Author Topic: Do I need a new lathe? (Read 17533 times)

Mosey · « **on:** January 17, 2013, 03:51:24 PM »

Well, since I am making many tiny bits these days, and I don't like my Derbyshire 750 for that, I need a new small lathe, don't I?
The Derbyshire is very nice, but it is a jewelers lathe so the saddle doesn't travel on the ways, except for unlock, move, relock.
What is out there in very small size that has high precision and a traveling cross-slide/compound?
Love to find something Swiss to keep the F1 company, maybe Habegger, Schaublin 70 mm, etc. Can't break the bank though.
Cowells? Sherline?( not precise enough) Unimat? No.
I definitely want precision or there is no point in switching from Derbyshire, which is fully accessorized.

b.lindsey · « **Reply #1 on:** January 17, 2013, 04:06:59 PM »

What kind of precision are you looking for Mosey?

Bill

Mosey · « **Reply #2 on:** January 17, 2013, 04:26:13 PM »

Not watchmaker, but sub-thousandths. Equal to my South Bend or better.
Today I'm making teflon buttons for my wrist pins, so I need diameter to fit snugly in wrist pin bore, that king of precision. A couple of tens.

steamer · « **Reply #3 on:** January 17, 2013, 04:54:34 PM »

Mosey,

If your sub 1/4" diameter...and not made out of tungsten.....I'd stick with the Derbyshire.

The spindle is really key...next is the cross slide.

Derbyshire has all that...and as you stated it's tooled.

And what costs the most is not the lathe...but the tooling!

A Schaublin 70 would be wonderfull! as it uses the same collets and spindle thread as the F1.
Bring your BIG checkbook though....they start in the "they want $3K for that piece of ()@*()!"
And go up from there....you and I have seen what's happened to F1's lately on the bay....

An old Stark or Ames or Pratt and Whitney....with 3C collets would be wonderful....but it needs to be pristine to be worth it....unless you REALLY REALLY want to share in my ill mental health

JMHO.......worth exactly what you paid for it......

Dave

b.lindsey · « **Reply #4 on:** January 17, 2013, 04:57:22 PM »

That's closer than most of us can or even need to work to consistently. Working to tenths would normally require a temp and humidity controlled environment as well. In the wrist pin button case, I am thinking that the wrist pin hole itself will grow with heat as much or more than the teflon but would have to look up the coefficients of expansion. Sorry, not much help there I know. Of those you mentioned I would think the Cowells would be a nice fit but certainly not cheap.

Bill

steamer · « **Reply #5 on:** January 17, 2013, 04:59:58 PM »

The Cowells is very good! but its about the same capacity as the Derbyshire...and takes the same collets...8mm. So other than a leadscrew and a saddle.... does it buy you anything?.....

Dave

steamer · « **Reply #6 on:** January 17, 2013, 05:14:59 PM »

http://www.ebay.com/itm/SCHAUBLIN-SV70-INV-4659-/350586829164?pt=LH_DefaultDomain_0&hash=item51a09a796c

Actually not too bad price wise....based on what I have seen before anyway......and fairly well tooled....

....but not cheap

Dave

Mosey · « **Reply #7 on:** January 17, 2013, 05:28:15 PM »

Dave,
Showing me Schaublins will probably get you a lawyers letter from my wife, "alienation of affections" I think it's called. But you still have to move the saddle, indicate it parallel with the spindle, lock it up, indicate again cause it moved, etc. Might as well use the Derbyshire and make the rest of the toys to go with it.
But don't you like to wipe off that shiny Swiss metal and look at the frosting for a couple of hours?
I think there's a Habegger for sale...
Keep the thoughts coming guys.

steamer · « **Reply #8 on:** January 17, 2013, 05:53:10 PM »

OK then

If rational thought is not part of the eqaution....well that opens up all kinds of opportunities!

Hell I could have all kinds of fun being a buyer for you!....Glad to help!

Of course I love touching all things Swiss!....

If the cross slide is in good shape on the Derbyshire or the Schaublin...you should be able to move it and it will maintian it's sqaureness to the spindle.
You do have the stop on the bottom side of the Derbyshire cross-slide....right?

Dave

ttrikalin · « **Reply #9 on:** January 17, 2013, 06:08:18 PM »

Mosey,
I have an informed opinion on Sherlines. I own two lathes and a mill from them.

Sherlines are cheaper than the nice machines. Depending on the operator, you can do sub-thou work. Trivially so under a microscope. Look at Jerry Kieffer's work.

For example, factory tolerance for spindle runout is 0.00025" - as per instructions, you can tighten the spindle nuts and halve the tolerance (with obvious impact on bearing life). Also, for small stuff, it can spin out to 10000 rpm (with a puley mod).

