Need Opinions: Academic Lab machine tool choices 7

[tygerdawg]

I come once again to tap into the wonderful expertise & opinions of Eng-Tips family.

Am helping specify lab equipment for a University shop facility. This facility supports the academic mission of teaching MechE, MfgE, MechEngrTech, & MfgEngrTech courses in Manufacturing Processes. We currently have a few each of Haas CNC mills & lathes of various flavors & vintages. Three manual knee mills & a couple of manual lathes. We struggle to teach Manufacturing Processes courses effectively with the current equipment & quantities. We have an opportunity to change / upgrade / replace / expand as needed to support the "Academic Mission."

I learned how to turn cranks back in the 70's with a big shop full of War Surplus worn-out machine tools. I'm not much of a machinist, but I know how not to embarrass myself (well...not too much, anyway) in the presence of a qualified tool maker. Rightly or wrongly, I believe the Academic Mission is summarized by We are not training machinists. We are training future TECH/ENGR grads what machinists DO. If the student wants to be a machinist, then they can learn it here but there are better venues for more intense training.

Our debate is about what best supports the Mission.
[ul]
[li]Re-stock the lab with more smaller manual tools (maybe SMITHY combo-type?) to focus on metal working fundamentals. Retain some CNC to provide exposure to CNC in later semesters. [/li]
[li]De-emphasize manual tools and focus more on CNC?[/li]
[/ul]

Would very much welcome opinions.

TygerDawg
Blue Technik LLC
Virtuoso Robotics Engineering

http://www.bluetechnik.com

 

[ScottyUK]

LOL. My first experience of climb milling was unintentional, I just didn't know better until after it happened.

I was using a great big Parkson universal machine, a decent-size slab cutter of maybe 3" diameter x 6" wide which happened to be on the arbor, and machining a smallish workpiece clamped to the table. The workpiece turned into a projectile which took a lump out of the brick wall to the right to the machine. It scared the crap out of me and annoyed the metalwork tutor no end. Lesson learned about using good quality clamps and paying attention to where the cutting forces are directed - a good lesson because I haven't forgotten it decades later.

 

[SnTMan]

An important skill, IMO, is to be able to measure, mark and layout. Fostered far more by manual equipment than NC, and kind of leads to the concept of tolerances and the stackup thereof..

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[SwinnyGG]

An important skill, IMO, is to be able to measure, mark and layout. Fostered far more by manual equipment than NC, and kind of leads to the concept of tolerances and the stackup thereof..

I would agree with this 100%.

It seems to me that GD&T, which is vital for anyone doing design work to understand as thoroughly as possible, is MUCH easier to grasp when you have actually taken a drawing, walked up to a mill, and had to think your way through how to hit the tolerances specified.

 

[mfgenggear]

some one else and I mention it also, it takes years and years and years of experience. 6 months will be a good start.

 

[tygerdawg]

You guys are great. Very much appreciate your input & insight, this helps me refine my course of action. I want my curriculum to produce good, effective engineers.

OK, let's shift gears to QUESTION #2: The same topic posted on another forum received more excellent advice. IMHO one of the best responses outlines a shop/training/skills migration scheme of:
[ul]
[li]Freshman / Beginner level using small-ish sacrificial import-quality machines[/li]
[li]Sophomore+/Intermediate level, moving to the better equipment[/li]
[li]Junior+/Advanced with higher-end / CNC equipment[/li]
[/ul]

...which in theory provides a self-sustaining pool of "student lab assistants" to help with running the lab exercises (which I desperately need).

Any recommendations for brand names to investigate for beginners? There are so many out there, and they all seem to be from Taiwan & China. It's just not my area of expertise.

TygerDawg
Blue Technik LLC
Virtuoso Robotics Engineering

http://www.bluetechnik.com

 

[KENAT]

Do you really want imported, or are you better off with used heavy duty stuff that can take a licking...

I ask because a now former colleague did a lot of buying & selling machine equipment and didn't seem like there was a lack of the stuff.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[JNieman]

Though the price may seem attractive, going with a bunch of Grizzly machines will leave you with buyers remorse after a short time. They will not take the beating students will inevitably unleash upon them. They're not the most rigid/sturdy machines for turning. If one of your students wanted to hop on a Grizzly lathe and turn a stainless steel gizmo, it'll be frustrating.

