Dc motor swap in south bend 16 lathe, pressurized bearings. - Page 2
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  1. #21
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    given how many people strip out 10EE DC motor generator set ups and replace them with 3ph+VFD, I think your idea of fun might be different to most other people. It's your lathe and you can do with it as you wish, but I think you're nuts for taking out a functioning 3ph motor and replacing it with a DIY DC set up instead of installing a $200 VFD.

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    Quote Originally Posted by Homebrewblob View Post
    This is why I started the thread, input and I appreciate it.

    I might be unnaturally attracted to a dc motor for some reason.

    I completely agree I will still have to change “gears” still but I hope to lesson that, consistent surface speed is a VERY attractive thing to me

    Does a vfd on a 3p motor allow constant speed under load?

    Vfd is the cheaper route for sure, I was attracted to the wide speed range of a 3600rpm dc motor, I know power drops off at an exponential rate, I’m pretty Content with my SB16 in general and it fulfills ALL of my lathe needs so far.

    I think I’m looking at it as a (my) life time tool, i wish to learn scraping in my future and hope to invest in the lathe over my lifetime, if possible I would maintain this girl until I’m dead.

    My plans of grandeur are variable speed dc drive, 3 axis DRO, full restore.

    I won’t get any of this money back from it in terms of resale and I’m not a shop so I don’t plan to “grow”.

    Like I said it’s a fun pet project, do you think a 2hp dc motor is good enough (assuming reasonable gearing) or do you think I should (like Tex suggested) go for a significant over size to “widen” the usable power band range?

    Do you guys see any issues running 5HP through a SB16? I feel like that might start tweaking things like (god forbid) castings.

    I truly mean it when I say I enjoy over complicating my stuff!

    And I find it strangely attractive to have a 50’s lathe to “upgrade”

    I think I’m the guy who plays a first person shooter video game and completely upgrades the pistol they give you at the start and keeps it until the end.


    Now you want to hear some CRAZY thoughts!?

    Ball bearing headstock mod and 3k spindle… now that’s going overboard lmao
    Not if you also run a salvaged Hendey tie-bar's brute-massive BED under the Iron-Deficieny-anemic South Bent, it ain't.

    By which point? You may as well graft on a better HS than either to a Frankenlathe as well. There's a Japanese maker as did large-bore and damned fine bearings.

    Some say a monotreme . such as a duck-billed platypus - is only a beaver designed by a committee of Ferry Porsche, Willy Messerschmidt, and the Devil, assembly contracted to Kelly Johnson's "skunk works" for Swedish-suana-soap formula reduction of body-odour.. and Western Electric phased- array ability to hunt prawns in muddy water by homing on their nervous system impulses with ampulae de lorenzini.



    "There was an old lady who swallowed a fly..."

    No point in suggesting you "make chips". Yer likely to take-up a cold chisel and the next thing we know great slivers of jerusalem artichoke, Semolina and Farina spaghetti-noodle are flung off that SB's bed at the rate of a Pickens, West Virginia alienanomaly blizzard.

    20 foot drifts on a day the same storm front drops but 3 or 4 inches on Morgantown or Pitttsburgh. Pickins - where we had kin that G'Dad claimed usta raise a great deal of poultry until the chikn's et it all up, is just up the 2-lane from Helvetica, WBGVA where Swiss cheese is made by genuine Swiss, many of whom even speak English, WBGVA's "Montani Semper Liberi" language dialects being near as much Swiss-German influenced as Scottish. Go figure they never heard of Caerphilly, Wensleydale, or Cheddar?

    If I owned a South Bent? I'd peddle it so fast as to make Burt Munro look as if his "world's fastest Indian" was but a birdturd-blessed cigar-store statue set in concrete!

    Last edited by thermite; 05-07-2021 at 12:31 AM.

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  5. #23
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    Quote Originally Posted by mattthemuppet View Post
    given how many people strip out 10EE DC motor generator set ups and replace them with 3ph+VFD, I think your idea of fun might be different to most other people. It's your lathe and you can do with it as you wish, but I think you're nuts for taking out a functioning 3ph motor and replacing it with a DIY DC set up instead of installing a $200 VFD.
    Isnt that a large complicated 3 motor setup?
    If Iím correct I believe itís common to gut all that and install a single dc motor with controller (similar to what Iím doing).