Accessories are expensive. Some work to make it "sub-thou" accurate may be needed. E.g., tailstock alignment will not be perfect out of the box. An adjustable center, or an adjustable tailstock modification eliminates the problem.

IMHO, turning a wristpin from teflon or steel to tenths accuracy is within the capabilities of the machine, right out of the box, without a microscope. (You may need the compound crossslide [an accessory, alas] to improve resolution by advancing the cutter from a tangent. )

What Sherlines *are not*, are sweet machines - compared to the Schaublins of the world, or Dave's Waltham.

tom

steamer · « **Reply #10 on:** January 17, 2013, 06:23:31 PM »

What Sherlines *are not*, are sweet machines - compared to the Schaublins of the world, or Dave's Waltham.

Wellllll it ain't sweet yet....but its getting there.....

Dave

mklotz · « **Reply #11 on:** January 17, 2013, 06:54:21 PM »

Quote from: steamer on January 17, 2013, 05:53:10 PM

Of course I love touching all things Swiss!

That's what James Bond said in Dr. No.

steamer · « **Reply #12 on:** January 17, 2013, 07:06:46 PM »

Quote from: mklotz on January 17, 2013, 06:54:21 PM

Quote from: steamer on January 17, 2013, 05:53:10 PM
Of course I love touching all things Swiss!

That's what James Bond said in Dr. No.

....and he did just fine!

Tennessee Whiskey · « **Reply #13 on:** January 17, 2013, 07:18:25 PM »

Jo-- animate or inanimate

Mosey, just as so many of the things us older kids enjoy comes down to is how bad you want it.
If you're striving for the 0.000000001 results it's there but it's gonna cost you. I think we would all agree that outside of something like as Marv said, a 17 cylinder rotary cross compound Corliss thingee that was fired by some kind of plutonium something or other, we could (or y'all could )build a real nice historic runner with any old lathe,hack saw,nice files, and good pillar drill with one of those HF milling tables. Get what you can get half - ss'd serviced and tooling for and enjoy it. On the other hand if the CFO and your accountant agree it's ok; I'll bet there some real nice Swiss CNC assisted stuff we'd all like to see you use.
Eric

Mosey · « **Reply #14 on:** January 17, 2013, 09:25:48 PM »

Yo Eric,

CNC is "can not cut" for now, or at least until I can make real nice things manually. Although, I admit, I love DRO's, so that is not far from it.
For now it is going to be get the Derbyshire singing and keep an eye open for a sweet Swiss miss.

Mosey

steamer · « **Reply #15 on:** January 17, 2013, 09:29:25 PM »

Let me know if you need any help fitting the rail on the bottom of that cross slide....

Dave

Mosey · « **Reply #16 on:** January 17, 2013, 10:17:34 PM »

The current problem is the DC motor speed controller is fried. So, I need to find a new one, and I don't know what to get(affordable). 115 vdc, 1/8 hp 1.2 amps 1725 rpm Series 500 Bodine motor. That is DC!
I don't have a clue about picking a controller. A new one at the motor shop is $282.00.
I guess I could control speed with a stepped pulley and moving belts. Or get a counter-shaft belt assembly.

Mosey · « **Reply #17 on:** January 17, 2013, 10:32:27 PM »

I am confused about fitting the rail on the bottom of the cross slide?
This is what the bottom looks like...

Don1966 · « **Reply #18 on:** January 18, 2013, 12:15:32 AM »

Mosey you can find DC drives at Little Machine Shop or look at K&B drives. Match the motor to the drive most drives have voltage and current rating. Your motor has this on the nameplate. If in watts drive the voltage into the watts to get the amps.

Don

Mosey · « **Reply #19 on:** January 18, 2013, 12:48:49 AM »

Thanks, Don.

I contacted K&B
Little Machine Shop doesn't list them?

Mosey

steamer · « **Reply #20 on:** January 18, 2013, 12:59:14 AM »

The cross slide should have the adjustable shoe for alignment. See the picture at the bottom

It appears though you have either the 750 or the A lathe....these are desireable ...they are more rugged...

http://www.lathes.co.uk/derbyshire/page17.html

dave

steamer · « **Reply #21 on:** January 18, 2013, 01:02:53 AM »

And looking at that lathe....I'd use a 1/4 HP 3ph with a VFD.

DONE!
Dave

steamer · « **Reply #22 on:** January 18, 2013, 01:04:20 AM »

The adjustable rail should bear right up against the angled surface of the lathe bed...nearest you....when it rests there...the bottom cross slide is square to the bed.

