from scratch cnc ?s

Discussion in 'CNC Machines and Conversions' started by Naiveambition, Jan 18, 2018.

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  1. Jan 18, 2018 #1

    Naiveambition

    Naiveambition

    Naiveambition

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    I've convinced myself in the past few weeks that I need a cnc machine.:thumbup: So I've been all over the net and i am starting to understand what is required but am now to the deciding phase and need help with directions to take.
    I would like this thread to take on work in progress kinda theme, meaning as I go thru the process of getting cnc I will ask for guidance and recommendations.
    Even though this is for me , at the end maybe another newbie can follow the same route.

    As of now I have zero, make that negative zero knowledge of cnc operations, but do have some machining exp. the machine will be the taig cnc model ready to go minus computer. I've picked this one for size envelope and power. I have a rf 45 clone , but if I make it cnc without knowing what I'm doing , the cost to fix is just that much more. If I feel like upgrading after to a bigger machine we can make that decision if I'm comfortable doing cnc.

    Other than what I've researched so far, my understanding is cad, then cam then control system such as Mach 3. As of now I have chosen designspark mechanical or draftsight for my cad and will upgrade later as needed. I'm also looking at dolphin cad/cam. More for the ability to show simulations than anything but looks to be a thorough program. It is a 1k$ though. A little pricey for me , but this will be a home shop, making one off parts and maybe a small $$ making on the side.

    So first thing is the computer.
    Research points to a 8-12 ram. With 16 and up being optimal. Not really knowing much about comp. performance , the gamer style comp. looks to be the one. Has the requirements of most cad cam programs for decent prices. Is this neededor right?, some are saying u need a special processors made for cad work, Or a purpose built machine.
    Granted all work, cad/ cam and cnc will be done with this so needs the power to do so, and will be a standalone working only unit. Will the gamers be the wiser decision?
     
  2. Jan 18, 2018 #2

    kvom

    kvom

    kvom

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    I can recommend CamBam for CAM. Inexpensive, and the online forum has lots of help available. It has some CAD functionality, but Draftsight is free and quite powerful. Unless you're doing 3D modeling the computer needed for CNC work is quite modest.
     
  3. Jan 18, 2018 #3

    blighty

    blighty

    blighty

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    more options, just to really confuse you:)
    I would go with Fusion 360. its up there with the likes of Solidworks/ Solidcam etc and the good thing about it is...... it's FREE

    RF45.... so's mine. i should still have the drawing's laying around somewhere for all the ballnut holders and end plates (that hold the stepper)
    as you're doing a RF45 i'll bore you with the details of my one. it was built 9 years ago so some things may of changed for doing one now.
    X,Y 960oz steppers running @61.5v
    Z 1240oz steppers running @61.5v
    class 5 ball screws and nuts. nuts have over sized ball's
    3hp 3 phase drive motor
    belt drive max speed of spindle 5000rpm @1.5hp
    stepper drives are Gecko 201
    SmoothStepper
    6axis brake out board (cant remember the maker of it at the mo)
    PC
    first pc was a 3.2 single core with 500mb ram. on board graphics. had no problems running with this pc.
    a few years back i upgraded it. because of reasons ;)*club*
    now has 3.6 quad, 8gig ram, 2gig graphics card.

    the machine has run with 7500mm/min (295in/min) and above. RF45 not relay solid enough to run at that speed. as when the table stops the machine will wobble a bit. it seems happy at 4500mm/min(177in/min)
    It has about 0.03mm (0.001in) of backlash on the X and Y. no backlash on the Z. will cut things with in 0.01mm (0.0004) ish depending on how its feeling:D
     
  4. Jan 18, 2018 #4

    Naiveambition

    Naiveambition

    Naiveambition

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    So 3D modeling would be say drawing a dragon, and say a v8 drawing would not be a "3D model" ? I get lost at 2.5d and 3D and 3D modeling. Reading suggests the difference being able to edit in 3D vs reverting to 2.5 for the changes.

    After a lengthy brain feeding session I was poking around and ran across autodesk , who make fusion 360. On the site their is an Autodesk academy you can enroll in for free. Courses are like tests to show advancement, but you get the full blown version for free, I think for 3 yrs maybe longer enrolling in their program vs another school. So am looking hard into that.
    Does anyone know if some offer a deal to disabled people. If I can turn this into work all the better.

    Gamer computers are not a viable option I suppose. Something with graphics. It will do it but will cause crashing and so forth sooner or later. I did find a local guy selling " workstation" comp. for 800$ which is roughly the same for a gamer and purpose built. I'd rather spend up front to save myself the agony of dealing with comp. issues. I really don't like computers. I like mechanical things where I can say that's what's wrong. In a comp. for me it's like a treasure hunt to find the issue:wall:
     
  5. Jan 19, 2018 #5

    ninefinger

    ninefinger

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    +1 for Fusion 360. It is completely free for student / hobbiest use, even small business up to $100K / year. Its easy to learn, and there are tons of online videos to show you how to do things if you get stuck.
    My interpretation of 3D modelling is that instead of drawing a flat drawing (like you would do on paper) you "model" the end product. In my opinion the way to go as you visualize the end product.
    Another reason to use Fusion 360 - once you've drawn / modeled the part you can simply switch modes within the same program and start the CAM side of things for making the output to go to your cnc machine. One less program to learn as many of the features are the same between the CAM and CAD, plus if you need to go back and make a change to the part the CAM model gets updates as well.
    I have switched to Fusion for home stuff even though I had access to an older "professional" cad system at work as Fusion was better (Pro-E WF4).

