Lathes for a student machine shop

We need to purchase some lathes for teaching mechanical engineering college students how to machine. Here's what we want:
1. about $2k per lathe. 2. 3-4 identical machines. 3. reasonably easy to use for beginners, no unusual safety risks. 4. doesn't require a great deal of work to get running well and looking good. 5. reasonably quiet since many machines will be running at once. 6. won't 'self-disassemble' if/when a student crashes the compound into the chuck. 7. able to get parts without a lot of work or expense 8. not such a treasure that it would be a tragedy if/when the students destroy it (so, no used Monarch 10EE despite how well built they are).
We don't expect to get everything we want. From reading the archives, either of the 12x Chinese lathes (belt-drive or gear-head version) are looking like the best options (flame-suit on). We initially wanted American iron, but new ones are of course above our budget and good used ones are hard-to-find (and we need 3).
The biggest risk with Chinese seems to be long-term parts availability. But, I think both these lathes have been around for a while (?), so if discontinued, I think parts would show up on ebay. I think the gear-head is more popular than the belt drive... not sure. Worst-case is we either a) make one lathe a donor, b) use our Haas machines to make replacements (a good advanced student project at that), or c) replace them.

quality and quietness, also the belt-drive should be better for abuse. The threaded spindle is not my pref, but I understand they have set-screws (or we could lock-out reverse). The main advantages of the 12x36 gear-head seem to be its camlock spindle and (probably) better parts availability.
On suppliers, I understand the machines themselves are the ~same, but that Grizzly and Bill's Tool Crib have the best service.
The 12x37 belt-drive lathe: Grizzly G9249 Enco '12x36' (actually 12x37) DP-510-2587
The 12x36 (or 12x24) gear-head lathe: Grizzly G4003 or G4002 Enco DP510-2589 BTC Birmingham 1236GH HF 33274-7VGA
FYI, the rest of our shop consists of two used but good Lagun mills (donation from industry), one each Haas toolroom mill and lathe, and Jet horiz. bandsaw, drill press, sander, etc. (all purchased before I started this year).
Any thoughts on which lathe is best for us/students, other considerations, or which supplier to use?
Thanks, David Malicky University of San Diego
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Two regulars on this NG could fix you up. Leigh Knutson (sp???) and Gunner Asch(sp???). They both hail from California, a bit north of you.

Why? I can see you want the controls to be about the same. But, wouldn't it be better to have both small and large units?
BTW, engineering students are the future managers of industry. Teaching a respect for old American iron would be a good thing, IMHO.
Karl
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Identical works in a school setting just like an industrial setting due to parts availability/interchangeability, one set of course/training manuals, etc.
--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
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Karl Townsend wrote:

Different is good in advanced courses. When you have a room full of people who have never touched a lathe (or computer or lawnmower engine or whatever you're teaching them to work with if it has any degree of complexity at all) then things go far more smoothly for the whole class if you've minimized the differences in what they are seeing to the best of your ability. Once they've got some clue of what they're about then it's time to start teaching them to deal with the idiosynchracies of different pieces of hardware.
At least that's my view--there is something to be said for variety at the outset, and if you can afford only the single lab that is to be used for the entire curriculum then you have to sacrifice pedagogical efficiency to get the necessary versatility.
Personally I think it's a good thing that he's got _any_ hands on in the ME curriculum--when I was in school we didn't even _see_ real tools unless we signed up for electives.

--
--John
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On Sun, 04 Dec 2005 12:02:13 GMT, "Karl Townsend"

Email Leigh, at snipped-for-privacy@aol.com
He is also a Jet dealer..and has some scratch and dent resources that may get the gent into decent lathes, in a batch for $2k each, plus/minus. Plus he knows where every batch of matching machines in California are.
Finding decent lathes in a batch like that..means either a school auction, or a shop going out of business. School lathes tend to have been abused..and there are not a lot of shops with lines of manual lathes anymore that arnt totally clapped out. Single lathes..thats doable..but its luck of the draw on what kinds and so forth.
I wonder if Scott Logan can locate a batch of Logan 11s. Those make decent learning machines, 5c, rigid enough for decent work, and parts are readily available.
The other option..is government surplus, which most colleges can get for free. Finding a batch..that may be interesting.
Gunner
"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner
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If the focus of the class is on teaching the basics of machining to a group of students, you want them all the same. If the focus of the class is to allow the students to build their various projects (under supervison of course!), you want a variety of machines, variety of sizes, and a variety of tooling.
Karl Townsend wrote:

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I would go with a belt drive over a gear drive. It should be safer for the beginner, and less parts to break when it crashes.
Vince
David Malicky wrote:

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wrote:

I second the thought that similar or identical machines are a good idea. In our shop we have (on my end) 11 S.B. lathes. Several different models and sizes. Two of the lathes are "two for one" ie moving the dial ten lines takes .020 off the part. Just something to make my life more interesting.
Also with identical machinery tooling is much more interchangable. That is if you have lathes with different size T slots in the compounds the tool post from one machine will not fit the next machine. Don't even think that every accessoriy will stay on the machine you put it on. Thant just doesn't happen with students. If something can be taken off and lost it will be!
Belt driven is the choice over gear driven by a long shot. Belts slip, gears break.
The more simple and uncomplicated you can set things up the better you will be. Believe me, if there is a way to screw something up a student can find it. Even when you think that you have eliminated all possibility of error they can find a way. After 18 years in a high school machine shop students still can surprise me with they creative ways they can f**k a project or a machine.
Errol Groff
Instructor, Machine Tool Department
H.H. Ellis Technical High School 643 Upper Maple Street Danielson, CT 06239
New England Model Engineering Society www.neme-s.org
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If I was setting this up, the first thing I would do to the machines is set up limit switches or some sort of proximity switches to shut off power just prior to crashing the lathe. It would be nice if these cut outs could be moved into place or adjusted prior to a certain jobs to limit destruction caused by operator error. Something like an adjustable carriage stop but with a cut out switch mounted on it that will trip a relay to the main power. I have been hitting the school auctions for a while, most of the machines from educational environments appear to be crashed on a weekly basis. Just something to consider.
Eddie
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Malicky says...

Our staff shop had two DV-59s. Granted you can't thread on them but they were great for quick jobs. These are solid and available relatively inexpensively. They need to have the tool compound slide and the tailstock though. One set of 5C collets would serve for two or three lathes.
Because there are no power feeds, crashes are kind of self-limiting.
<g>
Jim
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David Malicky wrote:

I can give you a parent's eye observation of Grizzly machines in a college environment. In addition to the real machine shop at Olin,
http://machineshop.olin.edu /
there is a "mini shop" available 24/7 for the students to work on their projects (MechEs, EEs, and Es all have to build many electromechanical devices). Olin is a new school, and they needed to be operational in a hurry, so the mini shop was equipped with a bench mill-drill, drill press, and lathe from Grizzly. In three years, the machines are history, having been replaced with a (beautiful) used Bridgeport, and a used American-made bench lathe. The Grizzly lathe is now used for coil winding. The kids did not enjoy working with the Griz tools because they required constant fiddling to get accurate results, and they had projects to get out.
Kevin Gallimore
-
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I teach various classes to a ME/EE mix including various levels in the ME machine shop. Our current setup is two Bridgeports, 15" Enterprise lathe, plus a Hardige toolroom lathe on the manual side, an older Haas VF-0 and turning center on the CNC side.
I would not even consider going the cheap import route for student use, way too much fiddling around, way too much breakage.
Sounds like you want to set up a 4 station lab for a total of $10k. Really tough to do unless you want to spend a LOT of lab supervisor time getting all the bugs out. Come to think of it, you WILL spend a lot of lab supervisor time getting the bugs out no matter what you do.
Also keep in mind that getting everything properly tooled will be $$$.
I think I'd call around to the used machine tool dealers and see what kind of deal you could get on 4 identical machines. Should be able to get some used SB lathes.
David Malicky wrote:

