Machining

[Conor]

I really don't have much knowledge of machining, but I'm really trying to learn. I've done a little programming on a CNC mill with some conversational language, but that's about it. I was wondering what types of machines you guys use and what type of language you use to program them. I've seen some really crazy things come out of FSAE projects and it boggles my mind that students are doing it. Just about custom everything, and it's really awesome to see. My hat is off to all those people. What I'm really trying to get at is, how do you guys go from basic design to finished part? I know this is going to vary for every part, but generally speaking, what types of setup methods do you use? Also, I've heard rumors of being able to export a part straight from ProE into a mill using a conversion program, completely eliminating the programming step. I have no idea if this is true, so if anybody could shed some light, I would be very greatful. As always, I appreciate all the feedback.

[Conor]

I really don't have much knowledge of machining, but I'm really trying to learn. I've done a little programming on a CNC mill with some conversational language, but that's about it. I was wondering what types of machines you guys use and what type of language you use to program them. I've seen some really crazy things come out of FSAE projects and it boggles my mind that students are doing it. Just about custom everything, and it's really awesome to see. My hat is off to all those people. What I'm really trying to get at is, how do you guys go from basic design to finished part? I know this is going to vary for every part, but generally speaking, what types of setup methods do you use? Also, I've heard rumors of being able to export a part straight from ProE into a mill using a conversion program, completely eliminating the programming step. I have no idea if this is true, so if anybody could shed some light, I would be very greatful. As always, I appreciate all the feedback.

[Boston]

Our team uses UG's Manufacturing component which writes our code based on the parts we model. Fairly simple to use.

[Jersey Tom]

You can never skip the programming step. You're always gonna have to figure out the order of operations, how you're gonna hold on to the part, how youre gonna switch your setups, what tools to use, speeds and feeds, toolpath strategies, depths of cuts, etc. All that is based on experience.

That said, there are design packages that have integrated NC modules, which I think are even bi-directionally associative. Unigraphics.. Catia.. they have stuff like that.

We use Solidworks05 and Mastercam 9.1 here. Real easy to pull in a solidmodel as a parasolid and write toolpaths off that.

As for CNC machines..

I'm employed in a shop on campus that has a Fadal 3016L, 7500rpm spindle, 15hp (peak), 21-tool carousel ATC. 3 or 4 axis. Rigid tap. Got 24/7 access to that.

I also have a key to the ME machine shop which has a nice Hurco VM1, 8000rpm spindle, 15hp (peak), 16 tool dual-arm ATC. 3 axis. Rigid tap. 24/7 access to that.

Aerospace shop just got a Bridgeport CNC lathe, all I know is it has a 4500rpm spindle and theyre workin on debugging all the operations in it.

Then there's the ITLL (which is an all-of-engineering lab basically) with its machine shop that has a couple old Milltronics CNC mills and lathes, which I refuse to use. They stall out cutting aluminum for cryin out loud.

Each machine has its own specific language but its all very similar to standard Fanuc G-code.

Tooling.. with the exception of drills and the odd tap and woodruff cutter, is solid or indexable carbide. With the timetable we run on, you'd be nuts runnin M2 or M42 HSS if you can get your hands on some C2 carbide. Never run any slower than 45ipm, and usually upwards of 85ipm, even on 3/4" tools. At that speed though you better be damn sure of your setup rigidity and toolpaths, or else you'll be slicing through vices and having 2-3 pound chunks of aluminum flying around.

I'd highly reccomend if you got even one good CNC machinist.. to have them design your most time-intensive NC parts. Keep stuff simple. Yea you can show off the crazy parts you can machine, but what's the point? Takes way too much material, tooling, and machine time.

