What's new
What's new

Dc motor swap in south bend 16 lathe, pressurized bearings.

Homebrewblob

Stainless
Joined
Apr 5, 2020
Location
Cincinnati
First my machines are in general a pet project, I like to modify things even when it’s not financially Beneficial, we all spend money on hobby’s of some kind, mine is to over complicate things and I enjoy it! (I must have some German in me)


I’m looking at a few different DC motors for my SB16 as I want variable speed AND power.

Im looking at 1hp and 2hp motors @ 12-24-90-180v 3600 rpm.

I’m leaning towards a 2hp 90v DC 3600rpm.

I want a high speed/ higher hp dc to make up for the power loss at lower spindle/motor rpm, I am keeping the flat belt setup (of course) but I’m gonna go with a wide synthetic belt.

I hope to see my top spindle speed up around 1500rpm while maintaining more then 1HP in the low speed.

I’ll still be able to utilize the back gearing for “crawl mode”.

I currently have a tachometer and I’m a hobby guy so the lathe doesn’t see more then a few hours a day/ few days a week of use, I’m not worried about shortening the lathes lifespan (within reason) as I’ll eventually upgrade to another lathe in the future.


Any suggestions on the motor (voltage/speed etc?) and controller?




Now heres the crazy side thought, pressurized oil system to the headstock bearings. This is still just a thought in its Infancy but I have played with low pressure displacement pumps. Anyone ever seen it done?
 
attachment.php
 
The 10ee guys have a ton more experience with the dc motors and controlllers. One real good thread of a controller put together with more modern and obtainable parts is here:
Parker/Eurotherm 514C/507 4Q SSD DC Retrofit into 1961 10EE Modular

10ee uses a 5hp dc in many cases. I might be inclined to go with that if i was attempting that experiment. A sb16 could come with 2hp motor original. Your weak link besides lube system is the flat belt, especially if you have a 4 step pully. The belt will just slip.

With power and lube. . . Spindle is stout enough to handle it. Bearings are plenty wide enough. Headstock. . . Maybe, the cast is pretty heavy. So to pressure lube, how much volume before oil over flow slings oil 360 degrees, floor, walls, ceilings lol. The oil trenches could return some, but i think they would be overwhelmed with volume.

Maybe pressure from 12 o'clock on cap. With return lines from where oil cups currently reside.

Just theorizing, because really this project would be total madness, lol. Id probably try to put the expense and effort into a machine naturally set up the way i want. But i get your point on experimenting for fun.
 
Well f**k.. I thot it was my Irish side as made me piss-away pots of gold to chase Unicorns by the light of moonbeams?

How about Bavarian-German backed up by SWISS German?

Tobler, yet. The very family of confectioners that invented those oddly sawtooth-shaped "Toblerone" chocolates... to slow you down ... by hurting your mouth! You'd have to know the Swiss idea of "frugal" even as applied to gluttony for chonklettes?

:)

Might have just what you need. 2 HP T.B. Woods branded 90/180 VDC selectable bought brand-new as NOS, and brand-spanking new it turned out to be - factory crate and all.

When I got it? Actually made by f**cking Bald-whore. In Mexico.
Nice enough motor.

If you like Baldwhores.

But I'm a Reliance, Bodine, or go TF HOME guy when it comes to motors AC as well as DC. T.B. Woods USTA BEE a power in their own right, back in coal-mining cuntry.

Even have bought brand-new from Galco and never-hooked-up KB DC drive for it.
Email me. No idea what I have in it, but even the tiny Burke B-100-4 mill it was bought for found itself a decent Reliance RPM-III after all.

I'm keeping only my Reliance herd. Four of 'em are large-frame Monarch 10EE, too!

Irony?

Company property sticker still on that used Reliance for the Burke.

Bugger came out of a Hershey Chocolate production line!

Can't seem to escape yer roots?

:)
 
Last edited:
Thanks Tex, yeah the flat belt 4 step cone is why I don’t want to go higher then 2hp, I feel in that aspect it does become a waste of Money.

I just want variable speed and low rpm power, With a synth belt and 2hp dc I think it would stick pretty good.

The pressurized oil system I imagine would supply oil at LOW pressure (maybe 1-2psi via a Orifice) either at the top as you said and I could even enlarge the drain holes, it’s just an idea ATM.

But the dc motor is a plan.

