# Oscillation/Vibration in lathe



## calgaryguy (Aug 8, 2022)

Another post about my Standard Modern 9" lathe:

While running in some speeds and most noticeably in the two highest speed settings, I can feel and hear (if I listen closely) a oscillation/vibration in somewhere in the gear works.

I've been working on getting my tailstock aligned, and with a dial indicator touching the tailstock, I can see a ~.005 harmonic/oscillation/vibration occur. I'm wondering what effect this might have on my lathe accuracy. I realize this is a ~50+ year old lathe (guessing), and some wear/imbalance is to be expected.

I'm trying to get a video either linked or uploaded.

EDIT: Video No Sound. Converting from .mov (iphone) to mp4 seems to have stripped the sound. THere is a very very slight audible harmonic noise that aligns with the dial indicator oscillation. If I put the palm of my hand against the gearbox/headstock I can also feel a very slight oscillating harmonic


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## calgaryguy (Aug 8, 2022)

I should add that this Harmonic/Oscillation is most prominent when running at the '900 RPM' gearbox/belt setting.


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## YYCHM (Aug 8, 2022)

Try lifting the motor and see if the vibration diminishes.  My machine is belt tension sensitive.   I find that the looser I make the belt the better.









						9" SM Utilathe Restoration
					

Hatched another birds nest today :rolleyes:    Man, those things just materialize in the blink of an eye.  Ya, I know, we have had this discussion already.




					canadianhobbymetalworkers.com


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## calgaryguy (Aug 8, 2022)

I've been wondering about that. I've got mine setup with the spring tensioner.  I'm also using a 'Powertwist' link belt instead of a traditional rubber belt. They usually run smoother than a traditional belt and you never have worries about the belt taking a 'set' if left unused for a few months.


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## YYCHM (Aug 8, 2022)

calgaryguy said:


> I've been wondering about that. I've got mine setup with the spring tensioner.  I'm also using a 'Powertwist' link belt instead of a traditional rubber belt. They usually run smoother than a traditional belt and you never have worries about the belt taking a 'set' if left unused for a few months.



The powertwist is good, I went with one as well.  Keep that.


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## jcdammeyer (Aug 8, 2022)

Too many variables in that video.  It's possible that the long shaft isn't clamped 'correctly' in the chuck and that it's just off center enough (from wear in one of the jaws) that the shaft is telescoping vibration to the tail stock.

Start with no chuck. No work.  Put the dial indicator on the headstock and on the tailstock and see if the vibration is still there.  What does it feel like when there's no chuck.

Then put the chuck on, close the jaws all the way and do the test again.  

Next put a short piece of stock in the chuck, center drill for the tailstock and then replace the drill with the center and check if there is vibration.  

Is your lathe bed level.  I just went through that.  True, a twisted bed will only pivot the tail stock so you'd get taper but it also pivots over an arc.  That means the end away from the chuck is no longer in line with the chuck but off center.

If you were turning this long shaft between centers you wouldn't see a problem but the chuck is trying to hold the stock straight out while the tail stock is pulling it over.

Just some ideas.


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## calgaryguy (Aug 8, 2022)

jcdammeyer said:


> Too many variables in that video.  It's possible that the long shaft isn't clamped 'correctly' in the chuck and that it's just off center enough (from wear in one of the jaws) that the shaft is telescoping vibration to the tail stock.
> 
> Start with no chuck. No work.  Put the dial indicator on the headstock and on the tailstock and see if the vibration is still there.  What does it feel like when there's no chuck.
> 
> ...



The oscillation is present with nothing chucked in the lathe. This is the first time I've been able to *show* it on video via the dial indicator needle bouncing. 

I was planning to swap in the 4 jaw chuck I have and see if that changes things. Both the 3 jaw and 4 jaw have backing plates, and both are aligned per the previous owners (SAIT College I assume) markings.

My lathe bed is 'level' 
from a flat to the world perspective: I've used a 6" starrett machinists level and levelled the lathe end to end and front to back within .0015
from a alignment perspective: I've turned a 6" shaft and measured taper in it, and added shims under the tailstock end of the lathe bed(not under the tailstock itself) until my taper measured over 6" was about .0005-.001. I couldnt get it any better than this - I suspect a bit of wear in teh ways.


