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View Full Version : CLAUSING 5913 5914 Vari-Speed Drive REBUILD Q's <---



bearzbear
03-22-2016, 02:33 PM
Just acquired a one owner CLAUSING 5913.
Holds <0.001" on ground rod from 2" from the chuck to about 14" out, held by the live center. Nice.

Ought to have looked more when I went to see the machine, but it was buy it and load it and drive, although I did run it and notice some excessive vibration. Frankly, I had not fully investigated the entire Vari-speed thing in advance. My bad. But this looked like just about the right lathe for me, or one like it - although the 14" version might have been better. Anyhow, it's here.

I've searched the web pretty extensively on this now. Close to maybe as expert as one can get from reading and not doing.
So a few Q's, hopefully someone has first hand experience.

1) the belt - apparently the 1930V400 (called for by Clausing) has a 30deg angle. But the cones have (apparently) 22 degree angle.
So, is the 1930V403 with a 22 degree angle actually the correct belt? Or does Clausing want a thinner - lighter contact
area for smoother running, and better adjustment, longer belt life??

1a) I have bought both belts, since they'd be needed no matter what, and I'm going to "pop them in" and see if the vibration in the drive is due to worn/out of spec belts or not.

Note: after looking at at least a dozen videos of 5913/4 lathes on Yoohootoobe, I heard only one that did not growl and rumble - that one was smooth and I only heard the whine of the spindle. That's what I want.

2) The shaft bushing rebuild.
2a) Method 1: Moglice + bored delrin bushing
Method 2: Bronze bushing on shaft + delrin bushing on pulley <---anyone done this or have an old lathe with the bronze bushie??
Method 3: Machined down shaft, polished & hard chromed : delrin or bronze bushing on pulley

Opinions? Ideas?

Anyone actually DONE the bronze bushie method? With the delrin, it seems fine since there will be no wear or lube issues with the bronze, so it can be a tough/hard bronze on the shaft. With either the pulley bore or the shaft hard chromed (seems like an attractive approach) my concern is about lube - even using an Oilite bronze bushie, they say that they want/need heat to maintain lube and with the simple short slide for occasional adjustment I don't see that happening. Plus standard lube tends to not work between tight smooth surfaces that have no way to hold the lube/oil in place, and there is the potential for slinging. But I like the idea of bronze on hard chrome (or even polished steel)

I'd actually like to avoid the moglice method, since the bronze bushie + delrin sleeve seems more straightforward - the downside (if there is one) is that it looks like one has to take more of the shaft off to fit the bronze bushing and have enough bronze thickness, unless you use one of these newer high techie (seemingly very thin) bushings - but then maybe the keyway becomes problematic.

Okay, (3) Direct drive? Skip the rebuild of the bottom keep the clutch, so the center cones can be shimmed and set fixed, or replaced as some have with a flat belt pulley - then the question remaining is AC or DC motor, and IF DC, what controller method? If AC, the controller is pretty straight forward, but what speed motor?

The motor speed becomes important at low speeds because the AC motor is losing torque. The DC motor is said to maintain torque at low RPM. So, try to find a 3450rpm (is that the right number) AC motor, and use a step down to bring it into standard range for the lathe, gaining some low end torque? Over size the motor??

Where's the trade-off balance point for all of this? Ease/simplciity/cost/smoothness of running/time to get the job done, that's the equation.

Your input is appreciated!

TOOLZNTHINGS
03-22-2016, 08:25 PM
Hi,

Look at 3 phase inverter duty motors with single phase in / three phase out VFD

JoeLee
03-23-2016, 12:13 AM
I replaced the bushings on my 5913. They are still nice and snug. The coating was OK on both. My machine is pretty quiet with the exception of the clutch plates that rattle when the spindle is in neural. The set screws on the motor pulley loosen up every now and then and have to be tightened, when they loosen up you can hear it.

JL..............

