CNC

You are not logged in. [ Login ] Why log in
(NOTE: Login is not required to post)

cnc accurecy

4/20/15       
Gilad

HI I could use some advice with my new cnc machine.
I mainly use the machine for cutting laminated MDF meant for cabinet fronts(square parts).I use Ardis optimizer and i space the parts away from each other 1mm more then the cutters diameter.
pieces that are larger than 300mm (width/length) turnout 0.3-0.4 mm smaller
then they should.
for example a piece 700mm*200mm
turns out 699.7mm*200m
I will be happy with any idea for asolution.
English is not my native language so plees make it simple.

4/21/15       #2: cnc accurecy ...
John Canary

check your tool diameter-it has to be perfect

4/22/15       #3: cnc accurecy ...
R4G3X Member

It is unlikely that the tool diameter/radius is off since smaller parts are the correct sizes. There are a few other things it could be could you give some more information.

Is it a new/used machine?

If you cut one part #1 299mm and part #2 301mm will #1 turn out to be exactly 299mm and #2 300.7mm? In other words is the error exactly 0.3mm at exactly 300mm length part? And does it matter where on the table the part is located it is always off this much, either in X or Y?

0.3mm error seems almost negligible in the woodworking industry especially for a part 300mm or greater.

4/23/15       #4: cnc accurecy ...
Gilad

Thanks for the replies.
The machine is new .
The problem occurs all over the work table.
I use a straight diamond bit with tow cutters.
the cutter spins at18000rpm.
the optimizer I use sorts the parts:
a part smaller than 400mm in1 of the dimensions will be cut first and at a feed rate of 7meter/min and is cut in 2 depth passes to prevent small parts moving.
big parts are cut at 12meter/min and 1 pass.
I didn't check the exact size were the problem occurs.
I will on Sunday.

4/23/15       #5: cnc accurecy ...
jerry Member

Can you rotate the part so it cuts the 700mmlong the other axis and see if the problem follows or if the 200 mm side is smaller

4/23/15       #6: cnc accurecy ...
Mark T.

Website: http://www.cnccustomservices.com

Rotating the part is a good test. Also, have you reviewed the actual code at the machine to compare if the numerical code values are accurate? If you are relying on a CAM package this could be a rounding error within the post processor which could grow proportionate to size of the feature.
Mark T.

4/27/15       #8: cnc accurecy ...
GILAD

HI again.
I tried rotating the parts it made no difference.
tool diameter is perfect.
I wold appreciate it if any one cold explain how to check "rounding error within the post process".
Besides that i had ordered a shorter
bit someone suggested me that might help.
THANKS..

4/28/15       #9: cnc accurecy ...
cabinetmaker

Are you common line cutting or actually cutting around the part ? That has hit us a few times.

4/30/15       #10: cnc accurecy ...
Gilad

I cut round the pieces.
I tried a different tool and had the problem was not solved.
I also realized that the problem worsens as the part is longer.
"kabinetmaker" i wold love to know waht was yore solution.

4/30/15       #11: cnc accurecy ...
R4G3X

Since it worsens as the part gets longer its very likely due to rounding in the post processor as Mark T. suggested.

Are you able to program at the machine directly using software that came with the machine? If not maybe have your cnc guy write/modify a program manually to cut a part say 700mm and see what happens. This way if it cuts correctly then you have your answer.

5/4/15       #12: cnc accurecy ...
Tom Galzin

Your machine needs to be calibrated. The calibration process starts by moving your machine a specific amount and then check the movement against a standard. Start by finding the most precise and longest steel scale (ruler) available, 1000 mm or longer. Carefully set the edge of a router at zero, then move the machine 1000mm under program control. Check the result of the movement against the scale. If it's not perfect, the machine needs to be calibrated. Contact the manufactures for instructions how to do it. There may also be local service companies that can do laser calibration, but it may be expensive.

5/4/15       #13: cnc accurecy ...
Gilad

Thanks Tom
I got a tec in the shop yesterday he calibrated the electrical pulses/mm.
The servo engines werent accuretly set up.
It seems the problem has ben solved.


Post a Response
  • Notify me of responses to this thread
  • Subscribe to email updates on this Forum
  • To receive email notification of additions to this forum thread,
    enter your name and email address, and then click the
    "Keep Me Posted" button below.

    Please Note: If you have posted a message or response,
    do not submit this request ... you are already signed up
    to receive notification!

    Your Name:
    E-Mail Address:
    Enter the correct numbers into the field below:
     

    Date of your Birth:



    Return to top of page

    Buy & Sell Exchanges | Forums | Galleries | Site Map

    FORUM GUIDELINES: Please review the guidelines below before posting at WOODWEB's Interactive Message Boards (return to top)