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## YYCHM (Aug 8, 2022)

calgaryguy said:


> The oscillation is present with nothing chucked in the lathe. This is the first time I've been able to *show* it on video via the dial indicator needle bouncing.
> 
> I was planning to swap in the 4 jaw chuck I have and see if that changes things. Both the 3 jaw and 4 jaw have backing plates, and both are aligned per the previous owners (SAIT College I assume) markings.



What's the run out on the 3J?

Try running it with out a chuck and see what the vibration is like.


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## jcdammeyer (Aug 8, 2022)

Remove the chuck and see if the vibration is still there.


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## calgaryguy (Aug 8, 2022)

YYCHM said:


> What's the run out on the 3J?


Measured where?

per my post I just added (prolly after you replied):

"
My lathe bed is 'level':
from a flat to the world perspective: I've used a 6" starrett machinists level and levelled the lathe end to end and front to back within .0015
from a alignment perspective: I've turned a 6" shaft and measured taper in it, and added shims under the tailstock end of the lathe bed(not under the tailstock itself) until my taper measured over 6" was about .0005-.001. I couldnt get it any better than this - I suspect a bit of wear in teh ways.
"


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## calgaryguy (Aug 8, 2022)

So before I dig deeper into this oscillation, its probably useful to ask "is it uncommon/rare for a lathe to have any sort of oscillation/harmonic?". I dont know whats normal and what isnt. Especially considering I have a 50plus year old lathe. And its a light duty lathe to boot (less cast to dampen harmonics I would suppose).


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## jcdammeyer (Aug 8, 2022)

My Southbend with ribbed belt stitched together with mig wire makes a once per belt rev ticking.  There's a certain amount of what you could call vibration on the tail stock at 1829 RPM.   But when you look at the belt from motor to 3 step flat belt pulley along with possibly out of balance pulleys I don't find the vibration overly onerous.


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## YYCHM (Aug 8, 2022)

calgaryguy said:


> Measured where?
> 
> per my post I just added (prolly after you replied):
> 
> ...



LOL.... You actually managed to use that 6" starrett machinist level?  I borrow one from @RobinHood and found it way too sensitive to do anything with.

Chuck something up in the 3J that you know is round (I use the shank from a broken 3/8" end mill) and measure the runout close to the chuck jaws.  I just reset my 3J on it's back plate yesterday.  It had developed 7 thou run out.  I can get that down to 1/2 a thou by tapping the chuck over relative to the back plate.

I don't think this has anything to do with the vibration you're seeing.


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## calgaryguy (Aug 8, 2022)

jcdammeyer said:


> My Southbend with ribbed belt stitched together with mig wire makes a once per belt rev ticking.  There's a certain amount of what you could call vibration on the tail stock at 1829 RPM.   But when you look at the belt from motor to 3 step flat belt pulley along with possibly out of balance pulleys I don't find the vibration overly onerous.



Do you think the vibration you experience affects your cut/finish quality or accuracy of cuts?


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## YYCHM (Aug 8, 2022)

calgaryguy said:


> So before I dig deeper into this oscillation, its probably useful to ask "is it uncommon/rare for a lathe to have any sort of oscillation/harmonic?". I dont know whats normal and what isnt. Especially considering I have a 50plus year old lathe. And its a light duty lathe to boot (less cast to dampen harmonics I would suppose).



Not uncommon for this class of machine.  If you were to step up to a 11" or 13" you would see a significant difference.


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## calgaryguy (Aug 8, 2022)

YYCHM said:


> LOL.... You actually managed to use that 6" starrett machinist level?  I borrow one from @RobinHood and found it way too sensitive to do anything with.



I had to machine 4 'feet' for my lathe cabinet from 3" solid bar, 2" thick with a levelling screw recess machined into each in order to be able to get any sort of fine adjustment and accuracy in the adjustments on the lathe cabinet adjusting screws. I can post pics if you like of the installed 'feet'. When the levelling screws were set straight on the concrete floor, adjusting the screws would either a) 'walk' the lathe cabinet around slightly as they turned, or b) seemingly dig into the concrete a little.