    Yeah this is strictly a personal decision not a logical one

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    I'm having trouble following this thread, might be the whiskey...I have a pallet full of boxed 3 ph motors in my storage yard that got yanked out of somewhere. They dont look new but they look good. I recall that they have no type of mount plate but no other details come to mind. IIRC they are Lawson or Leeson maybe? Let me know if you have any interest or want more details? I would give you one but the shipping that you pay might be cost prohibitive.

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    We have a SB 14.5 with think 2 hp 3 phase motor, have eaten since we cared...

    Picked up an Allen Bradley 3 HP vfd for $200.00 on eBay and some supporting parts like housing, pilot light and switches.

    Modifies the drum switch to be 3PDP independent with one making sooner for STOP and the result is drum switch controls same as the original and with a separate pot we have plenty of variation in speed from well above stock to MPR in back gear with plenty of torque.

    Converting to DC as Thermite explains sounds like s great option but the drive likely cost more than lathe is worth and result not much improvement.

    All of our add on are in a sub frame that bolts to the chip tray bolts and ends of the leg bolts, can remove and make stock in short order if needed and value of machine far exceeds the investment.

    Use the motor you have and get a good quality VFD

    Sent from my SAMSUNG-SM-G930A using Tapatalk

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  10. #26
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    Bill to be honest I just really like southbends,


    Like ALOT.

    I grew up as a kid and the only lathe I knew of or heard of was a south bend, so many love beepees even tho they are on the light side of the very mill world, I love southbends look and feel, I think they are just so perfectly era correct.

    And when I got my 10L I loved it but she was too far gone, this SB16 is in REALLY good shape, has no signs of ever being crashed, my compound is flawless, the paint is just so ugly.

    And that all plays back into my goals, I guess I just want to update the ole girl, logical or not.

    If I’m being honest I’d rather a SB16 then a 10EE, I just don’t have the skill nor environment to even get near harnessing the abilities of a 10EE, I don’t want to reach the peak of machining either.

    I’m quite content on staying at this lever (improving my hand skills of course) for the rest of my life, I have some experience with dc motors and prefer them over AC in an application like this.

    Replace the headstock!? Hell no! I love the flat belt old shit!

    I can’t wait for my son to be old enough to tinker with it with me, he’ll be dumbfounded that such a machine would have a LEATHER belt powering it!

    He will think belts are for pants not machines!

    By the time he’s 22 these beasts will be nearing 90years old.

    Although I suspect by that time tech will make these FAR obsolete.


    “Wow dad you have to actually turn the knobs yourself?
    The 27 axis table top monarch 1000EEE in moms kitchen can make cookies and then print out a 2 stroke engine ready to run!”

    Yeah son but this is how men did it back in the day.

    “The SB16 is sooooooooo slow though dad!”

    Not all things are a race son, sometimes you rather run from the finish line instead of crossing it.

    I don’t plan to ever get into machining past a lathe/mill, my dream garage is almost complete and I’m only 28 so I’m gonna try to speed my years enjoying life.

    And I like the idea of a “tricked out” southbend as long as it looks mostly original.

    Hide the DRO on the wall so it looks seprate, hide anything that don’t belong in 1957

  11. #27
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    Quote Originally Posted by thermite View Post

    If I owned a South Bent? I'd peddle it so fast as to make Burt Monro look as if his "world's fastest Indian" was but a birdturd-blessed cigar-store statue.

    I'd argue that a bit. Atleast as far as South Bend 16". Not as heavy as a Pacemaker 16", or a Monarch 16". But they have enough weight to be fairly rigid and smooth operating.

    Now all sorts of varibles for each guy. Budget, floor space,. . . is it the only lathe ? But a SB 16 is pretty handy to have for "general" stuff.

    The true upside is simplicity and ease of use. Even with something broken, you could be up and running is short order at a lower cost.

    I seem to recall you mentioning that with two lathes out of service, you need to hang on for dear life to what is operational. Which is where a simple, easy South Bend would fill a nice role while working on those projects.

    Now Homebrewblob is about to turn the "simple" part upside down. But I'm fond of cool and interesting projects. I might recommend a second lathe on hand though. . . you just never know.

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    Quote Originally Posted by Kevin T View Post
    I'm having trouble following this thread, might be the whiskey...I have a pallet full of boxed 3 ph motors in my storage yard that got yanked out of somewhere. They dont look new but they look good. I recall that they have no type of mount plate but no other details come to mind. IIRC they are Lawson or Leeson maybe? Let me know if you have any interest or want more details? I would give you one but the shipping that you pay might be cost prohibitive.
    Kevin my friend thanks for stopping by, you, monarchist, SLK001 and Texasgunsmith are the first guys to welcome me here and help answer my first questions, can’t forget you guys!

