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sanddrag 07-05-2015 21:43

Re: Shop Development
 
Quote:

Originally Posted by TheModMaster8 (Post 1479421)
Your students will learn a lot more from these machines than CNC.

That's somewhat antiquated and borderline bad advise. I understand the point you were attempting to make, but it comes across in an unfavorable way.

Many (if not most) schools require a classical progression of skills, from manual machining, up to CNC, and many older experienced machinists argue that any education that differs from this path is wrong and will never make a successful machinist.

However, we're beginning to see a shift in which manual machines are becoming increasingly irrelevant as most industrial processes are now automated, and to see something like a manual mill used in a production environment today is a rare sight, an a profit-losing one at that. I've even visited small job shops and R&D labs with plenty of CNCs, but not a single manual machine. Since we started on CNC, the only thing we use the manual mill for by choice is for awkward objects that just won't fit decently into the CNC.

I am a firm believer that it is certainly possible to teach students CNC milling before manual milling, with successful results, if approached in the right manner with the right instructor. Similarly, I learned and now teach TIG welding before stick, MIG, or gas. Go ask any trade school what they think of that. They'll tell you I'm nuts, but my welds and my student's welds speak for themselves.

That said, a decent manual mill is not a bad thing to have sitting around for educational purposes at the least. And a manual lathe is an absolute necessity, and in many cases preferred over a CNC for many types of work we do for FIRST robots and class projects.

On bandsaws, we recently acquired a Grizzly G9743 7x12 Horizontal and a Grizzly G0555X 14" vertical. The monster 1" blade on the 7x12 horizontal should be way better than the skimpy 3/8" blade on our old 5x6 horizontal. While I haven't yet had a chance to cut anything on them yet, they look like decent quality machines at first look after unboxing and assembling. On verticals, I'm in love with our 1960's vintage 18" Delta-Rockwell. You don't get that kind of quality in too many saws today. At home I have a ~2011 vintage 14" Delta. It's closest sibling today would be the 14" Porter Cable that Lowes sells or the 14" that Harbor Freight sells, both of which look better in a couple ways. The 14" Delta is a fine machine that had quite a following for many years, but even still, bigger and better saws are out there.

And as a final note on saws, we have a 14" Rage Evolution metal cutting saw. For the ~$250 it costs, it's a great tool to have around. It'll cut aluminum just fine, but it's not as precise as a higher speed Dewalt 12" compound miter saw with an 80T carbide tipped blade. On the Rage, the blade will cut through just about anything with little danger, risk, heat, or debris, but the teeth do clog with aluminum if a lubricant is not used. That said, it's an absolutely amazing and perfect tool for cutting steel tubing and unistrut.

apples000 07-05-2015 22:07

Re: Shop Development
 
Quote:

Originally Posted by sanddrag (Post 1480926)
That's somewhat antiquated and borderline bad advise. I understand the point you were attempting to make, but it comes across in an unfavorable way.

Many (if not most) schools require a classical progression of skills, from manual machining, up to CNC, and many older experienced machinists argue that any education that differs from this path is wrong and will never make a successful machinist.

However, we're beginning to see a shift in which manual machines are becoming increasingly irrelevant as most industrial processes are now automated, and to see something like a manual mill used in a production environment today is a rare sight, an a profit-losing one at that. I've even visited small job shops and R&D labs with plenty of CNCs, but not a single manual machine. Since we started on CNC, the only thing we use the manual mill for by choice is for awkward objects that just won't fit decently into the CNC.


For what we do in FRC, it is totally possible to teach students starting on CNC. Everything we do is aluminum, easy to fixture, and uses pretty basic milling operations with end mills that range from .125" to .5" diameter and the occasional fly cutter for face milling.

However, I don't agree with what you're saying about manual mills only being used in profit-losing situations. There are still plenty of machine shops effectively using manual mills to make parts.

asid61 07-05-2015 22:15

Re: Shop Development
 
Quote:

Originally Posted by apples000 (Post 1480932)
For what we do in FRC, it is totally possible to teach students starting on CNC. Everything we do is aluminum, easy to fixture, and uses pretty basic milling operations with end mills that range from .125" to .5" diameter and the occasional fly cutter for face milling.

However, I don't agree with what you're saying about manual mills only being used in profit-losing situations. There are still plenty of machine shops effectively using manual mills to make parts.

If you don't already, I would highly recommend switching to insert face mills over end mills and flycutters when you can. You get absolutely stunning finishes while running the things at 2000 or 3000rpm. I run a 2" face mill at 2000rpm on a manual mill and it has greatly sped up how fast I do my work, because I don't have to take a finishing cut and I can chug through metal really fast.

Regardless of whether you get a manual mill or CNC, buy an insert face mill along with the regular stuff.

apples000 07-05-2015 22:40

Re: Shop Development
 
Quote:

Originally Posted by asid61 (Post 1480935)
If you don't already, I would highly recommend switching to insert face mills over end mills and flycutters when you can. You get absolutely stunning finishes while running the things at 2000 or 3000rpm. I run a 2" face mill at 2000rpm on a manual mill and it has greatly sped up how fast I do my work, because I don't have to take a finishing cut and I can chug through metal really fast.

Regardless of whether you get a manual mill or CNC, buy an insert face mill along with the regular stuff.


Fly cutters will get you a better surface finish if you go quickly and have your head very square. See 4:25 in this video for a pretty cool demonstration of a good fly cutter:https://www.youtube.com/watch?v=Y2Xa0PMHM1U

I use face mills when using big rigid machines, but I've actually found that a sharp flycutter in aluminum can do a good job too.


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