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## YYCHM (Aug 8, 2022)

calgaryguy said:


> I had to machine 4 'feet' for my lathe cabinet from 3" solid bar, 2" thick with a levelling screw recess machined into each in order to be able to get any sort of fine adjustment and accuracy in the adjustments on the lathe cabinet adjusting screws. I can post pics if you like of the installed 'feet'. When the levelling screws were set straight on the concrete floor, adjusting the screws would either a) 'walk' the lathe cabinet around slightly as they turned, or b) seemingly dig into the concrete a little.



Post away, I'm interested in your levelers.  Basically what I concluded from playing with  @RobinHood 's machinist level.  Fine adjusters were in order, but, that's not practical in my case.


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## jcdammeyer (Aug 8, 2022)

calgaryguy said:


> Do you think the vibration you experience affects your cut/finish quality or accuracy of cuts?


I'm happy with what I get but whether it matches someone else's standards I don't know.  Could be that my cuts are garbage but I'm not clever enough to know.


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## YYCHM (Aug 8, 2022)

calgaryguy said:


> I dont know whats normal and what isnt.


Like you, I didn't know what was normal and what wasn't when I got my Utilathe.  The first time I saw @RobinHood 's 13" (or was it 11"?) in action I went Ahhhhh I see.

@Janger is really close to you.   Have him show you what his machine exhibits for vibration etc.  AND he's got a really cool CNC mill.

@Johnwa isn't that far away from you either.  You could see how his Utilathe and South Bend behave.

The absolute smoothest machine I have seen so far is @eotrfish 's Emco.


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## YYCHM (Aug 8, 2022)

Try this....  I just discovered I can displace the tail stock a thou just by pulling the chuck through by hand????  At 900 RPM I'm seeing a 2 thou flutter at the tail stock.  The displacement is being measured between the bench and the tail stock, so I question if that really means anything.


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## calgaryguy (Aug 8, 2022)

Couple of updates:

Removed 3 jaw chuck. Oscillation at 900rpm belt/gearbox setting is unchanged from what I observed and posted in the video. Tested all 7 other speeds available, some show next to no oscillation on the dial indicator, some show .001-.002. 900 RPM is the worst with about .005 oscillation as shown in the video. Oscillation at 1500rpm setting (top speed for this lathe) is almost nonexistant.

A side note on speeds on this lathe. The original 3 phase 1/3hp motor plate said something to the effect of 1650 rpm. Its since been replaced with a 1725rpm single phase motor. I havent measured spindle rpm yet with any sort of device but I suspect the actual gearbox/pulley speeds will be slightly higher than the original ones noted on the gearbox nameplate.


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## phaxtris (Aug 8, 2022)

You could have a gear in the spindle gear box that is slightly out of balance and happens to hit it's stride at the 900 rpm setting, might not even exist with the original slower motor


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## jcdammeyer (Aug 8, 2022)

Was the pulley used on the 3 phase motor transferred to the new single phase motor?  Or is it a different pulley?
The reason I ask this is I've found that the zinc pulleys I used on my Gingery Lathe were notoriously not really round nor were the shaft holes precise.  So it has vibration.

And having cast and machined my own pulleys (poorly I might add on bore size) the driving pulley on the mill is almost imperceptibly slightly loose on the motor shaft.  And it's enough that I also get vibration at the higher RPMs.  I've not fixed that yet because the plan is to change over to toothed belts.  

When I do it again, I'll make sure that the arbor used is identical in diameter to the motor shaft and the arbor will be a lot shorter.  The pulley was turned between centers so it could be taken out and reversed in order to be able to properly turn the pulley flanks without major reset of the compound slide and to make turning the hub easier.


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## calgaryguy (Aug 8, 2022)

Same pulley as was on the old 3 phase motor. Both were 5/8" shaft/bore size.


