Spindle

Hello guys,
I'm in the process of designing a 9" x 48" Non-CNC lathe with DRO, for possible later conversion to CNC. I don't want anything bigger than
13x40.
I'm just starting the planning and design process. Actually started last week.
Anyhow, Here's the details..
Motor: Single Phase, 110-120v AC, NEMA, 1/2 HP 1725 rpm. Mfg.:Dayton, Leeson or Reliable
Swing: 9" Bed length: 48"
Tail stock taper: #2 Morse Taper Headstock taper: #3 Morse Taper
Spindle Type: Threaded, 1-1/2" - 8tpi
Tail stock travel: 2-1/8" Cross Slide Travel: 5-7/8" (this dimenson not set in stone yet!)
Lead Screw: 1/2-10 ACME or 3/4"- 8 ACME (1/2" seems more common but is 3/4" better? Going to use "Rockford" Ballscrews.
Headstock bearings: ABEC 7 or 9 where available, undetermined size
Spindle Collet: 3C, 3J or 3AT (whichever is most common0
Spindle Through Hole: 3/4"
Spindle Lubricant: Hangsterfers Labs ISO VG grade Way Lube: Hangsterfers Labs way lube Cutting Fluid: ????
Spindle drive belt: Goodyear Industrial Power Transmission belts per their "Variable Speed" .PDF @
http://www.goodyearindustrialproduct...able_speed.pdf
Lathe Bed & Ways: V and Flats.
Spindle speeds: ~40 to 1270 rpm (maybe more???)
Gear Supplier: Boston Gear
Spindle Bearings: TIMKEN, Inc. maybe SKF, NTN,
Chuck: Cushman
Feed per Rev: Longit.: 0.0015"to 0.0213" Cross: 0.0004" to 0.0063"
Options: ER32 collet spindle nose chuck, Coolant Supply, Collets & Closer, 3 and/or 4 jaw Chuck, 2 Morse Taper Live & Dead Center, Steady & Follow Rests, Toolpost Grinder, Aloris AXA Q/C toolpost, DRO, Forward/Reverse & Emergency Stop, Taper attachment, Jacobs Ball Bearing drill chuck, threaded back plate, Face Plate, threading dial, micrometer carriage stop, power feeds(maybe a Q/C gearbox).
Ok, so this is the basic design specifications. I'll mostly be turning 12" lengths of 4140 and 4340 steel in 1-1/4" and 1-1/2' dia. and actually pretty regularly. Also, C1018, A36, Aluminum 6061 and 7075, brass, bronze, stainless, O1 & W1, Nylon 6/6 and PTFE.
May use a QC type gearbox or gearing based on a 40T stud gear.
I've had planned on using NTN bearings, similar to 620xT1B7 or 620xT1P7 which are ABEC7 ISO P4. I have a small list of the ones that are in stock. I also h ave available to me, the 620xLLBP4/2A series bearings, both where x = a # between 2 & 9. I thought about 720x series also. 620x's are easier to get here in the NW. The TIMKEN info was a little sparse on what I wanted to find, unless someone can match me to TIMKEN #'s from NTN #'s.
I decided on a Gates 3VX375 belt going to a motor. This is a 3/8" x 37.5" long belt. I also bought a 3V375 as a spare.
I see that 3C is more common than the 3AT or 3J used in Atlas lathes. I may make the spindle with reference to that collet.
I still need to figure out if it would be better to use 3/4"-8 ACME or 1/2-10 ACME. Which one is more accurate, rolled or ground?
I need to be able to acheive crossfeeds of 0.0005" to .0056" and longitudinal feeds of 0.0021" to 0.0162", and will have powered feeds.
I thought of using a 16, 24 or 32 stud gear. And, 30t thrugh 60t for the other set, in 2's. The other setup I had envisioned was a 18t, 72t, 80t gear train and then adding the 16, 24 or 32 Stud gear and Screw gear set of 30t through 60t gears x 2t's. All being roughly 18-22dp. Boston Gear will provide a set at cost. Any ideas here?
I also have availabile to me some 8630 or 8640 steel, as well as stressproof 4340 which I will use to make the spindle @ finished to 5 microns RMS or ~.000005'", and a friend of mine who works at a spindle shop here in town said he could CNC me one for $180-$225, if I included the blueprint drawing and/or specs.
I need someone with a South Bend 9" model A lathe to measure the tool post slot T in their compound, as well as the thickness of it, at least if I get there, I can design the compound. I lost my lathe booklet so I also need the dimensions of the flats and V's on the carriage.
As for the ways on the bed, another local shop which does grinding on machinery ways, etc. offered to grind flats and V's on my stock, as well as the headstockusing either a blanchard or surface grinder..
I still need to hear back from several linear scale & dro manufacturers to find out which scales will work the best and how to best mount each one.
Anyone know of a blueprint for S/B carriage stops or threading dials?
Oh and I chose a Hangsterfers Labs way oil and their brand of Vactra spindle oil, maybe ISO 32 or 68?? Being supplied to the headstock using ordinary Home Depot sourced WATTS brand plumbing fittings. Coolant?? well, I'm being treated to a small supply of some of the best stuff made. Though I know it will be deilvered through a length of LOC-Line
Don't know what to do about a stand, bench, etc.. but I will provide for leveling on using those cool leveling pads they show in the catalogs.
Handwheels and dials are std. catalogue items, but ultra high precison quality.
How about a Dayton motor? Oh, and how about a E-Stop button?? Gotta think about safety. I really haven't looked that much into that type of machine controls. The ones I know about are OMRON or made for drill presses of various types.
Oh, and as for chucks. I really think the biggest I'll get to use would be 6", but I ran across some 1/2-20 threaded back 4" chucks a guy could use too. PProbably meant for 6" or 7" lathes but, they look to have decent precision & tolerances. When I set out the money for one, I'll likely buy a Cushman.
Anyhow thats it for now. Suggestions & comments welcome!
I would love to hear your comments and suggestions.
Thank you for reading this thread,
Greg Bowne Seattle, WA snipped-for-privacy@yahoo.com
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<snip>
First impression is that is severely underpowered.
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On Fri, 09 Mar 2007 07:56:11 GMT, "Tom Gardner"