Royldean
03-23-2016, 07:30 AM
I removed my busted varidrive and replaced with a NON inverter duty motor and vfd. No problems whatsover (but I don't run this thing 24-7, 8-5, or even 2-1.... practically speaking). I did keep the clutch assembly, although I never use it and will likely remove it the next time I feel like doing machine work. I have the older style 5900 with the clutch lever on the head stock pillar, not the carriage... so it's inconvenient. FWIW, I don't worry about "low speed" with an inverter, as I just use the back gear.

bearzbear
03-23-2016, 07:34 AM
Hi,

Look at 3 phase inverter duty motors with single phase in / three phase out VFD

Sure.
But the question is about torque at low RPMs (machine RPMs) vs. motor RPM vs. motor torque.

So, what I questioned is perhaps look for a higher RPM motor, and run with a step down ratio at the
motor pulley to keep the motor RPM high for the equivalent spindle RPM, maintaining a good torque "headroom"??

TOOLZNTHINGS
03-23-2016, 08:58 AM
Hi,

I found great help by calling Automation Direct and talking to their techs about your application.

bearzbear
03-23-2016, 09:29 AM
Hi,

I found great help by calling Automation Direct and talking to their techs about your application.

I may do that, did not know about this place.
But I prefer to talk to people first before dealing with any commercial outfit, and know the lay of the land first.

Hoping folks here may have had experience in solving this or a similar problem and what they found.

JoeLee, iirc the "slop" in the clutch plates is adjustable with a threaded collar (with a setscrew) on the clutch assembly -
this from the photos and drawings - I haven't yet pulled the unit myself.

Btw, the belts came in yesterday, so somewhere in the next few weeks I hope to get a better look at the whole
thing and try out fresh belts, see if that smooths out the machine or not.

But thanks for the responses so far...

_-_-

softtail
03-23-2016, 02:42 PM
Not familiar with your drive, but sounds like it may be similar to my Boxford VSL in that it has spring loaded drive cones and an angled belt that rides inside to get 'variable' drive ratios. If so, check the surface of the cones, as they are prone to becoming stepped due to lathe being run at one speed, and belt wear (I'm guessing). The steps/grooves will grab the wider/upper edges of the belt and pull it until it releases over and over creating some substantial vibration. VFD would be nice fix, or possiby leverage the purchase of a second lathe to fix the first!-ST-

garyhlucas
03-23-2016, 09:22 PM
The varidrive gives constant horsepower to the spindle so the torque goes up as the speed goes down. To get the best life you should run it through the whole speed range often. Wear in one spot is a problem and I had to turn the pulleys on my bridgeport.

bearzbear
03-23-2016, 09:48 PM
The varidrive gives constant horsepower to the spindle so the torque goes up as the speed goes down. To get the best life you should run it through the whole speed range often. Wear in one spot is a problem and I had to turn the pulleys on my bridgeport.

Mine already has issues. It has been run up and down in speed by the previous owner, no sign of excessive wear spots - expect to face the pulleys (unless they look pristine) assuming it does get rebuilt.

Still hoping someone happens by who has personal experience doing the rebuild...

JoeLee
03-23-2016, 10:55 PM
I may do that, did not know about this place.
But I prefer to talk to people first before dealing with any commercial outfit, and know the lay of the land first.

Hoping folks here may have had experience in solving this or a similar problem and what they found.

JoeLee, iirc the "slop" in the clutch plates is adjustable with a threaded collar (with a setscrew) on the clutch assembly -
this from the photos and drawings - I haven't yet pulled the unit myself.

Btw, the belts came in yesterday, so somewhere in the next few weeks I hope to get a better look at the whole
thing and try out fresh belts, see if that smooths out the machine or not.

But thanks for the responses so far...

_-_- Yes, I am aware of that. I rebuilt the entire machine. The problem is if you tighten up the ring to eliminate the rattle it starts to put drag on the clutch plates. The spindle will sometimes slowly start turn when it should be stopped. So............ you have to have a little play in it. It's a fine line and I've fiddled with it off and on. I was thinking of putting a wad of silicone on the top edge of the clutch plates to keep them from rattling.

JL...............

