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08-09-2005, 09:03 AM #1
I would like to know what basic skills you guys feel a cnc machinist/operator should know to start cnc training.
I may be in a position to spend 30-60 days working with entry level people to bring them to a starting point. This could also be a tool to evaluate the new employee's skills.
Hopefully they will have some basic training but a check list of skills mastered may be a good tool before throwing them to the wolves.
I realise that an apprenticeship is 8000 hours and 160 hours is not much to work with.
I only have a small conventional shop so can only work on basic machining skills.
Care of machinery and tools
Tram to a hole/shaft
Align to two holes
Feeds and speeds
Do you people have any other ideas for a checklist
As always, thanks for any input
08-09-2005, 09:15 AM #2
Math skills, geometery and trig. as well as basic machining paractices.
08-09-2005, 09:58 AM #3
If you are evaluating young people for entry, I would say you need to reach further and deeper. The first thing I would try to find out is if they are mechanically inclined in a strong way. If they are not, those are the least likely to apply themselves and be "stickers". A good question might be "When did you first disassemble and clean and reassemble the coaster brake on a bicycle?". If you get a blank look, they need to go out the door. (On the other hand, this might be hopelessly dated, but you get the idea)
08-09-2005, 10:08 AM #4
One thing you might care to do is approach a pastor of a minority church and inquire if there are any young people (do include women) that might be interested in training AND have worked with their Dads on mechanical things (cars, church facilities, etc.)
You might find that if the pastor can recommend someone it should be based on fairly knowledgable observation.
Perhaps "stick-to-it-ness" is something you'll want to know about before extending an offer to participate?
Then your problem is transportation to your site and the young person's math skills. But then, you might also be offering them a role model that helps motivate their desire to improve so it could be a win-win all around.
Good luck - and thank you for being interested in the future!
08-09-2005, 11:15 AM #5
You might want to throw in some general machine safety issues. You would be suprised to see some ot the things green operators will try to do with a machine. We had a guy, who claimed two years machine shop experience, that decided to chuck up a tap in the drill press. NO tapping head mind you, just chucked it up in the chuck and went to tap a hole. Tapped it REAL fast about half way then broke. He was luck it didn't hurt him. Terminated that one REAL fast.....
08-09-2005, 12:17 PM #6
I've never played with a coster brake, but I disasembled and reassembled my first ten speed in 7th grade (first time I got my hands on one)
I've heard that their is an old device that is an in-hub 3 speed transmision & coster brake all in one. love to get my hands on one!
I recently took a guy who had just graduated from the undergraduate Industiral Design program at Pratt Univerity here in Brooklyn. It is supposed to be one of the better programs in the country. The guy had supposedly taken 2 courses in machining and 2 in woodworking as well as welding and scultpure. Well, turned out that the guy didn't know *basic* arithmatic. I had to spend a day teaching him how to divide 3 by 8 to get .375. I don't know how he got through a ID program with out being able to ADD and SUBTRACT!!!!
But I would suggest that addition, subtraction, multiplication, and division be on your starter course... at least a over view or quiz or something. And make sure it is something "tough" like 23.345 + .236 or 47/64. You might be supprised what you get.
PS. The guy ended up leaving after about 3 weeks because he was concerned that he wasn't being asked to use his "conceptualization" skills. I'm not sure how you can design (conceptulaize?) something with out understanding what you are designing, but perhaps that's why I'm an odd ball.
08-09-2005, 12:39 PM #7
Hire attitude and the rest will take care of itself. I would rather hire a kid who has no skills in the trade but really wants to learn than a kid with some skills with a bad attitude. [img]smile.gif[/img]
Professional Bench Top Work Positioners
08-09-2005, 12:48 PM #8
Well, Kap said "cnc machinist/operator" so I don't suppose I would waste time letting the students do much on the manual machines because there are simply not enough hours.
It would be better for the teacher to demo the procedures on very simple operations, with lots of explanation going on while the demo is being carried out. Ask the students "How do you think I should do this next step", and try to evoke real thought, rather than have them trying to memorize your procedures. When they pick the tool, then you can be ready to spring a thousand more "whys" and "hows" on them for that
It is good enough to have the students go through a "dry run" with the tools, without actually wasting time cutting, etc. Let them move the handles and pretend they are doing the cut. Its not ideal, but in a short time, what are you going to do.
What I'm suggesting is sort of a "kung-fu" style of teaching, where they learn to go through the motions, while the instructor watches and questions them.
