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CNC Machines

idbruceidbruce Posts: 6,197
edited 2011-01-31 06:12 in Propeller 1
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Comments

  • atlstangatlstang Posts: 20
    edited 2011-01-12 06:16
    Have a small 3 axis mill that has been converted over to cnc. Which works currently with no prop in it yet, but hoping sometime to add spindle speed display/control using prop. If i was somehow successful at driving the 1hp motor, down the line i'd maybe look at some other higher order functions that could be automated with the prop.

    Although by no means a circuit expert, driving the 1 hp (maybe its 3/4's hp) would be the biggest motor i have driven. Havnt really put the leg work in researching/googling how to drive such a motor safely yet. hopefully time will free up in the future, though if you come across a circuit do post.

    May i ask what your making with all that machinery... circuit boards??
  • idbruceidbruce Posts: 6,197
    edited 2011-01-12 06:34
    Atlstang

    Thanks for responding.

    In finding a suitable driver for your spindle motor that the prop can communicate with, the most important thing to know is the amperage of your motor. Most likely, you will end up driving it with an h-bridge that has mosfets that will handle high amperage loads. There is a lot of information on the internet pertaining to high load motor driving with h-bridges. In addition to the h-bridge, I would put some type of translator before the h-bridge which can handle PWM, then you can control and display the spindle speed with the Prop.

    As far as my machinery goes, the bending cnc and the packaging cnc, they manufacture and package a product for which I have a patent pending. As far as the circuit board drilling cnc machine goes, in the near future, I will be making motor driving circuit boards, as well as other various circuit boards.

    By the way, what are you using the mill for, metal or wood?

    Bruce
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2011-01-12 08:09
    Packaging machines are an area that is generally ignored here, but there is a huge market for good ones. I worked for a fellow that made his fortune in packaging food stuffs with mylar/poly wrap. He also was an early mylar balloon maker. I often imagine that with the Propeller one might find it much easier to control the critical timing involved.
  • idbruceidbruce Posts: 6,197
    edited 2011-01-12 08:21
    LoopyByteloose

    Thanks For Responding

    I think CNC machines are generally ignored here, not just packaging machines. I think the Propeller is perfect for controlling CNC machines that don't need attachment to an external mainframe.

    My packaging machine is designed for a specific type of clamshell type packaging. In the future, I do plan to make an attempt to market the machine to those who use similar type packaging. If I succeed in marketing the machine, then I will have several business ventures instead of one.

    I also plan to modify my plans for the PCB drilling machine to make smaller and more affordable. My primary thought is to make it ultimately compatible with Cadsoft Eagle software. In addition to that, I also intend to make smaller UV exposure boxes for the same reasons.

    Bruce
  • Graham StablerGraham Stabler Posts: 2,507
    edited 2011-01-12 08:31
    I have had an interest in CNC for a while, a few things are on my website:

    http://indoor.flyer.co.uk/personal.htm

    Some other stuff on my youtube channel:

    http://www.youtube.com/user/littlestworkshop

    I have more incomplete projects than complete probably. I got in to the propeller because of my wish to make a CNC wire EDM machine, I still think I could achieve this goal but at the moment just have no time.

    Projects:
    Proxxon MF70 conversion: complete
    Proxxon KT150 table conversion: works but needs cleaning up (building a stand for it now)
    4th axis for MF70: complete
    5th axis for MF70: complete but unused
    Digitizing probe: complete but now sold
    CNC router MK1: Incomplete, needs bed and motors mounting
    CNC router MK2: Incomplete, made from Parker ballscrew actuators with brushless servos (from Ebay and super cheap!), needs a frame and some wiring.
    Plasma cutter: incomplete, I have the torch and a good idea, the next thing to be completed.
    Wire EDM: incomplete, have researched the Smile out of it but currently off the menu
    3D printer: Almost finished but now distracted
    Plasma pipe cutter for making tubular frames: on the drawing board.

    And the rest.