    I’m talking about swapping my AC 1800rpm 3p 2hp motor for a 3600rpm 2/2+ hp DC motor.

    You don’t recall but I once said in my old thread I’m a “smash an ant with a sledgehammer” kinda guy and I don’t have plans to replace this lathe (unless I destroy it ) I’m going to install a DRO and restore the beast in due time but for now I’m working my way there.

    I plan to get into Richards scraping class to help my in my future endeavors!

    Any input is much appreciated

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    And Bill I’m THOROUGHLY enjoying your reply! It’s good to laugh.


    And DAMN IT BOYS IM FREAKING DOING IT!

    DONT TRY TO STOP ME OR I MIGHT GET CRAZY!




    “No point in suggesting you "make chips". Yer likely to take-up a cold chisel and the next thing we know great slivers of jerusalem artichoke, Semolina and Farina spaghetti-noodle are flung off that SB's bed at the rate of a Pickens, West Virginia alienanomaly blizzard.”

    Like this gold here!

    Had me laughing my ass off. Keep it coming good sir

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    Texasgunsmith I only have room for one lathe and the 16 fills EVERY inch!

    I love that I have a ďbigĒ southbend and just enjoy looking at the damn thing!

    I donít plan to rip it apart for a rebuild for a long time but Iím gonna see how I like the dc motor drive!, it cuts parts WELL within my requirements and skill, one day I hope to put wings on the damn thing and fly it, gonna call it Lead-Zepplin

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  18. #31
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    I do have a spare 5hp horizontal shaft Honda motor…

    No! Homebrew stop it! The dc is what we’re doing don’t be dumb!

  19. #32
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    Quote Originally Posted by mattthemuppet View Post
    given how many people strip out 10EE DC motor generator set ups and replace them with 3ph+VFD, I think your idea of fun might be different to most other people. It's your lathe and you can do with it as you wish, but I think you're nuts for taking out a functioning 3ph motor and replacing it with a DIY DC set up instead of installing a $200 VFD.
    True, some people remove the dc motors. And with vfd's used widely, there are, at face value, cheaper options. But I don't think they are getting the same spindle speed ranges either that the DC motor provides.

    And for posterity sake, , look at Thomas Utley's excellent SB 16 thread. He went way overboard on his 16". But really excellent work. Using a vfd, it appears he turns spindle speed to damn near 1800, lol:
    1943 South Bend 16" x 60" Lathe Resurrection

    But with vfd's you'll have some power loss over the motor's rated hp.

    And the DC motors can really grind out some torque. There are really some interesting and cool projects using DC. I'm much more familiar with 3 phase motors, with a nice comfort level there. But just for the learning curve and "cool" factor lol, I'm going to give it a go on a 10ee. It's not my only lathe though, so I feel my risk is lower.

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  21. #33
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    Quote Originally Posted by texasgunsmith View Post
    I'd argue that a bit. Atleast as far as South Bend 16". Not as heavy as a Pacemaker 16", or a Monarch 16". But they have enough weight to be fairly rigid and smooth operating.

    Now all sorts of varibles for each guy. Budget, floor space,. . . is it the only lathe ? But a SB 16 is pretty handy to have for "general" stuff.

    The true upside is simplicity and ease of use. Even with something broken, you could be up and running is short order at a lower cost.

    I seem to recall you mentioning that with two lathes out of service, you need to hang on for dear life to what is operational. Which is where a simple, easy South Bend would fill a nice role while working on those projects.

    Now Homebrewblob is about to turn the "simple" part upside down. But I'm fond of cool and interesting projects. I might recommend a second lathe on hand though. . . you just never know.
    ATW Pacemakers are for those who live on a spaghetti farm. Very narrow but several miles long for the daylight they waste.

    Paint? Some day. Mills and drillpress have first dibs. I'm lazy. They are not as much stooping and bending.

    I need to replace a munged OEM MG starter control switch on one of the 10EE, but it isn't but the work of an hour. New Allen-Bradley oil-proofs with nicer lighting are laying here.

    The other one's motor - out on a dolly for nice rebuild - needs the paint applied. I could shove one of the two spares in and defer the paint if I needed that one, too?