  • WOODWEB is a professional industrial woodworking site. Hobbyist and homeowner woodworking questions are inappropriate.
  • Messages should be kept reasonably short and on topic, relating to the focus of the forum. Responses should relate to the original question.
  • A valid email return address must be included with each message.
  • Advertising is inappropriate. The only exceptions are the Classified Ads Exchange, Machinery Exchange, Lumber Exchange, and Job Opportunities and Services Exchange. When posting listings in these areas, review the posting instructions carefully.
  • Subject lines may be edited for length and clarity.
  • "Cross posting" is not permitted. Choose the best forum for your question, and post your question at one forum only.
  • Messages requesting private responses will be removed - Forums are designed to provide information and assistance for all of our visitors. Private response requests are appropriate at WOODWEB's Exchanges and Job Opportunities and Services.
  • Messages that accuse businesses or individuals of alleged negative actions or behavior are inappropriate since WOODWEB is unable to verify or substantiate the claims.
  • Posts with the intent of soliciting answers to surveys are not appropriate. Contact WOODWEB for more information on initiating a survey.
  • Excessive forum participation by an individual upsets the balance of a healthy forum atmosphere. Individuals who excessively post responses containing marginal content will be considered repeat forum abusers.
  • Responses that initiate or support inappropriate and off-topic discussion of general politics detract from the professional woodworking focus of WOODWEB, and will be removed.
  • Participants are encouraged to use their real name when posting. Intentionally using another persons name is prohibited, and posts of this nature will be removed at WOODWEB's discretion.
  • Comments, questions, or criticisms regarding Forum policies should be directed to WOODWEB's Systems Administrator
    (return to top).

    Carefully review your message before clicking on the "Send Message" button - you will not be able to revise the message once it has been sent.

    You will be notified of responses to the message(s) you posted via email. Be sure to enter your email address correctly.

    WOODWEB's forums are a highly regarded resource for professional woodworkers. Messages and responses that are crafted in a professional and civil manner strengthen this resource. Messages that do not reflect a professional tone reduce the value of our forums.

    Messages are inappropriate when their content: is deemed libelous in nature or is based on rumor, fails to meet basic standards of decorum, contains blatant advertising or inappropriate emphasis on self promotion (return to top).

    Libel:   Posts which defame an individual or organization, or employ a tone which can be viewed as malicious in nature. Words, pictures, or cartoons which expose a person or organization to public hatred, shame, disgrace, or ridicule, or induce an ill opinion of a person or organization, are libelous.

    Improper Decorum:   Posts which are profane, inciting, disrespectful or uncivil in tone, or maliciously worded. This also includes the venting of unsubstantiated opinions. Such messages do little to illuminate a given topic, and often have the opposite effect. Constructive criticism is acceptable (return to top).

    Advertising:   The purpose of WOODWEB Forums is to provide answers, not an advertising venue. Companies participating in a Forum discussion should provide specific answers to posted questions. WOODWEB suggests that businesses include an appropriately crafted signature in order to identify their company. A well meaning post that seems to be on-topic but contains a product reference may do your business more harm than good in the Forum environment. Forum users may perceive your references to specific products as unsolicited advertising (spam) and consciously avoid your web site or services. A well-crafted signature is an appropriate way to advertise your services that will not offend potential customers. Signatures should be limited to 4-6 lines, and may contain information that identifies the type of business you're in, your URL and email address (return to top).

    Repeated Forum Abuse: Forum participants who repeatedly fail to follow WOODWEB's Forum Guidelines may encounter difficulty when attempting to post messages.

    There are often situations when the original message asks for opinions: "What is the best widget for my type of shop?". To a certain extent, the person posting the message is responsible for including specific questions within the message. An open ended question (like the one above) invites responses that may read as sales pitches. WOODWEB suggests that companies responding to such a question provide detailed and substantive replies rather than responses that read as a one-sided product promotion. It has been WOODWEB's experience that substantive responses are held in higher regard by our readers (return to top).

    The staff of WOODWEB assume no responsibility for the accuracy, content, or outcome of any posting transmitted at WOODWEB's Message Boards. Participants should undertake the use of machinery, materials and methods discussed at WOODWEB's Message Boards after considerate evaluation, and at their own risk. WOODWEB reserves the right to delete any messages it deems inappropriate. (return to top)


  • Forum Posting Help
    Your Name The name you enter in this field will be the name that appears with your post or response (return to form).
    Your Website Personal or business website links must point to the author's website. Inappropriate links will be removed without notice, and at WOODWEB's sole discretion. WOODWEB reserves the right to delete any messages with links it deems inappropriate. (return to form)
    E-Mail Address Your e-mail address will not be publicly viewable. Forum participants will be able to contact you using a contact link (included with your post) that is substituted for your actual address. You must include a valid email address in this field. (return to form)
    Subject Subject may be edited for length and clarity. Subject lines should provide an indication of the content of your post. (return to form)
    Thread Related Link and Image Guidelines Thread Related Links posted at WOODWEB's Forums and Exchanges should point to locations that provide supporting information for the topic being discussed in the current message thread. The purpose of WOODWEB Forums is to provide answers, not to serve as an advertising venue. A Thread Related Link that directs visitors to an area with inappropriate content will be removed. WOODWEB reserves the right to delete any messages with links or images it deems inappropriate. (return to form)
    Thread Related File Uploads Thread Related Files posted at WOODWEB's Forums and Exchanges should provide supporting information for the topic being discussed in the current message thread. Video Files: acceptable video formats are: .MOV .AVI .WMV .MPEG .MPG .MP4 (Image Upload Tips)   If you encounter any difficulty when uploading video files, E-mail WOODWEB for assistance. The purpose of WOODWEB Forums is to provide answers, not to serve as an advertising venue. A Thread Related File that contains inappropriate content will be removed, and uploaded files that are not directly related to the message thread will be removed. WOODWEB reserves the right to delete any messages with links, files, or images it deems inappropriate. (return to form)
    Onsrud Cutter Vortex Tool Company T-Tool USA