If money was no problem, what would you get??

RAY
Much appreciate the research on this.
"Tis good to listen to someone who has sold Lathes almost all his Life.

What does concern us a bit though is whether the SPINDLE BEARINGS would last the distance on this "VARIABLE-SPEED" driven Machine. U see, the Manufacturers stated top speed with the INVERTER is 2'000 RPM. We asked for this to be increased to 2'500 RPM with an similar increase in size of the MOTOR from 2 HP to 3HP. They agreed, obviously at a Price. However, we really don't know if that is what we will really get at the end of the day. We need the extra "Voom" more for very light finish cuts and POLISHING. Our present 14 x 40" running at 1'800 RPM top speed, does give us very satisfying Finishes, although it seems like we are pushing things a bit when it comes to continued POLISHING at these maximum speeds. We are working quite a bit on S/S and Ti and these Steels can be rather demanding both on machine and Labour.

Come to think of it, most of the top Branded HIGH SPEED Machines like the Hardinge copies ie., Eisen, Sharp and Cyclematic including the UK old stalwarts Colchester and Harrison are all today made in TAIWAN. So for us, there just might be a scare of the unknown factor lurking like a phantom.
Although this manufacturer we are dealing with may not be a top end Machine Supplier, we are sure, they are however exposed to the Standards of their competition and contemporaries in their own Country.
It all might just get together evenly.
Would like to know what U think.
Thanks again, graciously.
LORD BLESS
aRM

Splash lubrication is sufficient even for higher speed machines. My Colchester Chipmaster has a top speed of 3000 rpm and has a splash lubricated headstock. The headstock oil I use is Shell Morlina S2 BL 10 (which is the recommended oil). This oil has a viscosity of 10 and is pretty much like water.

At these speeds, the quality of your lubricant, size of your spindle bearings and stability of the machine is put to the test. This also means that the chucks you use need to be rated for these speeds and then you start talking higher level equipment. Both my 3 and 4 jaw chucks are rated to 3000 rpm and would likely cost the price of a cheap hobby lathe on their own so it's not simply a case of increasing the speed of a machine.

You really need to invest in good oil and keep a very strict maintenance routine when you start talking higher speeds. Regular checks are necessary at each day and checking that chucks and work are secure become critical. A 4 kilogram chuck spinning at 3000 rpm becomes an unstoppable missile.

I don't think it would be a problem to increase the speed to 2500 rpm, provided the mass of the work you turn is not too high or unbalanced as this would put a lot more strain on the bearings.

Paul.
 
I am pretty sure the effectiveness of splash lubrication depends upon the design of the headstock. It did not keep the low speed shaft bearings of our 16" Grizzly lathe at work from going bad. I have the brother of that lathe at home. It is still in very fine shape because it has been used a lot less. We made heavy axles and bearing boxes for many of the wagons and carriages in the museum on the lathe at work,running at slow speeds.

Another problem with Taiwan made lathes is they always seem to leak oil from their headstocks. I tried to fix the one at work,but never solved the problem. Oil leaks out through the shifting levers,where they come through the side of the headstock. In my case,using lighter weight oil would only make the problem worse.

About Hardinge copies: I believe even the copies state that they use at least grade 7 bearings,possibly grade 9. The Hardinge uses grade 9. Back on the 90's Hardinge wanted $1250.00 to change the headstock bearings. They wanted you to remove the headstock and send it to them,so they could install and pre load the bearings properly. These days that price has probably doubled.

I don't know what grade bearings the average Taiwan 14" lathe uses,but,no doubt,it affects bearing life,along with the lubrication efficiency.
 
Guys, just want to mention that I completely agree that a pressurized system is very desirable but, my definition of a "pressurized" system is not a small pump that trickles oil over a gear. My definition is more on the order of an automobile where channels and grooved bearing areas are fed under 30-40 PSI. There are lathes out there with that kind of system -but it's not in our price range.

