"A" verses "D" lathe spindle types.

[krems]

I've decided to upgrade the 40 year old lathe and have settled on a few items that I must have such as: 12-15" swing, one piece cast bed (2400 pounds or more), 30-40" bed, 1.5" spindle bore or greater, 3-5 HP motor, etc. I've looked at a bunch of models that seem to fit but I need advice on spindle types. Is their an advantage or disadvantage to an "A" or "D" spindles on a manual machine. I will be alternating 3/4 jaw work w/ collet work. So....if you had a choice would you prefer an "A" or "D" type spindle and why??. Is one type easier to change out and or more repeatable as far as accuracy is concerned.

Also....If you were starting from scratch which collet type would you prefer on a manual lathe and why..5c, 2j, 3j, 16c...????.......would you go for a lever closer, sojgren handwheel, draw tube, or adjust tru collet chuck.

Keep in mind I'm a hobbiest looking for a one lathe fits all. Most work revolves around gunsmithing type work (smaller precision work). I've got lots of time and am not looking to take .100" depth of cuts.

Looking forward to your opinions..............Krems

[wierdscience]

Nothing wrong with either spindle,but the D type are easier to get tooling for and offer a quicker change than the A type(cams vs bolts)

Collets,5c is common as dirt and priced accordingly.As to the type of closer,that depends on how much you want to spend vs how fast you need to change workpieces.The draw tube type are the simplest/cheapest,but also the slowest.Next would be the handwheel type closers.No much faster than the drawtube closers,but you should be able to find one on Ebay to fit the D spindles fairly easy.Lever closers are nice and they are quick,but unless you can find one to fit your particular machine you most likely will have to buy one and modify it.

The bigger spindle bore you can get the better IMHO.1-1/2 is fine,but 2-1/8" is better.

The 5c collet chucks,especially the ones made by Bison are nice and basically as fast as using a 3jaw chuck.

You might consider a ER32 or 40 collet chuck as well,better grip range,but will cost more than the 5c.

[Doozer]

There are more D's out there for manual lathes.
A's are found a lot on CNC lathes, all power chucks I have seen were A's.
I used a MoriSeki manual lathe with the bolt on A chucks, R&R ing the bolts is not bad. A's and D's are the same taper, just one is cam lock and one is bolts. I saw a guy crash a 16" manual lathe with a D-8. Chuck jaw hit the carrage wing in low gear. The chuck fell off and that saved the spindle from being bent. Then he put the chuck back on, and tightened the cams the wrong way (ccw) and continued on his way. He should have been fired for being careless, stupid, ignorant, and dangerous.
I like either mount. A's are better for heavy work. D's are more convenient.

--Doozer

[krems]

I never thought about the ER32 collets...I have a complete set with my milling machine. I have a few 5c collets but have always wondered if the larger collets would be a better choice if starting over. I've got a draw tube type closer on my lathe and don't really care for it.

Is it a reasonable assumption that the A spindles can handle higher RPM's and heavier work because of the way the chucks are attached. (bolts verses camlocks) I've found three machines I like and each has a different spindle type..A2-4, D1-4, D1-6. The D-6 had a larger 2 1/8" through hole however.

Lets say I had a Bison adjust tru 3 jaw chuck all dialed in to 1/2" round stock. I took the chuck off the machine to do some collet work. When I put that same 3 jaw back on the machine do you think the bolt on or camlock chuck mount would lend itself to repeating the accuracy as before with the same 1/2" stock..??


Doozer.....That dude running the lathe should have been fired!

[Doozer]

That's why I hated working there. Idiots running around, doing whatever they wanted, with no accountability. Drove me nuts. I'm outa there now.

--Doozer

[Black_Moons]

krems: AFAIK A and D style chucks both use the exact same taper so they would be just as precise. And yes, you can reseat chucks onto that taper 'precisely' so that you don't need to reset anything, else all collet chucks would need to be set true to be accurate.

[doctor demo]

Nothing wrong with either spindle,but the D type are easier to get tooling for and offer a quicker change than the A type(cams vs bolts)

Collets,5c is common as dirt and priced accordingly.As to the type of closer,that depends on how much you want to spend vs how fast you need to change workpieces.The draw tube type are the simplest/cheapest,but also the slowest.Next would be the handwheel type closers.No much faster than the drawtube closers,but you should be able to find one on Ebay to fit the D spindles fairly easy.Lever closers are nice and they are quick,but unless you can find one to fit your particular machine you most likely will have to buy one and modify it.