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## jcdammeyer (Aug 8, 2022)

calgaryguy said:


> Same pulley as was on the old 3 phase motor. Both were 5/8" shaft/bore size.


So somewhere in the chain something is no longer (or maybe never was) balanced or out of round.  Good that you've eliminated the chuck.


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## garageguy (Aug 8, 2022)

Have you checked for a loose bearing somewhere in the drive line? They can run smooth at certain rpm's and then start to vibrate as speed increases. (or decreases) Most common with bushing types.


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## YYCHM (Aug 8, 2022)

9" SM Utilathe Restoration
					

Would I lie to you??????? never,,,,,, I might BS you a bunch but never lie to you,LOL. So if you have the same jiggle with the spindle in neutral or engaged then I think I would take out the pulley shaft and check the bearings. Even if the bearings seem okay I would still remove the gear...




					canadianhobbymetalworkers.com


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## Susquatch (Aug 8, 2022)

If I may, I agree with what @jcdammeyer said earlier in v this thread. You have waaaay too many variables going on at once. The other thing is that your video really doesn't let me see what is happening there.

My advice is to get someone who lives around there to drop by and look at it. From my perspective it could be anything from bench feet to loose parts to harmonics to gears to balance to to to to. 

If you can't get somebody to drop by, disconnect everything and start with just a spinning motor - with no belt. Then add stuff one at a time. 

Your indicator could be harmonic indicator shake in the indicator itself. Unless you are sure it isn't lying, use your hands instead. If you really want to know what happening, use your teeth (just kidding but you get the idea). 

Best indicator for stuff that shakes is an old guy who grew up around machines like that. 

My two cents from half way around the world.


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## CWelkie (Aug 9, 2022)

Susquatch said:


> use your teeth (just kidding but you get the idea)


Reminds me of a story from the development of the Rolls Royce Merlin engine ... apparently test engineers would check for detonation in an engine running in a test cell with a piece of metal between their teeth.

Seems engineers were made of sterner stuff back then.


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## Susquatch (Aug 9, 2022)

CWelkie said:


> Reminds me of a story from the development of the Rolls Royce Merlin engine ... apparently test engineers would check for detonation in an engine running in a test cell with a piece of metal between their teeth.
> 
> Seems engineers were made of sterner stuff back then.



Don't know about sterner stuff.....

I was part of an engine design team for a portion of my career. Detonation creates an abnormal vibration in an engine because there are two flame fronts and peak pressure occurs too early in the process - typically before top dead center. Sometimes it is called knock if it causes the piston connecting rod to touch the bearings. More often it is a pinging noise caused by the two flame fronts.

Either way, I can see how a sheet of metal might send signals to a stern engineers head!

Today, we have inexpensive systems in the lab that can monitor the entire process in great detail. And of course most vehicles have knock sensors now so no engineers get injured or hurt in testing.

My joke actually has a serious side though. The teeth and tongue are very sensitive and things like knock and other vibrations are easily detected where other methods fail. For example the human tongue can detect a height difference of just one micron!

If one was so inclined...... One actually could get a bite on the tailstock and get an incredibly good sense of how much vibration was going on!

Anyone who tries it should probably not admit it......


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## historicalarms (Aug 9, 2022)

CWelkie said:


> Reminds me of a story from the development of the Rolls Royce Merlin engine ... apparently test engineers would check for detonation in an engine running in a test cell with a piece of metal between their teeth.
> 
> Seems engineers were made of sterner stuff back then.


  I got a lesson on sound transfer years ago by an old man and a D9 cat engine. I fire a D9 engine one morning to warm up for the crew and shortly after starting that ol' girl started hammering like a trip hammer. The old ( old enough that he shouldnt even have been on the jobsite) owner of the machine was close by and came over to investigate where 40 or 50 thousand of his dollars were going in the next few days. after listening for a minute we kind of came to a hopefull conclusion that it was just an injector knocking, not a rod....but now the question is "which hole" is hammering.
     That old dude walked to my pick-up and grabbed a length of surveying lath from the box...ya, one of those 4 ft long rough cut pieces of wood sharpened on one end. The old guy touched the sharp end of that wood to the engine block and the flat end tight against his "good ear"....I thought "well that old guy has finally flipped out big time and time to call his family" ...but damned if he didnt go down from cylinder to cylinder and turned to me and the mechanic who had showed up "its # 4". He handed me the stick to confirm but i sure didnt want to be the next on accused of being a lunatic so relented to the mechanic to giv'er a try . The look on his face when he got to #4 told me it was safe to take my turn....that 30 cent piece of wood was better than any stethoscope I ever used.