Don’t the 10EE use a ac motor attached to a dc motor or something crazy like that? Like a motor-generator
 
if you're going to be buying stuff to do this, rather than working with what you have at hand, a 1 1/2hp 3ph motor and VFD would be alot more straight forward and likely give you more options than a DC motor (accel/braking/ soft start/ spindle jog etc). 1 1/2hp is the limit for 110>220V VFDs, but if you have a 220V circuit or can put one in then there are more options for 220V VFDs (not just the power output, but more models).

I have DC motors on all my machines and am just finishing up a drive/ motor set up for my wide 9, but if I had the funds I would have gone 3ph for my mill and lathe. Also don't forget that you'll be 2x the stock motor speed at full speed, so you need to take that into account for the motor>countershaft pulley ratio.
 
and likely give you more options than a DC motor (accel/braking/ soft start/ spindle jog etc).

Are you NUTS?

I can shake a can of paint with a DC Drive on a Type T straight-shunt Reliance... or call up one revolution every 20 seconds and creep on-up to low Earth orbit RPM then brake to stop on a dime, give back 9 cents change - even hold a fixed "AT ZERO RPM" position if pushed OFF it, either direction of rotation, no resolver needed, no braking resistors required, either.

Bog-standard right out of the box Shackleton System Development AKA Eurotherm/Parker "SSD".... with the ripple-filter both of Reliance AND the DC drive maker agree is required.

Even my ignorant El Cheapo KB-Penta 4Q drives will do all but the zero-hold trick.

WTF are you running your Dee Cee WITH? Antique "1Q" external contactor-reversing fossils pushing freakin' treadmill salvage?

???

Two of the VFD I kicked out the shop door were new. The Schneider Altivar 71 wasn't exactly a lowball as VFD go, either.

No match for DC in machine-tool use.

Just fine for my clothes warsher, clothes dryer, linear-inverter fridge-freezer and inverter microwave though.

I don't "hate" VFD. I just don't mistake a variable-speed washing machine for a Cat D9G comes to moving Earth.
 
if you're going to be buying stuff to do this, rather than working with what you have at hand, a 1 1/2hp 3ph motor and VFD would be alot more straight forward and likely give you more options than a DC motor (accel/braking/ soft start/ spindle jog etc). 1 1/2hp is the limit for 110>220V VFDs, but if you have a 220V circuit or can put one in then there are more options for 220V VFDs (not just the power output, but more models).

I have DC motors on all my machines and am just finishing up a drive/ motor set up for my wide 9, but if I had the funds I would have gone 3ph for my mill and lathe. Also don't forget that you'll be 2x the stock motor speed at full speed, so you need to take that into account for the motor>countershaft pulley ratio.

I have a 100amp 240v 1P sub panel dedicated to my garage that feeds my 3hp RPC, the lathe has a 2hp 3p 60h 1800rpm motor in it atm, I’m leaning towards dc for the simplicity, vfd are a pain in the ass (to me) and all the parameters are more then I want to play with, I don’t really feel I need braking or jog, and yes I plan to have the dc motor running near top speed with spindle rpm at 1500. I want 1500 to get finishes I can’t get right now. I also want this to stay with the style of a 1957 southbend, and the oil system I’m thinking of is a hard thing to hide so that’s another Consideration. I’ve done some numbers and I think I can direct swap for a dc 2hp motor and controller for around 600$.

Like they say, it’s cheaper to keep her. I don’t want to upgrade to another lathe atm and I have grown fond of my 50’s era garage lmao

I want to avoid belt changes when possible, I’m planning to duplicate this for my 1HP 3P index mill too, it’s a step pulley and it’s a PAIN IN MY ASS.

The magnesium pulleys are chipping away more and more every day.
But first the lathe
 
Another consideration is the dc drive, I want a no bells/whistles drive. I found some that do fwd/rev 0-100 and that’s right up my ally, I’m just worried about finding a reliable drive, I suspect those 100$ 2hp dc drives are trash
 
Another consideration is the dc drive, I want a no bells/whistles drive. I found some that do fwd/rev 0-100 and that’s right up my ally, I’m just worried about finding a reliable drive, I suspect those 100$ 2hp dc drives are trash

"No bells and whistles" is exactly how you piss-away ALL the advantages OF Dee Cee.

KB-Penta are decent. Got a bunch of them here. So long as the load-motor is 90/180 VDC wound, straight-shunt, wound field, AND NOT "PM" field. AND NOT 230 VDC.

Just make sure to buy them BRAND NEW ...with full Warranty.. get ONLY "4Q" AKA "regenerative", top of their line, and in "NEMA 4X" 'washdown' housings is all.

Don't NEED "4Q"? Xin loi!