    Graham
  • idbruceidbruce Posts: 6,197
    edited 2011-01-12 08:38
    Graham

    Very Cool Stuff! I visited your website and checked it out. You are definitely tinkerer. Thanks for responding and participating.

    Bruce
  • StefanL38StefanL38 Posts: 2,292
    edited 2011-01-12 08:42
    I remmeber some threads that are cnc-related here are the links

    http://forums.parallax.com/showthread.php?125337-Hobbyist-CNC-router&p=936097#post936097

    http://forums.parallax.com/showthread.php?127402-Stepper-motor-question

    Maybe the users who started these threads like to post a short description about the status of their project?

    I'am working - from time to time - on a small CNC-mill. I got the mechanic as a thank you for electronic help of I guy living in the neighbourhood.
    It has small steppermotors (pretty small NEMA 17) and steppermotor drivers. based on the L297-L298 chips

    The software is in an early stage. I can set up a start and endpoint with X-Y coordinates and do single moves.
    But right now I'm on a non propeller-project for my students.

    best regards

    Stefan
  • idbruceidbruce Posts: 6,197
    edited 2011-01-12 08:49
    StefanL38

    Thanks for your input and thanks for responding. Once I get back to the PCB drilling machine, which is a three axis machine, I will have a lot more information to provide concerning three axis movement. You may be interested in the information that I will provide.

    Bruce
  • pjvpjv Posts: 1,903
    edited 2011-01-12 09:19
    idbruce;

    I have a great interest in CNC's, actually all mecha-tronics in general. In my shop I have a commerial CNC lathe with an 8 station tool holder, and a CNC mill with a 12 station tool holder. Also software to (help) generate the G codes. At present I am designing the first of a family of top-end 3 axis "hobby" CNC tables for sale. Progress is very slow as money paying jobs get in the way of development.

    Cheers,

    Peter (pjv)
  • Jack BuffingtonJack Buffington Posts: 115
    edited 2011-01-12 09:23
    I have a home-built heavy-duty CNC router (I cut steel on a somewhat regular basis) I'm currently using a PC to control my router but a prop might make sense for an upgrade some day. Right now my machine uses four steppers to control three axes so I think that I have maxed out Mach3 but I'm not sure. I'm really keeping an eye out for something that needs a fourth axis but so far haven't convinced someone to pay me to make something that would need a fourth axis. :) The prop is definitely well suited for CNC machine control. I'm most likely going to use it on a project soon involving several cameras that has six axes of movement that need to move in a coordinated way.
  • idbruceidbruce Posts: 6,197
    edited 2011-01-12 09:59
    @PJV - Sounds to me like you have some very serious equipment at your disposal. I wish I had your equipment when I started building my machines. In fact, I still wish I had it. :) It is my intention to have a very nice shop some day.

    @Jack Buffington - Yes the Prop is well suited for CNC control, especially with 8 cogs. I am currently using inline programming for most of my routines, however, I can't wait to get to the point where I can start using other cogs and multi-task. You also sound like you take CNC very seriously.

    Bruce
  • Duane DegnDuane Degn Posts: 10,588
    edited 2011-01-12 12:56
    Bruce,

    I'm seriously thinking of buying or making a small three axis machine (I'm thinking of a CNC router). I'm not sure what level the Propeller can start processing the information needed to cut parts.

    I understand one needs to convert the line drawings into G-code, I imagine this is a job for a PC. But once you have the G-code, can it be feed to the Prop and have the Prop know what to do?

    I've seen (on internet videos) CNC milling machines remove the copper from circuit boards. Is this a reasonable way of making custom PCBs? I'd think the same machine could drill the needed holes. Since you recently completed your UV exposure box, I'm guessing you think this is a better route for making your own boards. I like to hear what you concider to be the pros of your favorite method.

