Schaublin 135 (and maybe the 150) Anyone here upgraded the auto spindle brake ?

The automatic spindle brake on a Schaublin 135 is typically a Warner Electric PB-825. Attached to the back side of the main motor, it works well for braking... but can be noisy as the least bit of wear on the plastic bushings that move on three "bolts" and the heavy armature plate will move laterally, causing a knocking noise....especially noticable at slow speed.

But I found out today, that Warner makes a "Heavy Duty" version of the same PB-825, that uses a spline center rather than the 3 bolts, which seems like an infinitely better way to go. With "seems" the operative word, wondering if any of you have retrofitted this ?

Btw, the heavy duty version uses the same magnet assembly, so all that would need to be switched out would be the armature assembly...i.e. no wiring involved, no new expensive electromagnet needed. Only possible problem I see is Warner might not supply metric shaft diameter bushings but obviously that can be made or the closest inch version bored to fit. (of course for all I know the Schaublin motor shaft is inch already, but that would seem unlikely)

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As an aside, when I bought my 135 years ago, it had some annoying "knocking" sounds that turned out to be the brake. So I bought a retrofit kit and "rebuilt" the brake, which improved matters a lot. It still wasn't completely noise free, but I presumed that was the spindle gearing or the vari drive somehow.

Fast forward a decade or so, and the brake noise is back. This time I removed the brake and ran the lathe with no brake at all... just to see how much noise was brake and how much was everything else.

I was astounded at the difference....with no brake, the lathe is unbelievebly quiet....no gear noise, no vari drive noise...just the swish of air from the turning chuck !! So it turns out all these years I've been putting up with noise that was 99% from that stupid Warner brake !

Now I'm determined to get the brake to a noiseless situation, or I'll just go "brakeless" and leave the damn thing off ! But hopefully the "heavy duty" alternative will get the best of both worlds. So, I ask again, has anyone else done this already ?

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FWIW, for folks that have never delved into their Schaublin brake... if you are of average size or smaller*, it is possible to remove the brake without removing the motor. If your lathe has a coolant tank there should be enough extra electrical conduit to slide the tank out, lay down a blanket or whatever, and wiggle your body (with tiny flashlight in mouth) into the body of the lathe, where you can get to the brake that way. It's not easy, but doable...and a lot easier than removing that huge motor.

*actually your shoulder width is a determining factor as well. I think if my shoulders were an inch wider I couldn't have done it. I wonder if the 150 base interior is exactly the same ?

Not related to your query but...
I'm curious, is this on a Siemens motor? What is the hp of the motor?

sneebot said:

Not related to your query but...
I'm curious, is this on a Siemens motor? What is the hp of the motor?

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Pretty sure it's not Siemens but some obscure Swiss make. Physically it looks like 20 hp but is less than 5 HP (two speed)

FWIW, with the brake and the drive belt removed I literally cannot hear the motor when it is running even within 2 feet of it, it is so quiet..... which is due to a combination of my hearing deterioating a little, perfect bearings and 750 RPM speed ! But with the brake installed, it sounds awful !

Milacron: I do agree. However replacing the 3 bushings did wonders for me, the lathe is now as quiet as I could wish. But come to think of it, I did another thing as well; The rigging screw for adjusting the tension of the drive belt was a little noisy, I ran some locktite into the eyes, and presto: A small rattle disappeared.

Ole

Milacron said:

This time I removed the brake and ran the lathe with no brake at all... just to see how much noise was brake and how much was everything else.

I was astounded at the difference....with no brake, the lathe is unbelievebly quiet....no gear noise, no vari drive noise...just the swish of air from the turning chuck !! So it turns out all these years I've been putting up with noise that was 99% from that stupid Warner brake !

Now I'm determined to get the brake to a noiseless situation, or I'll just go "brakeless" and leave the damn thing off !

Click to expand...

Milacron said:

FWIW, with the brake and the drive belt removed I literally cannot hear the motor when it is running even within 2 feet of it, it is so quiet..... which is due to a combination of my hearing deterioating a little, perfect bearings and 750 RPM speed ! But with the brake installed, it sounds awful !

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On that score.. AND if this lathe is for your personal use.. I'd vote for not bothering to try to quiet-down an already proven to be marginal electro-mechanical brake design at all.

I'd leave it off, but also...

Send a note off to, for example member Jraef, tap his broad experience for a recommendation as to a suitable 'regenerative' VFD that could deliver all the braking actually NEEDED, with no wearing-parts mechanical brake of any kind.