All the REST of the goodness you DO need is only built onto the "4Q" models, not the El Cheapos. Swing a heavy lever-arm to turn a small shaft? 4Q will detect an over-running condition every rev, backpeddle automagically as the mass flops-over and tries to speed-up the downswing, hold RPM well without even a tacho or resolver. Provide a tacho? Bugger thinks it is a CNC servo drive.

"4Q" Parker SSD's and Control Techniques are the Bentley Arnage "Red Label" and Maybach Zeppelin of single-phase-input sub 12 HP DC Drives. Casing them is on yer own dime. I use a 10EE base Iron casting for the "case". Fair stout. BFD.

:)

Worth every dime of their modest asking price but a premium it can be.
 
if you already have a good sized 3ph motor already on the lathe then just get a VFD. It's not going to be any more complicated than installing a DC motor and setting up the drive. There's plenty of VFD knowledge on here and you don't have to set them up with all the bells and whistles, but you can if you want to. You can also overspeed your 3ph motor by at least 50% completely safely, which should help you up the top speed without messing with a different motor pulley.

I would still expect to change belts every so often though. All variable speed set ups have a range within which they work best for a given belt position. Those ranges usually overlap by a fair amount, but you won't be turning 1/8" brass doohickies and 12" brake rotors on the same belt position. It always feels like torque drops off a cliff below 30% motor speed, so oversizing the DC motor is a must if you want to spend much time down at the low end of the motor speed range.
 
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
 
Don’t the 10EE use a ac motor attached to a dc motor or something crazy like that? Like a motor-generator

There have been different configurations over it's history. One I saw at Swatkins shop appeared to have an AC motor turning a generator, which I assume powered the DC motor. An old thread showing a basic run down of that history:
History of the 10ee - Gospel according to Monarch

I'm attempting to save a 1962 version. It has just a 5hp DC motor and a controller. But this controller is a bit of a Rube Goldberg:

17.jpg

So when I get around to it, I might try something what I linked in the earlier post. But that's a couple projects away :D.
 
Why reinvent the wheel, get a vfd and a 3phase motor...Phil

My sentiments, exactly!

Why waste money on a fragile and complex step-by-step tiny-number-code keypad-programmed Digital VFD that can have its tiny-mind blown so easily, and with ephemeral capacitors and motor-nasty wave-forms?

.. when DC still exists, controllers are simple-rugged and long-lived analog-logic with screwdriver-tuned trimpots that do NOT "forget", and DC motors can do far the better job in machine-tool use, regardless!

Off an ignorant 120 V outlet, yet. Or 240. Motor parallel 90 VDC, series 180 VDC per dataplate. DC Drive? Move one wire.

Done. And reversible. Nothing "special" about it as 120 VAC in 1-P VFD need.

:popcorn:
 
I sent you a email bill, let me know if you got it!

Sure HOPE it was you? I've been exchanging emails all day with somebody!

That T.B. Woods motor? Straight shunt. Wound field. Drop a fixed wirewound into series with the field for "Hi/LO" range ELSE a medium stout wirewound rheostat?

Your available top RPM is up to what the SB's bearings will stand!

It ain't shaft-bender class like a 10EE's 690 RPM base large-frame Reliance but low-end will still slip belt. DC motors themselves cannot "slip" as AC does.

Move load. Die trying.

Pray there is a sane limit setting in a DC Drive else a CB or fuse.

DC drive is meant to cover that. Does so. No fear of damage to the motor.

They'll stand 6 to 9 times rated power for 90 seconds. That's why they still get to do "the hard stuff" that would reduce an unprotected AC motor into hot scrap and charred-phenol stink. Slow-ramp a heavy load up onto it's water-skis?

Oh lawdy me, is that EVER Dinosaur Current nachural!

Next step up for heavy Diesel is Nitrogen or Compressed-air-over-hydraulic motor start. Vee Effing Dee ain't even in the same building! Or flood-control dam.

:D
 
Yeah that was me bill lmao, don’t go selling my motor to anyone else now

Presuming I can FIND the sumbich amongst a whole tribe of political refugee RPM III Reliance as have sought asylum, here? It will have your name on it.

I'm keeping the sidecar, though. XJK-L is a long dam' way from the brand-new SS-100's humble beginnings a second cousin crossed the channel ferry in... tired, dark, and apparently forgot where he was oncet ashore and heading for Paris.

Kilt himself, wife, infant, and the poor Nordman Frenchman who WAS on "the French" side of the 2-lane, head-on, and at full gallop.

:(
 








 
Back
Top