    Duane
  • atlstangatlstang Posts: 20
    edited 2011-01-12 13:16
    @bruce: mostly used for metal, in particular aluminum parts. I enjoy designing (soldiworks) and making small parts etc for different projects. Am a grad ME student, the automation and electromechanical stuff interests me a lot more then computer stuff with the propeller, which is why this thread and your others been interesting.

    Its a retrofitted 3 axis using the mach3 software on a dedicated computer i built from old parts. the propeller seems to be a perfect chip to interface with the software and to allow control of such things, and display them on a custom screen. As it doesnt display speed etc. The motor on the side says 110V at 6.5A, Given i dont have a strong electronics background (but learning) just need time to research, which being a grad student doesnt give a bunch of time.

    Would be interested in seeing your machines in action, videos etc. After following all your posts :)
  • JasonDorieJasonDorie Posts: 1,930
    edited 2011-01-12 13:57
    I have a home-built CNC router that I use for cutting wood & plastic, circuit boards, and printing shirts with a sharpie. Check out my Facebook album. You can also look up JasonDorie on YouTube and see a couple videos of the machine in action.

    I originally built it to cut wooden parts for the flying thing I'm making, but I keep getting distracted by other things. I'm fairly seriously considering putting together a JoesCNC 4x4 Hybrid machine, but I have to clear out some space for it in the garage, and I need a chunk of time to do the build.
  • babinda01babinda01 Posts: 54
    edited 2011-01-12 14:23
    Hi, my name is Andrew and I'm a CNC-a-holic.

    I have only recently started trying to make my own controller based on the propeller. I am using a gcode compiler running on a pc which "preprocesses" the gcode into 1ms "go to this position" commands. This takes care of ramping and constant velocity etc etc. My plan was to shoot this down to the prop board via ethernet, and store the whole program on an sd card and then run the program from the sd. Very similar to how the NcPod worked originally. This would take all the gcode parsing from the prop, and should allow very good steps per second.

    Andrew
  • $WMc%$WMc% Posts: 1,884
    edited 2011-01-12 15:36
    babinda01 wrote: »
    Hi, my name is Andrew and I'm a CNC-a-holic.

    I have only recently started trying to make my own controller based on the propeller. I am using a gcode compiler running on a pc which "preprocesses" the gcode into 1ms "go to this position" commands. This takes care of ramping and constant velocity etc etc. My plan was to shoot this down to the prop board via ethernet, and store the whole program on an sd card and then run the program from the sd. Very similar to how the NcPod worked originally. This would take all the gcode parsing from the prop, and should allow very good steps per second.

    Andrew
    '
    If You don't mind sharing.
    What program are you using to read the gcode with?
  • idbruceidbruce Posts: 6,197
    edited 2011-01-12 15:46
    Hello Everyone

    Sorry it took so long to get back here, I had to get a little shut eye. As it appears that you guys are into G-Code, instead of addressing you all one by one, I will address all of you.

    If you have access to G-Code that is is available in text format, I have created a G-Code parser for Spin. This parser was particulary written for the G-Code that is written for making printed circuit boards which is contained in an Eagle DRD file, however, I am certain that it could be altered to suit your particular needs. If you are interested, leave a note and I will provide the source code.

    Bruce
  • bennettdanbennettdan Posts: 614
    edited 2011-01-12 15:50
    @Bruce I have just bought a large Bridgeport style mill and I plan to convert my Enco mill to CNC. I also plan to build a CNC gantry style for my plasma cutter and router.

    @JasonDorie what software are you using on your router. Also I am interested on the software you used to get the G code for PCB machining. The machine looks great what type of accuracy does it have. Also the Sharpie on Tee Shirts is cool ....

    @babinda01 I like the idea of the SD card holding the program and would be interested in the software you are using to "preprocess" the Gcode to 1ms commands this sound like a good start to a CNC machine that is realtime unlike a PC running windows.