I enjoy that sort of smooth and rapid stopping with 4Q DC Drives and DC motor on the 10EE.

I see no reason a comparable VFD - whether you need speed range variability or not - would be unable to deliver similar braking performance in the 3-P AC motor realm.

No need to change the motor. Seems to have a great deal of 'goodness' baked-in.

ole.steen said:

Milacron: I do agree. However replacing the 3 bushings did wonders for me, the lathe is now as quiet as I could wish. But come to think of it, I did another thing as well; The rigging screw for adjusting the tension of the drive belt was a little noisy, I ran some locktite into the eyes, and presto: A small rattle disappeared.

Ole

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Mine also was as "quiet as I would wish" after the first brake rebuild a decade ago.....and I suppose 10 years is acceptable but the actual use of the lathe in that period was probably no more than 20 hours, which is not acceptable.

Also now that I have experienced the machine with no brake the "as quiet as I would wish" factor has changed a bit. A bit of the old saying "Once they've been to Gay Paree, how are we going to keep them down on the farm ?"

Monarchist said:

Send a note off to, for example member Jraef, tap his broad experience for a recommendation as to a suitable 'regenerative' VFD that could deliver all the braking actually NEEDED, with no wearing-parts mechanical brake of any kind.

I enjoy that sort of smooth and rapid stopping with 4Q DC Drives and DC motor on the 10EE.

I see no reason a comparable VFD - whether you need speed range variability or not - would be unable to deliver similar braking performance in the 3-P AC motor realm.

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Yeah that was my next step....a post about the possibilities of VFD regen braking in the VFD forum...that would be cool.

S what is the noise from? The electric brake on my LeBlond is quiet.

If your machine is for home use, I'd just leave the brake off. Your machine probably slows down faster than my Graziano, particularly when rpm is modest.

Quiet would be nice!

Milacron said:

Yeah that was my next step....a post about the possibilities of VFD regen braking in the VFD forum...that would be cool.

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I want to hear more abut this solution- I'd like to do this on the FP4.

Milacron said:

Yeah that was my next step....a post about the possibilities of VFD regen braking in the VFD forum...that would be cool.

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IF...one only had to do it once, there are other brakes, too. Warner had US competition, and there is a virtual mountain of medium/low HP braking goods out there for groundskeeping, ATV and other recreational vehicles from Airhart & their competitors. Disk, internal drum, external band/drum, with actuators mechanical, electrical, air, hydraulic, and combinations.

The all-electric 4Q VFD or DC Drive, if 'good enough', sure beats crawling inside the machine, though. And... one can adjust how aggressively they brake, said adjustment not subject to drift from wear.

There IS still an entirely separate spindle "lock" for when really firm/fixed holding is needed, no?

Monarchist said:

There IS still an entirely separate spindle "lock" for when really firm/fixed holding is needed, no?

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Yeah, it's called the backgear

The smaller 102N-VM is more "advanced" in the sense that it has a foot pedal that activates a brake/clutch combination such that when you step on it stops the spindle instantly, but allows the motor to keep turning....pretty handy when you are sneaking up on a very precision diameter and need to stop the spindle frequently to check with micrometer. And that is all you do...just step on that pedal....no mucking about with the motor switch or lever until you are finished with that part.


Of course I doubt one would want to stop the 135 spindle "instantly"...too much weight and inerta in the 8 inch chuck compared to the little 4 inch chuck on the 102.

sneebot said:

I want to hear more abut this solution- I'd like to do this on the FP4.

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Does the FP4 have no motor brake ? Even though I owned it at one time been so long since I ran it, I can't remember.

Or maybe it has one, but it doesn't release at the instant of spindle on ?

Heck, I'm tired of typing.....why don't you ask about this in the VFD forum and I'll copy that And don't give this "no can do, too busy vacationing" excuse

Monarchist said:

IF...one only had to do it once, there are other brakes, too. Warner had US competition, and there is a virtual mountain of medium/low HP braking goods out there for groundskeeping, ATV and other recreational vehicles from Airhart & their competitors. Disk, internal drum, external band/drum, with actuators mechanical, electrical, air, hydraulic, and combinations.

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I have been corresponding back and forth for a few months about various Schaublin related issues with a fellow in Germany that is probably the most knowledgeable and meticulous rebuilder of 135, 150 and 160 lathes in the world. He also despises the standard issue Warner PB brake but has devised methods of balancing the armature and getting clearance just right so that it works acceptably.