Give them homework for the stuff like math evaluation and measurement stuff. Try to squeeze more hours in that way. Also, if they are too lazy to do the homework, then they're not really all that interested.
08-09-2005, 01:24 PM #9
I would add in how to inspect the machines before starting the shift. Stuff like checking fluid levels, checking previous work left in machine, and proper chip clearing methods.
They need to learn to not assume the previous operator left it ready to go.
08-09-2005, 02:15 PM #10
Personally I would like them to the cartesion coordinate system, orthographic projection, some basic drafting (how to read a simple drawing), and some simple "G & M" codes would be a good start. Also, they should know how to set up their tooling offsets in the tooling library (toll length and dia). IMHO [img]smile.gif[/img]
08-09-2005, 07:51 PM #11
first order of business is to have all aplicants take the General Motors Skills Assesment Test.
or write your own.
if the workforce cant do the simplest math skills your wasting your and their time.
using the midpoint of your 30-60 day window you only have 3.5 hours a day to teach them anything.
im afraid you will end up spinning your wheels...jim
08-09-2005, 07:56 PM #12
I'm with Les on this one...cleanup and not leaving a mess for the next guy goes a long way. It's too easy for this disease to spread where nobody takes care of anything..."he's not doing it, so why should I?"
Ingrained early you have half a chance.
08-09-2005, 07:59 PM #13
If they are going to be CNC operators it might be useful to have them get the feel of the cut thru turning the handles. have them play with the feeds and speeds, let them listen to the sounds, teach them how to read the chips, have them try to take a cut with a dull tool, have them try to climb mill on a sloppy mill. It's hard to get a feel for that stuff just running CNC and this might help them catch problems.
08-09-2005, 09:26 PM #14
Don't forget safety.
08-10-2005, 01:42 PM #15
Ask them why they want to get into the trade. Make certain that making things is a bigger motivation than $$$
08-10-2005, 02:07 PM #16
I have worked with both kinds of CNC machinests, those with manual experience and those without, I think those WITH do much better.
For short run job shop type work I think math skills are a must. Being able to figuire the X and Y coordinate of a hole on say a 3" bolt circle and 27 degrees rotated from one axis is one example.
Basic Basic speeds and feeds I teach are 80 sfm for HSS and 150sfm for carbide cutting tools, and sfm x 4 /dia gives you rpm, That is for most steels found in tool and die work in the soft state, yes you CAN run faster but for most of what gets done it is faster to use simple numbers and get the job done and move onto the next one. Plus many job shop machines like a fadal are not rigit enough to run a 1" solid carbide endmill where the book says it should be run..start at 80/150 and work up if cycle time warrents it.
feeds and how they work, IE feed per cutting tooth...count the teeth and do the math.
How to zero the machine to a work edge or hole, and how to command the machine back there to CHECK it is very important "G0 G55 X0 Y0" entered into MDI for example then the work checked with edge finder or indicator..takes 30 seconds..saves your butt now and then,
Taking scratch cuts .01" deep with new program and checking profile with calipers, fast, saves material and time.
most important for mill work I think is doing the job in the LEAST number of setups...and evaluating how best to do that...many many many jobs can be done in 1 setup if you saw the part off last with a woodruff saw 1/16" thick leaving a small remnant of the workpiece in the vise.
08-10-2005, 05:48 PM #17Ask them why they want to get into the trade. Make certain that making things is a bigger motivation than $$$
Yeah, they should want to work for the sake of working....And be happy with that. If the prospective employee should ask for fair compensation, laugh in their face and point at the door. Another sucker is surely on his way in.
08-10-2005, 06:47 PM #18
To "start" training a operator or a machinist needs nothing more above average intelligence and a willingness to learn.
08-10-2005, 07:27 PM #19
To answer Kap's question directly, I think Jon Bohlander said it right - some manual experience is a must. There is a feel and common sense that you cant get any other way, without expensive and/or dangerous crashes, accidents, downtime, wasted part, tears, etc.
I worked years ago with a book-smart a$$hole who couldnt tell two scewdrivers apart, never even used a hand drill, but he and his parnter decided to buy a retrofit CNC knee mill, therefore they knew everything automatically, by default. When I quit 7 years later, a/h was still making every part that had to be finished by me on a POS manual mill. :rolleyes:
08-11-2005, 12:03 AM #20
I have been teaching for going on 18 years now, and you seem to have quite a good list started there. I have some lathe info for you should you wish, though it is "proprietary" to a training program I will be doing with another company, and customized to a program I am starting next month - should it be released to the general public, this company would send hooded ninjas armed with the most painful killing weapons and bad breath after us both. I will try to edit it to just a "Gist". send me a note via the interplanetary message system that this board uses.