For a mill, I would get a Bridgeport knee mill. If you look in the area, you'll likely find used, good condition machines for a decent price simply because of market saturation. Some areas are better than others. They'll all have some manner of backlash - some worse than others. Given the university mission, you might find someone on "the other site" you asked this question who would help you out with getting used machines fixed up a bit.

For lathes, it's hard to beat old heavy iron, but again you're at the whim of the local market. Monarch, Hardinge, Emco, Handey, Leblond... Bridgeport has good lathes but they are much less common on the used market. A -heavier- model of South Bend may be good but it'll be a bit 'lesser' than the others. Depending on how much time you want to invest, it may be worth calling around to various shops in the area asking if they have something they'd be willing to let go. The company I work for now has given several machines to local tech schools over the years. No idea if they were sold or donated.

In general I don't know much about brand new machine brands for manual machines because in the professional realm, it's not a very common need I've run into.

For CNC machines in general, I believe HAAS is the best for your niche. They teach the principles and are user-friendly at the controller. Most CAM software already has a post that'll work for their machines. Students can still pop in a manually written g-code program or type it in at the machine. The only short comings / trade offs of HAAS machines are things you'll never have to worry too much about in your setting. They may not have the horsepower or long term rigidity or thermal control that other more expensive machines provide, but like I said... you're teaching beginners. HAAS is typically very friendly with educational institutions (or they used to be) as well.

I second @ornerynorsk in the statement regarding shapers. Your students will very likely never see one again after they leave the university shop. MikeHalloran has a point about seeing metal removal up close and personal, but I believe that's something that can be witnessed on a rigid, slow RPM cut on a manual lathe similarly. Shops that still have a shaper "from the old days" still find uses for it, from time to time, but I don't know of any shop that would go out of their way to buy one.

 

[SwinnyGG]

If I were running this 'shop', I'd want to avoid having 30 machines from 5 different sources (or whatever the final makeup would be) all needing different maintenance schedules and parts. In other words, I wouldn't want to have one set of machines for newbies and one set of machines for non-newbies, strictly because of the increased number of parts and maintenance operations you'll need to track. I would definitely want to avoid micro-size mills. Tiny machines use tiny tooling, so they're going to break a lot of cutters. That will blow your budget up, even if you buy cheapo 'disposable quality' cutters.

My assumption is that the goal of buying smaller machines for new students is to limit their exposure to danger. You can accomplish that goal by careful selection of the projects they work on. Start new students out with projects cutting MDF or plastics, where cutting forces are low, and tool life is not affected too much by feed/speed mistakes. When they (or you) are more comfortable with their skills, they can run a machine they are already familiar with, on projects in free machining metals.

You also probably don't need 15 Bridgeport machines. How big are the parts you plan to have student make in classes? My guess would be not very. Something like the Baileigh VMD-40G for milling and PL-1022VS for turning might be in range. Those two machines are capable of any basic operation you'd want to demonstrate, small enough that you can pack many of them in whatever space is available, they run on 110 (which I view as a good thing in a student environment- limited power and damage potential is not a bad thing in this case). That little mill uses R8 tooling so it can share with your Bridgeports, and has low enough speeds that you can work metals without much trouble.

 

[MikeHalloran]

Don't buy a Bridgeport lathe.
They were imported from Brazil, which by itself doesn't make them bad, but apparently no parts were ever imported.
So you can probably find one, for free, that needs just one part, but you will have to make the part.

Grizzly and similar tools are a bad idea as noted. They fall apart in normal use.

Don't buy a Bridgeport or clone mill that's been retrofitted with CNC (as opposed to just position readouts, which are handy). The problem is that, especially when cutting with coolant, they are a housekeeping problem, and there's no easy way to enclose them and drain off the coolant and chips.

i.e.,
If you're going to buy a CNC machine, buy one with a full enclosure, coolant sump, and chip conveyor.


Re Question 2:
Start with a ZERO-LEVEL class, where they learn to use a file and a hacksaw.








Mike Halloran
Pembroke Pines, FL, USA

 

[ScottyUK]

I like Mike's 'zero level' class idea.

One of our tasks in high school class, aged 13 or 14 I think, was to cut and file a randomly-shaped offcut of mild steel into a near-perfect cube of given dimensions, probably 25mm or 1". It's not an easy exercise using only a saw and file, as anyone who has tried this themselves will attest. Anyone inept, brave or stupid enough to present an object with convex surfaces or sides of unequal length faced derision, swearing and public humiliation from 'Sir' - it was a great environment to learn in but not one in which to fall short of his expectations. I loved it.