    Mike
     
  6. Feb 8, 2018 #6

    Naiveambition

    Naiveambition

    Naiveambition

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    Well step one is complete. Now am proud owner of an hp z600 workstation computer. After looking relentlessly for a local computer shop with used workstations to no avail. I noticed that all were located in north west Houston, so off I went. So picked one with a good price and went to their place, hmmm :eek: I think it was a hacker store that sold refurbished items that was in the front of a sketchy grocery store in a sketchy part of town. It reminded me of sidewalk bazaar more than anything, soooo. Decided to take a look anyways :rolleyes:
    After some updating all is working well as it should. It was originally posted as a gaming computer, but with some research I was able to find out it is a purpose built CAD computer. The graphics card (nvidia 2000) is more suited to cad work vs gaming, according to their community. I had looked at other cad ready units and base $ was around 350 and up depending on setup. 600$ was my limit and bought this for 350. Was just the tower with dual Xeon processors,12 core ,512 hard drive and 24 g memory. This a exspensive set up new and way more powerful than a desktop for the same price.
    Downloaded fusion 360 and sadly it looks like I might have to pay 300$ a yr for liscense. Although free for 30 days , it means to stick with this one I have to pay the fee, and while not bad price wise this is my first program learning. Have created a few sketches with some success but don't know what to do with em now:D.

    The plan is learn cad and cam while saving for the machine. So give or take 6-9 months I should have it down by then

    image.jpeg
     
  7. Feb 8, 2018 #7

    raspii

    raspii

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  8. Feb 8, 2018 #8

    nautilus29

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    Yep, I'll +1 to fusion 360 also. After 30 days you can register and tell them you are a hobbyist, and it's free.

    There are great YouTube videos on how to use it, plus Autodesks forums are amazing. They have support personnel on the forums that can download your drawing that you are having issues with, and then they make a video on how to do it properly. I've had good luck asking questions on it and getting good replies.

    Edit: Two more nice features about it... They are creating a desktop version of it where you can draw and view your parts out of chrome or edge. Still missing features but it's turning out pretty nice. I like it because I can view my printer or models on a computer without fusion. Another neat features is that since you get a cloud account when you sign up you can easily share your save files with other people that have 360. You can also create groups where many people can access the drawings (and even edit them if wanted).
     
    Last edited: Feb 8, 2018
  9. Feb 8, 2018 #9

    kvom

    kvom

    kvom

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    You generally don't need a lot of computer horsepower to drive a CNC machine, esp. if you go with a separate processor card to drive the timing pulses. My mill was new in 2010, and the motherboard is slow compared to new ones. It used kernel interrupts for the timing pulses in Mach3, and that limited my rapids to 75 ipm. I have since switched to a more modern computer with a Mesa card for the offboard pulsing. I could run the rapids at 300+ if desired, but I have it set to 140 which is fast enough for me. Jogging is 40% of that. I switched to PathPilot, which has been more reliable than Mach3, and I prefer the UI.
     
  10. Feb 9, 2018 #10

    Naiveambition

    Naiveambition

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    While researching auto cad and the likes I had run across nycnc that had this particular setup I want, and recommended a strong graphics area for the same reason you mention.
    What I got out of it was the cam simulations are running the graphics pretty hard which could cause missed steps etc while the cp catches up with itself. Also noticed that most reg comp. weren't getting the numbers needed vs workstations. If things work out I would like to be able to run auto cad, solidworks, etc so maybe this will save some money in the end.

    But with that said I am just learning the mountain of cnc (hence my screen name) -- naive ambition -- the ability to see a grand result without realizing the work in between:D:D
    On a side note for any comp. guys I've been working in fusion for the past few days and after downloading, the computer wants to download the Windows 7 updates while shutting down which has ranged from 195 to 175 . It will shut down after a good while , but when turning back on it says , downloading not successful and reverts back to original setting after a good while. :hDe: could this be a related issue with fusion being a cloud based program? Sending out the updates upon shutdown?
    I am running the Windows 7 version that was installed and was out of date, Fusion recommend Firefox so I did downloaded that also
     
  11. Feb 9, 2018 #11

    hanermo3

    hanermo3

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    A pc for running the machine is trivial with a motion control card like csmio for mach3/4 or mesa for linuxcnc.
    Any pc will work fine.

    Making real, detailed, large, assemblies in any cad is another matter.
    The models are huge, and you really need a proper graphics card.
    A second hand nvidia is a good choice. == 100 €

    Most make single pieces of moderate size and these are easy to do on any pc hw or sw.
     

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