    I have a full pro package of Alibre Cad design software it is very user friendly and lots of video tutorials nice software if anyone is looking.
  • $WMc%$WMc% Posts: 1,884
    edited 2011-01-12 15:57
    I've been trying for about 3 years to CNC my Manuel milling machine.
    So far I have the X and Y axis motor-controlled with 2 BS2. This makes for a nice power feed, but no CN control.
    I plan to replace the BS2s with a Prop. and add a motor drive to the spindle " Z ".
    '
    I'm time limited too,But maybe this thread will help us reach the completed stage.
    '
    I would like to see your gcode to spin parser.
  • idbruceidbruce Posts: 6,197
    edited 2011-01-12 15:57
    Duane
    I've seen (on internet videos) CNC milling machines remove the copper from circuit boards. Is this a reasonable way of making custom PCBs? I'd think the same machine could drill the needed holes. Since you recently completed your UV exposure box, I'm guessing you think this is a better route for making your own boards. I like to hear what you concider to be the pros of your favorite method.

    Duane there is a lot of people that create circuit boards this way. The biggest "PRO" for this method is that you eliminate all the hazardous chemicals. The biggest "CONS" are metal and fiberglass dust.

    With my UV exposure box, I can create some pretty fine detail that a milling machine would be unable to achieve. It all depends on your needs, how fine of traces do you actually need etc.... I chose making a UV box because I want to make professional looking boards.

    However, you are correct, you can mill and drill with the same machine. Considering that I have a UV exposure box and a pcb drilling machine, I actually have a choice which way I want to manufacture the board.

    Bruce
  • idbruceidbruce Posts: 6,197
    edited 2011-01-12 16:03
    $WMc%

    I would have to agree in swapping out the BS2's for a single Propeller Proto Board. There are many benifits to doing, here are a couple:
    • Fast instruction processing
    • 1 chip / 8 processors = multi-task potential
    Bruce
  • Cluso99Cluso99 Posts: 18,066
    edited 2011-01-12 16:29
    I have an interest in RepRap, a 3D plastic printer. A lack of time has prevented me from getting a working unit although I do have a prototype of the mechanics. Here is a link http://forums.reprap.org/read.php?4,57039

    I intend to use a prop to control the RepRap as I believe it is more suited than the ATmega/Arduino that is usually used. Also, I believe the cost can be seriously reduced, both in the mechanics and the electronics. I have worked some pcbs but that have not yet been done.

    It is nice to see all the other CNC work being done here :)
  • idbruceidbruce Posts: 6,197
    edited 2011-01-12 16:38
    Clusso99

    Pretty Cool Stuff. Thanks for the post Ray.

    Bruce
  • Invent-O-DocInvent-O-Doc Posts: 768
    edited 2011-01-12 16:40
    Good point idbruce. The new CNC machines, homeades and kits are a good fit with the things people are doing with the propeller and it seems like a great potential control platform for CNC and 3D printers.
  • JasonDorieJasonDorie Posts: 1,930
    edited 2011-01-12 16:57
    bennettdan wrote: »
    @JasonDorie what software are you using on your router. Also I am interested on the software you used to get the G code for PCB machining. The machine looks great what type of accuracy does it have. Also the Sharpie on Tee Shirts is cool ....

    I use Eagle to do the schematics, and there's a free script you can get for it that will generate all the necessary gcode files (mill, screen, and drill). The script is pcb-gcode, and it's mentioned/linked here. You'll need to monkey with it a little to get it all humming, but it doesn't take long. I also built a vacuum table to keep the boards held down nice and flat - When you're skimming thousandths of an inch of copper, you don't have a lot of room for slop.

    The machine itself has a resolution of 1/8000" (leadscrews + microstepping), but the accuracy is far less, probably around 0.002" to 0.005". It's good enough for what I want to do with it. I'm running Mach3 to control the router, and I have a few different CAM programs, including MeshCam, and Vectric's Cut2D.
  • JasonDorieJasonDorie Posts: 1,930
    edited 2011-01-12 17:07
    Duane Degn wrote: »
    I've seen (on internet videos) CNC milling machines remove the copper from circuit boards. Is this a reasonable way of making custom PCBs? I'd think the same machine could drill the needed holes.