Which is what I sort of did ten years ago, but just am amazed it only "lasted" 20 or so hours before needing work again, plus now realize that it the lathe is quietier still with no brake at all than it is with even the most perfectly "tuned" standard PB model.

He has also researched this and is going to eventually try one from this company-

http://www.mayr.com/synchronisation/documentations/k_891_v16_en_16_10_2015.pdf

The Mayr versions have much lighter armatures and thus would be less prone to the lateral movement knocking sound issues. He reports they actually cost less as well.

706jim said:

If your machine is for home use, I'd just leave the brake off. Your machine probably slows down faster than my Graziano, particularly when rpm is modest.

Quiet would be nice!

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Yeah, as I said earlier I could not believe how quiet this 135 is with no brake. And true, for my purpose I don't half need a brake anyway.

But mostly as a matter of curiosity I want to see if I can devise a way to have a brake that adds absolutely zero noise or vibration to the machine. I suspect even the "heavy duty" spline version would not be "perfect" in that regard (which was the point of this topic, to maybe find out from someone that has tried it already), thus the VFD regen idea is appealling....

Or perhaps re engineer the brake I have.... I can imagine pivoting rods holding the armature to the hub for example... bottom line is that armature plate needs a way to move in and out just 5mm or so, but without any possibility of centrifugal force induced side motion whatsoever.

moonlight machine said:

S what is the noise from? The electric brake on my LeBlond is quiet.

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That's not very meaningful without knowing the armature size, or at least the physical motor size (which would determine the armature size/weight) The 135 lathe is only about 4 hp but the two speed 750 RPM motor is huge...like 20 hp dimensions of a modern motor, thus requiring an equally huge brake, subject to centrifugal forces a smaller motor would have no problem with.

Or maybe LeBlond used the "heavy duty" PB model, like Schaublin should have done !

Milacron said:

That's not very meaningful without knowing the armature size, or at least the physical motor size (which would determine the armature size/weight) The 135 lathe is only about 4 hp but the two speed 750 RPM motor is huge...like 20 hp dimensions of a modern motor, thus requiring an equally huge brake, subject to centrifugal forces a smaller motor would have no problem with.

Or maybe LeBlond used the "heavy duty" PB model, like Schaublin should have done !

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Maybe LeBlond was wise enough to not use an El Cheapo Warner Electric clutch at all?
Some of the last century's finer lathes used multi-plate, oil bath clutches and brakes. Those goods are still out there.

As to torque, braking HP? I doubt that 4 HP motor needs anything 'special'.

The extra space its casing takes up would be for the space and mass of what it took to interpose two different speeds worth of stator windings, and those do not motate.

The armature and shaft may not have any more rotating mass than a single-speed, same HP & similar pole-count.

Monarchist said:

Maybe LeBlond was wise enough to not use an El Cheapo Warner Electric clutch at all?
Some of the last century's finer lathes used multi-plate, oil bath clutches and brakes. Those goods are still out there.

As to torque, braking HP? I doubt that 4 HP motor needs anything 'special'.

The extra space its casing takes up would be for the space and mass of what it took to interpose two different speeds worth of stator windings, and those do not motate.

The armature and shaft may not have any more rotating mass than a single-speed, same HP & similar pole-count.

Click to expand...

Regardless, Schaublin used a magnet assembly aprox the same diameter as the huge motor, thus requiring a rather large and heavy armature disk to match the magnet. It is ironic the one thing on what was probably the most expensive and elaborate manual lathe of it's size in the world, used a "Made in USA" component that was probably a poor choice.

Milacron said:

Regardless, Schaublin used a magnet assembly aprox the same diameter as the huge motor, thus requiring a rather large and heavy armature disk to match the magnet.

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Smaller and lighter than the solenoid-triggered hydraulic accumulator actuated cone clutch out of a late 1950's Laycock d' Normanville overdrive, certainly.

But THAT - 'çone' rather than flat plate - is the very sort of high-water mark that sets the bar for near-as-dammit silent operation.

Multi-plate - Barrufaldi - modern version of the Rockwell/New Departure bicycle 'çoaster' brake, is another.

Baruffaldi S.p.a.


Dings can get you a better brake, similar tech, to Warner, and to fit 'metric' motors:

http://www.dingsbrakes.com/products.htm

JMNSHO, but Warner clutch/brakes are better reserved for managing mower blades and auto AC compressors.

FP4 does not (currently) have a brake...