 

[berkshire]

I started metalwork class at age 12 in the UK, Our shop tools were a Myford ML7 lathe , a power cut off saw of unknown origin that took standard 12" hacksaw blades. My teacher used to say , " You can cut faster than that saw, but it does not stop for a rest.", a blacksmiths forge, Anvil, bench drill press, Guillotine 10" hand shear. There were no table saws or band saws. all cutting other than the cut off saw was done by hand.
One of my very first projects was to make a hacksaw frame, this was cut from 5/8" x 1/8" bar stock with the bends in the frame forged around. the end brackets were forged ,then riveted to the frame , a piece of 3/8" round bar was forged square at one end to fit through the bracket, the other end was tapered to a rat tail to fit a wooden handle. the opposite fitting was upset to get a square section, then the round end was fitted in the lathe where a screw thread was cut on with a single point tool. The teacher later explained to us, that this could have been done with a threading die, but he wanted us to get the experience of calculating the threads per inch and making the cut with the lathe. The only supplied part was the wing nut for the tensioner. I gave that saw to my father who used it in his work for some 20 years.
I really missed that teacher when he left the school to open an engineering shop.
B.E.

You are judged not by what you know, but by what you can do.

 

[dicer]

And from a real machinist. Rather than worry about changing the machines, unless of course they are completely worn out.
I suggest, some very complicated prints / parts to make, and with out of this world tolerances, like +_ .0002 inch, and to make production runs of the parts, not just a one off type part. If your machines are in okay running condition invest the money in cutting tools and holders, like good boring heads and the proper inserts and that sort of thing.
If you really want to teach the process, then that is what is needed, maybe a nice cell system would be nice with multi pallets, and lots of material to make the production runs. Others suggest manual machines, well yeah if we were in the 60's that would be a great idea. Its not a machinist course its a how to do production deal, right? Then CNC is the way to go, also a CMM, comparator, surface plates for inspection, and one or two cell systems with horizontal machines. And again most importantly complicated parts with very close tolerance bores and also burnished bores, as well as some gun drilling operations. Include some extremely long extensions for wheel cutters that would cut grooves with in deep holes in the parts. I would suggest that the parts would include using both aluminum and very hard stainless steels. They will learn more about production with these items than trying to run manual machines. In real life they will likely never see a manual machine, some are very hard to come by now anyway. Its not a machinist course, for a machinist then sure manual machines can help. But for the younger generations that grew up pushing buttons the cnc will keep there interest, and is what is now used.
Any new machines need to be something other than Haas. Fanuc controls would be best, it is what is the most prevalent out there.

 

[SwinnyGG]

And from a real machinist. Rather than worry about changing the machines, unless of course they are completely worn out.
I suggest, some very complicated prints / parts to make, and with out of this world tolerances, like +_ .0002 inch, and to make production runs of the parts, not just a one off type part. If your machines are in okay running condition invest the money in cutting tools and holders, like good boring heads and the proper inserts and that sort of thing.
If you really want to teach the process, then that is what is needed, maybe a nice cell system would be nice with multi pallets, and lots of material to make the production runs. Others suggest manual machines, well yeah if we were in the 60's that would be a great idea. Its not a machinist course its a how to do production deal, right? Then CNC is the way to go, also a CMM, comparator, surface plates for inspection, and one or two cell systems with horizontal machines. And again most importantly complicated parts with very close tolerance bores and also burnished bores, as well as some gun drilling operations. Include some extremely long extensions for wheel cutters that would cut grooves with in deep holes in the parts. I would suggest that the parts would include using both aluminum and very hard stainless steels. They will learn more about production with these items than trying to run manual machines. In real life they will likely never see a manual machine, some are very hard to come by now anyway. Its not a machinist course, for a machinist then sure manual machines can help. But for the younger generations that grew up pushing buttons the cnc will keep there interest, and is what is now used.
Any new machines need to be something other than Haas. Fanuc controls would be best, it is what is the most prevalent out there.

If the engineering program he is directing is anything like the one I passed through, he's attempting to teach the basics of how materials react to machining operations, not the theory of how to design a manufacturing line. There are specific (other) parts of the manufacturing and industrial programs for that.