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## PeterT (Aug 9, 2022)

I had a harmonic vibration on my 14x40 lathe that was related to the motor mount. Its kind of a swing plate affair. The idea is you can accommodate slightly different belt lengths or adjust for belt elongation to some extent. But once you get tension set, you are supposed to secure plate/motor in position so its locked. At some point I either ran out of adjustment room or got forgetful. With the plate a bit loose it would start to do a harmonic bounce at certain rpms, which was also evident in the cutting finish.

Did you think it was vibration free before & now something changed? Or do you feel you are picking something up that was there all along & you are just noticing it now more with run time familiarity?


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## YYCHM (Aug 10, 2022)

calgaryguy said:


> Same pulley as was on the old 3 phase motor. Both were 5/8" shaft/bore size.



Have you reached any conclusions regarding the vibration issue yet?


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## calgaryguy (Aug 10, 2022)

YYCHM said:


> Have reached any conclusions regarding the vibration issue yet?



Its either in the headstock (I dont think so instinctively), QC gearbox or lead screw (maybe?) or its in one or both of the drive step pulleys (most likely IMO). The baldor motor I put on this was brand new in the box and super smooth when bench run. 

Unless someone chimes in and says 'thats bad and it will affect the precision of your cuts' I'm inclined to ignore it now. This thread has had a fair number of views and if this was a common 'bad' thing I'm sure I would have heard by now.


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## calgaryguy (Aug 10, 2022)

PeterT said:


> Did you think it was vibration free before & now something changed? Or do you feel you are picking something up that was there all along & you are just noticing it now more with run time familiarity?


Its never been vibration/oscillation free. I've heard/felt the subtle oscillation in the past at the noted specific rpms, but had no idea how I'd communicate it in this forum to pose the question "is this bad/wrong?". The dial indicator oscillation in the video link above visually shows what I've been hearing and feeling in the machine.


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## YYCHM (Aug 10, 2022)

calgaryguy said:


> Its either in the headstock (I dont think so instinctively), QC gearbox or lead screw (maybe?) or its in one or both of the drive step pulleys (most likely IMO). The baldor motor I put on this was brand new in the box and super smooth when bench run.
> 
> Unless someone chimes in and says 'thats bad and it will affect the precision of your cuts' I'm inclined to ignore it now. This thread has had a fair number of views and if this was a common 'bad' thing I'm sure I would have heard by now.



Did you try lifting the motor and slacken the belt tension as I discovered?


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## calgaryguy (Aug 10, 2022)

YYCHM said:


> Did you try lifting the motor and slacken the belt tension as I discovered?


Yes I did. It didnt seem to have any effect on the oscillation.


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## jcdammeyer (Aug 10, 2022)

calgaryguy said:


> Yes I did. It didnt seem to have any effect on the oscillation.


You had a dial indicator on the tail stock.  Can you put it on the driving pulley and then on the driven pulley?  Obviously not powered.  
Is it possible to remove a gear or something so you are only turning the spindle and not a single gear?


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## RobinHood (Aug 10, 2022)

Generally, any vibration/oscillation affects the performance of machines. So if you can eliminate/reduce them, it would make your lathe perform better. Does the present condition stop you from using it? No. Is it annoying? Yes.

I believe it has been suggested above: try to find out which component (or component combo) causes the issue. I would start with the drive pulleys (you stated the motor itself runs smoothly on the bench).

Disconnect the belt. Run the motor with the drive pulley installed.

Connect the belt. Leave the lathe in neutral and feed disconnected. Run the motor. Repeat for all pulley combos.