JoeLee
03-23-2016, 10:58 PM
The varidrive gives constant horsepower to the spindle so the torque goes up as the speed goes down. To get the best life you should run it through the whole speed range often. Wear in one spot is a problem and I had to turn the pulleys on my bridgeport. Running it in one spot all the time is what wears the pulley halves. I try and run mine at slightly different speeds when I use it.

JL...............

bearzbear
03-24-2016, 12:22 PM
Yes, I am aware of that. I rebuilt the entire machine. The problem is if you tighten up the ring to eliminate the rattle it starts to put drag on the clutch plates. The spindle will sometimes slowly start turn when it should be stopped. So............ you have to have a little play in it. It's a fine line and I've fiddled with it off and on. I was thinking of putting a wad of silicone on the top edge of the clutch plates to keep them from rattling.

JL...............

Yeah, ok... I only hear a bit of "click---click" as the machine slows...
I'm unclear on the source of the noise I hear, and certainly the noise you hear.
So, I can't offer any potential solutions.

Silicone will dampen the sound, not eliminate it.

But thinking about it ---- If it's the plates that contact the clutch material, that would be different than if it were the clutch material itself, I would expect.
IF it is the plates, you might be able to adhere some elastomeric material (aka "rubber") of appropriate hardness and size to the where the
"ears" (that I think, if I remember the pix/prints) stick out so as to place a constant load on them - they'd squeeze ok when the clutch
was engaged, and not be free to rattle when off... of course they'll die after a certain number of hours... and you have to get them to stick...
maybe a solid ring can be fitted?

Maybe it's not worth the work/worry...

I know about the single speed wear issue, my vibration is not due to wear on the face of the Vari-speed pulleys.

_-_-

TOOLZNTHINGS
03-24-2016, 01:48 PM
Hi,

I bought a 1300 series Clausing lathe in 1978 new. I'm sure the drives are the same set per friend who has same lathe as yours. Used the lathe for over 35 years to make my living. Only replaced motor bearings once and seals on vari-drive pistons. Original clutch discs. I would think that restoring your drive to original specs would prove to be reliable.

RWO
03-24-2016, 02:57 PM
A sensorless vector VFD can maintain induction motor full load torque well below half speed( 30 HZ) The drive does cost a little more than the standard V/Hz drive, but is worth it IMHO.
As far a base motor speed is concerned, I recommend the following procedure: Decide what the max spindle speed will be on the lathe and what the fixed speed reduction ratio at the motor shaft will be. Chose a base motor speed that when run at 120 Hz( 2X base speed) comes close to matching the max spindle speed multiplied by the reduction ratio. You will probably end up with a 4-pole ( 1750 RPM) or a 6-pole (1150 RPM) motor. 2-pole motors don't have as good a low speed torque characteristic so are not recommended. 4-pole motors are more common and cheaper than 6-pole so are more desirable. In fact, it is probably worth it to redesign the speed reduction mechanism so that a 4-pole works out as the proper choice. A quality motor( TEFC enclosure recommended) will tolerate 120 Hz without damage. So, this give a speed range of about 120 Hz down to about 10 Hz or 12:1. I have used this arrangement on my 13x36 Jet ( belt-drive) w/ 2HP motor for about 17 years with satisfaction. I do have the option of moving the spindle drive belt and/or using back gear if needed, but I have not needed to do that in years.

RWO

bearzbear
03-25-2016, 10:35 AM
Thanks, good information on the motor/pole aspect.

This is pretty much what I expected as far as the gear ratio thing and the motor speed relationships are concerned.
Your report on the torque is encouraging.

Boiling it down, what remains is the cost vs. effort vs. benefits.

On the benefits side, I'm really wondering if running the lower half (the VSD part) of the drive with a flat belt and of course the VFD/motor
combo will result in a substantially lower vibration drive system or not? I'm pretty darn sure that a grooved flat belt (they must have a designator for them?) will run very smoothly, but how much more, if at all, than a clean & tight VSD pulley?

lakeside53
03-25-2016, 11:22 AM
You're talking "poly-vee" or Micro vee" (trade names) belts.