The bigger spindle bore you can get the better IMHO.1-1/2 is fine,but 2-1/8" is better.

The 5c collet chucks,especially the ones made by Bison are nice and basically as fast as using a 3jaw chuck.

You might consider a ER32 or 40 collet chuck as well,better grip range,but will cost more than the 5c.
I agree 100%
I have both the A and the D spindle tapers, and the D is way faster than messing with bolts. I also have a machine with the Loo style and it is good also , so don't turn Your back on a lathe just because of spindle nose style.

Steve

[lazlo]

You might consider a ER32 or 40 collet chuck as well,better grip range,but will cost more than the 5c.

Comparing the same accuracy/quality collets (i.e., Rego-Fix versus Hardinge), I think they're about the same cost: ~$20 - 25 each.

But because of the gripping range, there's a whole lot less ER collets in a complete set than 5C. 5C will be somewhat more accurate, because they're on-size for their nominal diameter (they have a very small gripping range), but that's way beyond the tolerance of a HSM'er.

[.RC.]

The A type is more rigid with the chuck being closer to the spindle bearings..

The D type is more convienant with it's camlock..

I have a lathe with an A1-8 spindle, it has a 14" 4 jaw chuck...It is hard to mount that as you have to lift it into position and hold it there while you get the first bolt in...


A1-8 spindle

http://img.photobucket.com/albums/v606/OzRinger/purcell%20lathe/purcelllatheathome009.jpg

[Black_Moons]

Wow weird spindle, why the two rows of bolt holes?
BTW what are the bolts that run 90 degrees to the camlock bolts in the D1-4 head? Are they camlock.. locks?

[tyrone shewlaces]

D-type is nice and quick enough. Also easier to find things to fit it. Probably your best choice for a newer machine.
I personally really like the L-type nose best because it's a bit quicker. On the D, I always go round the spindle twice - once to cinch them up, then once again to tighten them like I want it. 2X times whatever number cams are there (five or six?) so a dozen things to tighten vs. ONE for the L-type. Problem with the L-type is they have become somewhat obsolete and it's harder to find things to fit them. Unfortunate IMO. L00 is too small for through-spindle (draw tube) 5C stuff, so if possible I'd get at least L0 or L1 (bigger bore is nicer anyway).
So if you find an older well-tooled lathe with L0 or L1 (or an L00 with a 5C Sjogren chuck - no drawtube necessary), I'd say go for it. You'd have to be lucky to find one well-tooled though. Starting from scratch, D isn't that much slower and it is nice & easy, so I'd pick that.

As for collets:
I like 5C because they are easy and cheap to find AND since they aren't a "double-angle" you can grip really short pieces without jerry-rigging. You can grip on as short as 1/32" length depending on what you're doing! I'd say to get 5C going right away and begin gathering a selection of collets, then pick up or make some kind of ER or Jacobs Rubber-Flex along the way somewhere since those are nice for bar stock (just a few collets cover the whole range of size, but the stock has to be long enough to be gripped by essentially the whole length of the collet).

[whitis]

Wow weird spindle, why the two rows of bolt holes?
BTW what are the bolts that run 90 degrees to the camlock bolts in the D1-4 head? Are they camlock.. locks?

From internal drawings, it looks like they are screws with a rod tip that hold the cam's in place and also limit their rotational travel by fitting into a grove in the cam.

There is also a spring hidden inside, concentric with the cam shafts.

For the A1 spindle nose, A1 spindles have both the inner and outer bolt circle and A2 spindles outer circle only. A1 chucks use inner bolt circle and A2 chucks use outer bolt circle. B1/B2 versions similar to A1/A2, respectively, except the outer circle is through hole instead of tapped hole and the inner circle, if present, is tapped. I would guess that self centering A1 chucks have a scroll outside the mounting bolts and A2 chucks inside.

[Black_Moons]

whitis: So uh, any idea if I should have those really tight or loose or loosen when I need to release the cams or what?

Intresting about A1 vs A2, makes sense.

tyrone: Woah, I never knew that about double angle vs single angle collets. so thats (partly) why 5C is considered more for work holding and ER for tool holding. (rare you'd ever want to hold a tool by the tip!)

You mentioned jurry rigging, does that mean you can insert a short rod (same diamiter as workpeice) in the back of a double angle collet (and get it to stay there somehow) to get it to grip small parts properly?