Run the lathe in all spindle speeds (feed disconnected), no chuck installed.

Run lathe in all speeds with feed connected (run in all spindle speeds and all feed speeds).
Repeat for reverse feed.

Run the lathe in all speeds (feed disconnected) with 3J and then 4J.

Run lathe with 3J and 4J and feed connected (both forward and reverse) in all spindle speeds and all feed speeds.

I would make a spread sheet or a table. This is going to take a while.

You should be able to find which combo causes the issue.

If you need help, let me know and I can come over at a mutually convenient time.


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## YYCHM (Aug 10, 2022)

@RobinHood has had experience with the 9" Utilathe, so he has some feel for what to expect from one.  He had one for a bit.....









						SM 9" Utilathe for sale
					

I have a Standard Modern 9" Utilathe for sale. 22" between centers. QC gear box. Kobayashi (made in Japan) 3 jaw. Pratt (made in England) 4 jaw. Taper attachment. Steady rest. Drive plate. Face plate. QCTP + holders (this was made by the previous owner). Original lantern toolpost with tool...




					canadianhobbymetalworkers.com


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## Susquatch (Aug 10, 2022)

@calgaryguy - do everything that @RobinHood has suggested. 

As the last step, take him up on his offer. But my wise old advice is to make sure you have religiously done as he suggests first. You can bet when he comes he will do them over. You want your vibration fixed but you don't want that "RobinHood Look" as he draws his bow either. 

It's an ideal outcome for you. Some great advice and an old guy as per my earlier advice. 



Susquatch said:


> Best indicator for stuff that shakes is an old guy who grew up around machines like that.



If it doesn't get handled, then I would say you are gunna have to learn to live with it. 

If he bites on your tailstock, we all want a picture......


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## Degen (Aug 10, 2022)

Try remounting your pulleys, that can be a little out, same with some of your shafts.  Remounting can negate the effect or make it worse, but at least you know where it is.

The second suggestion is change you belts, if the have a touch of variation in them well the faster they travel the more you notice the vibration induced.


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## calgaryguy (Aug 12, 2022)

Degen said:


> Try remounting your pulleys, that can be a little out, same with some of your shafts.  Remounting can negate the effect or make it worse, but at least you know where it is.
> 
> The second suggestion is change you belts, if the have a touch of variation in them well the faster they travel the more you notice the vibration induced.



I'm using a 'link belt'. I had a brand new V belt on it before and the link belt, while a tad noisier, is smoother.


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## calgaryguy (Aug 12, 2022)

My answers to Robinhood's questions/suggestions inline below



> Disconnect the belt. Run the motor with the drive pulley installed.



Much less oscillation in this config. I'd call it negligible.



> Connect the belt. Leave the lathe in neutral and feed disconnected. Run the motor. Repeat for all pulley combos.



Oscillation is present in this config as previous reported/video'd. This tells me if its in the headstock its isolated to the input shaft. 



> Run the lathe in all spindle speeds (feed disconnected), no chuck installed.


Havent done this one yet



> Run lathe in all speeds with feed connected (run in all spindle speeds and all feed speeds).
> Repeat for reverse feed.



I have done this with and without the 3J installed. Same oscillation as previously reported/recorded - most noticable at the 900 RPM belt speed. 



> Run the lathe in all speeds (feed disconnected) with 3J and then 4J.
> Run lathe with 3J and 4J and feed connected (both forward and reverse) in all spindle speeds and all feed speeds.



I havent done this yet.

I really suspect the headstock 4 step pulley. Visually there seems to be no runout in it, but these kind of cast aluminum pulleys have given me vibration/harmonic issues in the past. 

*If* I do narrow it down to the headstock 4 step pulley, what can I do about it? Can new pullies be sourced? Can I have this one balanced? And I'm back to asking 'does it really matter' on a lathe of this size?





> I would make a spread sheet or a table. This is going to take a while.
> 
> You should be able to find which combo causes the issue.
> 
> If you need help, let me know and I can come over at a mutually convenient time.



Thanks so much Mr R. I sincerely appreciate the offer.