    The HBX-360-BC has been getting most of the attention. Two more steel spindle backplates, one set of variator seals, another of the tip-seals for the power feed shaft's telescoping sections, some spare chuck affixing screws are paid for and soon to depart the factory in France for USA. Close to USD $2,000 for that was wired and confirmed received arredy.

    Neither the Monarch's nor the Cazeneuve are "orphaned goods".

    - Monarch has "successor" support, and it is good as it gets.

    - Cazeneuve is still making new lathes, in France, not China. Most are "teach-in CNC" but they have good spares support for the 40 thousand-plus HB series they built before modernizing, and many parts are even still common.

    That Cazeneuve is a nice, light-medium industrial uber-precision lathe, actually.

    Nominal 14" X 30", it has 7 "AC" HP, about the same as 5 "DC" HP, variable spindle speeds to over 3,000 RPM, awesome inch/metric single-point threading - if even I needed that - can swing just shy of 16", and weighs only about the same as a 12.5" X 20" 3+ to 5+ DC-HP 10EE - just a skosh over 3,200 lbs Avoir . so it was even dead-easy to move, single-handed.

    One of the Franken-projects is to adapt a Mimik UT-2 hydraulic tracer I acquired "one and a half" of from another PM member to replace its OEM Cazeneuve proprietary tracer- which I also now have the full factory info on IF I decide to splurge more than $2,000 at an annual budget go and JF bolt it on.

    The Mimik was really economically priced. They are still in new production as are rebuild services, the powered slide is really close to the size and shape of the OEM French one, so I'm going to mess with that for a while, instead, given all I'd use it for is a taper attachment substitute.

    Lots of higher priorities, still-yet, at MY end, though.

    Meanwhile there's new brakes at all four corners of the Chrysler T&C, next few weeks, 42 square of Reinke Shake aluminium roof to put on before winter, doubled ply decking FIRST.. High grade roofer's safety harness just came in this week, given I'm no longer an acrobatic ninja.

    Two LARGE trees to hire removed, trackhoe to rent for a week afterwards, decorative gravel and other landscaping to finish this season, new windows and siding next year, "etc." Hopefully then back to several trips out to a new country to add to our 51, "so far", and an old one or three of our favourites to visit ... IF EVER this damned COVID abates, etc.

    Most days it is like a one-legged man in an ass-kicking contest. Pop by the keyboard, park my weary ass for a spell, catch-up two dozen global news feeds, not all in English, login to PM, try not to fall asleep in the uber-costly German-made comfy-chair ,go fix another gourmet meal in one of several "languages". Can't screw. Still enjoy good food!! I'm good with that. No choice, anyway, is there?



    Maybe at 86 I should slow down?

    Meahhhh.. Not if I can help it!

    Folks who go too damned slow end up dying young vs our usual mid-90's or so!

    G'dad was still fast over WBGVA mountain terrain in his 80's just to keep from getting wet between barn and house when it rained! Go figure he was going to dissolve or sumthin?



    I'm a 'nam vet so liquid or dry, it's only a form of sunshine. You can spot us in a crowd. A 'nam vet can't figure out why anyone would be bothered to own an umbrella simply to impair their situational awareness and irritate the piss out of strangers they are constantly pronging with the fool contraptions.

    Last edited by thermite; 05-07-2021 at 10:28 PM.

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    Tex I love that mans sb16 restore, I looked in awe before I even owned a SB!

    I want that casting he did! And the tach! Itís amazing.

    Did you see he crowdfunded the resto? Thatís a slick move!

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    Quote Originally Posted by Homebrewblob View Post
    Tex I love that mans sb16 restore, I looked in awe before I even owned a SB!

    I want that casting he did! And the tach! It’s amazing.

    Did you see he crowdfunded the resto? That’s a slick move!
    Funny story, and coincidence. Notice his reproduction looking brass plates and tags toward the end of thread ? I remembered he did them himself, really nicely done.

    Just a couple days ago in the Monarch section, someone mentioned a company in AZ doing one off, reproduction plates. Not cheap, but nice work. I searched up the company, and looking at photo gallery I recognized his work, lol. Its him, his company:
    Gallery | Von Industrial, LLC

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    Ok If you want a real bang up job, get out your check book and go shopping, no wimpy drive pack... but a full Ward Lenord drive with feedback and instant reversing...And a mg set. and constant surface speed for facing where the drive slows down as the diameter gets bigger, and of coarse all the safety,s over current, field loss, over speed...Phil

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    Wow the dudes a beast, makes me feel like Iím 12 again looking up to the adults. Shit what am I doing with my life...