[whitis]

whitis: So uh, any idea if I should have those really tight or loose or loosen when I need to release the cams or what?


Looks like the head of the socket head cap screw is intended to bottom out before the tip, so tighten and leave that way. When you tighten the cams with the chuck key, friction should hold them that way.

Found the drawing. It is on page 41-16 of the New American Machinist's Handbook (1955, reprinted later). Most others omit the internal details. This one shows internals but no internal dimensions.
http://www.amazon.com/New-American-Machinists-Handbook/dp/0070370656

[tyrone shewlaces]

tyrone: Woah, I never knew that about double angle vs single angle collets. so thats (partly) why 5C is considered more for work holding and ER for tool holding. (rare you'd ever want to hold a tool by the tip!)

You mentioned jurry rigging, does that mean you can insert a short rod (same diamiter as workpeice) in the back of a double angle collet (and get it to stay there somehow) to get it to grip small parts properly?

Well yea I guess 5C is known better for work holding, but it is used to hold tooling very often too so I wouldn't store that away just yet. Give the creative juices as few limits as possible. Actually 5C will grip on the whole length of the gripping surface as long as the size is really close to the collet size (like within a couple thou max). The thing that makes it possible to hold short stuff is that the back end is kind of fixed & supported and just slotted from the front.

ER collets & such are slotted from both ends so the whole length squishes down as you tighten it. Since it does that, if a piece is just stuck in the nose a short bit, the back end will continue down until it's at an angle which will kind of "spit" the piece back out. So yes, to rig it you shove a little spud of similar diameter in the tail end of the collet so it stays parallel as it grips. I never do that though because it's a hassle. Jacobs rubber-flex collets come with rubber spuds to accomplish this, but they never worked very well for me. When you need to grip short, 5C does this excellently, so the ultimate is to have both. Eventually I have scavenged up both for my lathe so I just pick the right one for the job at hand and move on.

If I had to have just one though, I'd go for 5C in a heartbeat. I use them constantly. I use the Jacobs rubber-flex to pull off the odd-bird job - probably a half-dozen times per year or less.

By the way, 16C or other large similar collets are very nice and obviously will take a larger range of things, but they are at least 5 times harder to find for cheap enough. You can buy them any day of the week new from Hardinge, but who has that kind of bling to throw around? Not me anyway.

[John Stevenson]

Ringer,
Never seen that method of fastening an A series, do the bolts go all the way thru ?.

Most of my machines are on A's but they follow the European [ usually russian ] way of fastening .

I'll nip out later and get some pics.

.

[krems]

Thanks for the info!!.......BTW I have an older clausing 13" lathe w/ the Loo mount. It is very quick and easy to change the chucks and this has been my only experience w/ a lathe. Definately harder to find accessories for. The lathe is also set up w/ the draw tube style 5c closer. Spindle hole diameter is 1.5" but the draw tube would limit the actual through hole to about 1 1/4".

Krems

[wierdscience]

I agree 100%
I have both the A and the D spindle tapers, and the D is way faster than messing with bolts. I also have a machine with the Loo style and it is good also , so don't turn Your back on a lathe just because of spindle nose style.

Steve

Definately agree on the Lxx spindles,the old Hendey at work has one.The only drawback is a smaller spindle bore,but they are ridgid and usually cheaper used than the D's.

The only thing I would shy away from are threaded spindles and those proprietary mounts that dot the landscape.

[.RC.]

Ringer,
Never seen that method of fastening an A series, do the bolts go all the way thru ?.

Most of my machines are on A's but they follow the European [ usually russian ] way of fastening .

I'll nip out later and get some pics.

.

The chuck is just held on with 5/8 cap head screws..

[doctor demo]

Thanks for the info The lathe is also set up w/ the draw tube style 5c closer. Spindle hole diameter is 1.5" but the draw tube would limit the actual through hole to about 1 1/4".

Krems
The thru hole of the 5C is less than that so in most cases that would not be an issue.

Steve

[John Stevenson]

The chuck is just held on with 5/8 cap head screws..

Thanks, Just got some pics of the A series on one of my lathes.

http://www.stevenson-engineers.co.uk/files/Aseries1.jpg

The shouldered studs and nuts stay like that on the back of the chuck, the nuts never need to be removed.
The hole in the spindle flange is slightly bigger than the diameter of the shoulder so the whole chuck assembly just pushes thru these holes.