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## Degen (Aug 12, 2022)

calgaryguy said:


> I'm using a 'link belt'. I had a brand new V belt on it before and the link belt, while a tad noisier, is smoother.


The link belt will definitely smooth somethings out.

Again check your pulleys,  since they are likely cast that can be the cause.


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## PeterT (Aug 12, 2022)

There have been some posts where people inherited an out of balance backplate adapter for their chuck or the chuck itself. The cavity pattern was not cast properly so has a counterweight effect. But I think it was described as mild at low rpm & really bad at increased rpm, which makes sense. Reading between the lines of your latest investigations, sounds like you've ruled that out.


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## RobinHood (Aug 12, 2022)

Any time Chris.

Just thought of something now that you suspect the pulley on the input shaft: how about taking it off and mounting it on the motor directly. Run the motor. If the vibration is present, it is definitely the pulley. If there is no vibration, then it is the input shaft itself. Could be a bad bearing (or both of them) on that shaft. My 9” Utilathe had bad input shaft bearings. The new owner replaced them first thing and reported noise/vibes went away.

One could try and balance the pulley. Or find a replacement/make one. A shop made one should be more balanced from the get go compared to a cast one.

I would try and reduce the vibes as much as possible. The lathe will be much more pleasant to run after.


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## calgaryguy (Aug 13, 2022)

:thumbsup:


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## Proxule (Aug 14, 2022)

This may not help you but I had similar issues, https://canadianhobbymetalworkers.com/threads/unbalanced-4-jaw-on-my-12x36.3701/
It was an unbalanced 4 jaw and 3 jaw chucks.
Gluck


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## calgaryguy (Aug 15, 2022)

Proxule said:


> This may not help you but I had similar issues, https://canadianhobbymetalworkers.com/threads/unbalanced-4-jaw-on-my-12x36.3701/
> It was an unbalanced 4 jaw and 3 jaw chucks.
> Gluck


Oscillation is present without chuck mounted. Thanks for the link tho!


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## Susquatch (Aug 15, 2022)

calgaryguy said:


> Oscillation is present without chuck mounted. Thanks for the link tho!



I thought that but didn't want to reply on your behalf cuz I wasn't positive.

I sorta like @Degen s suggestion to use an app, but couldn't find anything on Android that would do Fourier analysis to my satisfaction. Basically, you need something that does more than just comfirm that it's shaking. You need to know the component frequencies and their amplitudes to be able to use the info effectively. If you can find one with good ratings that is in your budget, it might be WAY better than biting down on the tailstock. Prolly not as effective as an old guy like @RobinHood though.


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## Degen (Aug 15, 2022)

Susquatch said:


> I thought that but didn't want to reply on your behalf cuz I wasn't positive.
> 
> I sorta like @Degen s suggestion to use an app, but couldn't find anything on Android that would do Fourier analysis to my satisfaction. Basically, you need something that does more than just comfirm that it's shaking. You need to know the component frequencies and their amplitudes to be able to use the info effectively. If you can find one with good ratings that is in your budget, it might be WAY better than biting down on the tailstock. Prolly not as effective as an old guy like @RobinHood though.


Some of the apps have 2 or 3 axis vibration sensors output (using the phones internals).  Lay your phone on the lathe and it tells you which axis is the worst.  Even if you rotate slowly by hand you can determine the source.

There is a video on YouTube of a guy setting up a machine eliminating the vibrations with this type of application (about 3-4 years ago).


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## Susquatch (Aug 15, 2022)

Degen said:


> Some of the apps have 2 or 3 axis vibration sensors output (using the phones internals).  Lay your phone on the lathe and it tells you which axis is the worst.  Even if you rotate slowly by hand you can determine the source.
> 
> There is a video on YouTube of a guy setting up a machine eliminating the vibrations with this type of application (about 3-4 years ago).



Degen has a very good point @calgaryguy. I was thinking more in terms of the frequency components, but directional components might be even more useful and there are lots of that kind of app out there.


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## Degen (Aug 15, 2022)




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## jcdammeyer (Aug 15, 2022)

That is pretty cool!  Thanks for posting that.


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