Centroid CNC
 

I am wondering if anyone here has experience using Centriod CNC products?

http://www.centroidcnc.com/

The cnc knee mill we have in the shop uses this control system.

Since our team does not have a cnc machinist, I am going to attempt to learn how to use Centriod's Intercon programming software.

I am a amateur machinist by trade, but most of my CNC experience is with turning centers. I learned how to navigate through the many different control systems at my previous job, so that is not a problem, but I have little programming knowledge.

I have made a few basic parts with Intercon, but thats as far as I have gotten with programming.

I would like to stay away from MasterCam because I want to learn how to program the right way and because it is hard to get files to the cnc.

Basically what I am asking if anyone in the CNC field knows of any good books or online articles that go into detail with G-codes and contain CNC mill "need to know" information.

We do have a manual for the control system, but I do not have it at the moment.

Learn CNC or Bust!

Re: Centroid CNC
 

There is this one manual I think is pretty good for learning G codes. While it does explain a lot of stuff applicable to HAAS only, it also explains a lot of G codes that are universal to any machine.
http://www.haascnc.com/training/Mill...m_PDF/xmwb.pdf

You may have some problems with syntax though as the HAAS machines are very forgiving of sloppy programming and other machines may not be.

Re: Centroid CNC
 

I've been a machinist since I was 7, it seems to get in your blood, or is that just the machining fluid :D . Anyway, I don't think you really need something like that, at work the only thing I use is notepad, auto cad, and virtual Gibbs (pretty complicated and expensive). I work on 11 axis swiss style lathes, and 3 axis cnc mills. The lathes cost almost as much as my car and use simple controls, but require extensive knowledge of G-code. I suggest just learning G-code, it's really simple. for most of the parts your going to probably make (IE. aluminum axles out of a solid bar, mounts, custom plates, drilled out sprockets + gears, etc..) you really only need to know a few commands. and the syntax is really simple too.

"G" is the command to tell the machine to go (duh)
"x" is the command for using the x-axis
"y" same thing only with the y axis
Z" same thing but with the z axis
"F" feed rate, it's followed by a number telling the machine how fast to move
"M" turns on and off the spindle, it's followed by either a 3 or a 5, 3 turns it on,5 turns it off.

thats about it for a 3 axis mill, if your putting on a rotary axis then instead of using X,Y, or Z you would use A.
so lets say i want to make an aluminum axle. the code would be as follows

(first zero off all Axis's)
"M3" <-- turns spindle on
"G0Z-.02" <-- put whatever the depth of the cut is, i suggest only cutting a maximum of .02 on each pass to increase life of machine and tooling
"G0X-5" <-- Put the length of your slot, make sure you know the travel of the Axis's or you'll prolly run the table off the track. And thats a negative sign next to the 5. it can also be positive.
"G0Z-.04"
"G0X0"
"G0Z-.06"
"G0X-5"
etc....

Don't put quotations around the commands and don't use the <-- thing , I just did it for demonstration purposes. If alot of people actually want to learn G-code maybe you can ask the moderators if we can get a topic on just Machining. When you start making curves and circles it gets a little more complicated. BTW my name is Phil. If you have any other questions feel free to PM me.

Re: Centroid CNC
 

I bet thats gonna be one awesome machine. And, thats an awesome link to the CNC stuff. Modern Machine Shop's "Handbook for the Metalworking Industries" has a whole section on CNC and G Codes for lathes and mills, in reference format. Its a great book in general too, for all sorts of info about materials, threads, etc. Our school just got a Prolight 1000 mill for our Project Lead the Way CIMs course. Anyone have experience with that machine? The teacher and I are still wiring it up and such. I worked in a machine shop over the summer using full size stuff, which was absoultly awesome, so im really excited to incorperate the cnc to our robotics. Youve gotta keep us up to date on your learning progress with the CNC.

Re: Centroid CNC
 

I worked at a cnc shop over the summer, didnt do too much with programming, but some of the other g-codes

M00 manditory stop in the program
M01 optional stop (controlled by the optional stop switch on the machine)
M03 is spindle on, forward followed by a spindle speed I.E. M03S2000 for 2000 rpm forward
M04 dont know, but given that M05 is stop the spindle, I think that it would be spindle reverse
M05, spindle stop

M08 coolant on
M09 coolant off

Thats all I leaned, didnt do any programming, just ran the machines.

