# 1340gt Splash Lubrication Limits?



## wrmiller (Apr 29, 2015)

What are the approximate rpm limitations of splash lubrication? For example if I wanted to run a 5c collet chuck at 2500-2600 rpm would the splash system be adequate? What about higher rpms? TIA.


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## coolidge (Apr 29, 2015)

Not sure what you mean by 'splash' Bill but without an enclosure around the machine anything more than probably those air/spritz/drop type coolant systems at higher rpms will have coolant flinging all over the place. That's one thing I like about fully enclosed CNC machines you can blast the coolant at high pressure regardless of spindle speed. An indexible drill with through coolant at 1,000 psi drilling a big ass hole so fast it looks like a crash, oh yeah OH OH OH.


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## darkzero (Apr 29, 2015)

He's talking about the headstock. It's a "splash" lubrication system, no oil pump.


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## wrmiller (Apr 29, 2015)

Yes, headstock gearing lubrication. I read somewhere a while back about someone saying that at some rpm level splash lubrication becomes ineffective(?) and you have to go to a pressurized type system.

I was looking at a 16x40 lathe today that can swing a 9" 3 jaw chuck at 2500 or 2600 rpm and it has a pressurized system, so I was wondering where the cutoff was. I 'assume' it's a function of rpm but that's just a guess on my part.


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## JimDawson (Apr 29, 2015)

Just a guess, but I assume that if you stay in the factory RPM range on any lathe, the lube system would be adequate be it splash or pressure.

Consider stick transmission in a car, that's a splash system and under a lot more load and RPM than most lathes.


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## wrmiller (Apr 29, 2015)

JimDawson said:


> Just a guess, but I assume that if you stay in the factory RPM range on any lathe, the lube system would be adequate be it splash or pressure.
> 
> Consider stick transmission in a car, that's a splash system and under a lot more load and RPM than most lathes.



Good point on the transmission. And I'm not saying I believe what this gentleman said about it's limitations. I'm just asking to see if anyone has any real world experience or expertise in the matter. I suspect that pressurized is more consistent in it's lubrication application which would become more critical as lathe size/load increases, but it is also more expensive which is probably one reason why you don't see this system on smaller/cheaper lathes.

I would be exceeding the factory rpm range, but I have seen other lathes in this size range that go up to ~2k with a splash system.


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## JimDawson (Apr 29, 2015)

My Jet turns 2000 and it has a splash system.  My only concern would be foaming on a prolonged run.  I think there are oil additives that prevent that.  I run AW 46 hydraulic oil in mine and have not noticed foaming, but I have never pulled the cover off after a high speed run, but the site glass remains pretty clear.


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## darkzero (Apr 29, 2015)

Automotive manual transmission would be similar but not really. Manual trannies are filled much more with oil than lathe headstocks in the class being talked about. They also mostly use helical gears which have a higher tendency to pick up & keep oil on the gears. Most use thicker viscocity oils also (gear oil, except Honda).

I personally don't think you will have an issue. Oil foaming would be my only concern aside from bearing ratings but you should be fine with that. As mentioned there are additives to reduce foaming & there are circulating oils formulated to reduce foaming as well.

If you plan to run at those high speeds often I'd consider going with a slightly thicker oil. But if you live in extreme cold climate the thicker oil might be a problem. I'm thinking about going with a thicker viscocity in my headstock only even though I don't have any immediate plans to increase my spindle speed, but I live in SoCal. I'm currently running ISO 68 in my headstock (lathe & mill), apron, & in my air compressor pump.


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## wrmiller (Apr 29, 2015)

No, I wouldn't be running much above the factory 1800 very often as I have a small lathe probably better suited for that. I was just asking Matt about the optional collet changer for the 1340 and was wondering what the upper rpm limit for the lathe might be. I'd probably be better off putting a 5c collet chuck on the little guy for small/high speed work and save the bigger lathe for the larger/slower stuff. Thanks everyone. (where's the 'thank' button?!?!)


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## darkzero (Apr 30, 2015)

IIRC, collet closers (if that's what you were referring to) aren't meant to be ran at very high speeds. The bearing(s) on the handle/closure end can run hot at high speeds for long periods of time. Especially if you don't have them tensioned properly. At least that's what I remember running them on Leblond Regal lathes.


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## mksj (Apr 30, 2015)

FYI, this came up recently regarding a G4003G. I would review the thread below, but the bottom line, probably 2000RPM to be on the safe side, unless QMT say you can go higher and not void the warranty. Heavier oil, in contrast to what one would assume, performs worse at the higher speeds with splash lubrication. It's a matter of getting the oil to the lathe bearings, and not the bearings themselves. Also the drag and heat formation can go up significantly with the heavier oil, and I have read a number of accounts that did not have good outcomes. Grizzly lathes and many other brands run ISO32 oil in these smaller lathes. Better off to use your 8K for high speed.

http://www.hobby-machinist.com/threads/maximum-safe-rpm-for-a-grizzly-g4003g.34408/#post-291473

I am going to purchase the tru-setting 5C D1-4 chuck from Lathemaster, very reasonable if the quality is decent.
http://www.lathemaster.com/lathemaster 5c collet chuck.htm


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## wrmiller (Apr 30, 2015)

Yea the collet closer is what I was originally asking about, but you're right the 5c chuck would be better for high speeds. I've seen high speed work done on a HLV w/closer but that machine is in a different galaxy compared to my stuff. 

I'll get a 5c chuck for the 8k and call it good. Thanks again guys.


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## qualitymachinetools (May 1, 2015)

I am not going to recommend it, but all I can say is that I have done it with no problem at all. Just keep an eye on it and if it gets pretty warm, stop or slow down. But normally when running a lathe, like that, you will have it on for a bit, stop, do whatever, maybe back on, not like its constant most of the time anyway.

  I wouldnt go too fast, but 2200-2500 RPM would be fine. For the lathe anyway, just be careful with the chuck. 
 Not with the lever collet closer as mentioned though. Too fast for that.


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## wrmiller (May 1, 2015)

qualitymachinetools said:


> I am not going to recommend it, but all I can say is that I have done it with no problem at all. Just keep an eye on it and if it gets pretty warm, stop or slow down. But normally when running a lathe, like that, you will have it on for a bit, stop, do whatever, maybe back on, not like its constant most of the time anyway.
> 
> I wouldnt go too fast, but 2200-2500 RPM would be fine. For the lathe anyway, just be careful with the chuck.
> Not with the lever collet closer as mentioned though. Too fast for that.



Hi Matt, thanks for the info on the lathe. As we talked about today, I'll try to do most of the high-speed work on the SB and save the 1340 for the larger/slower stuff. FYI the max rpm on the Pratt 8 1/4" is 4900 rpm so not worried about it. I'll let you know how the two-stage braking works with this big boy.


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## qualitymachinetools (May 2, 2015)

Hey Bill, OK Sounds great!


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## GarageGuy (May 10, 2015)

There is a quick and easy way to check the efficiency of the splash lubrication.  Just take the cover off your gear head, and fire it up at top speed.  My guess is that you'll be taking a massive oil bath (I didn't say it wouldn't be a messy test!)    When I run my lathe at top speed, oil tends to seep out of the gaskets and seals just a tiny bit.  I'm sure this is because there is a full fledged oil storm going on inside that gear case.  I wouldn't worry about lack of lubrication at high speed unless the oil in the gear case is very low or empty.

GG


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## qualitymachinetools (May 10, 2015)

No kidding, we have about an 18' ceiling in the shop here, and I am pretty sure that has been hit with oil before from doing just that.


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