    Here goes midlife crisis #6

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    Quote Originally Posted by Phil in Montana View Post
    Ok If you want a real bang up job, get out your check book and go shopping, no wimpy drive pack... but a full Ward Lenord drive with feedback and instant reversing...And a mg set. and constant surface speed for facing where the drive slows down as the diameter gets bigger, and of coarse all the safety,s over current, field loss, over speed...Phil
    I believe I need a DRO to enable constant surface speed right! And while I’m at it...


    Speaking of, I mistakenly said “constant surface speed” earlier. I meant under load, what’s that called? Won’t a dc motor controller automatically try to hold a set motor rpm regardless of load?

    My luck I would get the constant surface speed working and while cutting off a part the spindle fly up to 4600rpm and flip the lathe on top of me!

    No In all seriousness I do want constant speed under load!

    Edit: just looked that drive up. ISNT THAT THE 10EE type drive with 3 motors!?

    Why do I keep seeing that!?

    10EE are Insane.

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    Quote Originally Posted by Tony Quiring View Post
    We have a SB 14.5 with think 2 hp 3 phase motor, have eaten since we cared...

    Picked up an Allen Bradley 3 HP vfd for $200.00 on eBay and some supporting parts like housing, pilot light and switches.

    Modifies the drum switch to be 3PDP independent with one making sooner for STOP and the result is drum switch controls same as the original and with a separate pot we have plenty of variation in speed from well above stock to MPR in back gear with plenty of torque.

    Converting to DC as Thermite explains sounds like s great option but the drive likely cost more than lathe is worth and result not much improvement.

    All of our add on are in a sub frame that bolts to the chip tray bolts and ends of the leg bolts, can remove and make stock in short order if needed and value of machine far exceeds the investment.

    Use the motor you have and get a good quality VFD

    Sent from my SAMSUNG-SM-G930A using Tapatalk
    I like the idea of stashing everything under the chip pan, I have a 5gal bucket under there now with a fountain pump in it feeding my coolant to my tool post. It works great atm, although there’s no filter so the pumps impeller gets smaller by the hour lmao

    I removed one of the chip pan bolts and screwed a 1/4? NPT nipple to it that drains into my bucket.

    I seen a fella on here start a thread about his new haas clogging with chips and flooding, I was like I KNOW that feeling!! I didn’t notice until the feed hose went dead and I looked down to a huge mess

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    with regard to the bearings, adding a top oiler port is completely useless given the oil is fed at the bottom and when taking a heavy cut, the spindle is thrust upwards, the oil is dragged into the high pressure zone by itself.

    as long as the length to width ratio of the bearing is about 1:1 then you don't need to add oil to more than one location on the spindle.

    with regard to pumping oil into the bearing.. it will help keep it cool, which will substantially increase your max rpm limit. but at only 1-2 psi i doubt you will get enough oil flow to cool it off. at 20 psi or something you'll probably have too much oil flow for the existing oil catch groove and it will be spraying out of the bearing.

    i've heard people fear "oil whirl" with regard to plain cast iron headstock bearings, but as i understand it oil whirl is when you have far, far too much clearance.

    billions of car crankshaft and connecting rod bearings have lasted a trillion miles at a length to width ratio of .5, oil fed at 1 location for the main bearings and 2 locations for the connecting rod bearing, and a .001" clearance on a 2" diameter bearing, lasting 1000-10000 hours at 3000 rpm.

    i can run my southbend 9 at 1500 rpm no problem using low viscosity atf (which is a little thinner than velocite 10) and keep in mind this is oil being fed into the bearing by a wick.. a wick about 3/8" diameter.

    and using that very light oil, with a 56 pound shaft who's center of mass is 2 feet from the spindle, the minimum speed to build up an oil film is about 60 rpm. this corresponds to a downward thrust of about 200 pounds at the headstock and 150 pounds upwards at the left spindle bearing.

    200 pounds thrust on the bearings (and on the gear) is about what you get on a southbend 9 with its stock 1/3rd hp motor and in back gear at 40 rpm.

    no one runs lathes that slow, nor expect a southbend 9 to turn an unsupported 56 pound shaft 4 feet long, but it can, and maintain an oil film while doing so. 2hp at 500 rpm and you will have less force on the bearings than 40 rpm and 1/3rd hp.

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