Re: Centroid CNC
 

You don't always have to put the 0 on the m5 or m3 command, it will confuse some machines (trust me, confused machines aren't fun to be around). and i don't know why you'd want to reverse the spindle on a mill because the bit won't cut backwards. You only might use that once in a blue moon on cnc lathes, but never on mill unless your making reverse threads. And the spindle speed can be manually controlled on most machines using a knob in the back, you have to be carefull of the spindle speed, to fast and you could snap the bit, too slow and you'll either bind up the bit or make an extremely sloppy cut, and noone likes sloppy cuts :D .

Re: Centroid CNC
 

I belive conkbot is refering to large scale production machines, where the speed does need to be referenced. The knob, then is only used to tweak the speed Ie from %120 to %50 of the referenced speed. Anything more than a %10 change really should be edited in the program.
And dont forget about those infamous lefthanded drills. Or as was the case with the Bridgeport at school, if they hook the phases up in reverse. Then reverse comes in real handy lol.

Re: Centroid CNC
 

The machines I work on have a graphical interface for setting the speed (star cnc if anyone cares). But alot of the older machines have a knob, and it controls the speed from 0 - whatever. I work on high end production machines with automated bar feeders, pretty much they pay me to write the code, and then they pay someone to fill the bar feeder when it gets low. these machines can run for weeks making the same parts. unless of course the bit breaks or you loose power :D . Some of the Bigger ones (really really really big) have automated part placers so you don't have to hire another person to do it. I don't know if this interests anyone but their installing a robotic part picker in the building i work, they said it's supposed to be 3 stories tall, I'll get pics when it's finished. But basically your supposed to go to the interface, type in the part ID# and then it'll bring it to the window for you. But i think that only works when they guys in the parts department take the time to put the parts in the right slot :D .

Also you might want to think about useing labels, they act kinda like "If THEN" statements. that way incase the bit is in the wrong place, or if the spindle isn't the right speed, then it'll fix it before you have a bunch of useless broken bits.

Re: Centroid CNC
 

3 Stories?!? Yes, of course pics!!! Where do you work/ what are some machines you program? I ran a Nakamura-Tome 6 axis lathe for two days while the other guy was on vacation. That was pretty awesome. And i got to oggle the 2 toyoda FA450s with pallet changers. It never ceases to amaze me, the machinery they make.


Lets see if we cant get this thread going: Whats the best part for your robot any team has made on a CNC...or manual machine?

Re: Centroid CNC
 

We'll i work in any machine shop that i can get work in, but mainly Star CNC, i work on the smaller swiss style cnc lathes, like 9 or 11 axis. hmmm, my team doesn't use many parts that require machining, i made aluminum axles a few times, but thats about it.

Re: Centroid CNC
 

Bad brad

I used to own a centroid knee mill some 15 year ago when I first started in business.This is my 2 cent on learning G- code programing . I have been programming cnc mills for many years and owner of a machine shop.When I hire a new employee I really don't care if he or she knows what G55 or G00 are .What I look for is experience using my cam software (Computer Aided Manufacturing ) in my case we use mastercam .Mastercam is expensive to buy but there many other software packages and also student version that are not.
The advantage of programing with CAM is that you will be able to program any kind of mill . Please don't get me wrong Knowing some G code is great ,but if you have problems or crashes just know there is a better way .

Jim Schaddelee
Team 107 mentor

Re: Centroid CNC
 

I'm not too sure either, the only thing I can think of off hand is if your using a wire brush and you want a CCW brush pattern, but it doesnt hurt to know.

As for threading, the machines Ive worked with have a seperate G codes for rigid tapping (tap is held solid in the tool holder), and for the kind of tapping that allows the tap holder to move up and down independantly of the spindle, to a point. Its kinda neat watching the machines run the taps down into the hole so fast, and then reverse and back right out...

Jim, yes knowing how to run the CAM software is definitely important. When I worked over the summer, I saw the programmers add a toolpath to debur a part in a matter of minutes, and doing so manually would have taken hours. Once you get beyond basic parts, CAM software is pretty much absolutely needed.

