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03-04-2007, 07:46 PM #1
I not so long ago aquired a hardinge cataract bench lathe, it's just like the forum logo but with ball bearings and having the spindle lock pin at the back of the headstock. There are also two oilers (or should be when I get one replacement).
It is the same lathe I mentioned in the BA threads topic.
Anyway, it needs a motor, bench and odd bits and bobs plus a cross/compound slide in some form at a later date.
I've decided to use the two levers on the front of the lathe, linked to some switches (I'll probably make) along with a DC motor. There's also a kind of work bench at my grandparents which looks like it may be of a suitable size to mount it on.
The lathe is currently in my room (upstairs) and I'll work on one part at once, cleaning, oiling etc and then painting, until it is done.
Hopefully I can post some before and after pictures when I've gotten part way.
Before I start on the headstock I'd like to ask about the spindle and bearings.
In the past I have read the discription of replacing HLV spindle bearings but I don't know how similar the process is.
I'd like to know what to expect if I dare take them out (I say dare as the spindle has little runout).
Also, the headstock has the spindle brake missing, - I assume missing because I gather there's suppost to be something which rubs on the pulley.
Can anyone shed any light on this?
03-04-2007, 08:10 PM #2
There's actually a thread about this, somewhere
back there. [img]smile.gif[/img]
The spindle brake is probably just mis-adjusted,
it's mechanical probably and should operate
when one of the sticks is off teh center position.
If the countershaft has been shifted then the
brake needs to be adjusted to come on and off
03-04-2007, 11:57 PM #3
The mid-1930's Cataract lathes with enclosed headstocks (PM logo) have a brake inside the headstock. The adjustment is through the opening on the rear of the headstock, covered by the steel plate that has the serial number stamped on it. The one I rebuilt needed a new strip of friction material. It was flat braided stuff, maybe asbestos-rich, that I got from a local automobile brake shop. Today, I would not try to buy anything that might be asbestos.
The bearings were very difficult to remove. First the spindle had to come out. There were a bunch of internal snap rings in the headstock, holding a bunch of sheet cork oil seal rings. The cork broke into fragments. Replacement bearings cost a fortune. I made new cork rings, but the diameters and concentricity were difficult to get just right. I sold the lathe soon after I finished making it look like new and replaced it with a more modern 1945 model. It was much easier to rebuild, and I still have it.
The moral is, if the headstock bearings work, leave them alone. If the brake cannot be adjusted to work, leave it alone.
These days, at least in the USA, I think a three phase motor and VFD is a better bet than DC. But you work with what you have and understand.
03-05-2007, 10:36 AM #4
Agree on the 'leave it alone if it's not busted'
theory of life. The open belt ball bearing
headstock was not tough to re-work, and the
bearings were relatively inexpensive - but
I would say that trying to take the bearings
out of an *enclosed* headstock is more trouble
if only judged by taking my ESM-59 partially
apart - I am sure the factory had special
tools and wrenches, and the preload nut on
the spindle was hella tight.
I was unaware however of the intricacies of the
"PM Logo" type headstocks!
03-05-2007, 02:20 PM #5
My brake seems to be missing, depending how I feel I might decide to make one from scratch using something like a pivoting lever with a brake cork or small leather belt.
I'm still open to using a two speed 3 phase motor but I'd like create a setup bearing some resemblance to the original - using the two levers on the front of the lathe.
It depends if I find a suitable 3 phase 2 speed motor or a DC motor of suitable voltage and HP first.
It looks as though I'll definately be making two switches myself as I have suitable materials, so they can be linked to the hand levers.
Unfortunately the headstock cover plate on the back is missing.
Judging from the PM logo and parts of my lathe I'll be interested to see if the end of the bed is nicely finished when uncovered.
I have seen a couple of threads about the spindles but I decided to ask because I only found two and wasnt sure how much the open headstocks have in common with the enclosed type.
I'm quite fond of the "don't fix what isn't broken" phrase,
however I'm unsure whether to take out the spindle, mainly because I'd like to paint it properly (there's still a sample under the High Low badge which I'm in the process of removing), probably in Jap black, just removing the paint with the spindle in situ will require some extreme masking/covering to be on the safe side. Also I'll be able to clean out the old oil if it is disasembled.
03-05-2007, 04:35 PM #6
Here is an alternative to using a two-speed motor. Get a VFD and a three-phase motor with a low normal RPM. I suppose you have 50 HZ power in the UK, but I am used to 60 HZ, so I would look for a motor rated 3/4 or 1 HP at 860 RPM at 60 HZ. Then you feed it 120 HZ and it will run 1740 RPM. The motor cooling fan is designed to cool at 860 RPM and full rated power. The VFD will give you about the same power at 120 HZ, and the fan will be running twice its design speed, so the motor can't overheat. If you get a 1740 RPM motor, the cooling fan will be running at half design speed at 860 RPM, and at half rated power. That is why I like to use slow motors with a VFD.
You may already know that the original motor provided by Hardinge was 3/4 HP at 1740 RPM and 3/8 HP at 860 RPM, so you don't need a very big VFD and motor. Many small VFD's are designed to run on single phase power.
The original bench for these lathes had a countershaft under the headstock with a two-groove sheave to drive the lathe. The countershaft and motor had four-groove step sheaves. The drive provided eight different speeds.
See US Patent 2066560 for excelent details on the original Hardinge drive arrangement. Google Patents 2066560
You can construct a step pulley drive and simulate a two-speed motor using a VFD. At least some VFD's let you program several selected preset frequencies, like 60 and 120. You can select the preset speeds and forward-reverse with external switches, which could be operated by the levers on the lathe. The result would be just like the original drive, but without the exotic motor and drum switches used on the original.
03-05-2007, 06:25 PM #7
I'll bear in mind the idea of using a VFD but it's not really something I'm so keen on, but I do understand what you mean.
I had only guessed the motor would be around 3/4 hp but it's nice to know the details.
The patent is useful too, there are other pictures on the lathes website.