didnt notice that. yeah try 1 1/2 hp single phase as a minimum.
I can still stall a cut with a quarter inch square tool bit in free cutting steel with 1 1/2hp.
Staelth pilot
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Tom Gardner wrote:

Mine was that he's putting ABEC 9 or 7 bearings on a 9 inch swing lathe thats 4 feet long. Unless he builds it a little heavier than a Chevy truck, it'll flex far more than the bearing tolerances. :-)
But that's OK, he's having the bed ground at the local shop that probably is using a machine older than he is.
He wants a 4 foot long capacity to turn 12 inch pieces.
He wants to use tooling compatable with a 9"South Bend.
And I ran out of things to say about someone that would go out of his way to choke down his spindle bore to 3/4 inch to fit collets that each cost somewhere near the price of a 10 pound box of 5C collets.
I am in awe!
Good friggen' greif.
Listen to the voice! It says "buy a lathe!" and "quit pissing around!"
My second impression is that if this guy is serious, he either has more money than brains, or he's spending tax dollars on this one.
Cheers Trevor Jones
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My third impression is that I just got sucked in by a troll.
DoH!
:-)
Cheers Trevor Jones
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Come, come, Trevor! No troll - Naw ! It's the same guy that built a steam-powered V-8 for his pickup.
Bob Swinney

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And uses 4 of those cylinders for an air compressor.
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Ok. After watching the thread gather several replies, here's my next iteration. Yes, this is not a troll posting, although you may have it started to sound like one.
It's come to my impression that I'll need to design and build something a little bigger. I'd like no bigger than a 13" lathe. Most of the round stock I have comes in 12" cut lengths.
Why? Well.. yes I could go out and purchase one, or bits and pieces of one to put together to make what I want. But, that would be just too easy. Second is, that I have a South Bend 9" that I use a lot, though it's on loan to me.
For finances, $1,500 is my starting budget. Next month, I'll have more, probably half that more.
My first question, is that I've been hearing a lot of people want 5C in their spindles. Yes, I could do this, but.. why?
I figured it would be underpowered, but I still need to keep the same belt for now. 3VX375. Ok, so 1-1/2 HP. I planned on getting my pullies from McMaster-Carr. There's a good Dayton distributor in town, and could get other brands. Any ideas on which model? I've also added plans to purchase a VFD. Again, which one?
My feeds are still the same at crossfeeds of 0.0005" to .0056" and longitudinal feeds of 0.0021" to 0.0162".
One of my original ideas was, a larger threaded spindle (2.00" or bigger), or a D1 style spindle, maybe even a L type spindle? I couldn't find dimensioned drawings of D1 spindle noses, or instructions on how to homebrew one.
My headstock and tailstock going to be a bit "boxy" / "squareish". (I like things square! LoL)
Stealth Pilot, thanks for the dimensions!
I saw great plans for follow and steady rests too. I'll incorporate those.. once the design is built.
Yes, I'm going to probably have a backgear. I've used backgears the one I have for a long time now.
I really would like the lathe to be able to handle a reasonable 6" / 8" chuck, either 3 or 4 Jaw.. and to be able to handle common accessories. On that note, I could also use a Aloris BXA toolpost, if I built a bigger lathe.
The spindle bearings I had looked at originally were Timken Tapered Roller Bearings, with a 1.7716" bore.. roughly 45mm (for you metric nuts).
My original thoughts on materials used for building this lathe was stressproof / tooling plate in the 8600 series steel or stressproof 4340. Hopefully that would keep down the flex. I also have old 350 chevy engine pistions that could be melted down to make castings.
Boston Gear has been helpful in the past when I started building other projects that required gears. But, Yeah, I could take a QC off a SB or something like that, and mod it to work.
I figured ballscrews on a lathe would be a bit too much, but I could do that later on in the lathes history. Rockford Ballscrew offered to grind / roll my leadscrew with the correct LH pitch ACME on any size I chose, and include the required half nuts, etc.
Given how I've had my other lathes motors mounded, either underneath the lathe and behind the lathe on the bench. I found that behind the lathe was the best. I'd be open to other mounting styles.
About much finer feeds? What would you consider best?
I wouldnt need to mill or put anything on a face plate that would be bigger than what would fit on a 8" faceplate, at least not yet. Although, I just figured that 5-7/8" would allow me good access.
One thing I do regularly is drill 17/32" holes (0.53125") with a 17/32" #2 MT shank drill into steel and alum. The other size I use the most, held in my Jacobs 14N in the tailstock, is 5/16" (0.3125").
Thanks for your help!
Any other comments?
Greg
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snipped-for-privacy@yahoo.com wrote:

Just one. A fool and his money, are soon parted. Good luck at the soup kitchen.
Cheers Trevor Jones

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Just the response I thought was going to appear.
Gee whiz.
Greg B.
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You have $2300 and a Southbend lathe, and you want to manufacture another complete working machine capable of doing useful work?
Even if you had all the machines necessary (and you most certainly do *not*), you couldn't build a functional machine for that much. You bed will be cast. Have you looked up the price of a casting of that weight? You likely couldn't have the bed machined/ground for that much either, assuming the casting was free.
I'm not sure very many people here will have the time to explain the absurdity of your project (the list is *extensive*). You might be able to make a machine slightly larger than the Taig/Sherline machines with that kind of budget, but you won't be able to use any castings I'll wager...
Good luck with everything anyway.. It's at least a good mental exercise..
Regards,
Robin
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gbowne1 wrote:

Really?
Have you actually priced out any of the stuff that you are speccing ?
Start with the ABEC 7 and 9 bearings.
Follow that up with a quick price and availability check for 5c collets. New ones. Good name brand stuff, hardened and fit for accurate use. And 4C, and 3C. Check the availability of different sizes and shapes too. You may just figure out why 5C is the recommended choice.
Get a firm quote on exactly how much that ground lead screw is going to cost, too.
Then start getting firm quotes on the grinding time to grind the ways.
When it's all added up, you are blowing smoke up your own arse thinking that you could somehow reinvent the 1950's lathe, except with parts and tooling that are even harder to find, and made more complicated than it needs to be.
If that does not give you any clues as to why you have been treated like a troll or a lunatic, then nothing will.
You have some money. Buy a lathe. Make changes to the geartrain as you need, from cataloged parts and minimal custom made bits, likely such as an expanded gear quadrant to mount said gearing.
Or piss away $30K or so to build something that likely will end up the equivalent of a $1500 used lathe.
If you are just fantasizing , at least have better than mediocre goals in the fantasy.
Cheers Trevor Jones
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Yes, just as I suspected.
Greg
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On 8 Mar 2007 23:24:46 -0800, snipped-for-privacy@yahoo.com wrote:

yawn deleted

t slot is 2 1/2 inches long. 7/8" inch gap and the rest of the dimensions are all a quarter of an inch. measured off a hercus clone.
why dont you just buy a southbend and refurbish it ....or just use it to death as it is.
flats and v's on the carriage are a very close fit to the bedways. the bedways are easier to measure :-)
did I miss anything? Stealth Pilot
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You need at least 1hp, 1.5 would be better. Get an inverter rated 3-phase motor and VFD. The machine will run much smoother and will have infinite speed adjustability over a range of at least 10:1 without moving the belt(s). Are you planning to have a backgear?
Randy
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On 8 Mar 2007 23:24:46 -0800, snipped-for-privacy@yahoo.com wrote:

May be underpowered. For home use 110v/1p input make sense. I suggest you look at the VFD drives that have 110v/1p input and 200v/3p out. Three phase motors tend to run smoother, are smaller/lighter and this will give you [infinitenly] variable speed control, and very flexable with step pullies.

bed length or center distance? Will you have gap bed or sliding bed to allow largest possible face plate? With 5-7/8 cross slide movement you can face an 11 inch part.

Why not make the spindle large enough that it takes a 5C collet without an adapter. 3&4 jaw universal chucks are available with a 5C mount.