Re: Centroid CNC
 

My school has one (Prolight). I've been using it (virtually singlehandedly) for just over a year and have a bit of experience with it (as well as a techno-isel router/mill). Feel free to PM with any questions about it, no need to clog this thread.

With regard to Gcode - I know it (well, to put it one way, it was easier to learn than brain%@#$, the programming language). I have however never had to use it. Modeling in Rhino and CAMing in Mastercam (9, if anyone cares) is quite effective.

George

Re: Centroid CNC
 

Thanks

At the meeting tonight I got a former team member/coworker to show us some basic stuff. He walked us through the programming (80 or so lines) of a prototype part using G codes and M codes.

I did have a dimensioned print in front of me the whole time so that helped. I now also have an understanding of programming.

I just have to remember/know the G codes and M codes.

In the prototype part we programmed; we changed tools three times, did some peck drilling, and some circle pockets.

We ran it in open space, went through the flaws, and finally got it to work correctly.

One of the reasons for posting this thread was to spur some conversation so feel free to post anything you would like about CNC Milling.

Re: Centroid CNC
 

So we're still in the process of wiring the mill and finding a spare computer to run our software off of.
Have you (or anyone reading this) ever used inventor to edgecam? Thats what were supposed to be using for cadcam, and ive never used a cam program before, ive only edited Gcode.
What parts have you made with it so far?
What are the quirks/limitations of the machine?

Re: Centroid CNC
 

things I've made:
- engraved aluminum (1/4th 6061) keychains (they're kinda cool, wish I had a picture). This was the most challenging as we had to drill reference holes to face/mill/engrave on both sides. I've never spoken to a machinist, and if I did, I'd ask them how to cut things out without damaging the table. We put another aluminum plate under it to solve that. Worked for us, might not be the right way. Another note, about roughing. DO IT! Aluminum likes to be cut with slow spindle speeds, highish feedrates, multiple shallow cuts (roughing), and lots of lubricant/coolant. We kept dumping oil on it, which was effective, but probably not the best solution.

- aluminum mounts for the CIMs. Also 1/4th 6061. Above holds. The thing about the Prolight is that it is, if anything, overpowered. If you make a mistake, and the spindle's going too fast, or the cut is too deep, or your feedrate is too high, it will just keep pushing. It CAN and WILL melt the aluminum to the bit if you do this. Result: ruined and/or broken endmill/ballmill, and the lubricant will eventually start burning (almost happened, once). We now keep a fire extinguisher on hand.

- Various things of balsa. Mostly 3D milling, for a challenge. A mockup of an injection-mold for a vase. We don't have an injection molder yet, but we want one.

- Red lexan tetra clovers! That was fun. We cut 12 at a time (3 tetras cut from 4 stacked sheets). Wear ear protection, or go slow.

- Others. I don't remember them very well.

general guidelines:
- Stick with manual control of the spindle speed.

- Make sure the E-stop button works. If ours didn't, I'd have broken the machine a couple times.

- I've never cut steel, can't talk about that.

- Don't make heavy cuts with low feedrates and high spindle speeds on aluminum. It makes very sharp, very fine shavings, which pile up and resemble steel wool. Combined with the oil, it would make a very, very nasty fire.

- Having an overhead winch helps. The machine weighs around 350 pounds. Move it as little as possible.

- Try to shield your computer from aluminum shavings for obvious reasons. We had two hard drive head crashes last year, which may or may not have been because of shavings getting in the hard drive.

- Oil your linear bearings and ballscrews with a light oil (WD-40 works), and do not let shavings get on or in them. It will destroy the accuracy you have paid for.

- Clean the machine. Not only does this serve a practical purpose, but a psychological one as well. No one wants to use a dirty machine, and you'll be much more careful if you've put a lot of effort into maintaining it. That's how I feel, at least.