I did a conversion on a 6913 (?), bigger brother of yours, but very similar. I kept the clutch and brake mechanism on the central assy, vfd conversion for the rest. Even used the original motor as it was 3hp. Perfect..

http://i238.photobucket.com/albums/ff150/lakeside53/Clausing%20conversion/6913countershaftasssy.jpg (http://s238.photobucket.com/user/lakeside53/media/Clausing%20conversion/6913countershaftasssy.jpg.html)

http://i238.photobucket.com/albums/ff150/lakeside53/Clausing%20conversion/DSC_9061Custom.jpg (http://s238.photobucket.com/user/lakeside53/media/Clausing%20conversion/DSC_9061Custom.jpg.html)


You don't need the poly-vee pulley nearest to the left -I just modified the original left vari speed sheave to prove it could be done to spec. lol.

The only small change I'd make now is to increase the poly-vee ribs from 6 to 10. Engaging the clutch heavily at some speeds makes the 6 squeak (slip) a tad. More belt tension might help too ;)


more pics here : http://s238.photobucket.com/user/lakeside53/library/Clausing%20conversion?sort=4&page=1

koda2
03-25-2016, 11:47 AM
lakeside53,
Very nice conversion!
Any comments about low speed attainable and low speed torque?
I assume single phase to three phase, but it must be 220V input for 3 hp?
You must have a different speed control and shutoff that is easy to get to.
Dave A.

Edit: Oops, I see the control box.

lakeside53
03-25-2016, 12:01 PM
Yes, I integrated the controls into original hydraulic speed control and front panel.

No material issues at the low end. I had the original 3hp motor, iirc set the low at 15hz and the top at 90hz (old motor - 120hz is pushing it...) and adjusted the ratios to suit the original speed control markings almost perfectly . If you really wanted high torque at low speeds, just go to back gear. HP is what you need, so "normal torque" at say 5hz isn't going to do much work! Remember, at 15hz you have about 1/4 of normal 60hz hp , and at 90hz about the same hp but 66% of the torque. (theoretical). Lots of VFD parameters to fiddle with to modify torque and mid-base points, but the average guy should leave them alone. For optimal material removal you need about 1hp per cubic inch per minute in mild steel. Most of these number are meaningless and unimportant to a typical home user - just make chips! ;)

Yes, Single phase 240v input.

bearzbear
03-25-2016, 01:12 PM
Yes, I integrated the controls into original hydraulic speed control and front panel.
<snip>Yes, Single phase 240v input.

YES!

I found your pix before this post!
The pot placed back up in the varispeed lever/control is great!!
I'd have put something up there to give it some resistance, rather than let it float free on the pot itself.
Some heavy silicone grease between two close fitting surfaces would do that trick, I think.
Also, hope you put some mechanical stops into the arrangement so that the lever action from the extended control doesn't rely upon the
internal stops in the pot itself?

Looks great!

Can you characterize the smoothness of the spindle & sound/noise of the spindle/drive before and after? Or was there only
an after? As I mentioned earlier ( I think ) of all the Yoohootoobe videos of these lathes, only one had only the high pitch whine of the
spindle without growl or rumble from the drive. That was out of about a dozen that I found.

_-_-

lakeside53
03-25-2016, 08:35 PM
There is a heavy grease in the housing for drag.

The spindle sounded fine... smooth, no whining.

bearzbear
03-25-2016, 09:39 PM
There is a heavy grease in the housing for drag.

The spindle sounded fine... smooth, no whining.

Interesting.
But I guess I was less than clear - the noise I hear and heard on the yoohootoobe vids was from the drive, not the spindle.
The good one the sound was just a whirrr of the spindle, pretty much as far as I could discern.

I was asking about your mod and if it was smoother/quieter than the stock system on your machine??
Or are you pretty much down to the noise of the motor with that set up??

-------------

So, you do not have oil up top in the housing of the spindle???
You say heavy grease?
I'd have expected the heavy grease to sling and end up standing off the moving parts (especially the ones that are moving
fast), no?

What sort of drag are you getting?
And why do you want/like some drag on the spindle?
Very curious now!

And why not just a heavy oil, like automotive gear oil (the stuff that goes in the differential case)?
They make nice heavy synthetic these days...