Dave

Mosey · « **Reply #23 on:** January 18, 2013, 01:08:20 AM »

Quote from: steamer on January 18, 2013, 12:59:14 AM

The cross slide should have the adjustable shoe for alignment. See the picture at the bottom

It appears though you have either the 750 or the A lathe....these are desireable ...they are more rugged...

http://www.lathes.co.uk/derbyshire/page17.html

dave

It's both...a 750 with A head! 3C and 10 mm collets, complete sets
I have 3 jaw, 4 jaw, live and dead centers, etc.
It's smooth and tight.
And yes, I have the set of angled plates for the slide.

steamer · « **Reply #24 on:** January 18, 2013, 01:09:34 AM »

If you look at the two pictures here, you will see the part up against the angled surface.

Dave

steamer · « **Reply #25 on:** January 18, 2013, 01:10:10 AM »

You don't need another lathe....just tune that one up ! That's a little sweetheart!

Dave

Pete49 · « **Reply #26 on:** January 18, 2013, 01:52:20 AM »

Quote from: Mosey on January 17, 2013, 10:17:34 PM

The current problem is the DC motor speed controller is fried. So, I need to find a new one, and I don't know what to get(affordable). 115 vdc, 1/8 hp 1.2 amps 1725 rpm Series 500 Bodine motor. That is DC!
I don't have a clue about picking a controller. A new one at the motor shop is $282.00.
I guess I could control speed with a stepped pulley and moving belts. Or get a counter-shaft belt assembly.

Totally out there Mosey but what about a sewing machine moter complete with foot control? I would probably look at trying to make the foot control speed adjustable by hand feed of some sort. As it sounds like you don't take heavy cuts I reckon the motor will do the job. Just for an idea I used to use and still have my first portable key cutting machine which uses a sewing machine motor and I used it as a spare in my van via a inverter in the day. It would cut the deepest cuts in a key without probs as long as you didn't try to cut too fast .
Pete

steamer · « **Reply #27 on:** January 18, 2013, 09:49:53 AM »

Theres your Schaublin!.....If you want swiss with all that tooling....add a couple zero's to the lathe price

But to be honest....that Derbyshire looks up to no one!....Good Lathe!

See PM regarding motor/controller

BillTodd · « **Reply #28 on:** January 18, 2013, 11:19:23 AM »

Just a quick heads-up for anyone thinking of buying a lathe or other machine tool in the UK.

The scammers are still operating (see http://www.homeworkshop.org.uk/index.php?option=com_agora&task=topic&id=1057&p=4770#p4770)

They are advertising machines that do not exist, wanting bank transfers. They offer cash on collection inspection etc. but will always find away to put the buyer off (working away , snow etc. etc.) - no doubt they will offer free delivery if payment is made in advance.

Be careful people - it's a jungle out there*

*(what was the name TV show the ended/started like that????)

Bezalel · « **Reply #29 on:** January 19, 2013, 01:52:52 AM »

Quote from: BillTodd on January 18, 2013, 11:19:23 AM

Be careful people - it's a jungle out there*

*(what was the name TV show the ended/started like that????)

Monk Comes to mind... but that may just be the jingle in my head

Chris J · « **Reply #30 on:** January 19, 2013, 09:48:47 AM »

Quote from: Mosey on January 17, 2013, 03:51:24 PM

Well, since I am making many tiny bits these days, and I don't like my Derbyshire 750 for that, I need a new small lathe, don't I?.........

If it helps you with the discussion you'll need to have with any "significant other" I'm happy to back you up.

Get a new Mill as well would be my advice

IanR · « **Reply #31 on:** January 19, 2013, 11:27:23 AM »

Quote from: BillTodd on January 18, 2013, 11:19:23 AM

Be careful people - it's a jungle out there*

*(what was the name TV show the ended/started like that????)

Hill Street Blues, I think. I'm surprised I know that, as I haven't had a tv for years.

Mosey · « **Reply #32 on:** January 19, 2013, 01:16:34 PM »

But the adjustable angle plate only gets you an approximate alignment, as the surfaces are not perfect, and the screw is not absolutely tight, right?

Now I have to build a proper desk/bench for this lathe, with a cutout for belts and under-drive, motor mount shelf, swarf-pan, and some neat pencil drawers for stuff. I just might have one for it. This desk will also be good place for the sensitive drilling machine (tiny Micromark digital drill press with Albrecht chuck). Projects beget projects.

Then it's back to straightening my crankshaft (depressing)

Mosey · « **Reply #33 on:** January 19, 2013, 01:18:26 PM »

Quote from: Chris J on January 19, 2013, 09:48:47 AM

Quote from: Mosey on January 17, 2013, 03:51:24 PM
Well, since I am making many tiny bits these days, and I don't like my Derbyshire 750 for that, I need a new small lathe, don't I?.........

If it helps you with the discussion you'll need to have with any "significant other" I'm happy to back you up.

Get a new Mill as well would be my advice

Yup, first F3 that comes along! Call me, will you if you see one.

News:

Author Topic: Do I need a new lathe? (Read 17533 times)