On the rear of the flange is a keep plate that has 4 keyhole slots in it, once the nuts poke thru the keyhole plate to rotated and the nuts tightened.

http://www.stevenson-engineers.co.uk/files/Aseries2.jpg

Makes it very quick to change a chuck and there is no way they will come loose under interrupted cuts as a D series can.

.

[Doozer]

John, That is an odd (to me) chuck mount. Never seen a bolt on like that in the States. Those mini lathes use a bolt on chuck, but I don't think that is the same thing. Kinda neat though with that key-hole plate.
You say that is Russian style??


--Doozer

[Timleech]

John, That is an odd (to me) chuck mount. Never seen a bolt on like that in the States. Those mini lathes use a bolt on chuck, but I don't think that is the same thing. Kinda neat though with that key-hole plate.
You say that is Russian style??
--Doozer

I think it's a DIN standard, maybe properly referred to as C-series? I dunno, it gets confusing :rolleyes:

I like that system, used to have a TOS similar to John's, it's more secure than Camlock but no fiddling about inserting bolts as with A-series (which I have to admit I've never used). Tapers are exactly the same.

Tim

[John Stevenson]

Very common here, I have three lathes, all East European , all with different A series spindles and all have the keep plate fitting.

I just assumed that all A series had this, my old Herbert had a 3 bot fitting but it was simialer the the Chinese small lathes that bolt on requiring you to remove the nuts and refit them every time.

I have a 4 jaw D Series camlock here that's been modified to a 4 bolt A series because the tapers are identical.

I'm sure it possible to change an A to a D I'll dig it out and get a picture tomorrow.

[doctor demo]

Very common here, I have three lathes, all East European , all with different A series spindles and all have the keep plate fitting.


I'm sure it possible to change an A to a D I'll dig it out and get a picture tomorrow.
John, I would have liked to see that up close when I was there ,if I only knew.
I have never seen anything like that. I wish My A taper was like that.
How would one go about changing or adding a key-hole ring to the spindle?
If I was to do that to My lathe the ring would have to be a two piece job.

Steve

[.RC.]

http://users.beagle.com.au/lathefan/Pg%2088%20Spindle%20Nose%20Data.pdf If you look at what is says about the B2 spindle it says it has no tapped holes only holes for bolts..

[wierdscience]

Thanks, Just got some pics of the A series on one of my lathes.


The shouldered studs and nuts stay like that on the back of the chuck, the nuts never need to be removed.
The hole in the spindle flange is slightly bigger than the diameter of the shoulder so the whole chuck assembly just pushes thru these holes.

On the rear of the flange is a keep plate that has 4 keyhole slots in it, once the nuts poke thru the keyhole plate to rotated and the nuts tightened.

Makes it very quick to change a chuck and there is no way they will come loose under interrupted cuts as a D series can.

.

Now that is different,what's it like running in reverse under an iterrupted cut?

[John Stevenson]

Now that is different,what's it like running in reverse under an interrupted cut?
No problem, the drive is taken on a drive dowel the keyhole plate is only there to allow quick fitting and the nuts hold it secure, the drive is not taken on the keyhole plate.

The plate is held to the back of the spindle by two large headed rivets / screws that fit thru slots that allow it to rotate but keep it located at the back of the spindle.
The plate has to be the first thing fitted to the spindle before any bearings etc.


Sorry I can't get any better pic's as it's so close to the flange but he's a crap -o-cad drawing. :D

http://www.stevenson-engineers.co.uk/files/keyhole.BMP

.

[EVguru]

My 1963 Harrison L5 has the L00 spindle nose. When I bought it I got a good deal on a Burnerd 'Multisize' chuck with a complete set of EC collets from 1/8" to 1.5" capacity.

http://www.teikoku-chuck.com/products/eee.gif

[lazlo]

My 1963 Harrison L5 has the L00 spindle nose. When I bought it I got a good deal on a Burnerd 'Multisize' chuck with a complete set of EC collets from 1/8" to 1.5" capacity.

My Clausing also has a L00 spindle (same positive comments as above), and the Bernard Multisize ("MultiFlex" ?) collets were a (very) expensive option that I've never seen in the 'States. How do they work? Are those metal bands spring-loaded? Looks like a cross between a Sjogren and an ER collet?

[EVguru]

If you look closely at the image, you can just see the torsion coil springs.

Multiflex collets are made by Crawford and have the blades bonded into rubber.