George

Re: Centroid CNC
 

Thanks for the advice, now i cant wait to get the machine running and try all sorts of things. Im definatly making a keychain :D
The best way to clamp pieces which youre gonna cut out is using step blocks and clamps (Grizzly sells a cheap yet effective set with 3/8-16 threads to fit the table). If that scrap piece of Al moves under the work piece, thats a good way to ruin a project or break an endmill.
And, btw, machine oil really isnt the best lubricant for Al. Ive heard old machinists say kerosene which does work well, but im a fan of the synthetic cooltoolII for all sorts of metals. Its a great lube/coolant, isnt waterbased so it doesnt rust the machines and doesnt become a sticky mess when hot as ive found Tapmatics Aquacut does.

Re: Centroid CNC
 

Yep. Holding wasn't the problem (we were using step blocks and clamps, big ones too), and the scrap under it was larger, and clamped as well. It wasn't really a problem, just a (maybe) odd/different way of doing things.

We didn't use machine oil. Sorry I didn't make that clear. It was not a heavy oil, but it wasn't a specialized cutting oil either.

George

Re: Centroid CNC
 

Actually, the couple professional machinists I know generally run aluminum jobs at a very high spindle speed.

Re: Centroid CNC
 

High compared to steel and other metals perhaps - but compared to plastics and woods (things likely to be milled in a school shop), no. It's relative. Consider the context - a 12'' x 6" x 9" mill intended purely for education.

One note I forgot in my above comment:
- I don't remember what we were cutting at the time, but we had a shard of something fly up and shatter the splash guard. We took a heat gun, bent up some polycarbonate, and replaced it. I'm not sure if they've fixed that problem by now. Lesson? Wear safety glasses, because you SHOULD be watching the machine.

George

Re: Centroid CNC
 

Actually compared to wood and plastics, yes you can do aluminum at very high speed. Wood if fibrous, which doesn't let the shavings come out as well as aluminum ones, and thermoplastics which can melt have their speed limited in that manner also.

I've see aluminum roughed at 20,000 rpm spindle speed, and 1,000 ipm feedrate (yes, one thousand ipm), with a 3/8" endmill. I don't know the depth of the cuts or the step rate, but it wasn't exactly real light... For that machine, it was actually faster to do it that way than to take a few heavy cuts with a hog cutter. If that's only relatively fast for you, I want to see your setup :D

Oh and for work-holding with a key-chain, and other small things, at our work we used a lot of "soft jaws" they were pieces of extruded aluminum that you would bolt to your vice, and mill out as you needed to hold your work.

For a key-chain, I would have it sized so the step holds your stock to at least half of it sticks up above the top of the jaw. In the first step, it roughs out and engraves the top half. You flip it over into the next spot, which is a negative of the top of the key-chain, and you cut out the bottom and engrave it. If your interested I'll draw up a sketch or something. Not exactly the best for one-off stuff, but if your doing key-chains, I would guess your doing a bunch so it would work fairly well for you. Just put the pieces in, tighten the vice, tap them down, run the cycle, flip the piece over to the next op, tighten the vice, tap it down and run the cycle again. But step blocks and clamps are definitely great for single pieces.

Re: Centroid CNC
 

How much coolant? I'm curious - we don't pump coolant continuously onto the work, because we can't.

Re: Centroid CNC
 

We do it in our school but I have never used master cam, I have just never Had a chance to. PM rees2001 if you wanna know more he is my teacher.

Also, i have heard to use vegetable oil based lubricants, i heard they work good and clean up easy.

Re: Centroid CNC
 

I dont have GPM figured but it was coming from 2 nozzles a little under 1/2" and it would travel a good foot horizontally before it got any noticable amount of sag in the stream (we didnt keep them like that I was just fiddling aroud with the nozzles before we got the wash down hose hooked up...) so definitely quite a bit of coolant.

For our coolant we used Blaser Blasocut, mineral oil based, and doesn't stink, like our old stuff does.

What are you working with that you cant use coolant continuously?

Re: Centroid CNC
 

Aforementioned Prolight 1000 . I could probably rig something with a bilge pump and some filters, as the machine does have a chip tray, but I haven't because we're leery of modifying the machine (buying another isn't really an option if we break something...). I'll see what I can do - we do after all have a pump or two lying around, and the coolant could speed our machining greatly.

George

Re: Centroid CNC
 

ahhh ok... I was thinking it was a material restriction and not a machine restriction

Rather than a streaming coolant check out something that puts a mist of the coolant onto the work area. Even a bit would be better than none.