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I think it may not be the best idea to have special interlocks and no powerfeeds.
If the students cannot be taught how to properly operate the machines, they should not operate the machines at all. Industry does not have these special considerations in mind and engineers should not be treated differently. The students should have a healthy respect for the capabilities of these machines. They should also have a perfect understanding of how to safely operate the machines. Remember that their parts can be machined for a fee (much cheaper than losing a hand, for instance).
If a students breaks a machine, they should have to fix the mistake if it's the type of mistake that can be fixed. I understand their eagerness to complete their projects, but they're in school for an education. Taking responsibility for one's actions is important in industry. I found fixing the machines at school was some of the most rewarding and educational work I did there.
Having different machines is a good education as well. Learning how to operate different machines will allow them to become familiar with the machines at work much more quickly. The basic idea of a lathe doesn't change between manufacturers.
Just my $0.02 worth.
Regards,
Robin
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If you want to look at Jet lathes I can offer them at peanuts above cost. If you are willng to go the used route and have a few variations I can supply the lathes you need next week, including one very clean 12" x 30" Taiwan generic lathe. Call me at (949) 645-7601 tomorrow and we can talk about your plans. Leigh at MarMachine
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If you want to look at Jet lathes I can offer them at peanuts above cost. If you are willng to go the used route and have a few variations I can supply the lathes you need next week, including one very clean 12" x 30" Taiwan generic lathe. Call me at (949) 645-7601 tomorrow and we can talk about your plans. Leigh at MarMachine
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Thanks, everyone, for your replies. Sorry for the delay responding... it was balsa bridge project week and I had my hands full (tho worth it--a few teams got to around 1500lbs with ~0.5 lb bridges... seems they learned something!)
Yeah, we need identical machines for all the reasons stated. If/when we add an advanced machining course, then yes a variety of lathes would be needed. We can't teach them everything in 1 semester, so we need identicals to pull this off at all. Also safety is harder to achieve with different machines.
We were favoring a belt-drive machine as well, tho the 12x36import yahoo group recommended the gear-head... the cam-lock chuck and wider availability of parts were the main reasons (there are shear pins to protect the geartrain... not sure how effective). The cam-lock is a major plus for function and safety, imo. Reading the archives of that group and some others, it seems the 12x and up imports are much better quality than the 9x20 and 7x12 variety, or for that matter most anything at HF. I guess it takes $2000 and 1000 lb to get a reasonably well-made import.
There seems to be two ways of thinking about machines for students: 1) American machines are expensive but worth it since they won't break down (as much), or, 2) students will eventually break anything you give them, so there is little point in spending a lot of money (or time) in acquiring new (or used) American machines. I've seen student shops using either and both ways of thinking. We're still sorting this one out.
Errol--very interesting to hear about your experiences. I'm sure we'll be in for some, um, interesting experiences, too. Do you have any experience w/ the 12x imports vs. SB? Kevin--thanks a lot for the tips on Olin. I'd like to know if they got the 9x20 or the 12x36... I'll contact their instructors to get more of the scoop. Roy--yeah, we know it will be expensive and work, but thanks for the warning. We checked out some dealers but found nothing close to what we are looking for... we'll keep looking. Gunner--thanks for the leads. I partial to Logans, myself, and my last lathe was a Logan 11 which I ~refurbed. Also an ex-student lathe, and it showed. I'd like us to get what I already know, but I don't think a ball-bearing headstock would stand up to student use (I think we need tapered rollers or plain bearings). I hadn't thought of the government surplus route... good idea, will check that out too. Robin--I certainly agree with your words on safety, respect for the machine, and proper operation, but I'm also faced with the reality that beginners tend to make mistakes (no matter how well instructed) and so I also need to minimize risk. So we'll introduce risks gradually: for example, at first no power feeds at all, then power feeds as a dry run, then power feeds with a collet, then power feeds with a chuck. They prove proficiency at each step before moving on. Minimizing risks doesn't eliminate them so I still want a stout headstock. But I completely agree w/ your main point that proper instruction and skill development is the first priority and best line of defense. Leigh--I'll give you a call.
Thanks again! David
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