    As idbruce already mentioned, the biggest benefit of the CNC method is avoiding the messy chemicals. Other cons include:

    Speed : the CNC method is much slower than the UV / acid bath method for anything but the simplest of boards. Isolation bits are usually V-shaped, meaning the narrower your traces, the more times you need to go around the them to get the same amount of isolation, slowing it even further.

    Accuracy : You need a -very- accurate CNC machine to skim a few mils of copper off the top of a board. Runout on most spindles / routers plus mechanical slop limits the size of the isolation traces you can cut, so using this method for through-hole components is fine, but SMT stuff is probably unrealistic.

    Stress : The cutting head pushes on the copper and vibrates, putting mechanical stress on the traces. With very small traces, you may end up de-laminating them before you even start soldering.

    Using the photo-etch method to do the traces, but the machine to do the drilling would be the best of both worlds. I've never done a photo-etch board, and I have the CNC machine, so it was easier for me to do simple stuff this way. If I need to do anything "serious", I'll probably learn to etch.
  • idbruceidbruce Posts: 6,197
    edited 2011-01-12 17:11
    JasonDorie

    That was a much better explanation of the pros and cons than I gave. Thank you for your input.

    Bruce
  • wjsteelewjsteele Posts: 697
    edited 2011-01-12 18:22
    I have a few CNC machines. I have two MakerBot Cupcakes and a home made CNC Router. I'm currently working on a larger CNC Plasma cutter. It'll cut 4'x8' steel pretty easily. Once it's finished, I'm going to get a laser going.

    One of my MakerBot's is controlled by a Propeller and the CNC Plasma cutter will be as well.

    Bill
  • idbruceidbruce Posts: 6,197
    edited 2011-01-12 20:45
    Bill

    I would imagine that you are going to need a very serious laser to cut through some steel unless of course it is gum wrapper :) What are your plans?

    Bruce
  • Chris_DChris_D Posts: 305
    edited 2011-01-13 02:41
    I have been working on a CNC machine that is partially propeller controlled for a couple of years now (maybe more?). Designing and making a CNC control is not an easy task nor something to take lightly.

    Let's first clarify a few things here because you are referring to basic motion control devices as CNC. Marking machines, "Snow cleat installer", packaging machines are not CNC - they might be automation, but they are not CNC. CNC is a specific form of motion control relating to machine tools that cut (burn, bend, etc.) various materials. A plotter in not a CNC machine, close, but not. Assembly robots, are just that, robots. Marking machines are also just that - marking machines. Plotter are plotters, printers are printers. There wasn't much confusion when CNC resided within industry, now that it has entered the world of hobbiests, CNC often gets confused with ANYTHING that is motion controlled.

    There are many people that will tell you that you cannot use a micro for CNC type motion control. I can't say with certainty one way or the other yet, but so far I am getting close to having performance similar to that of early CNC machines (late 70's vintage). Doing an entire CNC control with a single propeller chip is unlikely unless it is very minimal in features. Most of the hobbiest have gone down the road of a PC as a CNC control and its obvious advantage is its ability to crunch numbers and ofcourse massive memory and storage capacity. There is a good amount of information on the web about making CNC controls, but don't expect most of it to perform at the industrial level. Many of the control examples I have seen are just a tiny step beyond that of a basic X-Y plotter. Furthermore, what also seems to happen a lot is that a project's source code, or notes, get published on the web at a point of being incomplete. In other words, there is a reason the project was abandond, the concept reached its natural limitation.

    While I certainly don't want to discourage anyone from trying to make a mico-based CNC control, I think it is important to know going in that a CNC control is a very complex system with requirements beyond that of basic motion control or even that of a basic X-Y plotter. It certainly will bring forth challenges and if you have a passion for it, it will certainly be fun.

    Chris
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