[kozak]

i think everyone is missing the fundamental step of learning how to machine. you need to become compitent on both a mill and lathe if you want to be a good cnc programmer/operator. it will keep you from making really basic mistakes and teach you the basics about cutting tools, collets, chucks, propper speeds and feeds, and depth of cut. just pay attention when someone else is making a part on a manual machine and ask alot of questions if not making the part yourself. i've seen and heard of other students break tool after tool and collet after collet and think nothing of it because they didn;t understand the process, and they trusted the program to much.

[Jersey Tom]

Well yea, yuo should only be jumpin into CNC once you have probably a couple hundred hours of manual. Or at least that's what I'd reccomend. Much safer. Going straight into CNC is mighty sketchy.

[KU_Racing]

jeez. I wish we had the machining capabilities that some of you guys have. We have 2 manual lathes, a 2-axis mill with a proto-trak control system. That is pretty much it. Oh, what I could do with that 4-axis machine....

[Jersey Tom]

I think total for the shops I/we can get to, tallies up to something like..

(2) 4-axis CNC Mill
(6) 3-axis CNC Mill
(2) 2-axis CNC Mill
(2) CNC Lathe
(10) Knee Mill
(13) Toolroom Lathe
(3) Engine Lathe
(1) Surface Grinder

Then theres another 2 or 3 non student shops on top of that with a few more CNC mills, lathes, surface grinders, etc

What I'm jealous of are schools that have Mori Seikis (I know one of you does), or Haas VF4s and what have you. In industry a Haas won't really cut it IMO, but its a mighty quick machine for engineering students to get to play with.

[KU_Racing]

christ! I bet we could finish our car 8 weeks earlier if all of our work wasnt bottlenecked onto our 1 mill and 1 lathe. Seriously.. Kettering needs to get with the program. Or I should just tranfer to colorado. I have a buddy that goes there....

[Jersey Tom]

Boulder is a tight campus.

We have a lot of machines, but a lack of good machinists, CNC especially. Couple decent/good welders.. and one alumnus who is a total badass on the TIG.

[KU_Racing]

hmm.. kettering sucks big balls. Maybe a transfer is in order?? Im an excellent welder and fabbie.. can run a lathe and mill.. Im a good driver too (lots of karting). hmm.. sounds like a formula sae application lol.

[Blake]

all i have to say is god bless waterjetting, simple 2d autocad file, and bam the machine does the rest, saved us countless hours
Blake
LSU FSAE

[Conor]

Jersey Tom,

That's an insane amount of machines. I had to beg and pull strings just to get on a CNC mill in our shop and it's only a 2 axis. I don't even know if we have upwards of a 2 axis available on our campus, despite the large number of machines we do have. The things I would love to do with a 5 axis.. what a wet dream that is...

[Jersey Tom]

Boulder has a damn lot of machine shops on campus.. 9 I think.. many of which can be used by students (at least if you do some convincing). 5 are in the engineering center alone. And a lot of the machines are pretty decent.

[SpdRcr]

jersey tom -

i am extremely jealous of your schools inventory. how did they aquire so many machines? i.e. big engineering school, alumni support, industry support?

We have one CNC machine at our school and we simply do not have access to it. Even more frustrating, I have had numerous conversations with the dept. chair. The damn machine barely runs. If we can't use it, or learn to use it, we should still be able to get parts made for us by those authorized to use it.

I told him it should be as simple as dropping off the part file to the CNC engineer and picking up the finished part in the evening. I was told thats not how it works. Correct me if I am wrong?

Right now we are 1 month behind our schedule because our CNC sponsor just hasnt come through with promised CNCed parts and we haev resorted to plan B for several designs. However, I believe one of our seniors just went down there and started making parts himself. Brackett you are an animal. I hope it wasnt a hostile take over. Now to get back on to Plan A...

[Conor]

B. Bell-

Fortunately, getting CNC time at my school isn't as difficult, but it is still a challenge. Professors keep kicking us off for their own projects and nobody on the team has access to the machine room with the CNC. In fact, I have to have a professor meet me every time I want to get in the lab.. it's pretty ridiculous. Either way, be persistent.. it took us quite some time to even get access to our machine. I wonder why schools are so uptight about this crap...