I worked on a lot of antique diesel engines and many had various forms of "flappers" connected to a convenient rotating part that splashed into the oil and enhanced the distribution. All the famed "Lister" engines worked this way (they used a 4" long rod connected to the crankshaft). If you have a much older machine whose design does not included the benefit of a more modern layout, I think a more effective method and less likely to cause foaming, is to make some cam-like fins or protrusions attached to an appropriate spinning component that splashs the oil where it's needed. I would not even consider this on any lathe where you do not suspect (and have verified) a problem.

Translated: If you value the warranty on your newer equipment, don't mess with it unless A) you really know what you're doing B) you've discussed it with the seller who supports the warranty.

If you've ever made the mistake of (or did it out of curiosity) running an engine with the valve covers removed, you'll have a rough clue of how vigorously the oil is splashed around inside a gearbox. If you're really that curious, cut a hole in your gearbox cover and make and install an acrylic sight glass...

Ray
 
Any ideas on small pumps that could be mounted on the backside of headstocks,with small copper pipes running to bearings?
 
George,

See the last post I made. Is there any way you can firmly attach a "flapper" of some sort that will splash into the reservoir and direct oil to the place it's needed? Maybe some small fins on the side of a nearby gear (of course, they would need to be attached very solidly).

I don't think an aquarium pump will do too well with 20-30 W oil. Even if it did manage to suck-up the oil, the air moving around from the turbulence of the exposed gears would might make it difficult to direct the trickle of oil on the place you want it most.


Ray
 
I deleted that,Ray. I forgot that an aquarium pump pumps AIR!! Senior moment. I used to use one to bubble through turpentine to thicken it into becoming terpene resin for making varnish for violins. Very hard to find genuine turpentine these days. Oh,you can buy a point of Grumbacher's artist's turpentine for $35.00. It's still genuine.


Old Chevy 6 cylinder engines had little scoops on the bottoms of their connecting rods. People would wear the engines out using them for dune buggies,and climbing steep dunes so the bearings would not all get oiled.
 
I assumed you meant a Pond Pump. My wife has these ponds in the front with small pumps but I doubt they will suck-up oil.

Yes, the old Lister engines for example had a 4" rod screwed into the counterweight on the crankshaft. The rod was peened flat on the end and bent to a slight hook. It splashed oil all the way up to the piston connecting rod and piston skirt. They were stationary engines on level ground. Many of those old engines were known to run for 20 years of near continuous use w/o a rebuild. Only turned off when changing the oil. They were 3.5 horsepower and weighed about 1200lbs. -Extremely high service rating.

Ray


I deleted that,Ray. I forgot that an aquarium pump pumps AIR!! Senior moment. I used to use one to bubble through turpentine to thicken it into becoming terpene resin for making varnish for violins. Very hard to find genuine turpentine these days. Oh,you can buy a point of Grumbacher's artist's turpentine for $35.00. It's still genuine.


Old Chevy 6 cylinder engines had little scoops on the bottoms of their connecting rods. People would wear the engines out using them for dune buggies,and climbing steep dunes so the bearings would not all get oiled.
 
I am pretty sure the effectiveness of splash lubrication depends upon the design of the headstock. It did not keep the low speed shaft bearings of our 16" Grizzly lathe at work from going bad. I have the brother of that lathe at home. It is still in very fine shape because it has been used a lot less. We made heavy axles and bearing boxes for many of the wagons and carriages in the museum on the lathe at work,running at slow speeds.

At low speeds I can understand the problem. I am not sure that the lathe running 2000 - 2500 rpm will suffer the same fate as the oil will be circulated and disturbed sufficiently to lubricate and cool. The best solution would be to open the headstock and have a peek.

Most of the higher quality lathes have channels or gutters that direct the oil to the various gears and bearings. The gears will fling enough oil to have a pretty consistent flow of oil. Splash lubrication is a little misleading as most people assume that the gears themselves have to create enough of a disturbance to direct oil droplets directly into the bearings.

The biggest benefit to a pressurized lubrication system is the aspect of filtration. I have not seen a splash lubricated headstock with filtering, which would suggest that the pressurized system would provide longer service life as less grit would find it's way into the bearings.