Slightly larger to accomidate a 5c internal bore spindle. For home shop use you will want a face plate.

Wider is better for milling.

Why ballscrews? $$$$ -- Steel leadscrews with brass/bronze or even babbit half nuts are well proven and last a long time. With the long bed a bigger leadscrew [under tension] would be a good idea. For power cross feed you will need another power feed shaft or a slot milled in the leadscrew to drive a gear.

Low production/high precision bearings are big bucks. In commercial operation they are justified. Have you considered using automotive/truck front wheel bearings. Plenty of load capacity, and are available large enough to take a spindle large enough for a standard 5C collet seat.

Use 5C -- very common and square/hex holes are available.

bigger is better and costs very little. Make it big enough for a 5C collet drawbar.

Check the Hardige late. Flats only.

Belts can be a pain to replace depending on how they mount. A linkbelt has lower vibration and are easy to fit/replace.

bigger is better. try to design so it is under tension. You will need a slot milled to drive a geat for cross slide and longitidunal feed or a seperate power shaft [generally square 1/2 to 3.4 inch.

Be aware that it is not considered good practive to use the lead screw as a "feed screw" because of the additional wear, although for home/hobby shop use this should be fine. You should have finer feeds available.

A one-off quick change box will be $$$$. See what you can adapt, or go for change gears. Change gears are far more flexable for metric and diametric/module pitches.

Lindsay books [see below] has many lathe instruction book reprints.

===========Nice fantasy project, but the machine tool makers have been doing this for 200 years. With the time and effort you are sure to expend, you will be far better off to simply buy a good used Hardige.
Before you get too much invested [either time or money] get the Gingery "make your own lathe" book and see what is involved. see http://lindsaybks.com/dgjp/djgbk/series/index.html also http://lindsaybks.com/bks10/sbl8/index.html http://lindsaybks.com/bks9/eal/index.html http://lindsaybks.com/bks/lathebk/index.html http://lindsaybks.com/bks/lnt/index.html http://lindsaybks.com/bks2/lnote2/index.html http://lindsaybks.com/bks3/ln3/index.html http://lindsaybks.com/bks4/ln4/index.html http://lindsaybks.com/bks9/ln5/index.html http://lindsaybks.com/bks8/chgear/index.html http://lindsaybks.com/bks7/sscut/index.html
There is always the danger of reinventing the shell or rediscovering fire.
Unka' George [George McDuffee] ------------------------------ Watch out w'en you'er gittin all you want. Fattenin' hogs ain't in luck.
Joel Chandler Harris (1848-1908), U.S. journalist. Uncle Remus: His Songs and His Sayings, "Plantation Proverbs" (1880).
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snipped-for-privacy@yahoo.com wrote:

Umm, why don't you just get an Atlas or Atlas/Craftsman 10" lathe? It would save you a LOT of time! If you don't like their bed, you could change that, and might still be able to use almost all of the pieces with a little machining.

These are plain ball bearings? What is the axial load rating of them? How much load rating is left after the preload is applied? That's why the Atlas uses Timken tapered roller bearings. They come in two pieces, a "cone" with the roller cage, and an outer race. You can combine the two parts to hit the right ID and OD.

If you really are going to make your own spindle, go larger so you can fit 5C directly in the spindle. Saves a LOT of trouble. You can always put a straight shank center in a collet. The 3/4" ID of the Atlas was always a limitation. That's why I moved up to a 15" Sheldon with a 2.25" spindle ID.

The stuff from McMaster-Carr is good enought to not bind up in a nut, and is designed for elevating heavy pieces, not as a machine tool leadscrew. Note that crossfeed screws are traditionally left-hand thread.

You could put a variable speed gearmotor (either DC or universal) on the screw for really fine feeds.

Yes, buy a quick-change box off a suitable lathe being scrapped. You'll save yourself hundreds of $ as well as aggravation.

I shouldn't ask, but why are you doing this?
Jon
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On Mar 9, 2:24 am, snipped-for-privacy@yahoo.com wrote:

So tell us... Why do you want to build your own machine?
Regards,
Robin
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On 8 Mar 2007 23:24:46 -0800, snipped-for-privacy@yahoo.com wrote:

greg dimensions of the ways. (just in case your post wasnt a troll)
/\_= /\_/\ | | | |
in ascii art that is the general arrangement <<<<is the side you'll be standing.
first peak 90 degrees, 17mm wide 8 mm tall. milled depression 1.5mmdeep 13.5mm wide. inner flat 17mm wide.
bed gap 55mm
first peak 17mm wide about 8mm high 90 degrees. milled flat area 14mm wide second peak 17mm wide and 8 mm high 90 degrees.
Stealth Pilot
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