[Jersey Tom]

To be honest, I have no idea how or why we have so many machines on campus. But its phenominal.

[Chas]

I'm also a CU student. Tom is the man.

I think our shops are a pain.

We can only get access to one on the weekends (without breaking any rules) and I can't cut aluminum in it with anything but a hacksaw. The mill has a socket wrench permanently stuck to the top bolt for loosening the collets (don't know the technical term).

Most of the things I have made for this year's car require me to go from shop to shop waiting for my turn to use the machines.

The best shop I have access to is always packed with freshmen and aero students. I spent 3 hours waiting in it last week for 20 minutes of machine time.

However after hearing about other schools' access, I feel blessed.

[BStoney]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Chas:

The mill has a socket wrench permanently stuck to the top bolt for loosening the collets (don't know the technical term). </div></BLOCKQUOTE>

YOU ARE TELLING ME THERE IS A WRENCH ATTACHED TO THE TOP OF THE SPINDLE?!?! So the wrench spins with the mill?? I wouldn't go within 100 yds of that machine while it was running!!

Man, I hope what I interpret is not what is actually going on!

[kwancho]

Maybe he just means a socket....
Sure hope so.

[Jersey Tom]

There is a socket pressed on to the top of the drawbar.

The deans office bought us a knee mill last year. A 'Grizzly' brand mill. There is no brake on the damn thing. Dead serious.

Now you may be asking yourself, "But Tom, without a brake, how the hell would you tighten or loosen the collets in there?" We asked ourselves the same question. We wound up using some rubber grippy thing to hold onto the nose of the spindle and then torque on the drawbar to get things tight.

Worked well until a drill chuck was left in there for a couple months, and got stuck. I wasn't around for this next bit of engineering.. they decided to press a socket on top of the drawbar and used an impact wrench to get the drillchuck outta there. Incredibly it worked. So now they use a socket wrench to tighten and loosen the damn thing.

Its also belt driven. Personally I refuse to use the thing. I feel dirty even going near it. Like visiting a 2 cent hooker.

[kwancho]

Oh gawd. I've used one of those. Made a racket, tore up the piece, and was in general not so fun. But an impact wrench... dang.

[BStoney]

makes me feel 100% better you don't have a 10" projectile whippin' around the top of the mill!!

but man, that sounds like a seriously shady setup, .02 hooker is right.

[Jersey Tom]

Shady is how we roll.

Seriously, tell me you guys have never done anything sketchy.. on one of those 3am nights where you're like, "well.. this has gotta get done.. and we do have an oxy acetylene torch, a pair of vicegrips, and an old ketchup packet. Ok here's the plan.."

[Bill Kunst]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Jersey Tom:
Shady is how we roll.

Seriously, tell me you guys have never done anything sketchy.. on one of those 3am nights where you're like, "well.. this has gotta get done.. and we do have an oxy acetylene torch, a pair of vicegrips, and an old ketchup packet. Ok here's the plan.." </div></BLOCKQUOTE>

Hmmm...Let me guess, the torch is for making the .050" press fit work, the vice grip is for making the -.050" slop fit work as a press fit, and the ketchup packet is the lube for both(also doubles as a loctite look alike after dried).

Seriously, that sounds like a "you might be on baja if..." http://fsae.com/groupee_common/emoticons/icon_razz.gif

[BStoney]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Jersey Tom:
Shady is how we roll.

Seriously, tell me you guys have never done anything sketchy.. on one of those 3am nights where you're like, "well.. this has gotta get done.. and we do have an oxy acetylene torch, a pair of vicegrips, and an old ketchup packet. Ok here's the plan.." </div></BLOCKQUOTE>

sorry, guess you didn't get sense the sarcasm..I hear ya though, sometimes you gotta do what you gotta do.