I know this is common knowledge to those who have worked on machines so I apologize if my posts look like I'm teaching people to "suck eggs".

Paul.
 
A couple thoughts...

Over the past 10 years (approximately) all the most serious flaws with lathes coming from Taiwan and China have been resolved. In the 1950's, Leblond, which is a very good lathe had problems with a feature called "Servo Shift". In time, the problem was resolved. It's the same thing going on here. Almost any lathe that is not a low end hobbyist machine is actually pretty good. The basic designs are good but quality control must be closely observed. Some brands of the same model are better than others and it depends if the factory was instructed to "make them real fast" or "pay attention to quality".

Most bench lathes have a top speed of about 1800 RPMs and some will go up to 2200. For bigger lathes, people usually work on bigger parts that have higher surface speeds and therefore 1800 RPM is usually fast enough. Most commercial chucks (3 Jaw and 4 Jaw) that are between 6" and 8" are only rated for speeds up to 2500 RPM. Collet chucks can spin much faster but can only hold smaller parts and they are more commonly found on smaller lathes that have higher speeds.

This is what the inside of most lathes looks like now (see below). You can see that most of the gears are under oil. Even the spindle bearings are half-way covered by oil. Nothing is going to go dry there. This is a Taiwanese gearbox and the design is very similar for many others -just bigger or smaller depending on the machine.


PM-1340GT-Headstock-Gears2-245x164.jpg

Here is a lathe from Taiwan. -Very high end machine. The spindle has 3 support bearings. It is not cheap but, I know these are available from dealers all over the world. I don't know what your financial budget is but, this machine is about $25,000 (USC). If you want more information about it let me know. Since this is a Hobby Machine website, I don't often discuss the high-end professional equipment but, I have some knowledge of what the best machines out there are and who makes them and what factory they come from. The machine here is as good as they come. It will go head-to-head with any big brand. The factory that makes these also makes the lathes for all the big brands -and this is their "house version". Top Of The Line Machine...

View attachment 61644

Ray
Hello RAY
Thanks again for this enlightening info.
We have our 14 x 40 for the heavier work which we are presently using with good results.
For the higher speeds we had planned on using our 5C COLLETS with a DRAW TUBE, more for the finishing, polishing and like U say, smaller work.
Regrettably we don't have an unlimited Budget, for now.
However, we think at around US $ 7K we would be able to get a decent quality machine.
Allow me to explain.
When we look at the numerous Grizzly ads for the approx sized Lathe in our Price/Size range, we envy the prices U Guys pay for Tooling. Let's do a comparison and look at our intended equivalent. Your 14x40 "Gunsmith's Lathe WITH ACCESSORIES retails for US $ 4'495.00. We reckon that this machine will deliver fairly good if not high ACCURACY, maybe not as good as Your Southbend or Precision mathews ???
Now compare my machine, ( pictures and details below ), costs US $ 4'990.00 - WITHOUT many ACCESSORIES.
The following Accessories had to be included at an extra US $ 2'141.00
"CE" Standardisation - including LEADSCREW COVER and CHUCK GUARD
FOLLOW REST
MICRO TYPE CARRIAGE STOP
QCTP WITH HOLDERS
5C HANDWHEEL DRAW TUBE
WORK LAMP
DRO (SINO) and
SURCHARGE FOR 3HP MOTOR from 2HP
The Total Price now loads up to just over US $ 7 Grand !!!
We reckon this figure should acquire us a fairly good machine. OK, it's definitely not in Your top bracket range, but it's almost 55% more than Your advertised GRIZZLY. And don't forget we want a smaller BED which is only 24" and not 40" !!!
Don't know if U agree with our line of thinking ???
However, we have supplied pics of the intended import and U can tell us whether this is a good buy.
Would be nice hearing from U.
kindest regards
aRM

1224BV~1340BV-2.jpg 1330_1440-1.jpg 1224BV~1340BV-1.jpg

PM-1340GT-Headstock-Gears2-245x164.jpg
 
Last edited:
Back
Top