You can evaluate in three days - I always give it three days for the initial evaluation though. What I look for in a minute though. Why three days? Well, day one the guy is unsure of you, and surroundings, let the guy or gal get their feet under them, and used to the surroundings. Maybe they had a crappy nights sleep, I know this happens to me on day one of any job. You as well, may be a bit on edge - new guy/gal, what do I expect - whatever. Day two, they are still nervous but have a bit of a feel and familiarity of the work area, and you are a bit more familiar and forgiving of them, and perhaps yourself, and also more prone to speak honestly about expectations, and able to judge better how they actually are. Day three, a day of either ease, or not.
I look for the makings of a trainable machinist by looking at the following. Initiative, craftsmanship, personal pride, and the ability to listen , take direction, and ask for direction. Initiative - I look for this in a very simple way. something on the floor like a rag right in the middle of an aisle, big gob of grease on the bench, trash in the aisle, work area, or bench. Does the trainee just look at it dumbfounded, "not my job", or take a bit of initiative to pick something up. Work areas, do they have a bit of pride in it.
Craftsmanship: does the person do the simple task of taking care of their tools, maybe cleaning the part off of chips after a run, putting the parts in a tray if applicable with the idea of not damaging the part. Does the guy clean the vise thoroughly - or chuck jaws - after being told that once - to prevent chip marks? Do they check tools after shown how, or just wait until sparks fly and the first scrap part comes off.
Personal pride - the way they treat themselves. "It is not my job" flys with me like a lead baloon, and is my instant sh*# list terms. This also flys with craftsmanship, but also extends to the guy calling me - the trainer or boss "dude". Anybody "swearing" just to impress me or show me they have that right to do so, or to show "Hey, I am a shop dude, I can swear like granddady in the mills" is also SH%$ list material. I realize people swear, but nobody has to impress me with it. It is even as simple as do they change their clothes after each shift or every other shift, or do they freaking shower and brush their teeth every third day. I know that is harsh, but think about it, CNC that involves advanced skills like programming, fixture design, and indicating and setting offsets to the .0001 takes some detailed attention. It is the idea that the guy wants to make the job right, and maybe even wants to improve over the job run. On a rate job, the guy may fret a bit over being behind rate, or set-up time, even when the situation and circumstances are totally against them, and not of their doing. They realize this is a "time is money" thing, and at least seek help rather than make excuses, and make you aware things are not going well quite a bit in advance...rather than "well, the job sucked, not my problem". Wants to do well, be a good person, and realizes that their work and habits reflect their own personal character to others.
Ability to listen - trust - Crappy excues and lying are true "list" issues with me....Something breaks because something happened, even when the trainee screws up - tell me the truth - stuff happens, we all screw up, and we get over it and learn from it. You forgot to lock the insert, opps, we hav ll done it. Set an offset positive instead of negative? Yup, been there. The machine is not always junk, we all have had "Operator malfunction". Excuses???? It will happen again and again...... I have to trust you, and you have to trust me. I will tell you how to do something, if you have questions, you better ask, and OH, take notes!!!!!!!! If you take notes, I will work with you to re-inforce this, refine your notes and processes, and make your operators notes and skills better. If I have to come back time and time again to show you the same freaking thing, and you just stand there like a lump, forget it..... I could have done that job myself...and a heck of a lot faster. If I have a comment about your work to help you improve, hear me out..it is not personal, it is my comments to make you better. If you have an idea, tell me!!!!!!
After three days, I can tell if I want to go forward and invest the lessons, shop profit in your case, nd taxpayer money in mine - beyond basic button pushing to make a great CNC machinist. If I even invest into basic button pushing at that point - they could even screw that up.
Oh BTW, I do look for this in my students, and in the past had many "three day wonders" wash right out on me. At one time in my pollyanna days, I really thought I could set them all straight, but now, I realize that each student is a reflection of my teaching skills to my industry counterparts. I got picky this past ten years, washed out the druggies If they are still butt stupid and/or lazy after three days, they tend to wash out within that time. I get some high power students these days, the slugs tend to hate me, and the good ones are trusted quite a bit.