1340gt Splash Lubrication Limits?

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
 
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. :)
 
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.
 
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.
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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. :)
 
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!) :grin: 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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