for them to setup a transformer bank and run it to the house is $10,000 plus a monthly surcharge for having the 3 phase power. The power company said what I needed was a delta 3 phase arrangement. I guess me and the converter will be spending many a long night together

Denny

[ListerDiesel]

Originally Posted by oldironcollector

Well, after looking high and low I finally bought a lathe. It is a LeBlond 15.5 " swing with lots of tooling . Now to get to work on that phase converter!! Denny

That looks nice!

Once you start using it in anger you'll wonder how you managed without it.

We've got some old iron in the workshop, a couple of Ward capstan lathes and the Beaver mill which I mentioned somewhere else last week.

We had 3-phase (440/230) put in when we moved here 18 years ago, best £200 ($350.00) we ever spent. Put in the new distribution board ourselves and laid the cable ducting for the utility to come and wire us up.

Couldn't do it now as they have 'funny' reg's about 3-phase in domestic dwellings!!

Peter

[Randy Hart]

Denny, Don't worry about your rotary.. I have one that I put together back in 1980 and it has been a faithful worker in the shop.. No motor problems.
One thing you must watch with a home spun rotary* unless you have magnetic starters kicking in your 220v a sudden power loss or flicker of power could drop your rotary speed enough to not start back up and it will pop a fuse or worse! My policy is, if I'm not in the shop within reach of the switch, the rotary is OFF.

When I set up the new shop I plan to use magnetic starters for the 220v and that will solve the problem.. Good luck ! Randy Hart Ohio

[Rick Strobel]

I think that you'll find this website interesting. Curt has very high quality control so you can take it to the bank. Interesting is the fact that he uses a clamp on ammeter to indicate and then balances the load on the phases.

http://www.oldengine.org/members/hol.../rotophase.htm


Have a good'un
RickinMt.